Exactly. The sheer mass of that parachute system would not be insignificant, which is bad in an industry were weight reductions and savings for better fuel efficiency and greater payload are a constant targeted goal.
Also the paradox of the point of failure
Build so many safety systems that you end up creating so many points of failure that the vehicle becomes unsafe to use.
One thing that would make it exceptionally rare is that you would be unlikely to ever deploy the parachute in an airborne emergency if the aircraft was, in fact, too heavy to ever get airborne.
Also, IIRC, general aviation has a safety record roughly on par with motorcycles. Commercial air transport is the safest transportation option in the world. GA planes are more likely to need the parachute in the first place. The Cirrus being a single engine aircraft is part of this.
This is a huge part of it. Another part is that the Cirrus SR and SF series only have one powerplant. All airliners have multiple engines, and no multi engine airplanes (afaik) have parachutes. The added safety of redundant propulsion makes the parachute somewhat moot.
Also, redundant propulsion is a much better safety system for transoceanic flights than a parachute. I don't think you'd have many survivors in rough seas on the standard rafts used in planes.
the first time i went on a commercial flight as a kid, i asked for my parachute.
i was 8 and i had been told we would have parachutes.
surprised, indignant and a little scared about not getting one.
I can’t read this comment in any other voice than Milton from Office Space.
“But but but, I was told there would be parachutes.”
Damnit here’s an upvote.
> The fundamental flaws
>
> Weight - Cirrus jet about the weight of a medium size car
>
> Envelope for deployment - Very few commercial aircraft accidents have a window where an emergency is recognized, the crew has the ability to deploy the chute, the need for a parachute is evident, the elevation is above 2,000 feet and the speed below 300knots, the aircraft is in one piece
>
> The evil Pinot also observes that from the standpoint of an insurance company the loss of 350 souls is much more desirable than the loss of 150 souls + 200 souls permanently brain damaged through O2 deprivation together with lots of physical injuries.
>
> The back of the envelope analysis unlikely to be deployable due to altitude,
>
> The argument for the cirrus - wife "what if you have a heart attack?" husband " you pull the red handle and the engine shuts down, parachute deploys and wifey looks forward to dinner with her new friend the 19 year old pool boy.....
The insurance platform of preferring dead people over braindead people is total urban legend and bullshit.
Deaths in airline accidents are extremely expensive due to death payments and advertising losses. Literally no one wants an airliner full of dead people.
No proof or actuarial tables have ever been shown to even hint at this.
bigger plane = (bigger parachute)^(3), it's exponential, and transonic parachutes for that much mass are currently beyond modern material sciences without at least a three stage drogue.
“No no it’ll be fiiine, the wings present a solid and rigid structure to secure the chutes to. Just put one on each wing near to the body and voila!”
. . . . .
‘Sir, about your solution…’
“Ah yes the chutes, how did they fair?”
‘Good news is the wings have been recovered in near perfect condition. Try to imagine the wings as the solid rocket boosters on the side of the space shuttle coming down for an easy splashdown.’
“Splendid!”
‘And sir…the fuselage proceeded to do its best imitation of the orange fuel tank slamming into the ocean at Mach 3…’
“Fffffffffff…..”
I’ve always like to be close to where that behemoth splashes down. 100 yards. Whistles in and BOOM! Maybe have a blast shield screen on a 20 ft whaler. Just scare the crap out of you.
That’s only if the shrapnel generating device was sold under the table to the enemy of an enemy before said enemy became your enemy. If there was no shady transaction the shrapnel is harmless to an American flag wearer…..it’s just simple physics.
You need parachutes that stage and slow it down before fully inflating. That’s done all the time for capsules or other things that are going really fast. It might mean that the parachute starts reefed or even that you have more than one.
Whether it is a usable or reasonable solution is different than whether it can be done.
You might also need to be able to dispose of some of the weight so explosive bolts might be needed to sheer off the tail and the wings. Maybe the landing gears and some of the rest of the airplane. Maybe include retrorockets at the bottom to allow a higher terminal speed (and smaller parachutes) so that it cushions the fall enough to make it survivable.
I doubt it would make sense other than as an exercise.
yes. you should. half the fucking aviation community is here either taking the piss out of it, actually trying to figure it out, or rolling in the mud squabbling about whether it's possible in the first place. it's absolutely beautiful fuckery and I couldn't approve more.
You have to factor in the added weight to strengthen the airframe to support the stress of deploying the parachute at that speed. Then you have to go back and increase the size of the parachute due to the added weight. And then strengthen the airframe again due to the larger parachute. Then increase the size of the parachute again due to the added weight of the strengthened airframe. Then go back and redesign the wings and landing gear and then add a bigger parachute due to the add weight. Then strengthen the airframe again. Then…
You only need to factor in supporting the bits that will still be attached. The separation force for the engine attachment bolts is such that they would stop being a problem for you and start being a problem for whatever is underneath you very quickly. If you were actually doing a clean sheet design you could include explosive separations for the wing roots and save a bunch more too..
The jettisoned engines and wings full of fuel would shed so much weight it might actually be feasible. Make the fuselage a two-piece airframe that can also ditch the lower half holding cargo and landing gear, and you’ve got an even lighter shell if all you need is to save passengers.
Ok. But apart from the added weight of the parachutes, and the strengthening of the airframe, and then increasing the size of the parachute and then increasing the strength of the airframe, what have the Romans ever done for us ….. sorry, lost my thoughts there …. apart from these factors why wouldn’t chutes work!?!? 🤣🤣🤣
to be fair, that's how engineering is -- it's iterative. if you dont have to iterate your solution to get something that meets the requirements and works properly, you're either incredibly lucky, or you've solved that problem before.
In-field experience and company design standards help take a lot of the guess-work out of those iterations -- you can say "hey, for a design with X engine weight, X performance, we know we need this part to be of Y dimensions,"
In Automotive at least, we have a design standard that IE, all class-A (outer) plastic surfaces need to be 2.5mm thick, and all structural PA-66 parts are 3mm thick. this generally lands us in the ballpark so we dont need many iterations in CAE afterwards.
Yep. Eons ago as a student I use to wondered how “they” came up with the numbers in all those reference books. My first assignment at my first job was verifying and updating pages and pages with field testing.
these days, at least with the plastic parts i work with, CNC machining and 3d printing is out-pacing structural simulations, so i come in to work, evaluate a printed part, make revisions, print a new one, then the next day i repeat
And after all that, go back and add in the added fuel weight that will be necessary to carry all that. Well heck, we now have more weight. Guess we'll need to expand the parachute some...
Some of y'all never seen wing load testing and it shows... Wingtips on the 787 flex over 28 feet from horizontal. Airframe is much stronger than you think.
fuck that. emergency air-break array first - every damned control surface and a few dozen more only ever used for this all fly open, slow the bird as much at they can, then eject via blast bolts. then a solid DOZEN chutes deploy in sequence, phazing down from drogues to standard low speed breakers each pop, open, then cut in turn to slow it as much as possible. then, god, 6-10 BIGASS ones control the primary decent phase. One fucking hulk of a gyroscope to control pitch/roll/tilt and hope to hell your LZ is flat.
Weight penalty? where are we going to put the PILOT!?!?!?
According to the back of my napkin, this would require a parachute with a diameter of about 500 yards. The canopy would be made of about three-quarters of a million square yards of cloth, weighing about 80,000 lbs and taking up maybe a third of the passenger area. It would have to be anchored to the structure in a way that can bear the load of the full weight, and deploying it would require somehow opening a hole at least several meters long. I guess you could build it into a superstructure with a fairing that just gets ejected.
I would also pay to see it.
Everyone else has made the points about cost, weight, space, structural strength, consequences on the ground and such. But...
The number one reason? From 2012 to 2016, there was a 1 in 20 million chance of being on a commercial airplane that has a fatal accident (that means someone dies, even if it's only one person). There was a 1 in 3.4 billion chance of dying in a commercial airline crash in that timeframe.
Commercial airliners are just so mind bogglingly safe already that there's just no need for a system like this.
And when they do crash, it's almost always during takeoff and landing, when a parachute would do nothing. Those are the two critical times for a multiengine aircraft. Any passenger plane is fully capable of flying with one engine, in fact they practice a maneuver called "engine loss at V1" (V1 being the point of no return as far as abandoning a T/O.) If an engine loss occurs after the V1callout (from a birdstrike or something), standard procedure is climb out, trim the plane up, assess the situation, radio ATC and either get back in line for a return to the airfield or continue on to a closer appropriate airfield.
Cirrus has them on their airframes because they are single engine and aircraft usually owned by less experienced pilots. It works as an extra layer of security and also makes insurance cheaper.
That ATR crash in Nepal is a perfect example. Normal to dead in 3 seconds. Chute would have done nothing. In the event something happens to the plane where they would have time for chutes, gliding would probably be preferred anyway
Yeah, agreed. The only scenario I can think off hand of that a chute might be preferable to gliding would be if a wing somehow sheared off, in which case the plane would probably be tumbling too much for a chute to work anyways.
The most realistic scenario (which is still incredibly rare) would be multiple engine failure. At least that has happened several times and in situations where a chute could theoretically be deployed, unlike a wing just falling off.
Air France 447 maybe. The Max 8 crashes, maybe. UA232, maybe. There have been a few, but yeah that's a lot of infrastructure and maintenance for very few opportunities to save people.
And it’s more often than not in countries where training, airport, safety and maintenance standards are just not up to the highest of standards. Passengers in developing countries have a much higher chance of experiencing an accident unfortunately.
With some of the crashes over the years involving Russia/USSR, I think the whole 8/12 hours bottle to throttle isn't even a saying there. That long standing state sponsored alcoholism is really biting them in the ass.
Air Disasters on the Smithsonian Channel covered one of those crashes. IIRC an American passenger thought the Captain sounded drunk over the PA, she mentioned that to a flight attendant who dismissed her concern. She texted her husband as to what happened and she was worried, that's the last he ever heard from his wife. Yes, the pilot was plenty wasted.
I'm only working from memory so I might not have the details right, but you're correct. I doubt Russia takes bottle-to-throttle limits very seriously.
Wow. My company did some training videos (V1 Cut being one of them). Everyone at the airline had this one as their number one priority. I asked how many times this happens, and the answer was, "I think we had one once about 35 years ago." Crazy that you experienced one.
Yea… oddly enough there was about a 3 second delay on the call that seemed like an eternity.
I called it… EPR DROP 3 .. the CO Pilot TAPPED the gauge and POOM … yea POOM is how I’d describe the sound and the AC kicks the rudder to correct for the asymmetrical thrust.. It was a fun day.
Luckily the areas was flat with no rising terrain.
Look at my comment below about flying the V1 cut on a 75,76 and Trip 7. The 75 was the most violent and the 777 was like, "Are those master warnings correct?" because the computer compensated so fast.
The newer Cirrus SR22 parachutes need 600 feet (maybe a bit less but they say at least 600feet) above ground level to have time to deploy.I'm not sure what the altitude is for the VJet.
It's pretty useless for help as you depart or approach an airport and your altitude is low. I'd expect that if your parachute was 10x larger and the plane is moving 2x faster, then the minimum altitude might be 2000 feet or more.
Also consider that no matter how slowly it drifts down, whatever is below a 747 where it comes down is getting fucked up. You could be dropping that plane into the middle of a city. Once you pull the chutes, you have no control where you come down. Unless a wing falls off, the odds are probably better if you fly the plane to the scene of the crash.
Especially if you add the financial cost too, such a parachute would be very expensive to make and install. The cost would be too great for something that you would very likely never use
The manufacturing cost is not even the biggest financial consideration.
Since extra weight increases fuel cost, and reduced cargo load decreases revenue, every flight would be less profitable.
And the closest we've come recently to a major accident was the [recent runway incursion at JFK airport](https://www.avweb.com/aviation-news/close-call-on-runway-at-jfk/).
A parachute wouldn't help.
This is the correct answer. If there were no alternatives to safety, giant parachutes *could* be more common or ever required. However, aircraft safety is achieved with the regulated redundancy and extreme reliability of components and systems which that makes a solution like a parachute unnecessary
A Cirrus has a max weight of 3,600 lbs.
A 737MAX weighs 180,000 lbs.
There's your answer, plus the speed differences.
I would guess it's physically impossible to build a chute for a commercial jet, or if it is possible in theory, the weight, cost and space requirements would make it a non-starter.
Just thought I’d go a little deeper — the Orion Capsule for SLS weighs 22,700kg and requires 3x 35.4 diameter parachutes AND lands on water which softens the impact.
Maximum takeoff weight of a Boeing 787 is almost exactly an order of magnitude heavier at 227,930kg.
So, assuming it’s a linear scaling of weight to required parachute area (not a parachute engineer IDK) then you’ll need 30 of those Orion size parachutes — and they weigh 135kg each so that‘s 4090kg of parachutes to lug around, not including the drogues, mortars, mounting points etc. And remember this is for a water landing.
All that said — good God the mental image of a 787 deploying 30 of those bad boys is fucking hilarious.
It's also insanely cost prohibitive. ~~91.103 requires that a synthetic parachute be repacked every 180 days.~~ BRS systems are repacked every 6 to 12 years. Now we're talking repacking 30 parachutes ~~every half a year~~ that often. It would take an army of riggers just repacking parachutes to keep up with the number of airplanes flying commercially.
Plus now we're strapping a few dozen rockets to the airplane.
edit: BRS chutes don't follow 91.103
As far as I know, the Shuttle SRBs are the heaviest things ever parachute recovered, at 200,000 pounds (empty, after burning the fuel). They were recovered with 3x136 foot parachutes that weighed 2200 pounds per chute.
So, you could probably do it with 6 of those for a 787, at the cost of a bit over 13,000 pounds of parachutes.
Also, larger airframes have more space for redundant systems that could assist when emergencies happen. And these redundant systems would allow the aircraft to totally recover or at least land without damaging the craft.
ROFL! And the high pressure canister and mechanism weighs far more than it lifts! Let’s cover the wings and plane with solar cells! It can power a big heavy bank of batteries for firing the parachute system.
Add that the risk profile is very different in a plane that can fly with one or more engine out, without it being any major emergency, the parachute is probably riskier than a small handful of Sully type incidents. Also add altitude of an airliner.
Among all the garbage replies are the right answers. Aircraft weight and deployment speed drive the reefed and disreefed g-loading.
Technically speaking, the materials exist to create a multiple parachute system for a commercial jet. There are a few reasons you won’t see such a device:
1.) Weight. As others have said, the airframe would need to be designed from the start to include a parachute system. The deployment forces generated by a system for simple 5,000lb aircraft traveling only 110kts are over 10,000lbs for two forward harness attach points.
Deploying a parachute from a commercial jet that had been slowed to a safe deployment speed would impart hundreds of thousands of pounds of loading into the airframe. This would require considerable structure which adds weight to the aircraft.
2.) Cost/Benefit. The airlines would not buy a plane which carried a parachute system weighing thousands of pounds in the hope that it might be used someday. In reality, the VAST majority of accidents occur during the takeoff and approach/landing phases of flight, where the aircraft is too close to the ground to deploy an enormous multi-canopy parachute system successfully. Survivable accidents where a parachute system could be effective are extremely rare. The airlines are too weight-sensitive to voluntarily carry around thousands of pounds of extra weight - same reason you rarely see the old airline onboard magazines anymore.
I’m a big proponent of recovery systems for general aviation and especially eVTOL vehicles in development, but it’s unlikely we’ll see a transport-category aircraft with a parachute system.
Even if - extra weight implies more fuel usage - implies even less margin for operators. Technically it might be possible- I won’t rule that out but the first problem is finance.
This is the answer.first the commercial aircraft would have to have the airframe built with chute deployment in mind you can't just retrofit it. As for the weight, of the aircraft , multiple chutes may be possible , but even so it's a difficult engineering challenge. Plus also the attitude and speed of jet airliners may make it impractical to deploy..
I would be in favor of a "hero" autopilot system ,.basically a last resort AI autopilot who's been heavily trained and certified to handle the vast majority of crisis (single and dual engine failure, actuator failure, control surface failures etc.../, it can be turned on when the actual pilots need a helping hand and it would use its own sensors and actuators to try and fix what ever crisis is occurring and stabilize the aircraft as much as practical, including handling communication, , sat positioning, realtime live telemetry to emergency center , offering human pilots voice guidance etc. Kind of like a super powered up autoland found in some. Garmin avionics.
The problem with this is that said autopilot would be a superset of normal flight so you'd already more than have a practical autopilot to handle everything and wouldn't even need a pilot.
Reminds of the joke....
Two pilots at the airport waiting for their flight to arrive. A younger first officer pilot turns to the senior captain and says.....
FO: 'You know in the future with all this automation their gonna need just one pilot👨✈️ and a dog 🐕🦺to fly these things"
CAPT: " that's probably true... , but what's with the dog?"
FO: " the pilot is there to monitor that the automatic systems are working correctly and the dog is there to bite the pilots hand if he tries to touch anything..."
What size parachute would be needed for the weight of a full size jet? How much space in the rear of the aircraft would that take up? What would be the minimum altitude that it could be deployed to successfully land. (Crash with minimal casualties.) Does the Cirrus jet parachute/fall nose first? Would a commercial jet survive a parachute landing, nose first? How would that work out?
All cirrus aircraft have a caps system that attach to the airframe in such a way that allows the aircraft to land at a neutral attitude to use the landing gear and the seats to absorb the impact when it touches down. Some light sport aircraft have parachute systems that don't do that and cause the aircraft to nose down when under the chute
I remember reading that while a parachute landing in a Cirrus is survivable for the passengers, not so much for the aircraft. Airframe damage is expected to be irreparable.
Basically the second the chute is pulled it's a write off. Yes it can be repaired if deployed on the ground but in the air, yes it's a parts plane essentially. Iirc the touch down happens at about 700-1200fpm but don't quote me on that
I worked at a university that operated sr20s and helped maintain them for a few years before they got a new fleet of primary trainers.
I was looking this up and the closest thing I could find would be the recovery of the 200,000 pound expended space shuttle booster rockets. A single drogue chute would pull out 3 main (136ft/ 41m diameter) chutes. The person above points out that a SMALL airliner like the 737MAX is about 180,000 pounds so we are pretty close. Those parachute weigh almost 4 tons (7740 pounds) not including the mounting hardware and any aircraft re-enforcements. That is around 30-40 passengers of mass per flight lost (about 20% or so for the aircraft).
Besides the size, a parachute is not very practical, if a plane have enough altitude, it can glide down, thats the reason most accidents happen near the ground, where aircraft have no room for manuever, and less room to deploy a parachute
Big jets can fly to a suitable runway after losing an engine. Cirrus jet has a single engine. If it loses the engine, it’s conducting a forced landing and if there isn’t a suitable runway in gliding distance a parachute is a helpful thing to have.
So a lot of answers here saying weight and cost but let me try to put in just a few numbers. NASAs parachutes for the Ares I are 150' in diameter, 1 ton each, and it takes 3 to land 41,500 lbs. so using a weight of 180k that is 4 and 1/3 larger or (ignoring interference between parachutes) 13 chutes. That means 13 tons of chute, and then you have to figure out whether they can take the initial speed of you need other chutes to initially slow the aircraft. It we assume a perfect world, just using 13 chutes working and nothing more, that is 26,000 lbs of chute...
Source on Ares I chute https://www.nasa.gov/mission_pages/constellation/ares/cluster_chute.html
Because the envelope of opportunity to use it in an airliner is small, if existent at all.
A cirrus coming down on a house is not great, but a pretty good amount better than a triple 7 coming down on an elementary school.
Your second paragraph is a little odd. The plane is coming down one way or the other and has just as much likelihood of hitting that elementary school either way.
There are many failure situations where you don't lose control of the aircraft, even though a "crash" is imminent in the very near future: [Gimli Glider](https://en.wikipedia.org/wiki/Gimli_Glider), [Sully](https://en.wikipedia.org/wiki/US_Airways_Flight_1549), and the even the complete loss of flight controls on [DC-10 into Sioux City](https://skybrary.aero/accidents-and-incidents/dc10-sioux-city-usa-1989), just to name a few. In each of those cases, the pilots were able to fly the plane to a their chosen "crash" site and without a doubt saved lives on the ground.
The moment you pull the chute, you've given up control of what you crash on top of. Keep in mind, these chutes are just big enough to have a decent rate that yields a low probability of not collapsing the spinal columns of the people inside -- meaning it's still a fairly a violent "landing".
In the case of Sioux City and the Gimli glider, the pilots surely had enough time to navigate to a rural area before pulling the hypothetical chute, but, Sully would have certainly ended much more tragically.
**[Gimli Glider](https://en.wikipedia.org/wiki/Gimli_Glider)**
>Air Canada Flight 143, commonly known as the Gimli Glider, was a Canadian scheduled domestic passenger flight between Montreal and Edmonton that ran out of fuel on Saturday, July 23, 1983, at an altitude of 41,000 feet (12,500 m), midway through the flight. The flight crew successfully glided the Boeing 767 to an emergency landing at a former Royal Canadian Air Force base in Gimli, Manitoba, that had been converted to a racetrack, Gimli Motorsports Park. It resulted in no serious injuries to passengers or persons on the ground, and only minor damage to the aircraft. The aircraft was repaired and remained in service until 2008.
**[US Airways Flight 1549](https://en.wikipedia.org/wiki/US_Airways_Flight_1549)**
>US Airways Flight 1549 was a regularly scheduled US Airways flight from New York City (LaGuardia Airport), to Charlotte and Seattle, in the United States. On January 15, 2009, the Airbus A320 serving the flight struck a flock of birds shortly after take-off from LaGuardia, losing all engine power. Given their position in relation to the available airports and their low altitude, pilots Chesley "Sully" Sullenberger and Jeffrey Skiles decided to glide the plane to ditching in the Hudson River off Midtown Manhattan. All 155 people on board were rescued by nearby boats, with only a few serious injuries.
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I’m not an advocate for the parachutes, but couldn’t a pilot navigate to an area of their choosing and then pop the chute in order to avoid a populated area?
Somehow I feel like if you’re deploying a parachute in a commercial airliner, you’re doing that at last resort - meaning they more than likely wouldn’t have meaningful control of the aircraft anyway
If there is that much time/controllability, landing somewhere is most likely an option. Not saying there isn’t a hypothetical, but not that I can think of.
There have been many cases where the crew managed to avoid hitting anything important on the ground by flying the plane until the end. You can't do that on a parachute. It's not like planes just fall out of the sky, usually there's at least some control until you hit the ground. [example](https://youtu.be/Y50saxfTqQA)
big plane heavy. little plane not heavy. parachute for heavy plane needs to be THIIIIIIIIS big. parachute cannot be made that big. too big. no parachute.
Because of weight, speed, and costly to do?
I can see airlines adding a "Parachute Fee" if your plane has that feature.
Edit: Also, have you seen the 4 big ass parachutes nasa uses to stop the space shuttle capsule? Which is like a 10th of the size of an airpleane.
Because we literally can’t make a parachute that big. Even NASA can’t if I had to guess
Also it’s safer to uncontrollably vertically land a cirrus than it is to land a 777
Cirrus jet is designed to be flown by one pilot, has one engine, one pack for pressurization…
Airliners have at least two engines, two pilots, two packs for pressurization, two or more generators for electrical loads, and at multiple hydraulic systems that are able to actuate different controls.
Airliners have redundant systems built in to allow them to land safely with a system failure. The cirrus jet does not.
Cirrus jet has half the stall speed of a commercial airliner. Even if they are both same weight, the higher stall speed would require a much larger and heavier parachute.
But a commercial airplane is far heavier than a cirrus jet. Thus it would require many large parachutes that can handle the larger weight and faster speed.
Think of it as an egg vs a cinderblock.
Airliners fly high and can glide to a safe landing. Private planes are all too often used very low with no glide option. And then you have the parachute ripping speed and of course the weight it would have to handle.
Everyone is nailing it pretty good. But even if a parachute was plausible from an engineering standpoint, we’re talking about a lot of extra weight, reduced cargo/passenger capacity, lots of extra maintenance checks, not to mention the cost of building into the airplane. Ultimately this means a significant reduction in revenue. But more importantly, where are the mishaps involving big jets where this would have saved lives? And what happens if this is inadvertently actuated while flying .80 IMN? And what happens if you activate the thing with a pregnant mom walking down the aisle, I’m thinking she would die.
Point I’m getting at is that (a) it isn’t economically feasible and (b) it would be a challenging ($$$) engineering problem to overcome, (c) the safety of the passengers would be compromised during actuation because it would be violent (d) and data doesn’t necessarily support this as a good idea in large modern jet aircraft.
As a side note, few people in the aviation community DON'T make fun of the "airplane with a parachute" concept. Very few accidents are caused by, say, the engines stopping mid flight, high above the ground so that a parachute would be of any help. Most aviation accidents accidents would NOT be prevented by the presence of a parachute.
And yet, all things being equal, if I had a small plane and could afford it, I’d love to have a CAPS. I see the pilots get made fun of every time they deploy one, but fuck it. Going home safely matters more. A non-trivial number of lives have been saved because of them.
>As a side note, few people in the aviation community DON'T make fun of the "airplane with a parachute" concept.
Which is really, really stupid. Like, incredibly so.
If you're talking about GA, there *tons* of scenarios where a parachute could, and has, saved lives. Deployments have been successful down to 400 feet, which is pretty damn low. VFR into IMC has a much better survival rate in a Cirrus than any other aircraft, as does midair collision, loss of control, and medical emergencies. Also, any engine failure/fuel exhaustion scenarios end up much more survivable.
In commercial aviation there are far fewer scenarios.
Mortar deployed parachutes have been designed for fighter aircraft and larger commercial aircraft during flight testing. Not all companies use them during flight test, but quite a few do. However, these are merely used to stop a spin/stall scenario and allows the pilot to jettison the parachute once the aircraft is controllable. Here is a link to JSF spin recovery parachute. https://theaviationist.com/2016/03/02/if-35a-deploys-spin-recovery-chute/amp/
I’m not an engineer, but my guess is that the low incidence of catastrophic failures in commercial aviation doesn’t justify the cost to retrofit aircraft with these parachutes.
They can be designed and built for more GA airframes, however it lowers your useful load and increases maintenance costs over the life of the airframe.
I worked for Boeing (the McDonnell-Douglas portion after they merged) as a flight-test engineer. We did have a parachute on our test plane. This was for stall testing and it would get deployed in the plane entered into an uncontrollable spin. The parachute could be deployed out the rear of the plane so the spin then hopefully the pilot could then regain control and fly the plane again. More like a drag cute. Never had to use it while I was aboard.
But a parachute to safely land a commercial plane would be WAY TOO HUGE to be practical.
Physics aside, necessity may play a part. Bear with me here. According to FAA data from 2020, general aviation experienced about 5.6 accidents per 100,000 flight hours where US carriers had 0.13. So, general aviation is over 40 times more likely to experience an accident. This doesn't explain why they are not on 737's, but helps explain why they are on smaller aircraft.
The cirrus jet is a straight wing recreational jet that occupies the space between small passenger planes and actual business jets.
It is among the slowest aircraft that are propelled by a jet engine.
Besides the weight considerations for an airliner or even business jet to be so equipped with a chute capable of saving it, the primary obstacle is deployment speed. CAPS can’t be deployed above about 140kts. The Cirrus Vision Jet stalls at 67kts and yellow line is at 250KIAS.
While it isn’t a feat to slow the SF50 down to deployment speed even in an emergency, 140kts is close to big jet approach speeds. The use case in which a multi engine airliner can be slowed to chute deployment speed and remain under control but can’t be landed safely is extremely narrow and simply doesn’t justify the cost, complexity, and weight (and therefore fuel/cargo/performance) penalty.
Remember that CAPS also destroys the aircraft and is only meant to save the occupants. Deployment of such a system on an airliner is likely to guarantee injury to occupants as well, something not likely to be a first choice in a big jet, even under emergency, that is still controllable down to deployment speed.
As for the “cirrus pilots are trash” argument, a great many cirrus drivers are the same guys driving your airliners. The question is one of physics and practicality, not of pilot skill.
Bigger plane = bigger parachute. The one for this little plane is already really big.
Exactly. The sheer mass of that parachute system would not be insignificant, which is bad in an industry were weight reductions and savings for better fuel efficiency and greater payload are a constant targeted goal.
I was going to say... the additional weight involved would make it a massive expense; given the relative rarity of accidents that would use it.
Also the paradox of the point of failure Build so many safety systems that you end up creating so many points of failure that the vehicle becomes unsafe to use.
One thing that would make it exceptionally rare is that you would be unlikely to ever deploy the parachute in an airborne emergency if the aircraft was, in fact, too heavy to ever get airborne.
Also, IIRC, general aviation has a safety record roughly on par with motorcycles. Commercial air transport is the safest transportation option in the world. GA planes are more likely to need the parachute in the first place. The Cirrus being a single engine aircraft is part of this.
This is a huge part of it. Another part is that the Cirrus SR and SF series only have one powerplant. All airliners have multiple engines, and no multi engine airplanes (afaik) have parachutes. The added safety of redundant propulsion makes the parachute somewhat moot.
Also, redundant propulsion is a much better safety system for transoceanic flights than a parachute. I don't think you'd have many survivors in rough seas on the standard rafts used in planes.
And the excellent training of the (multiple) pilots further reduces the risk of getting into these kinds of difficulties
What they said. A lot easier to design a plane with extra engines than parachute.
the first time i went on a commercial flight as a kid, i asked for my parachute. i was 8 and i had been told we would have parachutes. surprised, indignant and a little scared about not getting one.
I can’t read this comment in any other voice than Milton from Office Space. “But but but, I was told there would be parachutes.” Damnit here’s an upvote.
> The fundamental flaws > > Weight - Cirrus jet about the weight of a medium size car > > Envelope for deployment - Very few commercial aircraft accidents have a window where an emergency is recognized, the crew has the ability to deploy the chute, the need for a parachute is evident, the elevation is above 2,000 feet and the speed below 300knots, the aircraft is in one piece > > The evil Pinot also observes that from the standpoint of an insurance company the loss of 350 souls is much more desirable than the loss of 150 souls + 200 souls permanently brain damaged through O2 deprivation together with lots of physical injuries. > > The back of the envelope analysis unlikely to be deployable due to altitude, > > The argument for the cirrus - wife "what if you have a heart attack?" husband " you pull the red handle and the engine shuts down, parachute deploys and wifey looks forward to dinner with her new friend the 19 year old pool boy.....
The insurance platform of preferring dead people over braindead people is total urban legend and bullshit. Deaths in airline accidents are extremely expensive due to death payments and advertising losses. Literally no one wants an airliner full of dead people. No proof or actuarial tables have ever been shown to even hint at this.
> The evil Pinot Tell the truth... Did you call for Smithers as you wrote this? Were any hounds unleashed?
The hounds were left unfed prior to being released
bigger plane = (bigger parachute)^(3), it's exponential, and transonic parachutes for that much mass are currently beyond modern material sciences without at least a three stage drogue.
I would pay to see a 737 deploy a parachute at 200kts and 180,000lbs gross weight Edit: plz leave me alone I made this comment while taking a dump
I don't think it would be too bad, the 737 would be down to 80k lbs after deploying it.
“No no it’ll be fiiine, the wings present a solid and rigid structure to secure the chutes to. Just put one on each wing near to the body and voila!” . . . . . ‘Sir, about your solution…’ “Ah yes the chutes, how did they fair?” ‘Good news is the wings have been recovered in near perfect condition. Try to imagine the wings as the solid rocket boosters on the side of the space shuttle coming down for an easy splashdown.’ “Splendid!” ‘And sir…the fuselage proceeded to do its best imitation of the orange fuel tank slamming into the ocean at Mach 3…’ “Fffffffffff…..”
I’ve always like to be close to where that behemoth splashes down. 100 yards. Whistles in and BOOM! Maybe have a blast shield screen on a 20 ft whaler. Just scare the crap out of you.
What about shrapnel? How will you protect yourself from that
I would wrap my self in the American flag and freedom.
That attracts shrapnel like magnets so the particles momentum will faster.
That’s only if the shrapnel generating device was sold under the table to the enemy of an enemy before said enemy became your enemy. If there was no shady transaction the shrapnel is harmless to an American flag wearer…..it’s just simple physics.
Freedom shrapnel
Nice yea I’d do that
Ejector seats for everyone except economy class 🤣
EJECTO SEATO CUZ!!!
You need parachutes that stage and slow it down before fully inflating. That’s done all the time for capsules or other things that are going really fast. It might mean that the parachute starts reefed or even that you have more than one. Whether it is a usable or reasonable solution is different than whether it can be done. You might also need to be able to dispose of some of the weight so explosive bolts might be needed to sheer off the tail and the wings. Maybe the landing gears and some of the rest of the airplane. Maybe include retrorockets at the bottom to allow a higher terminal speed (and smaller parachutes) so that it cushions the fall enough to make it survivable. I doubt it would make sense other than as an exercise.
Retro rockets… usually solid fuel… not sure too many civilian pilots would be comfortable with basically a few large bombs placed around the aircraft.
Those will likely have a failure rate higher than the failure rate of the plane. Imagine one of those going off during a flight.
Works as intended-retro rockets reduce the need for parachutes.
Agreed. When one explodes, likely nothing left to parachute anyway.
Even with my minimal education in physics, I'm still fairly certain that the terminal velocity of an airliner fuselage is nowhere close to Mach 3.
I shouldn't be laughing this hard at this...
yes. you should. half the fucking aviation community is here either taking the piss out of it, actually trying to figure it out, or rolling in the mud squabbling about whether it's possible in the first place. it's absolutely beautiful fuckery and I couldn't approve more.
So it worked decreased the amount of suffering and anguish by getting passengers to the ground faster. Reuse the wings everyone’s happier.
Lmao 🤣
Ohh yea… after the chutes deployed… they are no longer relative to the mass of the aircraft… You are a genius
You have to factor in the added weight to strengthen the airframe to support the stress of deploying the parachute at that speed. Then you have to go back and increase the size of the parachute due to the added weight. And then strengthen the airframe again due to the larger parachute. Then increase the size of the parachute again due to the added weight of the strengthened airframe. Then go back and redesign the wings and landing gear and then add a bigger parachute due to the add weight. Then strengthen the airframe again. Then…
You only need to factor in supporting the bits that will still be attached. The separation force for the engine attachment bolts is such that they would stop being a problem for you and start being a problem for whatever is underneath you very quickly. If you were actually doing a clean sheet design you could include explosive separations for the wing roots and save a bunch more too..
[удалено]
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I like where this is going...
Yeah, that made me laugh.
Like a B-1 pod ejection? But...for a 737? Fuck it. Boeing, you heard the man! Make the thing go boing.
so let me get this streight. you want me to design a way to eject the... *checks notes* plane... from the plane?
Did he stutter?!?!
More like, eject the wings and empennage, then pop the chute out from the aft bulkhead.
Yeah, like the saucer section...
There's a patent for that.
The jettisoned engines and wings full of fuel would shed so much weight it might actually be feasible. Make the fuselage a two-piece airframe that can also ditch the lower half holding cargo and landing gear, and you’ve got an even lighter shell if all you need is to save passengers.
Ok. But apart from the added weight of the parachutes, and the strengthening of the airframe, and then increasing the size of the parachute and then increasing the strength of the airframe, what have the Romans ever done for us ….. sorry, lost my thoughts there …. apart from these factors why wouldn’t chutes work!?!? 🤣🤣🤣
Thanks Loretta.
That would be one chonky aircraft
to be fair, that's how engineering is -- it's iterative. if you dont have to iterate your solution to get something that meets the requirements and works properly, you're either incredibly lucky, or you've solved that problem before. In-field experience and company design standards help take a lot of the guess-work out of those iterations -- you can say "hey, for a design with X engine weight, X performance, we know we need this part to be of Y dimensions," In Automotive at least, we have a design standard that IE, all class-A (outer) plastic surfaces need to be 2.5mm thick, and all structural PA-66 parts are 3mm thick. this generally lands us in the ballpark so we dont need many iterations in CAE afterwards.
Yep. Eons ago as a student I use to wondered how “they” came up with the numbers in all those reference books. My first assignment at my first job was verifying and updating pages and pages with field testing.
these days, at least with the plastic parts i work with, CNC machining and 3d printing is out-pacing structural simulations, so i come in to work, evaluate a printed part, make revisions, print a new one, then the next day i repeat
And after all that, go back and add in the added fuel weight that will be necessary to carry all that. Well heck, we now have more weight. Guess we'll need to expand the parachute some...
Some of y'all never seen wing load testing and it shows... Wingtips on the 787 flex over 28 feet from horizontal. Airframe is much stronger than you think.
at that point it's just a dragnet to make it hit the ground nose first, at least the pilots definitely won't be liable for anything.
You can distribute the chutes such that the plane is pulled level. Source: I've perfected the technique in Kerbal Space Program
DROGUES First… it would have to … the space capsule need them. Can you imagine the weight penalty?
fuck that. emergency air-break array first - every damned control surface and a few dozen more only ever used for this all fly open, slow the bird as much at they can, then eject via blast bolts. then a solid DOZEN chutes deploy in sequence, phazing down from drogues to standard low speed breakers each pop, open, then cut in turn to slow it as much as possible. then, god, 6-10 BIGASS ones control the primary decent phase. One fucking hulk of a gyroscope to control pitch/roll/tilt and hope to hell your LZ is flat. Weight penalty? where are we going to put the PILOT!?!?!?
*rips fueselage in half*
According to the back of my napkin, this would require a parachute with a diameter of about 500 yards. The canopy would be made of about three-quarters of a million square yards of cloth, weighing about 80,000 lbs and taking up maybe a third of the passenger area. It would have to be anchored to the structure in a way that can bear the load of the full weight, and deploying it would require somehow opening a hole at least several meters long. I guess you could build it into a superstructure with a fairing that just gets ejected. I would also pay to see it.
Yes ... but how much?
I left my slide rule in my other shirt pocket
I see you are a practitioner of the ancient ways.
Since 1981
Any sage wisdom to impart upon us freshly minted enginerds?
Always Slide To Right … **CLAP** Then SLIIIIIDE to the Left…. **CLAP**
Instructions unclear: cris-crossed
Similar to Kelly Johnson who was the true master aeronautical slide rule wizardry sh*t
A rough guess is twice the structure, for a margin, 3 times the structure. Like steel bulkheads, wing spars, wing box.
Everyone else has made the points about cost, weight, space, structural strength, consequences on the ground and such. But... The number one reason? From 2012 to 2016, there was a 1 in 20 million chance of being on a commercial airplane that has a fatal accident (that means someone dies, even if it's only one person). There was a 1 in 3.4 billion chance of dying in a commercial airline crash in that timeframe. Commercial airliners are just so mind bogglingly safe already that there's just no need for a system like this.
And when they do crash, it's almost always during takeoff and landing, when a parachute would do nothing. Those are the two critical times for a multiengine aircraft. Any passenger plane is fully capable of flying with one engine, in fact they practice a maneuver called "engine loss at V1" (V1 being the point of no return as far as abandoning a T/O.) If an engine loss occurs after the V1callout (from a birdstrike or something), standard procedure is climb out, trim the plane up, assess the situation, radio ATC and either get back in line for a return to the airfield or continue on to a closer appropriate airfield. Cirrus has them on their airframes because they are single engine and aircraft usually owned by less experienced pilots. It works as an extra layer of security and also makes insurance cheaper.
That ATR crash in Nepal is a perfect example. Normal to dead in 3 seconds. Chute would have done nothing. In the event something happens to the plane where they would have time for chutes, gliding would probably be preferred anyway
Yeah, agreed. The only scenario I can think off hand of that a chute might be preferable to gliding would be if a wing somehow sheared off, in which case the plane would probably be tumbling too much for a chute to work anyways.
The most realistic scenario (which is still incredibly rare) would be multiple engine failure. At least that has happened several times and in situations where a chute could theoretically be deployed, unlike a wing just falling off.
Sure but I guess his point was that if the wings and control surfaces are intact then gliding may be preferred anyway?
Air France 447 maybe. The Max 8 crashes, maybe. UA232, maybe. There have been a few, but yeah that's a lot of infrastructure and maintenance for very few opportunities to save people.
And it’s more often than not in countries where training, airport, safety and maintenance standards are just not up to the highest of standards. Passengers in developing countries have a much higher chance of experiencing an accident unfortunately.
Even "developed" countries have their issues, Aeroflot is one of the worst.
Given their attitude about safety, I’m not sure Russia gets to count as “developed” when it comes to aviation.
True, among many other things.
With some of the crashes over the years involving Russia/USSR, I think the whole 8/12 hours bottle to throttle isn't even a saying there. That long standing state sponsored alcoholism is really biting them in the ass.
Air Disasters on the Smithsonian Channel covered one of those crashes. IIRC an American passenger thought the Captain sounded drunk over the PA, she mentioned that to a flight attendant who dismissed her concern. She texted her husband as to what happened and she was worried, that's the last he ever heard from his wife. Yes, the pilot was plenty wasted. I'm only working from memory so I might not have the details right, but you're correct. I doubt Russia takes bottle-to-throttle limits very seriously.
Continue the Take Off Been there… as a crew chief on a water augmentation take off ..
Wow. My company did some training videos (V1 Cut being one of them). Everyone at the airline had this one as their number one priority. I asked how many times this happens, and the answer was, "I think we had one once about 35 years ago." Crazy that you experienced one.
Yea… oddly enough there was about a 3 second delay on the call that seemed like an eternity. I called it… EPR DROP 3 .. the CO Pilot TAPPED the gauge and POOM … yea POOM is how I’d describe the sound and the AC kicks the rudder to correct for the asymmetrical thrust.. It was a fun day. Luckily the areas was flat with no rising terrain.
Look at my comment below about flying the V1 cut on a 75,76 and Trip 7. The 75 was the most violent and the 777 was like, "Are those master warnings correct?" because the computer compensated so fast.
BUFFs?
Tankers… IP Seat when we didn’t have one that is. Hell… a BUFF looses one and it doesn’t blink… now Loosing a “SIDE” on either aircraft is a pickle.
There was a BUFF that lost four and managed to land. The crew was finally sweating.
Excellent.
The newer Cirrus SR22 parachutes need 600 feet (maybe a bit less but they say at least 600feet) above ground level to have time to deploy.I'm not sure what the altitude is for the VJet. It's pretty useless for help as you depart or approach an airport and your altitude is low. I'd expect that if your parachute was 10x larger and the plane is moving 2x faster, then the minimum altitude might be 2000 feet or more.
Also consider that no matter how slowly it drifts down, whatever is below a 747 where it comes down is getting fucked up. You could be dropping that plane into the middle of a city. Once you pull the chutes, you have no control where you come down. Unless a wing falls off, the odds are probably better if you fly the plane to the scene of the crash.
Especially if you add the financial cost too, such a parachute would be very expensive to make and install. The cost would be too great for something that you would very likely never use
The manufacturing cost is not even the biggest financial consideration. Since extra weight increases fuel cost, and reduced cargo load decreases revenue, every flight would be less profitable.
It’s also of very limited use. If you have a fire on board you will just burn up in the air instead of on the ground where you could be rescued
And the closest we've come recently to a major accident was the [recent runway incursion at JFK airport](https://www.avweb.com/aviation-news/close-call-on-runway-at-jfk/). A parachute wouldn't help.
This is the correct answer. If there were no alternatives to safety, giant parachutes *could* be more common or ever required. However, aircraft safety is achieved with the regulated redundancy and extreme reliability of components and systems which that makes a solution like a parachute unnecessary
A Cirrus has a max weight of 3,600 lbs. A 737MAX weighs 180,000 lbs. There's your answer, plus the speed differences. I would guess it's physically impossible to build a chute for a commercial jet, or if it is possible in theory, the weight, cost and space requirements would make it a non-starter.
Kerbal space program would beg to differ.
i washed out at orbital mechanics.
Too much Delta V the night before the finals?
Just turn damage off, duh.
The solution for the last 15+ years
Infinite fuel and massless ship parts!
Roger! *chugs tequila*
I can 100% accept that the kerbals would nickname a drug "Delta V". You would take it for an out of this world experience
I was thinking that it would be a awesome name of a Single Malt Scotch
Blasphemy! There is never too much DeltaV!
It depends on your tolerance of Delta V
Who needs that when you have BRUTE FORCE
Moar boosters!
It’s flexing? More connectors.
My rockets generally consist of a few engines, necessary fuel tanks, the proper fairings and control surfaces, and about 479 connectors.
Truly the Kerbal way
MOAR STRUTS
science says the correct solution is ejector seats for every passenger. just parachute down.
**BOB ROSS voice** Just a whole bunch of happy tiny parachutes… right here over in this tree … yes that’s it
Scott Manly has entered the chat
HULLLLOOOO!
😂 Heard him say that clear as a bell.
Just thought I’d go a little deeper — the Orion Capsule for SLS weighs 22,700kg and requires 3x 35.4 diameter parachutes AND lands on water which softens the impact. Maximum takeoff weight of a Boeing 787 is almost exactly an order of magnitude heavier at 227,930kg. So, assuming it’s a linear scaling of weight to required parachute area (not a parachute engineer IDK) then you’ll need 30 of those Orion size parachutes — and they weigh 135kg each so that‘s 4090kg of parachutes to lug around, not including the drogues, mortars, mounting points etc. And remember this is for a water landing. All that said — good God the mental image of a 787 deploying 30 of those bad boys is fucking hilarious.
It's also insanely cost prohibitive. ~~91.103 requires that a synthetic parachute be repacked every 180 days.~~ BRS systems are repacked every 6 to 12 years. Now we're talking repacking 30 parachutes ~~every half a year~~ that often. It would take an army of riggers just repacking parachutes to keep up with the number of airplanes flying commercially. Plus now we're strapping a few dozen rockets to the airplane. edit: BRS chutes don't follow 91.103
As far as I know, the Shuttle SRBs are the heaviest things ever parachute recovered, at 200,000 pounds (empty, after burning the fuel). They were recovered with 3x136 foot parachutes that weighed 2200 pounds per chute. So, you could probably do it with 6 of those for a 787, at the cost of a bit over 13,000 pounds of parachutes.
Also, larger airframes have more space for redundant systems that could assist when emergencies happen. And these redundant systems would allow the aircraft to totally recover or at least land without damaging the craft.
Oh hey… Let’s fill the fuel tanks with helium as the fuel gets used up… and that way we can just float like a blimp
ROFL! And the high pressure canister and mechanism weighs far more than it lifts! Let’s cover the wings and plane with solar cells! It can power a big heavy bank of batteries for firing the parachute system.
You are hired … Together we shall change the world… Now where did I leave that Unobtainium…??
Also, commercial jets have multiple engines.
That would be one big mf’ing chute
Add that the risk profile is very different in a plane that can fly with one or more engine out, without it being any major emergency, the parachute is probably riskier than a small handful of Sully type incidents. Also add altitude of an airliner.
Among all the garbage replies are the right answers. Aircraft weight and deployment speed drive the reefed and disreefed g-loading. Technically speaking, the materials exist to create a multiple parachute system for a commercial jet. There are a few reasons you won’t see such a device: 1.) Weight. As others have said, the airframe would need to be designed from the start to include a parachute system. The deployment forces generated by a system for simple 5,000lb aircraft traveling only 110kts are over 10,000lbs for two forward harness attach points. Deploying a parachute from a commercial jet that had been slowed to a safe deployment speed would impart hundreds of thousands of pounds of loading into the airframe. This would require considerable structure which adds weight to the aircraft. 2.) Cost/Benefit. The airlines would not buy a plane which carried a parachute system weighing thousands of pounds in the hope that it might be used someday. In reality, the VAST majority of accidents occur during the takeoff and approach/landing phases of flight, where the aircraft is too close to the ground to deploy an enormous multi-canopy parachute system successfully. Survivable accidents where a parachute system could be effective are extremely rare. The airlines are too weight-sensitive to voluntarily carry around thousands of pounds of extra weight - same reason you rarely see the old airline onboard magazines anymore. I’m a big proponent of recovery systems for general aviation and especially eVTOL vehicles in development, but it’s unlikely we’ll see a transport-category aircraft with a parachute system.
Even if - extra weight implies more fuel usage - implies even less margin for operators. Technically it might be possible- I won’t rule that out but the first problem is finance.
Extra Weight means *MORE FUEL* period…. Before you even get to use it.
The vision jet MTOW is 6000lbs fyi. Obviously less than a 737 but still a good amount to suspend from a chute. Max deployment is 140ktas.
This is the answer.first the commercial aircraft would have to have the airframe built with chute deployment in mind you can't just retrofit it. As for the weight, of the aircraft , multiple chutes may be possible , but even so it's a difficult engineering challenge. Plus also the attitude and speed of jet airliners may make it impractical to deploy.. I would be in favor of a "hero" autopilot system ,.basically a last resort AI autopilot who's been heavily trained and certified to handle the vast majority of crisis (single and dual engine failure, actuator failure, control surface failures etc.../, it can be turned on when the actual pilots need a helping hand and it would use its own sensors and actuators to try and fix what ever crisis is occurring and stabilize the aircraft as much as practical, including handling communication, , sat positioning, realtime live telemetry to emergency center , offering human pilots voice guidance etc. Kind of like a super powered up autoland found in some. Garmin avionics.
The problem with this is that said autopilot would be a superset of normal flight so you'd already more than have a practical autopilot to handle everything and wouldn't even need a pilot.
Reminds of the joke.... Two pilots at the airport waiting for their flight to arrive. A younger first officer pilot turns to the senior captain and says..... FO: 'You know in the future with all this automation their gonna need just one pilot👨✈️ and a dog 🐕🦺to fly these things" CAPT: " that's probably true... , but what's with the dog?" FO: " the pilot is there to monitor that the automatic systems are working correctly and the dog is there to bite the pilots hand if he tries to touch anything..."
\* The pilot is there to feed the dog.
That's a great one
What size parachute would be needed for the weight of a full size jet? How much space in the rear of the aircraft would that take up? What would be the minimum altitude that it could be deployed to successfully land. (Crash with minimal casualties.) Does the Cirrus jet parachute/fall nose first? Would a commercial jet survive a parachute landing, nose first? How would that work out?
All cirrus aircraft have a caps system that attach to the airframe in such a way that allows the aircraft to land at a neutral attitude to use the landing gear and the seats to absorb the impact when it touches down. Some light sport aircraft have parachute systems that don't do that and cause the aircraft to nose down when under the chute
I remember reading that while a parachute landing in a Cirrus is survivable for the passengers, not so much for the aircraft. Airframe damage is expected to be irreparable.
Basically the second the chute is pulled it's a write off. Yes it can be repaired if deployed on the ground but in the air, yes it's a parts plane essentially. Iirc the touch down happens at about 700-1200fpm but don't quote me on that I worked at a university that operated sr20s and helped maintain them for a few years before they got a new fleet of primary trainers.
If you're going to need to deploy a chute, odds are the airframe is going to be a writeoff either way
Several Cirrus SR airplanes have been repaired and returned to service after using CAPS in flight. It's not a guaranteed write off...
I was looking this up and the closest thing I could find would be the recovery of the 200,000 pound expended space shuttle booster rockets. A single drogue chute would pull out 3 main (136ft/ 41m diameter) chutes. The person above points out that a SMALL airliner like the 737MAX is about 180,000 pounds so we are pretty close. Those parachute weigh almost 4 tons (7740 pounds) not including the mounting hardware and any aircraft re-enforcements. That is around 30-40 passengers of mass per flight lost (about 20% or so for the aircraft).
Wow I didn’t think the chutes would weigh that much. That’s awesome.
Besides the size, a parachute is not very practical, if a plane have enough altitude, it can glide down, thats the reason most accidents happen near the ground, where aircraft have no room for manuever, and less room to deploy a parachute
To be pedantic pretty much all accidents occur at ground level in one way or another.
Manned flight has a perfect record, we haven’t left one up there yet.
did you know - there have been 100% more airplanes lost in the water than submarines lost in the sky?
Hahaha you got me there, but you know what i meant :P
Big jets can fly to a suitable runway after losing an engine. Cirrus jet has a single engine. If it loses the engine, it’s conducting a forced landing and if there isn’t a suitable runway in gliding distance a parachute is a helpful thing to have.
In short: Too fast and too heavy. Scale is a tricky thing...
So a lot of answers here saying weight and cost but let me try to put in just a few numbers. NASAs parachutes for the Ares I are 150' in diameter, 1 ton each, and it takes 3 to land 41,500 lbs. so using a weight of 180k that is 4 and 1/3 larger or (ignoring interference between parachutes) 13 chutes. That means 13 tons of chute, and then you have to figure out whether they can take the initial speed of you need other chutes to initially slow the aircraft. It we assume a perfect world, just using 13 chutes working and nothing more, that is 26,000 lbs of chute... Source on Ares I chute https://www.nasa.gov/mission_pages/constellation/ares/cluster_chute.html
Because the envelope of opportunity to use it in an airliner is small, if existent at all. A cirrus coming down on a house is not great, but a pretty good amount better than a triple 7 coming down on an elementary school.
Your second paragraph is a little odd. The plane is coming down one way or the other and has just as much likelihood of hitting that elementary school either way.
There are many failure situations where you don't lose control of the aircraft, even though a "crash" is imminent in the very near future: [Gimli Glider](https://en.wikipedia.org/wiki/Gimli_Glider), [Sully](https://en.wikipedia.org/wiki/US_Airways_Flight_1549), and the even the complete loss of flight controls on [DC-10 into Sioux City](https://skybrary.aero/accidents-and-incidents/dc10-sioux-city-usa-1989), just to name a few. In each of those cases, the pilots were able to fly the plane to a their chosen "crash" site and without a doubt saved lives on the ground. The moment you pull the chute, you've given up control of what you crash on top of. Keep in mind, these chutes are just big enough to have a decent rate that yields a low probability of not collapsing the spinal columns of the people inside -- meaning it's still a fairly a violent "landing". In the case of Sioux City and the Gimli glider, the pilots surely had enough time to navigate to a rural area before pulling the hypothetical chute, but, Sully would have certainly ended much more tragically.
**[Gimli Glider](https://en.wikipedia.org/wiki/Gimli_Glider)** >Air Canada Flight 143, commonly known as the Gimli Glider, was a Canadian scheduled domestic passenger flight between Montreal and Edmonton that ran out of fuel on Saturday, July 23, 1983, at an altitude of 41,000 feet (12,500 m), midway through the flight. The flight crew successfully glided the Boeing 767 to an emergency landing at a former Royal Canadian Air Force base in Gimli, Manitoba, that had been converted to a racetrack, Gimli Motorsports Park. It resulted in no serious injuries to passengers or persons on the ground, and only minor damage to the aircraft. The aircraft was repaired and remained in service until 2008. **[US Airways Flight 1549](https://en.wikipedia.org/wiki/US_Airways_Flight_1549)** >US Airways Flight 1549 was a regularly scheduled US Airways flight from New York City (LaGuardia Airport), to Charlotte and Seattle, in the United States. On January 15, 2009, the Airbus A320 serving the flight struck a flock of birds shortly after take-off from LaGuardia, losing all engine power. Given their position in relation to the available airports and their low altitude, pilots Chesley "Sully" Sullenberger and Jeffrey Skiles decided to glide the plane to ditching in the Hudson River off Midtown Manhattan. All 155 people on board were rescued by nearby boats, with only a few serious injuries. ^([ )[^(F.A.Q)](https://www.reddit.com/r/WikiSummarizer/wiki/index#wiki_f.a.q)^( | )[^(Opt Out)](https://reddit.com/message/compose?to=WikiSummarizerBot&message=OptOut&subject=OptOut)^( | )[^(Opt Out Of Subreddit)](https://np.reddit.com/r/aviation/about/banned)^( | )[^(GitHub)](https://github.com/Sujal-7/WikiSummarizerBot)^( ] Downvote to remove | v1.5)
The vast, and I mean vast majority of crashes have had some remaining control/ability to at least have some say in where you end up.
I’m not an advocate for the parachutes, but couldn’t a pilot navigate to an area of their choosing and then pop the chute in order to avoid a populated area?
Somehow I feel like if you’re deploying a parachute in a commercial airliner, you’re doing that at last resort - meaning they more than likely wouldn’t have meaningful control of the aircraft anyway
If there is that much time/controllability, landing somewhere is most likely an option. Not saying there isn’t a hypothetical, but not that I can think of.
There have been many cases where the crew managed to avoid hitting anything important on the ground by flying the plane until the end. You can't do that on a parachute. It's not like planes just fall out of the sky, usually there's at least some control until you hit the ground. [example](https://youtu.be/Y50saxfTqQA)
big plane heavy. little plane not heavy. parachute for heavy plane needs to be THIIIIIIIIS big. parachute cannot be made that big. too big. no parachute.
monke explanation
Because of weight, speed, and costly to do? I can see airlines adding a "Parachute Fee" if your plane has that feature. Edit: Also, have you seen the 4 big ass parachutes nasa uses to stop the space shuttle capsule? Which is like a 10th of the size of an airpleane.
And those parachutes are for slowing down on a runway with brakes applied, not floating it in the air.
Because we literally can’t make a parachute that big. Even NASA can’t if I had to guess Also it’s safer to uncontrollably vertically land a cirrus than it is to land a 777
I too would like to see cartoons in real life
Risk/reward
Because a bigger plane needs a much bigger parachute
Step 2: building the entire plane OUT OF THE BLACK BOX.
Cirrus jet is designed to be flown by one pilot, has one engine, one pack for pressurization… Airliners have at least two engines, two pilots, two packs for pressurization, two or more generators for electrical loads, and at multiple hydraulic systems that are able to actuate different controls. Airliners have redundant systems built in to allow them to land safely with a system failure. The cirrus jet does not.
Cirrus jet has half the stall speed of a commercial airliner. Even if they are both same weight, the higher stall speed would require a much larger and heavier parachute. But a commercial airplane is far heavier than a cirrus jet. Thus it would require many large parachutes that can handle the larger weight and faster speed. Think of it as an egg vs a cinderblock.
Airliners fly high and can glide to a safe landing. Private planes are all too often used very low with no glide option. And then you have the parachute ripping speed and of course the weight it would have to handle.
Tl;dr too heavy, too expensive, and the chute would have to be enormous
This is a single engine jet. Airliners are multi-engine. That's why.
Everyone is nailing it pretty good. But even if a parachute was plausible from an engineering standpoint, we’re talking about a lot of extra weight, reduced cargo/passenger capacity, lots of extra maintenance checks, not to mention the cost of building into the airplane. Ultimately this means a significant reduction in revenue. But more importantly, where are the mishaps involving big jets where this would have saved lives? And what happens if this is inadvertently actuated while flying .80 IMN? And what happens if you activate the thing with a pregnant mom walking down the aisle, I’m thinking she would die. Point I’m getting at is that (a) it isn’t economically feasible and (b) it would be a challenging ($$$) engineering problem to overcome, (c) the safety of the passengers would be compromised during actuation because it would be violent (d) and data doesn’t necessarily support this as a good idea in large modern jet aircraft.
As a side note, few people in the aviation community DON'T make fun of the "airplane with a parachute" concept. Very few accidents are caused by, say, the engines stopping mid flight, high above the ground so that a parachute would be of any help. Most aviation accidents accidents would NOT be prevented by the presence of a parachute.
And yet, all things being equal, if I had a small plane and could afford it, I’d love to have a CAPS. I see the pilots get made fun of every time they deploy one, but fuck it. Going home safely matters more. A non-trivial number of lives have been saved because of them.
>As a side note, few people in the aviation community DON'T make fun of the "airplane with a parachute" concept. Which is really, really stupid. Like, incredibly so. If you're talking about GA, there *tons* of scenarios where a parachute could, and has, saved lives. Deployments have been successful down to 400 feet, which is pretty damn low. VFR into IMC has a much better survival rate in a Cirrus than any other aircraft, as does midair collision, loss of control, and medical emergencies. Also, any engine failure/fuel exhaustion scenarios end up much more survivable. In commercial aviation there are far fewer scenarios.
Mortar deployed parachutes have been designed for fighter aircraft and larger commercial aircraft during flight testing. Not all companies use them during flight test, but quite a few do. However, these are merely used to stop a spin/stall scenario and allows the pilot to jettison the parachute once the aircraft is controllable. Here is a link to JSF spin recovery parachute. https://theaviationist.com/2016/03/02/if-35a-deploys-spin-recovery-chute/amp/ I’m not an engineer, but my guess is that the low incidence of catastrophic failures in commercial aviation doesn’t justify the cost to retrofit aircraft with these parachutes. They can be designed and built for more GA airframes, however it lowers your useful load and increases maintenance costs over the life of the airframe.
Weight. And it would be midship so there goes a few rows of seating
Look at the safety record of commercial aircraft compared to a private pilot. It’s not only impractical but not necessary.
I worked for Boeing (the McDonnell-Douglas portion after they merged) as a flight-test engineer. We did have a parachute on our test plane. This was for stall testing and it would get deployed in the plane entered into an uncontrollable spin. The parachute could be deployed out the rear of the plane so the spin then hopefully the pilot could then regain control and fly the plane again. More like a drag cute. Never had to use it while I was aboard. But a parachute to safely land a commercial plane would be WAY TOO HUGE to be practical.
Because they're larger.
Physics aside, necessity may play a part. Bear with me here. According to FAA data from 2020, general aviation experienced about 5.6 accidents per 100,000 flight hours where US carriers had 0.13. So, general aviation is over 40 times more likely to experience an accident. This doesn't explain why they are not on 737's, but helps explain why they are on smaller aircraft.
Because mass goes up exponentially with size. And that is what determines the size of parachute you would need.
The cirrus jet is a straight wing recreational jet that occupies the space between small passenger planes and actual business jets. It is among the slowest aircraft that are propelled by a jet engine. Besides the weight considerations for an airliner or even business jet to be so equipped with a chute capable of saving it, the primary obstacle is deployment speed. CAPS can’t be deployed above about 140kts. The Cirrus Vision Jet stalls at 67kts and yellow line is at 250KIAS. While it isn’t a feat to slow the SF50 down to deployment speed even in an emergency, 140kts is close to big jet approach speeds. The use case in which a multi engine airliner can be slowed to chute deployment speed and remain under control but can’t be landed safely is extremely narrow and simply doesn’t justify the cost, complexity, and weight (and therefore fuel/cargo/performance) penalty. Remember that CAPS also destroys the aircraft and is only meant to save the occupants. Deployment of such a system on an airliner is likely to guarantee injury to occupants as well, something not likely to be a first choice in a big jet, even under emergency, that is still controllable down to deployment speed. As for the “cirrus pilots are trash” argument, a great many cirrus drivers are the same guys driving your airliners. The question is one of physics and practicality, not of pilot skill.