A380X4TRENT900
Topic Author
Posts: 15
Joined: Tue May 31, 2005 9:19 am

Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 09, 2006 8:00 pm

I have thought about this for years:

why the hell don't airline manufacture's/company's like boeing and airbus install parachutes for emergency situations?

If a plane is travelling at 40 000 feet, travelling at 850 km/h, and looses power because it ran out of fuel (the pilots were unaware due to either undetected fuel leak or incorrect fuel gauge reading) - what happens it slows and glides out of stable flight because their is no thrust to confront drag, weight or gravity!

Why don't they have parachutes (that could be released at say 400 km/h) to slow down the plane enough to not cause death/serious injury/destruction of aircraft in crash situations?

Could the pilots control 200 tonnes with a parachute 1km wide holding it back?
 
tepidhalibut
Posts: 183
Joined: Fri Dec 10, 2004 8:19 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 09, 2006 8:48 pm

A fine idea. You could eliminate the seats from the top deck of the A380, and install parachutes instead. The lower deck passengers would be happy to pay double the airfare knowing that in the event of fuel loss, the pilots have a choice of gliding to the nearest airport, or parachute into the middle of the sea. Actually, why not install huge bouncy castles under each wing / fuselage to make the landing less traumatic.

An even better idea would be to fly at 30mph, only 5 ft above the ground, so that if the fuel runs out, the passengers can jump out the windows to the ground.


Apologies for the sarcasm, but the weight / strength / cost of the parachutes would be enormous, and all for a failure mode which hasn't actually casued any fatalities in the past few decades (I hope someone can confirm that.)

Flying is inherently a travel mode with risk. There are risk that don't exist with cars/boats/trains, but still people are willing to accept a small level of risk for the benefits. Aircraft parachutes would not contribute any significant benefits to to 99.999...% of flights, but would contribute weight / cost penalties to 100% of flights. (Not to mention the new risk of parachute deployment during take-off.)

Right. I'm going back to work.
 
A380X4TRENT900
Topic Author
Posts: 15
Joined: Tue May 31, 2005 9:19 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 09, 2006 9:01 pm

I have watched air crash investigator's on channel seven in Australia, and I believe the documentary on the Boeing 757 crashing into the sea due to tape being left on the static port on the left hand side (captain's side) of the aircraft is a situation were a parachute could've helped!

It may have slowed down the plane enough to land in the ocean and not break up and kill 150 people!

Plane's are always's travelling TOO FAST when all hell breaks loose so a parachute may work!
 
oly720man
Posts: 5755
Joined: Fri May 21, 2004 7:13 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 09, 2006 9:01 pm

What would the parachute do? In all aircraft that use them it is for braking after landing. The only reason some (light) aircraft have them for use in the air is in the event of structural failure. With engine failure you're better off gliding to the ground.

In a large civil aircraft the deployment speed would have to be low otherwise either the parachute or fuselage would be damaged. In civil aircraft the whole of the fuselage is the structure of the plane so having a hole in the roof for any paracute to be deployed through would add massively to the structural weight. And the deployment would have to be through the roof so when the aircraft had slowed enough it would hang vertically below the parachute. Having the parachute at the tail would just make the plane slow down and hang nose down. Either way you'll hit the ground with a big thump and end up with a plane full of people with spinal injuries or crushed as the plane landed on its nose and then fell in a direction dictated by the aerodynamics of the parachute.


If there is an engine failure the last thing you need is extra drag until you're on the ground, and this is the only situation where a parachute may be of some use. The more speed you have the further you can fly to a diversion field or the more time you have to look around to find somewhere to land.



Quoting A380X4TRENT900 (Thread starter):
what happens it slows and glides out of stable flight because their is no thrust to confront drag, weight or gravity!

Planes glide. Why should a plane glide out of stable flight? How many gliders glide out of stable flight?
wheat and dairy can screw up your brain
 
User avatar
EGTESkyGod
Posts: 1460
Joined: Wed Jun 01, 2005 11:27 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 09, 2006 10:03 pm

As is stated, and as we student pilots are trained, if your engine fails... trim for the glide. If you have more than one engine, continue with that engine. If that engine fails.... GLIDE!! You see what I'm gettin at here? The plane will still fly in the glide. A giant, heavy, costly parachute wont solve anything.
I came, I saw, I Concorde! RIP Michael Jackson
 
bond007
Posts: 4423
Joined: Mon Mar 14, 2005 2:07 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 09, 2006 10:20 pm

Quoting EGTESkyGod (Reply 4):
As is stated, and as we student pilots are trained, if your engine fails... trim for the glide. If you have more than one engine, continue with that engine. If that engine fails.... GLIDE!! You see what I'm gettin at here? The plane will still fly in the glide. A giant, heavy, costly parachute wont solve anything.

Well, that's all well and good, but I think the circumstances where you might think about about parachutes is when you have an uncontrolled aircraft...perhaps due to control surface problem or an airfram failure of some type (highly unusual). The Alaska MD80 crash comes to mind, as does a few B737 rudder incidents, and the Airbus rudder crash.

That's the theory for the parachute system that the Cirrus uses (an option on Cessnas). If it can glide, then keep gliding - if not, then pull the chute.

As for deployment speeds - they also have a mechanism for doing this, where the chute opens slowly depending on the speed.

Heck, I don't think it's at all practical for an airliner. You'd need huge chutes and many of them. The extra weight would be enormous.



Just some other comments.


Jimbo
I'd rather be on the ground wishing I was in the air, than in the air wishing I was on the ground!
 
User avatar
EGTESkyGod
Posts: 1460
Joined: Wed Jun 01, 2005 11:27 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 09, 2006 10:30 pm

Quoting Bond007 (Reply 5):
Well, that's all well and good, but I think the circumstances where you might think about about parachutes is when you have an uncontrolled aircraft...perhaps due to control surface problem or an airfram failure of some type (highly unusual).

Ok, I take your point, but as you say it's highly unusual, so huge amounts money will not be spent on something that isn't likely to ever be used.

Quoting Bond007 (Reply 5):
Heck, I don't think it's at all practical for an airliner. You'd need huge chutes and many of them. The extra weight would be enormous.

Plus that, too.
I came, I saw, I Concorde! RIP Michael Jackson
 
User avatar
Starlionblue
Posts: 17117
Joined: Fri Feb 27, 2004 9:54 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 09, 2006 10:37 pm

It's a common misconception that large parachutes are just scaled up smaller ones and that there aren't too many design issues. But in reality large parachutes (Apollo CM, Mars landers, ...) are extremely difficult to design. Any small mistake and they are ripped to shreds. IIRC, the Apollo chutes had to open within a very specific time interval to work at all.

Actual weight is one issue. Another is maintenance. These chutes would have to be inspected regularly. I've seen reserve chutes being inspected. It takes a long time to do, and you need an expert to do it.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
Mich
Posts: 33
Joined: Wed Feb 01, 2006 1:18 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Fri Mar 10, 2006 1:08 am

There was a production on the Discovery channel roughly 2 years ago on parachutes for planes.. There was a company at the time that designed a parachute system for small planes cessna and the like that was installed behind the rear seats near the planes center of gravity, it fired out the top of the plane using a rocket type apparateus.

They went further to explain with various experts that on a 747 you would need several chutes and would equal a volume and mass bigger then the plane itself when deployed to hold 400,000lbs.. So the weight of the chutes and loss of useable space are an issue but also the opening of parachutes above a certain speed at the size they need to be wouldnt work either.
 
tu204
Posts: 1423
Joined: Wed Mar 08, 2006 12:36 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Fri Mar 10, 2006 1:18 am

Well, the only feasible parachute that I can think of is a stall recovery chute. I do not know about other manufacturers, but on all of our prototypes we have a "braking parachute" installed in the tail which can be deployed from the cockpit if the aircraft goes into a stall or spin. This chute actually saved the Tu-154M prototype when they were "looking" for it's stall speed (well, they found it  Wink ) The predicted stall speed ended up being 5km/h too high and the test pilot (who was flying the 154 for the first time in his life) pulled it into a stall and a flat spin followed. The commander (Agapov) deployed the stall chute and recovered the plane.
The chute does not take up much space and does not weigh that much. Maybe we could install something like this into aircraft? I guess it is only needed on older aircraft as newer planes with fly-by-wire will simply not let you stall.
I do not dream about movie stars, they must dream about me for I am real and they are not. - Alexander Popov
 
pilotpip
Posts: 2820
Joined: Fri Sep 19, 2003 3:26 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Fri Mar 10, 2006 2:50 am

A BRS (Ballistic Recovery System) like the system in use on Sirrus, and other small GA aircraft is in my mind, a crutch. As others have stated, planes don't just fall from the sky, they still develop lift and glide. The added weight doesn't justify it. The BRS has been deployed a couple times on purpose and in all but one case the passengers still had serious injuries or died. There have also been a couple instances where the chutes have deployed by accident and caused fatalities.

If you look at successful instances like Gimli, a chute would have likely killed all on board by the time rescue crews got the the aircraft when it went into the ocean short of that airport.
DMI
 
User avatar
Starlionblue
Posts: 17117
Joined: Fri Feb 27, 2004 9:54 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Fri Mar 10, 2006 2:59 am

Quoting Tu204 (Reply 9):
Well, the only feasible parachute that I can think of is a stall recovery chute. I do not know about other manufacturers, but on all of our prototypes we have a "braking parachute" installed in the tail which can be deployed from the cockpit if the aircraft goes into a stall or spin. This chute actually saved the Tu-154M prototype when they were "looking" for it's stall speed (well, they found it Wink ) The predicted stall speed ended up being 5km/h too high and the test pilot (who was flying the 154 for the first time in his life) pulled it into a stall and a flat spin followed. The commander (Agapov) deployed the stall chute and recovered the plane.
The chute does not take up much space and does not weigh that much. Maybe we could install something like this into aircraft? I guess it is only needed on older aircraft as newer planes with fly-by-wire will simply not let you stall.

I have seen this on the F/A-18 E/F test flights as well.


Stall recovery chutes sound like a nice idea, but how many air crashes are due to stalls? A vanishingly low amount.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
joness0154
Posts: 650
Joined: Sat Nov 19, 2005 12:56 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Fri Mar 10, 2006 3:07 am

Quoting Pilotpip (Reply 10):
The BRS has been deployed a couple times on purpose and in all but one case the passengers still had serious injuries or died.

You seem very uninformed on the Cirrus CAPS system. It is VERY successful and most passengers end up walking away! I don't know where you got the information from, but it is totally false!

Read the first sentence here:
http://brsparachutes.com/DesktopModu...ts/ViewDocument.aspx?DocumentID=77

3 people walked away from this one:
http://biz.yahoo.com/prnews/060114/nysa014.html?.v=23

This one too, no injuries:
http://www.flttechonline.com/Current...%20Cirrus%20Extends%20Contract.htm

And I think this website speaks for itself:
http://brsparachutes.com/Default.aspx?TabId=28
I don't have an attitude problem. You have a perception problem
 
grandtheftaero
Posts: 247
Joined: Sat Nov 29, 2003 1:05 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Fri Mar 10, 2006 3:31 am

Quoting A380X4TRENT900 (Thread starter):
why the hell don't airline manufacture's/company's like boeing and airbus install parachutes for emergency situations?

And to that I will add... The black box always survives a crash. Why don't they just make the whole plane out of the material they use to make black boxes? (Death by sarcasm.)

Quoting Starlionblue (Reply 7):
But in reality large parachutes (Apollo CM, Mars landers, ...) are extremely difficult to design.

This is absolutely true. There are some conditions (induced by prevailing winds and/or good ol' Newtonian dynamics) where a parachute will actually increase your horizontal velocity so that even though your descent rate has slowed you'll still plow into the ground... fatally.
 
Bobster2
Posts: 1523
Joined: Mon Jan 17, 2005 3:04 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Fri Mar 10, 2006 4:23 am

Quoting Starlionblue (Reply 7):
the Apollo chutes had to open within a very specific time interval to work at all.

Yes. Apollo had to carry an extra chute in case of failure. One did fail, Apollo 15 landed with 2 chutes instead of 3.

And Nasa's Genesis crashed when the chute failed to open. That was supposed to be the easiest part of the mission. They didn't think they needed a backup.
"I tell you this, no eternal reward will forgive us now for wasting the dawn." Jim Morrison
 
MrChips
Posts: 933
Joined: Wed Mar 30, 2005 2:56 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Fri Mar 10, 2006 5:43 am

Quoting Pilotpip (Reply 10):
The BRS has been deployed a couple times on purpose and in all but one case the passengers still had serious injuries or died.

The early problem with CAPS was that many pilots were not familiar with the capabilities of the system, and made no effort to make themselves familiar with it in the first place. The CAPS has an envelope in which it can be deployed; if I recall correctly, any speed below Vno and any altitude above 800' AGL gives you a rough idea how big this envelope is.

Many of the early fatalities were attributed to these two factors:

1) Pilots were not familiar with the capabilities of the CAPS, and as such attempted to deploy the parachute outside its envelope of operation;

2) Because the aircraft had this system installed, pilots were venturing into situations that they would not previously have in a previous aircraft; in essence, the parachute provided a false sense of security, so we had pilots flying into moderate and severe icing (in an aircraft that was not certified into known icing, no less), around thunderstorms, night VFR in mountainous terrain, and other situations where the level of risk goes up considerably.
Time...to un-pimp...ze auto!
 
tu204
Posts: 1423
Joined: Wed Mar 08, 2006 12:36 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Fri Mar 10, 2006 6:43 am

I think that one of the main factors is the weight! I will take a wild stab and say that it would be somewhere in the range of 600kg to a tonne on a A320/B737 size aircraft. That would translate to about $4 million in (wasted) fuel. Not to mention the cost of the system itself. If we were on a quest to make aviation that safe, we might want to start with rear-facing seats.  Wink

Quoting Starlionblue (Reply 11):
I have seen this on the F/A-18 E/F test flights as well.
Stall recovery chutes sound like a nice idea, but how many air crashes are due to stalls? A vanishingly low amount.

I would have guessed that they could just use their braking chutes for the same result  Silly
I do argee with you that there are not that many crashes from stalls, especially now with idiot proof fly-by-wire systems (On a Tu-204, the only way you can stall the plane is to go into "command mode" to bypass the computer and pull up - no way in hell you can stall with the flight envelope protection engaged.) But "back in the day" there more than a few 732's and other transport jets that stalled and crashed; but then again, they usually did this on final aproach/initial climb + during a turn where you would have to have lightning reflexes in addition to the stall recovery chute to save the aircraft  Sad
I do think that it should be installed on prototypes and I also think that "stall recovery" should be a part of the certification process. (The Tu-154 stall incident that I described in the previous reply showed that the plane performed MUCH worse than was predicted, and recovery from the flat spin was virtually impossible without the chute. (Agapov fought to recover for about a minute before deploying the chute)
I do not dream about movie stars, they must dream about me for I am real and they are not. - Alexander Popov
 
User avatar
Starlionblue
Posts: 17117
Joined: Fri Feb 27, 2004 9:54 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Fri Mar 10, 2006 7:57 am

Quoting Tu204 (Reply 16):
(On a Tu-204, the only way you can stall the plane is to go into "command mode" to bypass the computer and pull up - no way in hell you can stall with the flight envelope protection engaged.)

What do you know, we'll soon have B vs. T wars on A.nut about envelope protection. Big grin
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
bond007
Posts: 4423
Joined: Mon Mar 14, 2005 2:07 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Fri Mar 10, 2006 12:57 pm

Quoting Tu204 (Reply 16):
I do think that it should be installed on prototypes and I also think that "stall recovery" should be a part of the certification process.

Actually stall recovery chutes are installed on many (if not all) US jet proptotype aircraft. I know that all the Cessna business jet prototypes have chutes, so no doubt true for the others. It may even be a FAA requirement.

Quoting Pilotpip (Reply 10):
The BRS has been deployed a couple times on purpose and in all but one case the passengers still had serious injuries or died. There have also been a couple instances where the chutes have deployed by accident and caused fatalities.

Hmmm....totally false.

Over 20,000 installed!

188 lives saved.

Read here for 10 pages of would be fatal crashes: http://www.brsparachutes.com/Default.aspx?TabId=28


Jimbo
I'd rather be on the ground wishing I was in the air, than in the air wishing I was on the ground!
 
pilotpip
Posts: 2820
Joined: Fri Sep 19, 2003 3:26 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Fri Mar 10, 2006 1:24 pm

Well, since my info was wrong, and the wrong police came out, I decided to check on the SR-20 and 22 to see if what I was stating was correct, and it wasn't. The hangar talk got in the way of real numbers.

Does the manufacturer's website list this one? The NTSB does.

http://www.ntsb.gov/NTSB/brief.asp?ev_id=20020326X00393&key=1

Upon further review, the accidents I found with an accidental deployment were all in homebuilt aircraft. Installation error can be attributed to those instances.

The Sirrus isn't a dangerous aircraft, but as Mr. Chips said, the equipment in the aircraft leads many pilots to believe that they are able to get out of any situation. It's amazing that there are so many accidents contributed to CFIT and inadvertant flight into IMC with that aircraft given the lack of time it has been on the market.
DMI
 
wingscrubber
Posts: 806
Joined: Fri Sep 07, 2001 1:38 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sat Mar 11, 2006 2:33 am




Works for light aircraft, not so practical for big birds though.
Resident TechOps Troll
 
milan320
Posts: 818
Joined: Mon Jan 03, 2005 2:25 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sat Mar 11, 2006 4:14 am

Quoting Pilotpip (Reply 10):
If you look at successful instances like Gimli, a chute would have likely killed all on board by the time rescue crews got the the aircraft when it went into the ocean short of that airport.

Sorry to nitpick, but I think you meant the Air Transat incident in the Azores. Gimli is in Manitoba, no ocean there at all.
-Milan320
I accept bribes ... :-)
 
Grbld
Posts: 349
Joined: Tue Dec 06, 2005 9:25 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sat Mar 11, 2006 4:18 am

There's a reason why this works for small aircraft and it doesn't for big ones.

If for some reason, this pretty Cirrus would land upside down or on its side with the chute, then no biggie, the people inside will likely not get hurt any worse than if they come down right-side-up.

A big aircraft (any commercial passenger aircraft, regional or bigger) will have serious problems with balancing. Imagine a 747 coming down on its nose or its left wing. Whoa! Major structural damage and fatalities.

The sheer forces on big aircraft will preclude use of these chutes. Imagine a 400 tonne aircraft flying at 250mph with these chutes deploying, it will be a massive force exerted on the chute and attachment points. The plane would instantly have to decelerate to near zero (think air carrier F-18 arrester cable landing) in two seconds, otherwise the chute would go to shreds.

Bottom line in safety is that you can't prevent all mishaps, it's not possible. If you can name a handful of structural failures (that have all resulted in improved procedures, maintenance and manufacturing) on the millions of flights that have been flown, then that's a probability that's unbelievably small.

You might as well wear a lightning-rod on your head everytime you go outside...


Grbld
 
tu204
Posts: 1423
Joined: Wed Mar 08, 2006 12:36 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sat Mar 11, 2006 4:31 am

Quoting Starlionblue (Reply 17):
What do you know, we'll soon have B vs. T wars on A.nut about envelope protection.

We can have a tag team match! Big grin I and B vs. A and T  box  Apparently Illyushin (haven't even been inside the cockpit of one, I am only spreading rumors  Wink ) also considers that the pilot should be the boss in the cockpit rather than the computer. (No offence to myself, but I would much rather the computer be the boss than myself  ashamed  )

The chute is just too impractical on a large commercial jet. Too big, too fast, too heavy.
I do not dream about movie stars, they must dream about me for I am real and they are not. - Alexander Popov
 
Grbld
Posts: 349
Joined: Tue Dec 06, 2005 9:25 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sat Mar 11, 2006 5:12 am

Quoting Tu204 (Reply 23):
No offence to myself, but I would much rather the computer be the boss than myself

Huh? Why? The computers are there to aid you and help you prevent stupid errors, but the other way around, you may have a reason for doing something that the computer cannot do or foresee or even think of. The pilot needs final authority over the machine.
 
User avatar
Starlionblue
Posts: 17117
Joined: Fri Feb 27, 2004 9:54 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sat Mar 11, 2006 6:12 am

Quoting Grbld (Reply 24):
Quoting Tu204 (Reply 23):
No offence to myself, but I would much rather the computer be the boss than myself

Huh? Why? The computers are there to aid you and help you prevent stupid errors, but the other way around, you may have a reason for doing something that the computer cannot do or foresee or even think of. The pilot needs final authority over the machine.

Settle down. I'm pretty sure he meant it in jest.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
eilennaei
Posts: 1003
Joined: Tue Nov 23, 2004 8:41 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sat Mar 11, 2006 6:13 am

Quoting Tu204 (Reply 9):
I do not know about other manufacturers, but on all of our prototypes we have a "braking parachute" installed in the tail which can be deployed from the cockpit if the aircraft goes into a stall or spin.

Yep, there once was a Finnish trainer airplane design in the 80s. There was also a chief test pilot and a design engineer who wanted to a ride on the right hand seat of the prototype, sot they pulled out the parachute mechanism. That was to be the last mistake in their lives. Flat spin.
 
tu204
Posts: 1423
Joined: Wed Mar 08, 2006 12:36 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sat Mar 11, 2006 6:19 am

Quoting Grbld (Reply 24):
Huh? Why? The computers are there to aid you and help you prevent stupid errors, but the other way around, you may have a reason for doing something that the computer cannot do or foresee or even think of. The pilot needs final authority over the machine.

Which I can get by pressing (and holding) a magic red button on the yoke  Wink
I would rather have my cake and eat it - have the flight envelope protection in case something should go wrong on my part, and final authority in case of the computer going wacko by going into command mode. Big grin It is not that I do not trust myself, but I am only human  Smile I am sure we have all made (stupid) mistakes in simple situations for whatever reason, but in this field of work that stupid mistake can lead to dire concequences (just look at the site with all the 737 hull losses - about 20% of them were due to stupid mistakes made by the flight crew)  Sad
You are right, the computer is not programmed to react to alot of technical problems with the plane; for example, if starboard flaps/slats fail to retract while the port ones do, the aircraft is not programmed to compensate for this because there are far too many variables and according to the op manual the pilot should assume emergency command; it will shut off automatically is if you loose both engines (but it will warn you with an audio messege).
I do not dream about movie stars, they must dream about me for I am real and they are not. - Alexander Popov
 
User avatar
Starlionblue
Posts: 17117
Joined: Fri Feb 27, 2004 9:54 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sat Mar 11, 2006 6:28 am

Quoting Tu204 (Reply 27):
it will shut off automatically is if you loose both engines (but it will warn you with an audio messege).

"Hi! This is the airplane your ass is situated in. How are you today? I just lost both engines and can't take it any more. I'm leaving you in charge. My suggestion is that you grab your ass with both hands!" Big grin
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
tu204
Posts: 1423
Joined: Wed Mar 08, 2006 12:36 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sat Mar 11, 2006 6:49 pm

Quoting Starlionblue (Reply 28):
"Hi! This is the airplane your ass is situated in. How are you today? I just lost both engines and can't take it any more. I'm leaving you in charge. My suggestion is that you grab your ass with both hands!"

Lol! Have you seen the Simpson's episode when Homer is a trucker? "Both engines have failed, I am going to eject to safety now, good luck :P"
But really, it is a gal's voice saying "Warning, Warning, direct command engaged" (the same messege that plays when you turn the computer off with the button - the gal has a nice voice too, we call her "Nadya" (short form of a Russian name - Nadezhda, which means "hope") :P and I really would not mind meeting the actuall gal that recorded those safety warnings - I think it is the same voice as the computer on the MiG-29's and Su-27's)
I do not dream about movie stars, they must dream about me for I am real and they are not. - Alexander Popov
 
User avatar
zeke
Posts: 9937
Joined: Thu Dec 14, 2006 1:42 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sat Mar 11, 2006 8:29 pm

Quoting A380X4TRENT900 (Thread starter):
why the hell don't airline manufacture's/company's like boeing and airbus install parachutes for emergency situations?

If a plane is travelling at 40 000 feet, travelling at 850 km/h, and looses power because it ran out of fuel (the pilots were unaware due to either undetected fuel leak or incorrect fuel gauge reading) - what happens it slows and glides out of stable flight because their is no thrust to confront drag, weight or gravity!

Why don't they have parachutes (that could be released at say 400 km/h) to slow down the plane enough to not cause death/serious injury/destruction of aircraft in crash situations?

Couple of reasons:
1) they have more than one engine
2) they have more than one pilot
3) hundred's of computers monitoring the systems
4) SOPs

Quoting A380X4TRENT900 (Thread starter):
Could the pilots control 200 tonnes with a parachute 1km wide holding it back?

Doubt it, pilots don't control aircraft now, its all done via hydraulics, too much force is required.

Quoting A380X4TRENT900 (Reply 2):
I have watched air crash investigator's on channel seven in Australia, and I believe the documentary on the Boeing 757 crashing into the sea due to tape being left on the static port on the left hand side (captain's side) of the aircraft is a situation were a parachute could've helped!

It may have slowed down the plane enough to land in the ocean and not break up and kill 150 people!

Could have started with a couple of pilots who could keep the wings level, and pitch at 15deg nose up, climb above the cloud and land VMC at another airport.

Poor decision making crashing a perfectly serviceable aircraft that had a little tape on it.

Quoting Bond007 (Reply 5):
Well, that's all well and good, but I think the circumstances where you might think about about parachutes is when you have an uncontrolled aircraft...perhaps due to control surface problem or an airfram failure of some type (highly unusual). The Alaska MD80 crash comes to mind, as does a few B737 rudder incidents, and the Airbus rudder crash.

Could not have seen one help in any of those situations.

Quoting Bond007 (Reply 5):
That's the theory for the parachute system that the Cirrus uses (an option on Cessnas). If it can glide, then keep gliding - if not, then pull the chute.

The product is being pushed more towards single engine aircraft for a reason, they have one engine. If at night or in IMC it is very difficult to suggest to pilot that the resulting landing after gliding would be survivable.

If in VMC you have a good chance.

Quoting Starlionblue (Reply 7):
It's a common misconception that large parachutes are just scaled up smaller ones and that there aren't too many design issues. But in reality large parachutes (Apollo CM, Mars landers, ...) are extremely difficult to design. Any small mistake and they are ripped to shreds. IIRC, the Apollo chutes had to open within a very specific time interval to work at all.

Actual weight is one issue. Another is maintenance. These chutes would have to be inspected regularly. I've seen reserve chutes being inspected. It takes a long time to do, and you need an expert to do it.

Very true, not to mention the explosives to deploy the chute.
We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
 
Grbld
Posts: 349
Joined: Tue Dec 06, 2005 9:25 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sat Mar 11, 2006 9:12 pm

Quoting Tu204 (Reply 27):
have the flight envelope protection in case something should go wrong on my part, and final authority in case of the computer going wacko by going into command mode.

Alrighty then!  Smile
 
User avatar
Starlionblue
Posts: 17117
Joined: Fri Feb 27, 2004 9:54 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sat Mar 11, 2006 9:32 pm

Quoting Tu204 (Reply 29):
But really, it is a gal's voice saying "Warning, Warning, direct command engaged" (the same messege that plays when you turn the computer off with the button - the gal has a nice voice too, we call her "Nadya" (short form of a Russian name - Nadezhda, which means "hope")

In Western aircraft this voice is often called Betty, as in "Bitching Betty".

Quoting Tu204 (Reply 29):
and I really would not mind meeting the actuall gal that recorded those safety warnings - I think it is the same voice as the computer on the MiG-29's and Su-27's)

How do you know she isn't 50+ and ugly as sin? Big grin
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
David L
Posts: 8552
Joined: Tue May 18, 1999 2:26 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sat Mar 11, 2006 11:10 pm

Quoting Starlionblue (Reply 32):
In Western aircraft this voice is often called Betty, as in "Bitching Betty".

"George" does all the work and "Betty" does all the bitchin' - typical!  duck 
 
mandala499
Posts: 6459
Joined: Wed Aug 29, 2001 8:47 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sun Mar 12, 2006 1:18 am

I really would not mind meeting the actuall gal that recorded those safety warnings - I think it is the same voice as the computer on the MiG-29's and Su-27's)

Bwahahaha... our air force pilots on the Sukhois share the same wish!

Anyways... back to the parachute.

In the event of loosing all engines, what you really need is ENERGY! Kinetic (your speed) and Potential (altitude). Now, you're not going to hit a mountain at 40,000ft.

Why ENERGY? You want to have the ability to stay up there as long as possible so you can decide how are you going to deal with the situation and where are you going to put the aircraft down. This involves distances to nearest airports, terrain obstacle avoidances, etc...

if you're above an airport, you can always circle down to it. If the airport is somewhere at the end of the glide distance, you'll need all the potential energy you can harness to make it there...

Now, shove a parachute into it and you'll loose all that! Planes don't spin out of control and fall like a brick when all the engines dies while cruising.

and...

If a plane is travelling at 40 000 feet, travelling at 850 km/h, and looses power because it ran out of fuel (the pilots were unaware due to either undetected fuel leak or incorrect fuel gauge reading)

Well as Zeke explains...

Couple of reasons:
1) they have more than one engine
2) they have more than one pilot
3) hundred's of computers monitoring the systems
4) SOPs


You can expand #3 to include comparing the calculated fuel remaining vs the actual fuel remaining vs fuel burn to figure it out... and when there's a significant difference between calculated fuel remaining vs actual fuel remaining, the FMC or the airplane's other system would yell out a warning to check your fuel status...

Could the pilots control 200 tonnes with a parachute 1km wide holding it back?

I seriously doubt it. 1km wide? You'd be looking at a tail structure separation or other structural failures... and if it's still attached to the (somehow undamaged) aircraft, you'd be dangling under the parachute in no time. When you release it at 400km/h or less, you'd be at a diving angle and loosing precious altitude very very fast... wasting valuable potential energy.

I have watched air crash investigator's on channel seven in Australia, and I believe the documentary on the Boeing 757 crashing into the sea due to tape being left on the static port on the left hand side (captain's side) of the aircraft is a situation were a parachute could've helped!

No... proper visual check with reasonable preventative measures such as using contrast coloured tapes could have prevented it! Prevention is always better than curing!

And yes, poor decisions... whether it was caused by poor judgement or confusing alarms and warnings is a different matter all the time. With hindsight, I'll re-quote what Zeke said... "Could have started with a couple of pilots who could keep the wings level, and pitch at 15deg nose up, climb above the cloud and land VMC at another airport."

The Alaska MD80? Well, proper maintenance would have prevented it... simple!

The Airbus rudder crash... let's see... deploy parachute, plane dangles under parachute and lands into a dense urban area... While just a wait before take off could have prevented it altogether.

In Western aircraft this voice is often called Betty, as in "Bitching Betty".

And what do we call Mr. "RETARD" ?

Mandala499
When losing situational awareness, pray Cumulus Granitus isn't nearby !
 
msllsmith
Posts: 387
Joined: Fri Feb 20, 2004 3:25 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sun Mar 12, 2006 2:10 am

Quoting Bond007 (Reply 5):
That's the theory for the parachute system that the Cirrus uses (an option on Cessnas). If it can glide, then keep gliding - if not, then pull the chute.

Also another small note about the parachute system in the Cirrus a/c. I believe it is, ideally, for making a landing in terrain which is inhospitable (ie: mountainous) to making a survivable forced landing. Or... in the case of structural failure. Even then it would have to be in conditions which will allow a parachute to function. Not the kind of wx associated with Thunderstorms etc.
There's nothing more beautiful than flying into the dawn.
 
User avatar
Starlionblue
Posts: 17117
Joined: Fri Feb 27, 2004 9:54 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sun Mar 12, 2006 6:07 am

Quoting Mandala499 (Reply 34):
I have watched air crash investigator's on channel seven in Australia, and I believe the documentary on the Boeing 757 crashing into the sea due to tape being left on the static port on the left hand side (captain's side) of the aircraft is a situation were a parachute could've helped!

No... proper visual check with reasonable preventative measures such as using contrast coloured tapes could have prevented it! Prevention is always better than curing!

It should be noted that the mechanic who put ordinary duct tape there instead of colored tape was not certified, and his supervisor was not on the job at the time. Eduction helps!

Quoting Mandala499 (Reply 34):
In Western aircraft this voice is often called Betty, as in "Bitching Betty".

And what do we call Mr. "RETARD" ?

I suppose we have to call him "Pestering Pierre".
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
Pyrex
Posts: 4051
Joined: Thu Aug 25, 2005 7:24 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sun Mar 12, 2006 7:22 am

Quoting A380X4TRENT900 (Thread starter):
what happens it slows and glides out of stable flight because their is no thrust to confront drag, weight or gravity!

In that situation what generally happens is commonly known as a "disaster".
Read this very carefully, I shall write this only once!
 
User avatar
Starlionblue
Posts: 17117
Joined: Fri Feb 27, 2004 9:54 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Sun Mar 12, 2006 7:25 am

Quoting Pyrex (Reply 37):
Quoting A380X4TRENT900 (Thread starter):
what happens it slows and glides out of stable flight because their is no thrust to confront drag, weight or gravity!

In that situation what generally happens is commonly known as a "disaster".

Indeed. Also, I can't help but note that Mr. A380X4TRENT900 wrote "weight OR gravity" (my emphasis). Hmmm...
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
bond007
Posts: 4423
Joined: Mon Mar 14, 2005 2:07 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Wed Mar 15, 2006 6:24 am

Quoting Zeke (Reply 30):

Quoting Bond007 (Reply 5):
Well, that's all well and good, but I think the circumstances where you might think about about parachutes is when you have an uncontrolled aircraft...perhaps due to control surface problem or an airfram failure of some type (highly unusual). The Alaska MD80 crash comes to mind, as does a few B737 rudder incidents, and the Airbus rudder crash.

Could not have seen one help in any of those situations.

Well assuming there was a parachute system that would allow an aircraft that size to descend to the ground slower than crashing ... it could have helped a great deal. I think in all those examples I mentioned, the pilots knew at some point that they weren't going to make it and could have pulled the big red handle labelled 'chute'.

Now, it's not practical or even possible perhaps, to have chutes on airliners, but that wasn't my point...it was assuming there was such a device (or devices).

Jimbo
I'd rather be on the ground wishing I was in the air, than in the air wishing I was on the ground!
 
YYZflyer
Posts: 3516
Joined: Sun Feb 19, 2006 9:54 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 16, 2006 4:14 am

Quoting Mich (Reply 8):
They went further to explain with various experts that on a 747 you would need several chutes and would equal a volume and mass bigger then the plane itself when deployed to hold 400,000lbs.

I remember watching that, the 747 required 21 parachutes the size of a football field each
Avoid hangovers, stay drunk.
 
YYZYYT
Posts: 906
Joined: Tue Apr 05, 2005 12:41 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 16, 2006 6:46 am

Quoting Bobster2 (Reply 14):
And Nasa's Genesis crashed when the chute failed to open.

That's a cover up.

Everybody knows that Khan detonated it.
 
VC-10
Posts: 3546
Joined: Tue Oct 26, 1999 11:34 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 16, 2006 9:07 am

1. How many a/c incidents have required such a piece of equipment in the last 50 years?

2. What is the total number of flights in that period?

3. Would you be prepared to pay in your airfare the cost of carrying that extra weight (fuel) and the maintenance of the system for the minute chance it would be needed?
 
777236ER
Posts: 12213
Joined: Sat Aug 18, 2001 7:10 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 16, 2006 9:22 am

Quoting VC-10 (Reply 42):
1. How many a/c incidents have required such a piece of equipment in the last 50 years?

2. What is the total number of flights in that period?

3. Would you be prepared to pay in your airfare the cost of carrying that extra weight (fuel) and the maintenance of the system for the minute chance it would be needed?

When was the last time life jackets were used in anger?
Your bone's got a little machine
 
David L
Posts: 8552
Joined: Tue May 18, 1999 2:26 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 16, 2006 9:32 am

Quoting 777236ER (Reply 43):
When was the last time life jackets were used in anger?

That's a reasonable point but how much do life jackets cost and how much (or little) do they weigh? How much of an impact do they have on the price of a ticket?  Smile
 
777236ER
Posts: 12213
Joined: Sat Aug 18, 2001 7:10 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 16, 2006 9:42 am

Quoting David L (Reply 44):
That's a reasonable point but how much do life jackets cost and how much (or little) do they weigh? How much of an impact do they have on the price of a ticket? Smile

http://www.aircruisers.com/vests/AC1000.html

This lifevest is 0.4kg. Times that by 200, that's 160kg. Or 2-3 people.
Your bone's got a little machine
 
User avatar
Starlionblue
Posts: 17117
Joined: Fri Feb 27, 2004 9:54 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 16, 2006 9:50 am

Quoting 777236ER (Reply 45):
Quoting David L (Reply 44):
That's a reasonable point but how much do life jackets cost and how much (or little) do they weigh? How much of an impact do they have on the price of a ticket? Smile

http://www.aircruisers.com/vests/AC1000.html

This lifevest is 0.4kg. Times that by 200, that's 160kg. Or 2-3 people.

So less than 21 parachutes the size of a football field each then?  Wink BTW 21 parachutes that size would be a bit (note: understatement) of a problem deploying.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
777236ER
Posts: 12213
Joined: Sat Aug 18, 2001 7:10 am

RE: Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 16, 2006 9:54 am

Quoting Starlionblue (Reply 46):
So less than 21 parachutes the size of a football field each then? Wink BTW 21 parachutes that size would be a bit (note: understatement) of a problem deploying.

Well no, the parachute idea is ridiculous. But if we're going by the number of lives saved by cost ratio, life jackets and life rafts are very small.
Your bone's got a little machine
 
VC-10
Posts: 3546
Joined: Tue Oct 26, 1999 11:34 am

RE: Would Gigantic Parachutes Help A Powerless Jet

Thu Mar 16, 2006 5:05 pm

Quoting 777236ER (Reply 45):
This lifevest is 0.4kg. Times that by 200, that's 160kg. Or 2-3 people.

Look at the economy seat pitch on any airliner, it doesn't give me the impression that they could sqeeze in those extra 2 or 3 pax if they got rid of the lifejackets. Mind you, Ryan Air might.
 
Grbld
Posts: 349
Joined: Tue Dec 06, 2005 9:25 pm

RE: Would Gigantic Parachutes Help A Powerless Jet?

Thu Mar 16, 2006 5:48 pm

Quoting 777236ER (Reply 47):
But if we're going by the number of lives saved by cost ratio, life jackets and life rafts are very small.

But it's not quite comparable. In the case of parachutes, all control of the aircraft is lost and you just have to sit there and wait till you hit the ground.

But in the case of an emergency landing on water, it's nice to know that your attempt (as a pilot) to do a successful ditching is still valid. If you're ditching and you know that there are no flotation devices on board, you might as well give up as everybody will drown anyway.

Who is online

Users browsing this forum: arluna and 14 guests