Can Airliners Fly Upside Down?

[Deepwater6]

http://www.cnn.com/2013/01/10/travel/flight-movie-united-232/index.html?hpt=hp_c2

 

I have yet to see the film with Washington as a pilot. As a result I'm not too sure why he would need to roll the plane all the way over. Of course Hollywood can make very good scenario's when needed.

 

Obviously these airliners were not designed to fly this way. I don't know of any incidents where this has happend and the plane landed safely. I would think no matter how high the flight is, it would be very difficult to get the plane righted and regain lift.

 

I read a long time ago about pilots discussing doing a loop with a helicopter. At the time the helicopter models could not pull it off, but today I believe there are models out there that can preform this maneuver.

 

I used to fly when I was younger. I no longer do as I have a fear of it. Although I have a much better chance of death through a car accident than flying, I'm still prone to driving instead.

 

As you will see if you read some of the comments at the bottom of the article many people believe letting older pilots go is a terrible waste of experience for this industry. I have seen the same thing in my industry. For some reason either upper management doesn't seem to appreciate experience or they are only concerned with getting rid of their presumably highest paid employees to save money.

 

Whatever the reason cutting people with experience is somthing that can come back to haunt the company who carries it out.

[Buffy]

Seeing is believing:

 

 

When I was a kid my mom had a friend who was a test pilot for Lockheed. The things he did with a Cessna (with me, jaw dropped, in it) were not to be believed. It's all about knowing the particular plane's "envelope".

 

Too lazy to look it up right now, but I know that pilots LOVE 737's because they're very overpowered, and while it's doubtful anyone's done much testing of how long you could keep it inverted (as opposed to a barrel roll like above), it could probably do it. I've been on flights out of places with short clearance on the runway (Burbank with Santa Ana winds points you right at the Angeles Crest range) that were lightly loaded and the pilot took us up to 10k feet in what seemed like a few seconds in a 737.

 

If you want to grow old as a pilot, you've got to know when to push it, and when to back off, :phones:

Buffy

[CraigD]

http://www.cnn.com/2013/01/10/travel/flight-movie-united-232/index.html?hpt=hp_c2

Pretty good news article. I appreciated the mention of 1989’s US Airways Flight 1549, which is number 3 on my informal personal list of brilliant emergency commercial aviation. Unlike emergencies where everyone aboard lives, flight 232, where about a third of the passengers were killed when the plane broke up on landing, has an ambiguous status of both a disaster and an amazing save. Had the crew fared better in the last few seconds of the landing and kept the DC-10 on its wheels and on the runway, their work would have been hailed as an unequivocal success, and be number 1 on my personal list.

 

I read a long time ago about pilots discussing doing a loop with a helicopter. At the time the helicopter models could not pull it off, but today I believe there are models out there that can preform this maneuver.

Sustained inverted flight with remote control helicopters is now common. There are hours of videos on the internet of people doing it.

 

In 1980, I worked for a former Army helicopter pilot who claimed to have, in the 1970s, barrel rolled a UH-1 military helicopter, several times unintentionally “falling out” on the top of the maneuver and experiencing negative g force in the inverted position. Though I believe it occurred, I’m unaware of true inverted flight of a helicopter being documented until recently, by a civilian helicopter pilot sponsored by Red Bull, who does loops and inverted flight in a specially built BO-105, some of them at air shows. (see this Popular Mechanics article)

 

Returning to the title topic, whether inverted flight of an airliner is possible

Obviously these airliners were not designed to fly this way. I don't know of any incidents where this has happend and the plane landed safely.

I’ve not read or heard of such an incident, either, though one may be documented. Aviation incidents where nobody dies or is badly hurt are rarely publicized.

 

I’m fairly certain the way to definitively answer the question – actually roll an airliner on its back and try flying it inverted for a while – has never been attempted. I don’t think this has much to do with the maneuver’s technical possibility, but because airliners are very expensive, and with rare exceptions, lack provisions for a pilot bailing out (using a parachute to escape) if things went catastrophically wrong (test pilots are also expensive ;)). Before they’re put into service, airliners are tested, but as it’s never expected that one would fly inverted, this isn’t part of the testing.

 

That said, essentially all commercial jet aircraft are fast, powerful, and built to withstand high upward and downward forces on their wings and other airframe components. Their fuel and lubrication systems are the pressurized, rather than gravity-fed kind. At least some fuel tanks on some of them have multiple intakes that are usable at any attitude. For all their size, airliners are surprisingly nimble. So I can think of only one reason any of them couldn’t be flown inverted, that being that their elevators might not be able to be moved down (forward on the control yoke) far enough to maintain level in the inverted position.

 

I had the opportunity in the mid 1990s to spend an hour flying a fairly realistic simulator (an accurate cockpit mockup, as realistic flight physics as possible given its computer hardware), and during that time, actually rolled to and flew a fueled, passenger/cargo-less 747-400 inverted for a couple of minutes. Starting the roll in a slight climb, and as expected, the nose fell down during the role into a slight dive, I had to press the yoke nearly as far forward as it would go to keep the nose up and level in the inverted position, and had the feeling that if it got away from me, I might not have enough travel to get the nose up before airspeed became a problem. I didn’t mess with elevator trim (which on 747s, moves the whole horizontal stabilizer surface), which should have been able to relieve this.

 

Now, this simulator didn’t include realistic simulations of all the plane’s mechanical systems – in particular, I was told, it didn’t allow for drooping of the wings under unusual load – and couldn’t predict if some mechanical system such as fuel supply might fail, or something in the airframe break in an unusual situation like inverted flight, but my guess is that my little amateur (despite both parents and lots of friends who are private pilots, a brief stint working for a small aircraft rental business, and an attempt to get it cheaply, I never got a pilot license, though in my mid teens, my parents often let me do all their piloting, takeoff to landing to parking, in single engine planes), which I’m sure others have duplicated at greater length, show that a 747 can be flow inverted for at least a minute or two. I expect this is true of later generation airliners as well.

 

I would think no matter how high the flight is, it would be very difficult to get the plane righted and regain lift.

Not at all. Turn the wheel (or tilt the stick to the side, in planes with those), a plane rolls, center it, it stops. If the wings have a non-zero angle of attack and are moving fast enough, they produce lifts, in one direction or the other. This is true for planes large or small. What else the plane does while you're doing this is the challenging part. :)

 

Seeing is believing…

That’s a cool video. However, as test pilot Tex Johnson’s narration describes, the maneuver is actually a chandelle – a steep climbing turn – where, although the plane has a roll attitude over 90 degrees, so is inverted (from the looks of the video, the angle was something around 135°), it is performed under a near constant 1 downward g. A passenger not looking outside would have no sensation to tell her that the plane was doing more than a slow ordinary turn. Sustained, straight-and-level inverted flight involves a constant -1 g – everyone is hanging from their seatbelts, or situated somehow on the cabin ceiling if not strapped down.

 

Johnson’s account on the video of the conversation he had a day or so later, answering a Boeing executive question “what did you think you were doing?” - “I wash showing the airplane … it’s a 1 g maneuver, absolutely non-hazardous, it’s very impressive” and the exec’s reply “you know that, we know that, just don’t do it anymore” illustrates why non-pilots are skeptical that an airliner can perform aerobatic maneuvers, and why professional pilots are reluctant to discuss the subject. Airline passengers want to think of airliner as big, docile flying trains, when in reality, they’re more scaled-up jet fighter planes.

 

As you will see if you read some of the comments at the bottom of the article many people believe letting older pilots go is a terrible waste of experience for this industry. I have seen the same thing in my industry. For some reason either upper management doesn't seem to appreciate experience or they are only concerned with getting rid of their presumably highest paid employees to save money.

 

Whatever the reason cutting people with experience is somthing that can come back to haunt the company who carries it out.

I’ve only personally known one retired large airliner pilot. He had only glowing things to say about his treatment by his employer. Between US Social Security based on nearly 25 years of high income, and an employer-paid pension, he was enviably comfortable, financially.

 

His retirement was, however, ca. 1988. Since then, largely I believe due to deregulation of the airlines since the late 1970s, large airliner pilots have been less well treated by their employers, their salaries and pensions greatly reduced. See, for example, this 2009 article.

 

The question of the value of older, more experienced pilots is a complicated one. Older people, no matter how experienced and innately talented, have lessened sight, hearing, physical and mental quickness, and are more likely to be sick. Very old (80+) private pilots are IMHO foolish to continue flying, practically accidents waiting to happen, and are responsible for a disproportionate fraction of light aircraft accidents.

 

The money major airlines spend of pilot salaries pales next to what they pay when a fatal crash occurs, so I expect they remain, as they were when my friend was flying airliners, to be willing to pay what they must for pilots who won’t screw up and crash.

 

This is less so, I gather from intuition and news anecdotes, for smaller “commuter airlines”, which are often contracted by larger ones, and use the larger one’s names and logos. There have been clear cases (such as 2009’s Continental Connection Flight 3407) with these smaller airliners where their pilots were clearly not properly trained, resulting in fatal crashes that would not have occurred had better trained pilots been flying the planes.

 

Identifying the quality of “won’t screw up and crash” in a person is more arcane psychological art than science, though, and not clearly linked to age or previous experience. What is clear is that training makes pilots better.

 

Just keeping older pilots as long as possible is not, I think, a good approach to commercial aviation safety. Training, especially of new pilots, is. As pilots age, they eventually become unable to fly safely, and should retire long before that, so well trained new pilots are essential.

 

As best I can tell, this is also the opinion of retired airline pilot and safety instructor Chesley “Sully” Sullenberger, most famous for the successful 2009 “miracle on the Hudson” ditching of US Airways Flight 1549 - which is number 2 on my list. :thumbs_up Though Sullenberger retire from piloting after that 2009 flight, at the age of 58, I understand he planned to retire as a full-time pilot within a year.

 

I have yet to see the film with Washington as a pilot.

I’d seen a preview, and being an aviation fan still (this likely need not be said, given my near 2000 word rant on the subject in this post :)), immediately wanted to see this movie, Flight. Washington’s character, “Whip Wittaker”, who counteracts alcohol with cocaine in order to straighten up enough to fly an airliner, yet responds to a catastrophic failure by pulling off a brilliant maneuver and crash landing, saving almost all the lives on board, resonates with my recollection of so many pilots from my formative years in the 1970s and ‘80s.

 

Added to my Netflix disk-in-the-mail queue. :thumbs_up Thanks for reminding me of it, Deepwater.

[LaurieAG]

Hi CraigD,

 

Sustained inverted flight with remote control helicopters is now common. There are hours of videos on

the internet of people doing it.

 

The 3D flight in RC Helis is only possible due to a change in the Throttle/Pitch curves made via a switch. You cannot take off in 3D mode but must turn it on when you get to a stable hover.

 

The main problems with real Helicopters doing 3D is flexible booms. A couple of years ago a young local pilot pushed the envelope a bit too much and chopped his boom off.

[Buffy]

Pilot pay has gone through the floor with deregulation. When I was a kid, I knew a few airline pilots and they were royalty. Now, you really need to want to fly for a living to put up with how little pay there is except at the very highest levels of seniority and class (e.g. international and long-haul domestic). "Sully" lives in a suburb about 10 minutes away from me (my hairdresser works there), and while its comfortably upper middle class, it's still middle class. He wasn't exactly rich from his pilot pay. Book sales will probably pay for his daughters' college bills. :)

 

My favorite resource on pilot and airline related topics is Patrick Smith's Ask The Pilot: He's a pilot and writes about it extensively (on Salon.com until recently and now at his own site AskThePilot.com). His descriptions of what pilot life at the mid- and lower-echelons should give anyone pause if you fly a lot (and for many years I was a 100K/year flyer). Too lazy to find the links, but go to his site and also search the archive on Salon (link above goes directly to the archive).

 

I tell you, we got two categories of pilots around here. We got your prime pilots that get all the hot planes, and we got your pud-knockers who dream about getting the hot planes. Now what are you two pud-knockers gonna have? Huh? :phones:

Buffy

[Deepwater6]

http://en.wikipedia.org/wiki/Air_France_Flight_447

 

Buffy, That is one crazy pilot. I would think to even try a roll in that size plane you must have nerves of steel.

 

CraigD, with your experience maybe you can answer a question I have about the Air France crash 447. I added the Wik link above.

 

I know there were multiple pilot mistakes with the Air France crash. The loss of airspeed was just one part of the accident, but a major contributor to the crash non the less. The Wik link tells of how they failed to apply the "unreliable airspeed procedure", and maybe my question is covered in that procedure.

 

If a pilot were to get in this situation isn't there a way through engine speed to get to a stable speed? It will not be perfect and weather can be a big factor, headwind changes etc. but can't they set the speed at say 60% of engine output to give them an idea of their speed? Such as is in normal conditions 60% of engine output equates to x amount of airspeed. Is there also some "home" settings for the elevators and other equipment. Is there a all things being equal setting for large airliners in regards to speed and settings?

 

Of course this would not be perfect, but it will get them back to some idea of where they stand. At the very least if they were confused going back to the airspeed they were before the trouble began wouls also help would it not? Of coure hind sight is great and with their lack of experience and all the confusion they may not have been thinking too clearly.

 

Just curious

DW

[Buffy]

What Patrick Smith had to say about 447:

Otherwise, what we’ve learned from the initial findings isn’t terribly different from what some of us were expecting. The jet encountered terrible weather, suffered a series of systems failures, stalled and crashed.

 

It’s the “stalled and crashed” part that reporters are seizing on, pointing to a series of erratic — and incorrect — control inputs made by the pilot.

 

A plane stalls when, loosely put, its wings are no longer able to generate sufficient lift. This can happen for a number of reasons: flying too slowly; flying too fast; banking or pitching too steeply; or some combination thereof. All pilots experience stalls in their primary training, usually in light aircraft where the phenomenon tends to be tame. Stalling in a jetliner, on the other hand, is an extremely serious thing, and a fully developed stall may not be recoverable. For this reason, pilots always fly with a substantial buffer, at speeds and angles that are well clear of a stall onset. Nevertheless, if things go wrong, there is plenty of advance warning of an impending stall — not only aerodynamic seat-of-the-pants cues, but cockpit alarms as well. Should a crew ever find itself in such a position, the recovery technique is piloting 101 stuff, the gist of it being that you lower the nose, not raise it, while leveling the wings and adding power.

 

How the pilots of Flight 447 found themselves on the verge of a stall in the first place, and why they reacted the way they did — apparently pulling the nose up rather than pitching it forward, creating a series of worsening oscillations that ultimately resulted in a full, non-recoverable stall — is not yet clear. It may never be understood fully.

 

Read the whole thing at the link.

 

The bottom line is to realize that a lot of this has to do with probability: Was there a single fatal error? Probably not. Was this a situation where a whole lot of unlikely things all happened at once thus dooming the plane? Sure looks like it. It's sometimes boggling to realize the BILLIONS of passenger miles that elapse between crashes. You're infinitely safer in a plane than you are driving to the local supermarket.

 

If a pilot were to get in this situation isn't there a way through engine speed to get to a stable speed? It will not be perfect and weather can be a big factor, headwind changes etc. but can't they set the speed at say 60% of engine output to give them an idea of their speed? Such as is in normal conditions 60% of engine output equates to x amount of airspeed. Is there also some "home" settings for the elevators and other equipment. Is there a all things being equal setting for large airliners in regards to speed and settings?

One of the problems when you're in a storm with jet stream winds, it gets very difficult to "sense" how fast you're going: without those instruments, you're really in very dangerous territory. The things that Patrick mentions "sensing" above come in two forms: when you've hit a stall because your seat falls out from beneath you like running off a cliff--at that point you're way beyond avoiding a stall--and before that point, in good weather you'll notice it too, but when you're being pitched around in extreme turbulence, it's much much harder to notice. And once you go into a stall, things can get pretty nasty: even if you start to recover, the plane can start oscillating, which requires a deft touch to pull out of.

 

Anyone who's taken the controls of a plane will tell you that the desire to pull back on the stick is the most instinctive and deadly thing you can do as a pilot. The black box on 447 shows pretty clearly that even experienced pilots (and you don't get to fly international routes until you're considered really, really good), do the wrong thing like pulling up when they should be pushing into a dive to gain airspeed when a dozen other things are going wrong.

 

I've never done pilot training, but I know from the driving on tracks that I've done that one of the hardest things to learn is to "point the wheels into the slide" when you get loose: you really have to think about it even after you've done it dozens or even hundreds of times.

 

 

The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at and repair, :phones:

Buffy

[Deepwater6]

I agree driving to the supermarket should be a terrifying experience compared to flying according to the odds. I have tried to analyze my irrational fear of flying. As I said I used to fly, but no longer do. When I stop to think about it I see the reason for my fear is not the crash itself, everyone dies, it's the terror before the crash.

 

I can't speak for all people who fear flying, but for me that 7-8 minutes of my seat falling out from under me would be unthinkable. To know you are falling out of the sky for whatever reason is what I fear most. A car accident doesn't usually last for 7 or so minutes, An accident is quick and in my mind relatively painless. ;)

 

So from the data of the black boxes it was determined that the plane went down in a vertical tail first dive to the water? :huh: I understand that the pilots got confused with the series of events and may not have realized they were in a stall at first, but at some point everyone on board must have felt that something was wrong. Even 4-5 minutes doesn't seem like a long time, but when you are staring death in the face it must feel like forever. :(

[Buffy]

...When I stop to think about it I see the reason for my fear is not the crash itself, everyone dies, it's the terror before the crash.

 

I can't speak for all people who fear flying, but for me that 7-8 minutes of my seat falling out from under me would be unthinkable. To know you are falling out of the sky for whatever reason is what I fear most.

 

Well, to get a little morbid here, virtually all airplane crashes actually occur on takeoff or landing. That'll happen pretty quick too. Takeoff and landing speeds are usually at least 160 MPH, and the traffic safety films you've seen show the aftermath of going at less than half that speed. Dale Earnhardt obliquely tapped the wall at that speed at Daytona and it snapped his neck. He never knew what happened to him. But no one who watched that crash in real time (and I did) thought that anyone would be hurt in that crash. Just goes to show how fragile the human body is.

 

Now when you're talking about the extremely rare, hardly-ever-happens scenario of "falling out of the sky" there are several possibilities:

 

• Fast cabin depressurization: This happens every so often, but the surprising thing is that when it does, it usually does not result in a catastrophic loss of the plane. There's the famous case of the Aloha Airlines 737 that lost a huge chunk of its roof in mid-flight: only a stewardess died, and the plane landed safely (yet another reason to follow the advice to keep your seat belt on the entire flight).

• Slow cabin depressurization: Normally when this happens (and it actually happens a lot: there really are all sorts of holes in a fuselage), the systems catch it, warn the pilot, pilot descends at a rate of speed appropriate to the pressure loss, and only if necessary hits the oxygen masks. Sometimes the pilot won't even tell you. In very unusual circumstances, the warnings won't come on, and everyone passes out and the plane continues to fly until the gas runs out (this is what happened tragically to pro golfer Payne Stewart).
  
• Engine loss: amazingly, these giant things really can fly without engines. While for efficiency, power from the engines is normally used to power systems on the plane, there are literally dozens of independent auxiliary power units (batteries), to run things. Because engines are designed to be completely independent of one another, the vast majority of the time, you're going to see only one engine go out. And these engines have gotten so reliable, that Boeing finally got clearance with first the 767 and then later 777 to fly transoceanic routes with 2 engine planes (for a very long time, 3 engines was the minimum, thus the popularity of 3-engine planes like the DC10 and L1011 in the 70's). That clearance basically meant if you lost one engine the plane was rated to basically complete the trip on the one that was left. Losing all engines is very hard, so when it does happen, it's not the engine, it's something much more catastrophic to the rest of the plane. Nonetheless, what's amazing is that these giant things actually can glide: this is exactly what happened to Sully, and here's a link to a variation where a giant 777 was landed (at Hong Kong, and they were lucky they didn't have to do this at the old Kai Tak airport where the landing path flies BETWEEN high rises (nothing compares to that experience)) with "no engines" (really, one lost and the other malfunctioning) gear down on the runway, minimal injuries.
  
• Stall at high altitude with clear weather: in spite of the thread so far, under the right conditions, a stall is recoverable, just so long as the plane does not get completely out of control. Hitting an "air pocket" is something that's an inevitable experience for most frequent fliers (and the reason we all keep our seat belts buckled), and it's really just a stall: you hit a low pressure bubble and the amount of lift on the wings drops dramatically and you fall some unknown number of feet, sometimes *hundreds* if it's severe enough. Usually these pockets are small and you just hit the other side, but if you're passing through the edge of a weather front, the pilot has to do the right thing: nose down, hit the engines to recover. Normally events like this do nothing to change the attitude of the plane, so control is maintained: airspeed is critical, but heck you're supposed to be going 600 mph, so it's usually not a factor.
  
• Stall in extreme weather: Weather at 35,000 feet is normally pretty stable, which is why planes fly that high. But under the right conditions, you can get mashing currents that will toss around a plane like a toy boat in a bathtub. I had one memorable flight from Sydney to Adelaide once (on a completely clear day, but it was winter and there were storm fronts coming in from several different directions) that I was sure wasn't going to make it, sitting in my window seat watching the wing tips on this 737 whip up and down like they were going to snap off, but these amazing pieces of machinery really are built to take that. But what stormy weather *can* do is that in the extremely unlikely occurrence that you do a real stall (like 447 did), the clashing winds can whip the plane out of a "stable configuration" and cause the plane to tumble in a completely unrecoverable stall. The thing about this is that when this happens, the fuselage will be whipping around so fast, that you're going to lose consciousness *very* quickly, and most probably you'll wink out just like Dale Earnhardt did, before you really even know what's happening. Note this is exactly why it's misleading to say that 447 hit "tail-first", because while it did, it was wildly out of control the whole way down.
  
• Explosion: Due to the amazing structural integrity of these machines, most explosions do not cause a complete loss of the airframe (see Aloha Air above). If they are big enough to take out the plane and really make it unflyable, they're quite likely to take *you* out with it, with the pressure of the explosion itself likely to cause unconsciousness instantly if you're lucky enough to be at the opposite end of the plane when it goes "boom." "Lost"-like scenarios where the plane breaks up in the air and everyone's screaming all the way down (let alone half the people walk away from it) just doesn't happen.
  

 

So, really, when you consider that A) the likelihood of anything happening is tiny, and B ) the likelihood that if it does happen, it will actually probably happen FASTER than it would in some feebly slow conveyance like a car, no you really have very little to worry about.

 

But then again, your reasoning is exactly why I stay in California where earthquakes happen instantaneously, as opposed to hurricanes and twisters where you have minutes, hours or days to worry about what is about to happen to you....so I feel your pain. Just trying to help a bit. :cheer:

 

See you in another life, brother, :phones:

Buffy