That’s funny - I had the opposite reaction when I flew in a friend’s small plane. I was amazed at how light and fragile it seemed. I had always had this conception of airplanes as being heavy and rigid, like an automobile. But when my friend needed to move the plane on the ground, he simply grabbed it from the front and pulled it along on the ground like a child pulling a wagon.
This has to be the slowest download EVER.
Pilot-dopers will be along to confirm or rubbish me shortly, but I believe it’s standard practice to give co-pilots maximum opportunities to gain experience in take-offs and landings.
IANAP but confirm that Pilots and First Officers both handle takeoffs and landings, and as stated by GorillaMan it is a form of OJT. After a decade of reading NTSB reports, the people in both seats have an equal propensity for doing really stupid things, after which physics wins the hand.
I suppose I should start by saying I am not a Big Airplane pilot so if the jet jockies show up and correct me at any point pay more attention to them.
That said - while the NTSB isn’t perfect they are the best we have on a regular basis and I wouldn’t toss their conclusions out lightly. I know the conspiracy fans like to protest about this-that-or-the-other accident being really caused by X and not Y, but it’s pretty damn rare the NTSB is ever shown to be wrong.
For better or worse, one or more of the pilots are frequently assigned some or all of the blame for an aircraft accident. Since the pilot is the one who has final say in whether or not take-off occurs, and has final legal authority over the flight, and in the event of emergencies has some extremely broad rights, it’s fair to say that with that authority also comes great responsibility… including responsibility for whatever goes wrong as well as whatever goes right.
Unfair? Perhaps… but also quite typical. Having read the some of the NTSB material concerning this accident, I get the sense that no one is blaming the co-pilot for the whole of this mess. It’s more a matter of them saying “in hindsight, he shouldn’t have taken this particular action to this degree” after which they go on to dump some blame on both the airline and the airplane manufacturer.
Fact is, some pilots for some time have complained about over-sensitivity on some models of Airbus. Airbus maintains their airplanes are great and the pilots just need to learn to fly better. I’ll leave the rest of that debate to those with more experience in the world of big jets.
The NTSB does not consider liability, they are supposed to consider only the evidence and state the facts. If they assign blame, it’s because they have found evidence of fault.
Of course, once the facts are stated that might well have implications in a court of law.
IANAMOTNTSB but near as I can figger…
“Get out of it” is probably short for something like “Get out of this wake turbulence”. Meaning they were in the turbulence left in the wake of the plane in front of them. Airplanes, like boats, leave a wake, a major difference being that you can see a boat’s wake but you normally can’t see the one an airplane leaves.
If I recall, they were following a Boeing 757 (correct me if I’m wrong). The 757 is infamous for having a much heavier wake than you would assume from its size. Riding through such a wake would be unpleasent in any airplane of any size following a 757.
“Let’s go for power, please” probably means something like “Let’s apply more power to either climb above the turbulence or to get through it faster”
It wasn’t a bomb. The vertical stabilizer snapped off almost like it was cut, I distinctly remember seeing them haul it out of the water on the TV news. That’s the look of structural failure (which may or may not be due to structural flaw), not the blast pattern of explosives. It was NOT a bomb. The structure of the airplane itself failed.
It’s probably not something you want to hear, but it’s quite possible to subject any airplane you care to name to forces great enough to tear the wings off by using the controls in the correct sequence. Under the right circumstances (which are easier to create than the average passenger wants to know about) yes, an abrupt and full pull-back can, indeed, make the wings fold like an umbrella turning inside out. Fortunately for those aboard airplanes, it also is usually ridiculously easy to AVOID such abrupt movements, which is why it is exceedingly rare for such events to occur.
In this respect, airplanes do differ significantly from cars. Even a glider, an aircraft without an engine, can be made to exceed its safe operating speeds or attempt manuvers that are physically too much for the airframe to cope with. One appeal of fly-by-wire is that a computer can (in theory), when designed properly, help avoid such situations. This of course implies the fly-by-wire is designed properly in the first place.
I doubt it - but that’s no excuse not to make better designs than we currently have.
A very important point. Wake turbulence is frequently described as a “horizontal tornado”, and in the case of big jets they aren’t exaggerating much, if at all. The wake of a big jet can entirely overturn or physically damage a smaller plane. It certainly imposes significant forces on even a very large jet. It was probably the combination of rapidly changing rudder input AND flight through a wake that added up to lethal force on the vertical stabilizer. If this is a design flaw, it’s one that requires some unusual circumstances to come to the fore. This is NOT normal cruise mode we’re talking about here.
Not entirely true. Yes, a rudder is designed to produce only yaw forces, but an airplane in flight is a balancing act and what effects one axis is likely to effect all.
OK, press a rudder pedal and the plane will yaw - let’s say, in this example, it yaws to the right. Well, that will tend to increase the speed of left wing, and decrease the speed of the right wing relative to the path of travel as the plane pivots around its center of gravity. Increasing speed tends to increase lift, reducing speed tends to decrease it. As a result, in our example, the lift on the left increases, the lift on the right decreases. When you increase lift on one side and decrease on the other the airplane rolls, or pivots around the longitudinal access. In this case, the left wing rises, the right wing falls, and you roll right. Therefore, a yaw to the right will also tend to cause a roll to the right. A well designed plane will help keep the unintended motions to a minimum, but the forces still act on the airplane.
So… if you’re stomping the rudder and thereby causing a yaw/roll combination, which maybe you’re adding to with the ailerons as well (which create roll, which also create unintended yaw) just as wake turbulence slams against the vertical stabilizer in an opposite vector… well, it does literally induce a twist on the tail and if the forces in both directions are sufficient… yes, something could snap. In this case, it looks like it did.
If that’s the case, why did it take this long to happen? Well, as a general rule pilots try to avoid wakes entirely, which fact alone reduces the number of possible occurances. This effect may be possible only with a wake+full rudder combination, or something equally as rare.
The pilots up front normally take turns doing all phases of flight, the point being that the less experienced can thereby gain more experience and eventually become the more experienced pilot.
The point of having “pilot” and “co-pilot” not to designate who is more experienced or more skillful (it is not impossible for a designated co-pilot to have more hours or more experience than the designated pilot) but to make clear who is the final authority, the guy in charge. It is usually the guy with the most senority in charge. But under a particular circumstance he might yield to someone with less job senority but more experience. The one that comes most immediately to mind is the Gimli Glider incident where the landing of an unpowered 757 was turned over to the co-pilot. Why? The co-pilot was a world-class competitive glider pilot as a hobby and thus had more experience at landing unpowered aircraft than the captain did. See how that can work?
In this case, with good weather and what was anticipated to be a routine trip, it was probably just the co-pilot’s turn to perform the take-off and thus he was at the controls at the time. Since you aren’t allowed to be a co-pilot without first demonstrating an ability to fly the airplane in an acceptable manner this isn’t really an issue in and of itself. Which is why the focus of the report is not on his status as co-pilot but rather his training and habits. If it had been the captain at the controls they would have scrutinized his skills, training, and habits in exactly the same manner.
You’re both right, and you’re both wrong.
First of all - even a wood and fabric airplane can be surprisingly strong. On the other hand, due to weight considerations, aircraft are built strong only where they need to be strong - non-structural elements might be quite weak since they aren’t required to bear a load. Much of the skin of a plane is largely for streamlining and may be quite thin, in fact. A part is designed to bear a certain load plus a given safety factor and no more - additional structure would only add weight to no purpose.
It was a 747. Before even taking off, they discussed the wake.
…but by the way, thank you for a thumping great post.
And something that a lot of aircraft builders and engineers forget is that when it comes to the I’m about as excited and in a hurry as I can get cause we are about to smite the earth with a nasty prang pilots will mostly revert to their oldest and strongest habits.
Now, a pilot who had say about 10,000 hrs and started out in say Cessna 150’s and built time into the thousands of hours by doing flight instruction, going to college, hauling parachute jumpers and flying small planes as a Part-135 pilot and then finally gets to the airlines and flys many hours in old 727’s and Mad Dog -80’s and stuff and such and all these planes use and he is taught to use the rudder in roll control and rough air penetration upsets and stuff and such.
Now he get assigned to the Air Busters and all of a sudden he has to keep his feet on the floor.
Well, no problem in the sims and on check rides because he knows the stuff is going to hit the fan ---- A LOT…
Then, since he does not practice keeping his feet on the floor for thousands of hours, when it comes to * Oh Shit* time, the oldest and strongest habit takes over.
Ask anybody who flew the Cessna 175’s when they first came out with the * carb heat * and the mixture control switched in position from every other single engine aircraft in the world…
Ask the poor guy who has to switch to a Beach Baron twin from any other Cessna, Beech, Piper et al that has the prop and throttle control switched from all the rest. You have to be very careful for a long time and not do much type shifting so that your strongest habit is the correct one for that aircraft.
That is why most controls have a standard place, shape and feel.
Saves a lot of trouble.
A lot of the blame can be put on AA and Airbusters but the guy flying forgot for a critical second what was a no no in that airplane.
Like Broomstick said, you can break just about any airplane if you really try but IMO, they should all be similar enough that the good safety habit on all the other planes is not a liability on just one different one. In this day and age, that is just bad design IMO.
For another example, some of the older folks here who spent their first 10 years of driving doing so in a stick shift car will prolly smile about the left foot stomp in panic situations that they do trying to hit the clutch in their automatic transmission cars during a * panic * stop…
It is the same kind of thing.
ping Pilot 141 and his contemporaries …
Great post, Broomstick.
I never said they shouldn’t made better designs. I was just questioning the implication that merely because the co-pilot’s control inputs resulted in a structural failure, that there necessarily must be a design flaw. That doesn’t necessarily follow, right? So while it may be possible to improve the design, the fact that there was a structural failure doesn’t prove that the design was poor, does it?
Hmmm…I thought that was exactly my point. How am I wrong?
I thought that was my point, too; specifically about it being “surprisingly strong”.
The rudder is above the center of gravity, so applying left rudder will have a slight tendency to roll the plane to the right. Using the rudder to apply force in either direction will create small amounts of induced and parasitic drag. And since the rudder hinge is not vertical (relative to the direction of flight), it probably deflects the air very slightly upwards which would tend to push the tail down. I did say those effects are negligible.
What you go on to describe is sort of the opposite of adverse yaw. Swept wing aircraft are also susceptible to a phenomenon called a dutch roll. Those are both consequences of the yaw force and movement that the rudder is designed to produce.
Just trying to clear that up a bit. A great post as always, Broomstick.