I saw just this evening, on the news, the plane that came down on only one gear, and it blew my mind, the presence of mind the pilot had, to put it down that nicely…
I’m wondering, what exactly he did (or you assume he did), as he was taking it down… kind of like you were writing it down as what to do, in a POH.
Glenoled
The thing about that kind of landing is, the pilot actually has a fair amount of time to get ready for the landing.
Presumably, when the gear first malfuctioned, he did all the prescribed things to get it down - many planes have a back-up gear extension system. Probably flew by a control tower so the controller could take a look and make sure there actually was a problem with the gear and not malfunctioning indicator lights. He also probably had a chat with the local controllers and went to an airport with emergency equipment for this sort of situation.
Next step was to fly in circles above the airport to burn off fuel, the idea being that the less fuel on board the less danger of fire. He would particularly want to drain any in-wing fuel tanks on the side with malfunctioning gear. This also would give emergency crews the time to get into position and review rescue procedures. And, of course, it gives the news media time to show up with cameras (like this guys needs any more pressure).
When the time comes to actually land it, on final descent there will be a point where the pilot actually shuts off the engines, fuel flow, and electrical system. On the video I saw of the landing you can actually see the propellors slow down and stop prior to touch down. Again, this is to reduce the risk of fire in case the following touch down isn’t the best. The landing is done at the minimum safe speed given the conditions at the time, the idea being that if something goes drastically wrong it’s better to be going slower rather than faster (you don’t hit the planet as hard, it’s easier for the fire crews to get to you if the wreck stops sliding sooner, and so on).
Airplanes frequently land one wheel before the others - it’s a common cross wind landing technique performed with the flight controls. In a gear-up landing like the one in question the pilot uses a similar technique to keep the side with the wheel down and the wheel-less side up. Eventually, because the plane slows down (no power, friction with the runway) the flight controls, which depend on a certain rate of airflow to operate, become less and less effective, the unsupported wing droops to the ground, and that side of the airplane drags along the ground until the plane comes to a halt. Which is why the pilot would want to get as much fuel out of any tanks in that wing as possible, because dragging the wing like that can generate lots of heat from friction and even sparks.
Successful landing in these cases depends a lot on a good set up - a runway oriented with the wind so you have minimum cross wind to deal with, fuel management, a proper final approach, and so forth. It also requires someone who can remain cool under a lot of pressure. Pilots are supposed practice emergency drills frequently so when this sort of thing happens they know exactly what to do and are mentally prepared to do it. It also requires a certain amount of luck, in the sense that nothing else go seriously wrong while attempting a landing of this sort.
I wouldn’t be surprised if some of the more experienced Doper Pilots drop in to elaborate on the above, but that’s the basics.
That’s the BASICS? Sheesh. How much more detail does one need? 
One thing I noticed while watching the landing, he had the ‘good-gear-side’ engine shut off before touchdown, while leaving the ‘bad-gear-side’ engine on until the last possible moment… I understand that that’s to compensate for the malfunctioning gear… but I’m still not really understanding the physics behind it…
I only saw a glimpse of the video and didn’t hear the story, but here’s my wag on your question, Glenoled:
When the bad side drops and the wing starts scraping, it’ll drag and force the plane in that direction (left, IIRC, in this case). Almost as if you’d pinned the wing to the ground… the plane wants to go in circles. By keeping the bad side’s engine on, he’s producing thrust on that side to counteract the friction produced by the scraping wing. The good side engine being turned off would produce no thrust on that side, helping the cause of the engine on the bad side. I’d also guess he was braking like hell on the good gear and giving it full right rudder as soon as the wing dropped. I can’t think of anything else to do in order to keep the plane on the runway. What I’m not sure about is whether the guy shouldn’t have just bellied it in. Seems to me it’d be safer than landing on one wheel.
Well… I didn’t think you wanted me to recite actual checklists and precise airspeeds…
Given the hypothetical situation of one or more of the wheels falling off the airplane I usually fly (it’s not a retractable, so the wheel would have to actually fall off) I could go down a very precise and detailed list of things to do, the order in which I would do them, the speed at which I’d be flying, my relation to the runway, and contingency plans at certain points in case other stuff went wrong. I need the detail because I’m the pilot - you don’t. Unless you really do want to know.
Would you believe on bad weather days pilots like to sit around the hangar dissecting various catastrophes they’ve either heard about or lived through, then think up even more hair-raising sceanarios to ponder? :eek: Yes, we actually think this is fun.
OK, here’s another stab at a “basics” explanation. Power is what keeps an airplane in the air. Power is supplied by the propellor, which is in turn supplied with power by the engine.
This is a simplified explanation, but it’s also true. A certain power setting keeps you at a steady altitude. If you supply more power, you go up. If you reduce power, you go down. If your engine quits (or you’re in a glider) at altitude you still have considerable potential energy, which will be released as gravity pulls you down towards the center of the Earth. Landing with no engine power is a matter of controlling the release of that energy (often easier said than done).
So we’re back to energy management. A pilot is able to travel down a runway with just one wheel down with the wings level as long as the engine on the wheelless side keeps suppling a certain amount of power to the prop. Essentially, the no-wheel side of the plane is flying at an altitude of zero.
Problem is, you do have to stop at some point. Below a certain airspeed the wing is not generating enough lift to stay in the air. (I could insert a really complicated discussion of the relationship between lift, power, and angle of attack, but that would no longer be “basic”) But by waiting until the last possible moment to turn off the engine on the bad side, the pilot will be rolling down the runway at a slower overall speed than if he totally cut the power to both engines.
Remember, a slower speed means less impact if you hit something, and less time that the wing is dragging along the ground potentially causing all sorts of havoc. But you want to turn that engine off before the wing drops, because all sorts of bad things can happen when a moving prop hits something, like pavement. Let’s be real here - at the speed a prop moves, it doesn’t hit something as much as go through it. But I’ll skip the gory details.
Non-pilot here, so I might be totally wrong (there’s a first time for everything :))
I’d always heard that a 1-wheel landing is more dangerous than a NO wheel landing because of the uneveness of the landing and the one wing slamming down, etc.
So, wouldn’t the guy have been better off retracting the one good wheel and belly landing (or, since he didn’t do it, have I answered my own question about which really is safer)?
The pilot may have also been thinking about how much it’ll cost to repair this thing if I pull this off. Once safely on deck, under control (sorta), and starting to slow, killing the engine on the “good landing gear” side also reduces the chances of trashing that engine and prop; “thrust” me, neither is cheap.
Since we don’t know exactly what went wrong with the landing gear, it could be that the pilot couldn’t retract the one wheel down. It’s possible the gear was completely jammed.
Although there is something to be said for a belly-landing vs. one-wheel landing, this is arm-chair quarterbacking we’re doing here. There are a lot of general rules that may need beaking in a particular situation. For whatever reason, the pilot decided to land as he did. Since everyone walked away, it was a good landing.
You could also have blown a tire on liftoff (about the only way you’d know you had a bad landing gear – though I suppose you could lose tire pressure in flight and somehow know it) or have hit an obstruction that leaves the gear on but not suitable for landing.
It’s also very informative and could save your life if you take a lesson from others’ mistakes.
Good point. A lot of beginning pilots think altitude is controlled by the elevator or stabilator. I was taught that the throttle controls the altitude and the elevator controls the airspeed.
When I flew fixed-wing I routinely landed with the engine at idle. Granted, there is still thrust; but it could be called a “power off” landing. Of course, Cessna wings tend to be fat with lift. Generally I’d pull the throttle when I turned base and select full flaps (40º on the 1970 C-172) on base or final. Since it was dad’s airplane I wanted to be nice to his brakes. The strong winds in the desert where I flew sometimes made it necessary to add power and/or not use full flaps (i.e., not go to 40º instead of going all the way down and then backing off of them). If I had to delay turning base I’d delay the flaps, but I almost always landed with the throttle closed. It was like a game: Deduct points for using the throttle.
The helicopter is different. I carry between 17" and 19" Hg. for the descent depending on weight and temperature. Autorotating every time would make people think I was a kamikazi.
Nice, informative posts, Broomstick.