The UPS class I mentioned upthread was taught (in part) by the copilot of UPS 1307. Fascinating and downright frightening story of going from clear air on the flight deck with a bit of a “campfire” odor to can’t-see-the-instruments smoke, yet still miles away from landing, in a matter of seconds. He mentioned the simulator-induced habit of removing the oxygen/smoke goggles as soon as the aircraft stops. Apparently when you do that in a smoke-filled aircraft, you can’t breathe. Lots of lessons learned from 1307, not just for pilots, the FAA, the cargo carriers, and airport firefighters got a lot out of (and from) that one incident.
UPS is not alone in the cargo fire world. FedEx has had some fairly significant fires themselves, most notably in Newburgh, New York in 1996. Both carriers have developed in-flight cargo fire extinguishing systems for their aircraft as a result.
Air France flight 447 fell from about 40,000 feet for 3.5 minutes in a stall before hitting the Atlantic Ocean.
I suppose if you wanted to try a novel procedure, you could nose up into a stall, then pancake downward until the last possible minute, nose down and glide to a landing. Assuming a pancake nose-up stall can be recovered from reliably…
You can’t nose down because there is a speed limit in a dive - too fast may damage the aircraft, especially any flight control surfaces. If you exceed the safe velocity then try pulling up, the airstream force may bend or break the control surfaces. Things like airbrakes, flaps, and landing gear are not designed to deploy anywhere near cruising speed. Diving at (or close to) the speed of sound may stress the aircraft itself more than is safe.
I’m wondering why you’re even trying to land a cargo plane on fire. Why not just point the thing somewhere safe and bail out when you get to a survivable altitude?
It can’t be. Swept wing jets do not have good stalling characteristics. That’s why we have things like stick pushers and, in the Airbus family, alpha floor protection so that the pilot is not allowed to stall the aeroplane. Of course if you fight the pusher (Colgan Dash 8 crash) or have a degraded system and no idea what is happening (AF447) they can still be stalled. Unlike small piston engined trainers, airliners are not routinely stalled, even in testing.
Actually air brakes and lift spoilers are generally ok to deploy up to max speed. Your maximum descent rate is gained by pointing the nose down to the ground (about 10º nose down in our aircraft), selecting the engines to flight idle, and deploying any drag devices that are able to be selected at max speed. You then adjust the angle of the dive so that you stabilise the speed at the maximum. This is how you achieve an emergency descent after a pressurisation failure. Any thing like intentionally stalling would likely be far more risky than the situation you are already faced with.
I said survivable, not safe, but ~10K feet ASL and ~3K feet AGL are about the limits, aren’t they? Any higher for the former and you run into oxygen problems per the FAA; any lower for the latter and you may not have time to clear the plane and open your parachute.
Or did you mean a safe direction or attitude? For which read an impact point that won’t kill anyone - I’m sure most pilots and crew would rather go down with their plane than cause casualties.
Do airliners even usually have doors that can be safely used to bail out? I’d assume that a fire would restrict the pilots to only using the forward doors, since the cargo is in between them and other doors, but wouldn’t that just dump them straight into the wing (or engine)?
The first Bombardier CS100 had to have a special escape hatch for the test pilots (you can see it in this video), which I assume was because the normal doors wouldn’t be suitable.
Nitnitpick: the tank truck measures fuel in gallons/liters. The airplane on the other hand doesn’t care about volume only weight. So without an operating fuel totalizer (gas gauge) it was the fuel truck operator’s job to put in enough gallons/liters to satisfy the weight of fuel requested by the Captain. Working from memory he grabbed the wrong conversion factor. He was pumping liters but converted for gallons to lbs. So instead of having enough fuel for a trans-con flight they had about half that amount. Oops.
We have discussed the bailing out of an airliner before, and why that is completely impractical. The first thing is the lack of parachutes, but the next biggest thing is that if you can get an airliner (cargo or passenger) to a controllable point that you could jump out, then you have enough control to land it. So…no point.
What people don’t realize is how really, really bad a fire onboard an airliner can be. The UPS 747-400 that crashed in Dubai - when they started to get smoke in the cockpit the pilots donned their oxygen masks (which have goggles as a part of the assembly). The UPS masks were an older design, but still certified. They declared an emergency and tried to figure out where the closest airport was. They missed one (Doha, Qatar), but that is understandable based on their NAV database.
After a few minutes the Captain thought or perceived that his oxygen was running out. He got up out of his seat and went back to find a walkaround oxygen bottle. They are inside the cockpit - meaning within 10 feet of where he was sitting. He left his seat and never came back.
The First Officer was flying the airplane, but the smoke was so intense that he could not see the radio pedestal to his left or his instruments in front of him. The majority of the vectors that he got were relayed by other aircraft over the emergency frequency because he could not see as far as the length of his arm in order to change a radio frequency. There has since been a move to add a “bag” to the oxygen mask that can be inflated and provide at least two feet of clear air vision if needed.
So within a few minutes this fully loaded 747-400 has become a smoke-filled deathtrap. The only person alive is flying the thing, and if he takes off his oxygen mask for any amount of time he will be overcome with smoke and incapacitated. He also cannot see even an arm’s length in front of him to the flight instruments. He gave it the old college try but the odds were against him, and they crashed.
And just crashing a freighter is not such a no-risk thing. El Al 1862 (a 747 with only 4 people onboard) crashed on takeoff into an apartment complex and killed 39 people on the ground. A large airplane full of fuel is dangerous, regardless of how many people are onboard the airplane.
The best course of action, be it a passenger or cargo airplane, is to make an emergency descent and land the thing.
IIRC that is what Transport Canada argued but (again IIRC) the captain successfully argued that it was his job to order the correct amount of fuel and the truck driver’s job to out that amount in.
And here it depends on how much weight is involved. Just like a train you can slow down a fully loaded wide body plane like you can in a little puddle jumper. Forward inertia prevents this. For those who don’t understand, there is a trade off between a change in altitude and air speed. The faster the plane goes down, the higher the air speed until maximum structurally safe speed is achieved.
In the example of the Gimli Glider the pilots had to deploy everything they had and then cross control it to add more air flow resistance to slow the plane down. Not sure I’d try that on an Airbus.
That was when they were on final. When they were at cruise and lost the engines they were trying to maintain altitude and find a place to put down that was gliding range.
That’s true. But to the op’s question, there is a limit to the rate of descent and that’s the air speed. You can dirty it up to slow it down but once you hit that structural limit then that’s it.
Agreed but the Glider is a very poor example of how to get on the ground as fast as possible. They were trying to stay in the air as long as possible to make the airport, the exact opposite of what the OP asked.
If they had been at altitude and had functioning engines when would have been on the ground sooner.
Fair enough. Wasn’t there also some confusion in that the refueller didn’t realise the pilots intended to reach Edmonton with the fuel they had? They loaded up at, I can’t recall, Montreal? and did not intend to take on more fuel at Ottawa.
The fuel guy didn’t know this, and actually thought he’d put in a lot more than was normally needed for the trip.