quote:

Originally posted by Otto Pilot:

I hate be That Guy...but I'm going to anyway.

It all depends on weight. When I was doing my new hire training on the Whale, one of my simulator instructors gave me and my partner a "confidence exercise". With the airplane set at about 500,000 pounds, we took off, and lost an engine right before rotating (V1 cut). We climbed out did a visual pattern and did a touch and go. right at rotation we lost a second engine. We climbed out a bit more crookedly and flew a visual pattern to a another touch and go. Right after rotation, we lost a third engine. We climbed out quite slowly, leveled off at pattern altitude, flying quite sideways, and limped around the pattern to a landing. The airplane handled it fine.

Now granted that was a solid 350,000 lbs below max take-off weight, and a very heavy airplane on one engine would be in trouble, but it was more than 100,000 above a minimum realistic flight weight. At a lighter weight, it could fly plenty level on one engine and even climb a bit.

Yes, one engine is a very serious and likely devastating situation, but not automatically a crash. The devil is, as always, in the details.

And if you will indulge me a moment, I am curious about your comment about heat in the fuel cells. I've never heard of an airliner that had any kind of heat system in the fuel tanks, just fuel/oil heat exchangers to cool the oil and warm up and thin out the jet fuel before being it gets shot into the burner cans. The MD-11 could warm the fuel a bit by automatically running the fuel pumps to recirculate the fuel, but that's about it.

quote:

Originally posted by sns3guppy:

quote:

Originally posted by Otto Pilot:

...

And if you will indulge me a moment, I am curious about your comment about heat in the fuel cells. I've never heard of an airliner that had any kind of heat system in the fuel tanks, just fuel/oil heat exchangers to cool the oil and warm up and thin out the jet fuel before being it gets shot into the burner cans. The MD-11 could warm the fuel a bit by automatically running the fuel pumps to recirculate the fuel, but that's about it.

Your comments indicate that you were a crewmember on the 747, and yet you say you've never heard of fuel heat?

As a former captain on the 747, I find that very hard to believe.

You're not familiar with the fuel heat exchanger on the 747, or the critical nature of fuel temperature on long range flights?

quote:

Still, down to one engine will impact pressurization and other systems, and will impact fuel heat in various cells, sharply limiting the amount of fuel at altitude over a given period of time.

quote:

Originally posted by Otto-monkey-Pilot:


... Right after rotation, we lost a third engine. We climbed out quite slowly, leveled off at pattern altitude, flying quite sideways, and limped around the pattern to a landing. The airplane handled it fine.


After we crossed the numbers and greased it in on that single engine, the instructor asked us to go ahead and make another go around, then pushed the FIRE button and shutdown the last engine, the APU kicked in and we made a slow and laborious crawl down the runway and as the nose tires touched the gravel if the overrun, the whale slowly clawed its way skyward, we raised the gear and flaps, and nosed it down a bit to pick up speed, and about .83 Mach, we gently pulled up into a nice half Cuban eight, and on rolling wings level, deployed the flaps, dropped the gear, touched down without even smoking the tires, and rolling out as we met the oncoming equipment, we shut off the APU, and rolled to a gentle stop.

And that is the end of the Whale Tale....

quote:

Originally posted by sns3guppy:

quote:

Originally posted by BBMW:
I don't think a 4 holer can stay up on one engine. I'm not sure they can with two. Twins are designed to do their entire flight envelope on one engine.

SOP during training and sim checks in a four-engine aircraft is a two engine approach and landing.

I'm personally familiar with two different four-engine failures in a four engine airplanes. One reciprocating powered, one turbofan.

Three-engine approaches are not a big deal, though with loss of one engine, the flight will continue with approximately the same fuel burn as with all four turning.

quote:

Originally posted by valkyrie1:
When my dad worked for Pan Am in the test cell back at JFK he would mention that the 747 was capable of flying on one engine, he loved that aircraft..

Your father was partially correct. It's not going to be cruising or holding altitude, but it will be descending on one. Performance is minimal on two engines, especially two on the same side. One engine not only sees loss of the other three, but a drag increase offsetting the asymmetric thrust means that less than 25% of the original thrust is available for flight. Additionally, because each engine powers more than just thrust, but has bleed for leading edge devices and anti-ice, electrical, and hydraulic powering one of four systems, numerous functions on board are lost with each engine.

The 747 is designed very well and has redundancy among certain controls and systems, double controls in some cases. Still, down to one engine will impact pressurization and other systems, and will impact fuel heat in various cells, sharply limiting the amount of fuel at altitude over a given period of time.

Loss of one engine is an abnormal situation, not usually an emergency. Loss of two can be. Loss of three is unquestionably so.

There's an old story about a couple sitting in business class over the ocean when there's a bang and a rumble, and out the right window they see an engine flame, smoke, and go out. The over the public address, they hear "This is your captain speaking. We've lost our number four engine, but not to worry, the 747 flies perfectly well on three. We will, unfortunately, be one hour late into Heathrow."

Some time later, another rumble is heard, and out the left wing, some flame, then smoke, then the vibration goes away. Again on the PA, "Ladies and gents, this is your captain. We have lost our number one engine, but fear not. The 747 flies perfectly well on two engines. Unfortunately, we shall be delayed two hours into Heathrow."

Some time later, on the right side, a ball of flame erupts from another engine, the aircraft shakes and shudders, then the engine smokes, and goes out. The Captain announces "Ladies and gentlemen, I regret to tell you that we have lost our number three engine, but you needn't fear. The 747 will continue on one, but we'll be three hours late."

The husband shakes his head and says to his wife, "Just great. If we lose one more, we'll be up here all day."

quote:

Originally posted by sigmonkey:

quote:

Originally posted by Otto-monkey-Pilot:


... Right after rotation, we lost a third engine. We climbed out quite slowly, leveled off at pattern altitude, flying quite sideways, and limped around the pattern to a landing. The airplane handled it fine.


After we crossed the numbers and greased it in on that single engine, the instructor asked us to go ahead and make another go around, then pushed the FIRE button and shutdown the last engine, the APU kicked in and we made a slow and laborious crawl down the runway and as the nose tires touched the gravel if the overrun, the whale slowly clawed its way skyward, we raised the gear and flaps, and nosed it down a bit to pick up speed, and about .83 Mach, we gently pulled up into a nice half Cuban eight, and on rolling wings level, deployed the flaps, dropped the gear, touched down without even smoking the tires, and rolling out as we met the oncoming equipment, we shut off the APU, and rolled to a gentle stop.

And that is the end of the Whale Tale....

quote:

Originally posted by Otto Pilot:...You were there! Were you hiding in the closet or something? No...hmmm...you're definitely out of the closet...

It was beautiful man.