Completely not RV related, but you guys know everything

MSFT-1 · #1 06-13-2006, 07:44 AM

I flew my RV-8 past the Air Force Base at Dover, Delaware yesterday. You can still see the wreckage of the C-5B that crashed there a couple months back. I was mentioning the crash to a friend of mine who loves a good "discussion" on just about anything aviation related.

He said (with no evidence to back it up), "I am sure it was pilot error, because airplanes like that are designed to fly on only one engine, those guys must have screwed up".

I have no idea about whether it was or was not pilot error, but I am pretty sure that most four engine freighter type jets can not fly on a single engine.

So the bar bet we made was:

His statement:

"All heavy jets are designed to fly on a single engine at MTOW, they may not be able to take off on one engine but they can fly on one for as long as they need to"

My statement: (after calling in to question both his sanity and intelligence):

"You are thinking specifically about twin engine jets that have ETOPS certification. Four engine planes at MTOW can not fly with three engines out"

Comments please (especially from the heavy pilots out there).

thanks,

bruce
N297NW

Bill Dicus · #2 06-13-2006, 08:29 AM

From very limited experience as a flight surgeon in the 60's I know the KC-135 can fly (maintain altitude) on one outboard at altitude and mid weight. On the A model with short tail and no rudder boost, pressure required was about 70# on the engine side rudder. Also was told that Junior Burchinal in Paris Texas gave a WWII flight experience which included a brief period of one engine level flight and a few turns in the B-17. This was said to be hard work. Supposedly a lot of astronauts took his WWII course, involving multiple wartime aircraft. Bill

MSFT-1 · #3 06-13-2006, 08:45 AM

Perhaps at a light weight it is possible to fly but the bet was at MTOW.

A friend of mine who flies P-3s told me that they routinely shutdown two engines (out of four) but that one outboard engine would be impossible to fly on.

bruce
N297NW

bsacks05 · #4 06-13-2006, 11:36 AM

I worked on C5's for a couple years and cannot image that monster flying on one engine. (I will research it some more since I am a sheet metal instructor at the AFB museum and have some access to that kind of info.) From what I have heard so far, the cause of the crash has not yet been determined, but to have all the occupants walk away after the fact is pretty impressive even if the pilot screwed up initially.
I did work on a C5 which had an engine hit by a rocket coming out of Baghdad a couple years ago. It returned to the airport on three engines. I wouldn't be surprised if it could fly on the two inboard engines, but one engine?! How much is the bet?

mtclay · #5 06-13-2006, 04:21 PM

I am a retired Air Force pilot, and I've flown everything from the lowly O-1 Bird Dog (L-19), to jet fighters, to the C-130, C-141, and C-5.

In the C-130 we used to routinely practice two engine out landings, but only at minimum gross weights -- the AF outlawed that practice in the mid 80's as being too dangerous.

I can assure you that the "heavies" (4 engine) mentioned above can not operate at MTOW on one engine. They can't even operate at MTOW on three engines. With even a moderate load on board upon loss of one engine you must calculate a "driftdown altitude" and start descending toward the new altitude immediately to avoid loss of airspeed and subsequent stall. With two engines out you do the same thing only usually you must also jettison fuel and/or cargo to keep the airplane flying. A three engine out situation would be virtually impossible to deal with -- dump maximum fuel, try to jettison all cargo, bail out if chutes are available, if no chutes then try to control the crash or the ditching.

I am aware of a few succesful two engine out landings (including one of my own), but zero successful three engine out landings.

So Bruce, you win hands down.

Mike

Brian130 · #6 06-13-2006, 04:35 PM

I've tried it in the sim just for grins and we had enough rudder authority to handle the assymetric thrust, but we could not hold level flight with 3 dead at any weight - much less MTOW. We can hold level with 2 dead, but like was said, that's at almost min fuel. All our 2 engine work now is in the sim.

Kyle Boatright · #7 06-13-2006, 04:54 PM

My house is 2 miles from the Lockheed plant where the C-5's were built and where the crashed aircraft was recently updated. I have a bit of insight shared by people supposedly "in the know".

The bottom line is that the pilots got distracted by the new FMS during their approach. This was followed by getting low and slow, which was followed by a high rate of descent and ground impact.

Jeff Vaughan · #8 06-14-2006, 06:52 AM

See the attached link for the Airforces report.

http://www.aero-news.net/news/milita...bc62&Dynamic=1

Jeff Vaughan
RV7A
West Chester pa

Yukon · #9 06-14-2006, 07:16 AM

Sounds to me like a 2 engine approach! Ooops!

John

Paul Tuttle · #10 06-14-2006, 07:18 AM

As an airport Firefighter I had the misfortune of responding to a 747 crash that was a direct result of the thrust to weight issue. The finding was that the wrong load information was entered into the computer and an improper power setting was selected for takeoff with all four burning at 93% 0r something like that. The aircraft was too far down the runway (8800 ft.)for the pilot to take any effective action and the aircraft and crew were lost.

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