Controlling ME aircraft by engines alone

[cumulus]

Evening all

I Have just read the thread on the DHL A300 that the crew managed to land after a missile strike. After remembering back to the DC10 that crashed in Sioux City a few years ago after loss of all hydraulics, I was wondering if any of you could give me any info on how controllable ME aircraft are, when all you have is engine power. I have only ever flown singles, and while I can see how using asymetric thrust can be used to control heading of the a/c, I wonder how you would pitch a/c up for landing etc.
Is this something that is routinely practised in the simulators?

yours
Cumulus

[TopBunk]

cu

No - not practised in sim sessions. The reason for this is that it is not a situation deemed possible to happen. We do on occasion paly around with degraded control authority which on the A320 might be mechanical backup (pitch trim, rudder and engines only) but that is only seen as a temporary state of affairs until more functionality is regained. On the 737 we used to practise loss of Sys A and B hydraulics which left you with cables to the ailerons and elevators and hydraulic rudder - extremely heavy to handle (actually did it for real on a test flight over Boscombe Down - just like the sim).

The fact that the Sioux City guys found the airfield, let alone the runway and people survived speaks volumes for their abilities and airmanship - real heroes imho.

[cumulus]

Thanks TopBunk

:ok:

cumulus

[Lu Zuckerman]

On October 9th of this year a Northwest Boeing 747-400 suffered a hard over on the lower rudder. The cojoe ran through all of the checklists to determine how to counter the problem but to no avail. The flight diverted to Anchorage and the pilots used asymmetric thrust to maintain direction of flight during the landing and approach.

It was mentioned above that this sort of problem is not presented in the simulator. Maybe it should be covered in the syllabus.

:E :E

[rottenlungs]

Hi Cumulus

With the DC-10, there was an incident back in the early 70`s where the floor collapsed due to the loss of a cargo door, causing severely degraded control authority. The AAL crew (Bryce McCormack, R Paige-Whitney and Burke) managed to successfully land the aircraft at Detroit, using a combination of assymetric thrust and the remaining controls. Look up the "Windsor Incident" for more information, or get hold of the book "Destination Disaster", which details the events leading up to and after the THY DC-10 crash near Paris in 1974.

What McCormack found, in the sim, was that the trijet configuration of the DC-10 (with the centre engine thrustline above the C of G and the wing engines thrustline below the C of G) allowed the pitch to be controlled (to some degree) by controlling the centre engine. Apparently McCormack had practised this in the sim before the Windsor Incident as he felt there was inherent risks with all-hydraulic controlled aircraft, especially one where all the control line converged underneath an engine.

As TOPBUNK said, both these guys, and the crew of the Sioux City aircraft were real heroes.

Cheers

[FJJP]

Used to occasionally practice major hydraulic failure in the sim. Used the engines to contol pitch and roll right down to a controlled crash landing on or near the runway. A useful exercise, that gave one confidence that it could be done in the extreme event...

[FE Hoppy]

Came in handy on the Nimrod when Aileron lock-up was the flavour of the year circa 1993 if I remember correctly.

[keithl]

Yes, it certainly was practised in the Nimrod Sim. Outboard engines for roll/yaw, inboard engines for pitch, using the fact that the thrust line was not through the CG. About 50% success rate in achieving a survivable landing.

[eagerbeaver]

i had a go at this in the sim for fun once. The aircraft was a 737/300. first attempt i managed to fly a series of turns then get the aircraft onto the centreline . i landed the aircraft although not entirley on the runway, the second attempt was dog doo (got a little unstable in roll.) so possibly luck....
Overall i found it not difficult but, a challenge to control the aircraft - the trick is (in my opinion) is small changes slowly and smoothly so as not to get in this business of chasing the aircraft because of over-controlling. It can be done successfully just requires practice.
Would never ever ever want to have to do it for real, think you would escape one in a million attempts only. Made me think of sioux city in particular and what legends those guys are.

[Bokomoko]

After that experience in Sioux City, certain modifications were made to the MD-11 hydraulic system 3. MD-11 has 3 hydraulic systems and in case of system 1 and 3 failure, there is an electrically operated shutoff valve and some special features in the system 3 supply line to keep some hydraulic power to the flight controls. However, if a break occur in hydraulic system 3 aft of the bulkhead (for example: a catastrophic failure of number 2 engine), the shutoff valve will close, preserving hydraulic fluid and pressure forward of the bulkhead. But, with dual failure of hydraulic system 1 and 2 and a limited system 3 the MD-11 will lose rudder, elevators, flaps and spoilers (except one panel on each wing) control. Only aileron control will remain and pitch attitude is controlled by thrust.
This maneuver can be made during simulator training but it’s decidedly hard to keep the airplane flying.
Bkmk

[Human Factor]

Am I right in saying that the Sioux City flight was replayed in a number of simulators and no-one could repeat it?

Wow.

[SkySista]

HF,

seems you recall correctly. Apparently they ran it on sims and no-one even got anywhere remotely near the field.

Have read a fair bit about that incident, AL Haynes was the captain, I believe they were also assisted by an off-duty United pilot on the flight, thus giving them an extra pair of hands.

Damn good flying that!

And if you read the CVR transcripts, Haynes was awesome, able to keep himself that controlled -even cracking a few jokes. That's what I call a pilot.

Sky