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What to do when the throttle is stuck

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What to do when the throttle is stuck

Old 20th Jun 2017, 20:45
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What to do when the throttle is stuck

a Boeing 757-200 aircraft , was conducting flight 7070 from point A to Point B. During cruise at FL390, the flight crew selected speed intervene and manually selected a lower speed due to light to moderate turbulence. The right thrust lever retarded normally, however the left one did not move. The auto throttle system was disconnected and the first officer tried to move the left thrust lever manually, without success. The flight crew referenced the QRH for a jammed thrust lever; however there is no listed procedure. A PAN PAN was declared at this point.

During the descent through FL230, the flight crew noticed that the TAT was 3į Celsius and attempted to move the left thrust lever, which worked normally with manual manipulation. The auto throttle system was re-engaged and worked normally. The aircraft landed safely with
ARFF on standby.

The operatorís maintenance inspected the aircraft and returned the aircraft to service under MEL 22-30-01-01 (Auto Throttle System).


Wait for it to thaw.
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Old 20th Jun 2017, 21:37
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Tarom 371....
https://en.wikipedia.org/wiki/TAROM_Flight_371
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Old 20th Jun 2017, 21:47
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The similarity is truly startling.
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Old 20th Jun 2017, 22:22
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I know of one case where this happened on a B737-400, and it thawed out as well in the lower levels. No issues found on ground as the "evidence" had disappeared.
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Old 21st Jun 2017, 00:02
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The Tarom incident was preceded the year before by a similar crash of a B737-300 in China which had not yet released a summary report.

The industry strengthened its reaction to such failures in recommended pilot recognition and response training.

Seems like this crew handled it well.
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Old 22nd Jun 2017, 11:42
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https://en.m.wikipedia.org/wiki/Cath...fic_Flight_780
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Old 22nd Jun 2017, 14:25
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Get an Airbus rating.
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Old 22nd Jun 2017, 17:30
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A330 jammed thrust
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Old 22nd Jun 2017, 17:32
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This scenario started at FL390 and lasted until FL230 after much head scratching, I'd expect. The CVR would be very interesting in a training sense.

I TL at idle 1 TL at crz. How did they descend? Ever decreasing circles? Side slip?

How did they expect to make an approach in a controlled manner? Did they consider shutting down the engine? An over speeding engine requires a shut down. Fortunately this fault cured it self, but what if..........

'ground test, found satis' seems a bit glib. Why should it not happen again? or were they restricting the a/c to FL230?

There is more to this, and much to learn; both pilots and engineering: from what has been reported by the thread starter.
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Old 22nd Jun 2017, 19:50
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I had a similar experience on a 747 Classic some years ago.

Following heavy rain during the ground turnaround the subsequent departure and climb to cruise appeared normal, however upon making a step climb to FL370 we discovered the No3 T/Lever was immovable. We were able to accomplish the climb without difficulty and at the new cruise level the FCU provided substantially normal cruise thrust.

Suspecting ice build up had affected the T/lever control run, the TOD brief included a planned descent with the rogue engine at cruise thrust, managing any excess speed with speed brake, if the T/lever was still immovable at 10,000' the intent was to shut the engine down.

In the event it became necessary to shut the engine down and continue with an engine inop approach, the T/lever finally freed up at about 2,500'. It was quite interesting trying to manually handle the other three T/levers with the 'rogue' stuck in the cruise position.

After landing the engineers spent an hour chipping ice out of the No3 engine pylon, apparently the drain holes had somehow become blocked allowing the pylon to fill with water during the earlier turnaround which, then of course, froze on the subsequent climb out.
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Old 22nd Jun 2017, 20:44
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Originally Posted by fantom View Post
Get an Airbus rating.
Didn't help on Tarom 371.
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Old 23rd Jun 2017, 09:58
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Slightly different problem on the A300/310. The teflon inner liner was prone to "snagging " the cable. The solution was to turn on the engine anti-ice to " overheat " the pylon and throttle cable run.
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Old 25th Jun 2017, 09:54
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@spannersatcx,

The A330 incident mentioned was not due to 'jammed thrust levers' but severe fuel contamination affecting various engine fuel componenets, including the stator vane actuator system.
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Old 25th Jun 2017, 11:50
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The point is, the thrust levers did not do anything and the eng was stuck at a fixed thrust, the point being even though there are no cables to jam on an airbus, it can still happen!
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Old 26th Jun 2017, 04:05
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For sure, any aircraft is potentially at risk from fuel contamination, but that is not relevant to this thread, which is about jammed thrust levers/throttles.
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Old 27th Jun 2017, 05:24
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Cranfield,Jodel,1980....
After a 5000' climb I found that the throttle remained at full power...
Turned back towards the field,pulled the mixture,and deadsticked back on the runway.
Some consternation to owner,who viewed the tip dihedral as a crashed aircraft,due heat shimmer on the hot tarmac!
Back to thread!
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Old 27th Jun 2017, 10:08
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It also happened to me on a L1011 in the late 90s. I seem to recall cruising at FL390 and on starting descent one of the thrust levers wouldn't move. The FE said that he had seen this before and selected Engine Anti-Ice on. After a couple of minutes the thrust lever moved again. I have no idea why.
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Old 27th Jun 2017, 22:13
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Heat melted the ice. I think this may have been a 727 technique as well for certain things.
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