A340 nose wheel steering failure
Discussion
Could someone in the know explain what happened here?
We landed at LHR on friday eve on a Thai 340-600. The roll-our carried on for an unusual amount if time, passing a few exits that could have been taken. I know pilots are encouraged to vacate asap due to other traffic, so I knew things weren't quite right.
Anyway, we eventually and lethargically exited 27R, and stopped as soon as clear. I had the nose camera on, and a few airport cars turned up at the front of the plane with a couple of firetrucks with lots of flashing lights.
Captain then came on an explained that they had lost the ability to steer the plane, and they were awaiting a tug.
So, given that he appeared to have a problem on roll-out, how did he steer the plane off, and what could have failed?
We landed at LHR on friday eve on a Thai 340-600. The roll-our carried on for an unusual amount if time, passing a few exits that could have been taken. I know pilots are encouraged to vacate asap due to other traffic, so I knew things weren't quite right.
Anyway, we eventually and lethargically exited 27R, and stopped as soon as clear. I had the nose camera on, and a few airport cars turned up at the front of the plane with a couple of firetrucks with lots of flashing lights.
Captain then came on an explained that they had lost the ability to steer the plane, and they were awaiting a tug.
So, given that he appeared to have a problem on roll-out, how did he steer the plane off, and what could have failed?
el stovey said:
Brigand said:
The pilot can use the rudder to steer with enough airflow over it, but once you drop below a certain speed he'll have to use the wheel.
This. Depending on type it's around 60 kts when you transit from rudder via pedals to nose wheel steering via the tiller
What it required was an extra dimension.fatboy b said:
The roll-our carried on for an unusual amount if time, passing a few exits that could have been taken.
That said - the high speed exits were probably all passed.
That means the exit was probably a 90 degree turn from low speed. The rudder would not have enough airflow over it to make any difference to the direction of travel. Normally a rudder input will also deflect the nose wheel steering. We do not know if the nose wheel would have reacted to the rudder, but even if it did we can discount it making any difference because it only commands up to 6 degrees.
So from low speed the only way to vacate the runway which they would have been under HUGE self imposed pressure to do, would have been to use power (probably asymmetric) and differential braking. The nose wheel will drag around really easily to be honest. At least it did in the A320 family and the B757 and B767.
For those with a technical interest ...
Edited by R1nur on Tuesday 11th March 09:43
Gassing Station | Boats, Planes & Trains | Top of Page | What's New | My Stuff