braking while aircraft moves aft.
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braking while aircraft moves aft.
I read on a different thread that you should not apply brakes on an airplane while it's moving aft.
I remember when i was a f/o at a md-80 operated airline some commanders put on the electric hydraulic pump (not engine driven) during push back and start up. This, they explained, was a back up incase the towbar broke during the push.
Now i'm in the left seat on the same type and our sop's don't include having the pump on during pushback but i still imagine that braking is the only thing one can do if the towbar collapses......
Can someone explain why you shouldn't apply the brakes in such a situation?
I remember when i was a f/o at a md-80 operated airline some commanders put on the electric hydraulic pump (not engine driven) during push back and start up. This, they explained, was a back up incase the towbar broke during the push.
Now i'm in the left seat on the same type and our sop's don't include having the pump on during pushback but i still imagine that braking is the only thing one can do if the towbar collapses......
Can someone explain why you shouldn't apply the brakes in such a situation?
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Applying the brakes while aircraft is moving backwards may well cause it to tip backwards causing a tailstrike. However if the towbar brakes and your engines are not running your only way to stop would be using tour brakes carefully. But you should have brakes available from acc pressure anyway.
Hope this helps.
Hope this helps.
Did a lot of power-backs from stand during my time as capt. on the Fokker 50. After start, release parking brake and both pilots FEET ON THE FLOOR so as not to inadvertently use the brakes to stop the airplane. Coming out of reverse to just a bit of fwd power would stop the airplane quite smoothly.
I had a towbar break during pushback, in a B707 years ago, with three of the four engines started. The first thing I knew about it was the tug rapidly moving away from the aircraft because we were rapidly chasing it, even with only three engines at idle. The brakes came in handy then.
If the engines weren't running and the towbar broke then I doubt whether the aircraft would roll much at all and if it did there should be enough pressure in the accumulator to stop it. There should be enough hydraulic pressure with the engine cranking before lightoff to stop the aircraft.
Regards,
BH.
If the engines weren't running and the towbar broke then I doubt whether the aircraft would roll much at all and if it did there should be enough pressure in the accumulator to stop it. There should be enough hydraulic pressure with the engine cranking before lightoff to stop the aircraft.
Regards,
BH.
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I knew someone would ask this, after that other thread about the A380. 
While it would not be "normal" to do that, it is done GENTLY sometimes, as you mentioned during pushback, and also I have seen it regularly on MD80s when reversing out from the gate under power (not pushback).
As others have said, BE CAREFUL though............
While it would not be "normal" to do that, it is done GENTLY sometimes, as you mentioned during pushback, and also I have seen it regularly on MD80s when reversing out from the gate under power (not pushback).
As others have said, BE CAREFUL though............
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I had a cracked towbar during pushback on A321. The aircraft was heading (tailing) to the terminal windows
. Ramp agent was yelling "Set parking brake."
Smooth pedal pressure was applied. Aircraft nose came up significantly but tail didn't kiss concrete.
. Ramp agent was yelling "Set parking brake."Smooth pedal pressure was applied. Aircraft nose came up significantly but tail didn't kiss concrete.
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Had the towbar break during pushback in Lima in a 747-200 some years ago, slightly downhill behind us.
We had no choice but to hit the brakes, no tailstrike tho...
Next time I would perhaps hit just one brake pedal, make for a softer stop.
We had no choice but to hit the brakes, no tailstrike tho...
Next time I would perhaps hit just one brake pedal, make for a softer stop.
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Brakes Backwards
A very old "War Story"
Many many years ago as a very young space cadet I was trying to bum a ride at RAF Abingdon.
The Squadron (can't remember which!) operated Blackburn Beverleys.
As we were being escorted out to our steed of the day for a low level navex arround the south of England we saw a Bev powering back, first time I had ever seen an aircraft move backwards under its own power.
I asked the Loadmaster who was escorting us how it was able to do that and he explained about Beta range propellors etc. Being an irritating little ****** I asked how the pilot could see and he explained that the loadie watched from the rear doors and told the pilot to tuen left or right etc.
As we watched an RAF jeep shot past the rear of the aircraft. Obviously the loadie shouted stop. Instead of moving the prop levers forward the pilot stood on the brakes!!
The aircraft pivoted over its main wheels and the tail boom and endplate fins got closer and closer to the ground, the nose wheel must have been at least 6 feet off the ground.
The pilot realised what he had done and released the brakes. The nose wheel hit the ground with a resounding crash that could be heard above the sound of the engines.
The aircraft was shut down and the crew climbed out and clustered around the nose gear.
The aircraft was last seen by us as we taxied out in our Bev, being towed very slowly towards the maintenance hangar, where I believe it stayed for several weeks.
Moral of this story- POWERBACKS BAD, using brakes whilst moving backwards even worse. If the tail doesn't hit the ground the nose gear will.
Surf Bum
Many many years ago as a very young space cadet I was trying to bum a ride at RAF Abingdon.
The Squadron (can't remember which!) operated Blackburn Beverleys.
As we were being escorted out to our steed of the day for a low level navex arround the south of England we saw a Bev powering back, first time I had ever seen an aircraft move backwards under its own power.
I asked the Loadmaster who was escorting us how it was able to do that and he explained about Beta range propellors etc. Being an irritating little ****** I asked how the pilot could see and he explained that the loadie watched from the rear doors and told the pilot to tuen left or right etc.
As we watched an RAF jeep shot past the rear of the aircraft. Obviously the loadie shouted stop. Instead of moving the prop levers forward the pilot stood on the brakes!!
The aircraft pivoted over its main wheels and the tail boom and endplate fins got closer and closer to the ground, the nose wheel must have been at least 6 feet off the ground.
The pilot realised what he had done and released the brakes. The nose wheel hit the ground with a resounding crash that could be heard above the sound of the engines.
The aircraft was shut down and the crew climbed out and clustered around the nose gear.
The aircraft was last seen by us as we taxied out in our Bev, being towed very slowly towards the maintenance hangar, where I believe it stayed for several weeks.
Moral of this story- POWERBACKS BAD, using brakes whilst moving backwards even worse. If the tail doesn't hit the ground the nose gear will.
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If you do not have any forward thrust available, then use the brakes VERY, VERY GENTLY. In both incidents that I experienced, the aircraft was being pushed towards parked aircraft when it became detached from the tug.
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brake break brake break
Brake and breaks...
The airplane has breaks...
The towbar brakes... or is it the contrary...?
xxx
I assume same would happen when discussing 'hangar' and 'hanger'...
And 'their' or 'there'...?
Correct spelling optional.
xxx
Happy contrails
The airplane has breaks...
The towbar brakes... or is it the contrary...?
xxx
I assume same would happen when discussing 'hangar' and 'hanger'...
And 'their' or 'there'...?
Correct spelling optional.
xxx
Happy contrails
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Brake and breaks...
The airplane has breaks...
The towbar brakes... or is it the contrary...?
xxx
I assume same would happen when discussing 'hangar' and 'hanger'...
And 'their' or 'there'...?
Correct spelling optional.
The airplane has breaks...
The towbar brakes... or is it the contrary...?
xxx
I assume same would happen when discussing 'hangar' and 'hanger'...
And 'their' or 'there'...?
Correct spelling optional.
Aircraft have brakes.
A towbar sometimes breaks.
The Aircraft would go into the hangar.
But my shirt is on the hangar.
And their Aircraft is over there.
Of course this is English, not American.
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Of course this is English, not American.
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I did use to fly with an old Captain that always used the term 'aircrafts'. I tried to correct him
I worked for about 12 months some years back in New York, and that was the hardest part of the job, hardly anyone spoke English.
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Further to the above answers. I had a tow bar that wasn't attached properly disconnect during push back. We were rolling back towards the taxiway & the grass beyond (at about 2 kts) so I very gently dabbed the toe brakes.
There was a big lurch. The nosewheel oleo extended by what felt like about 3 feet & the steward in the forward toilet peed all over his shoes!
There was a big lurch. The nosewheel oleo extended by what felt like about 3 feet & the steward in the forward toilet peed all over his shoes!