Idle Reverse
Idle Reverse
Join Date: May 2000
Location: Seattle
Posts: 3,197
Likes: 0
Received 0 Likes
on
0 Posts
Depends on the airplane, runway, weather, and airline policy.
In general, in airplanes where reverse thrust is available, AT LEAST idle reverse will be selected on touchdown. More reverse thrust may be used, in accordance with all the factors above.
In general, in airplanes where reverse thrust is available, AT LEAST idle reverse will be selected on touchdown. More reverse thrust may be used, in accordance with all the factors above.
, when using idle reverse is it required to select a higher setting of autobrake?Join Date: Jun 2000
Location: UK
Posts: 865
Likes: 0
Received 0 Likes
on
0 Posts
Again depends on aircraft. On the 757/767 the autobrake is a 'deceleration rate', so if you use more reverse then the aircraft simply uses less brake, so in answer to the question, no.
Join Date: Jul 2000
Location: Sydney, Australia
Age: 43
Posts: 40
Likes: 0
Received 0 Likes
on
0 Posts
To expand a little.
As expidite said the autobrake setting is a deceleration rate, if full reverse is selected it will make no difference to the stopping distance, as the brakes will simply release a bit, to maintain the same rate of deceleration. ATC expect you to take the first available taxiway given your aircraft type, which will usually require autobrakes 2 or 3. When this is the case we use full reverse, as it saves the brakes from becoming too hot (although with new carbon fibre brakes this may not actually reduce brake wear). If we're ever given a roll-through, or dont have to take the first available taxiway, then autobrakes 1 is selected and idle reverse used. It depends on the situation, and will largely be based on your previous experience at that airport.
The only other consideration is if you're operating off a wet/slippery runway, in this situation you cannot be assured the wheels will grip well, making the wheel brakes useless, you MUST use full reverse in this situation. (this all applies to 767 ops).
The definition of idle reverse is simply deploy the reversers (engine cowl slides back, blocker doors direct airflow forward not back) without increasing the engine power above idle.
As expidite said the autobrake setting is a deceleration rate, if full reverse is selected it will make no difference to the stopping distance, as the brakes will simply release a bit, to maintain the same rate of deceleration. ATC expect you to take the first available taxiway given your aircraft type, which will usually require autobrakes 2 or 3. When this is the case we use full reverse, as it saves the brakes from becoming too hot (although with new carbon fibre brakes this may not actually reduce brake wear). If we're ever given a roll-through, or dont have to take the first available taxiway, then autobrakes 1 is selected and idle reverse used. It depends on the situation, and will largely be based on your previous experience at that airport.
The only other consideration is if you're operating off a wet/slippery runway, in this situation you cannot be assured the wheels will grip well, making the wheel brakes useless, you MUST use full reverse in this situation. (this all applies to 767 ops).
The definition of idle reverse is simply deploy the reversers (engine cowl slides back, blocker doors direct airflow forward not back) without increasing the engine power above idle.
Join Date: Jun 2001
Location: Surrounded by aluminum, and the great outdoors
Posts: 3,780
Likes: 0
Received 0 Likes
on
0 Posts
Idle reverse basically cancelles out any "residual" forward thrust produced produced by the powerplant at the idle setting, which varies depending on the engine as installed on a specific airframe..which varies widely by type...equivalent to "ground fine/ground idle" setting on most turboprops..which tends to be more effective at higher forward speeds..many noise abatement procedures specify idle thrust only settings during landing rollout, unless required for safety considerations (weather minimums, braking action etc..) most turbojet performance considerations do not take into account the use of reverse thrust in any case..
