Idle Reverse
Thread Starter

Joined: Dec 2003
Posts: 138
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From: New Forest
Idle Reverse
I've heard this used on seveal cockpit videos and its been mentioned on Pprune etc but could someone explain it in a bit more depth for me? I'm assuming idle reverse means just deploying the reversers but wth the throttles at idle? Does this create a reverse thrust effect on the aircraft or does it just cancel out the positive thrust? And realise this is a very hypothetical question but what is the more efficient braking system, assuming the other was u/s, wheel brakes or reversers?
Thanks
Thanks


Joined: May 2000
Posts: 3,204
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From: Seattle
It is, indeed, deploying the reversers but remaining at idle thrust. It is a good trechnique in the final portion of the rollout so the brakes need not fight any forward thrust.
There is some amount of reverse thrust, but it may not be enough to actually move the airplane. Remember that with cascade reversers in high-bypass engines, reverse thrust is only about 40% that of forward thrust at best.
There is some amount of reverse thrust, but it may not be enough to actually move the airplane. Remember that with cascade reversers in high-bypass engines, reverse thrust is only about 40% that of forward thrust at best.
Per Ardua ad Astraeus
Joined: Mar 2000
Posts: 18,575
Likes: 4
From: UK
A couple of other threads you can look at
http://www.pprune.org/forums/showthr...hlight=reverse
http://www.pprune.org/forums/showthr...hlight=reverse
http://www.pprune.org/forums/showthr...hlight=reverse
http://www.pprune.org/forums/showthr...hlight=reverse
Joined: Nov 2005
Posts: 86
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From: UK
It will also depend onthe airlines own procedure as to 'normally' use reverse above idle. Watch the aircraft land at say LHR and you will notice some airlines will always use reverse above idle, others will just stay at idle. One reason is that the extra cost of fuel, andwear and tear etc when using full reverse, is more than the cost of the wear on the brakes. The modern carbon brakes do not wear asquick as the older style ones, and with the cost of jet fuel.....
Certain airports runways will almost always require a fair ammount of reverse, (on the larger jets) EWR is one that springs to mind.
Certain airports runways will almost always require a fair ammount of reverse, (on the larger jets) EWR is one that springs to mind.




