Lewis From Greece, joined Jul 1999, 3723 posts, RR: 4 Posted (14 years 7 months 2 weeks 4 days 5 hours ago) and read 7116 times:
I am not quite shure but i clearly remember that when i went to NEW YORK (JFK) in 1993 we landed without using reverse thrust. Is this really possible? It is not possible to have missed it because the 747-200s make really loud noise so it is always noticeable.
Airbus_a340 From Hong Kong, joined Mar 2000, 1566 posts, RR: 19
Reply 2, posted (14 years 7 months 2 weeks 4 days 4 hours ago) and read 6991 times:
in some airports like in Hong Kong, Chek Lap Kok, i have noticed the reverse thrust doors open, but i didnt notice if reverse thrust was activated, this is because i did not hear much of a rumble, this has occured on 3 out of 4 of the landings. I have been told that this is called "idle reverse thrust" where the doors of the reversers are just opened to stop the air flowing straight through the engine scince reverse thrust is not so effective on some aircraft.
Can someone please clarify, i was told this, i am giving you infomation from a pilot not me.
Trevor A.K.A. Airbus_A340
People. They make an airline. www.cathaypacific.com
ILS25R From Germany, joined Jan 2001, 28 posts, RR: 0
Reply 5, posted (14 years 7 months 2 weeks 4 days 1 hour ago) and read 6909 times:
for landing, thrust reversal is not included in the performance calculation. It's used as an additional factor of safety and therefore not necessary but it reduces the braking distance about 20%.
The maximum share of thrust reverse is about 30% of the total braking effect on a dry runway.
At some airports the use of reverse thrust, except idle reverse, is not allowed, except for safety, due to noise abatement.
Prebennorholm From Denmark, joined Mar 2000, 6841 posts, RR: 54
Reply 6, posted (14 years 7 months 2 weeks 4 days 1 hour ago) and read 6891 times:
In Copenhagen (CPH) use of thrust reversers is banned due to noise restrictions.
Normally they open the doors and spool the engines up a little higher that idle. I guess that it is only to get a faster responce if the reversers are needed - in case of a problem with the wheel brakes.
In case of any problem they are of course allowed to do what they can do.
Best regards, Preben Norholm
Always keep your number of landings equal to your number of take-offs
JETPILOT From United States of America, joined May 1999, 3130 posts, RR: 27
Reply 7, posted (14 years 7 months 2 weeks 4 days 1 hour ago) and read 6891 times:
It has been found that aircraft using carbon brakes have much less brake wear if the wheel brakes are used exclusively to slow the plane down.
Carbon brakes wear siginificantly less when they are hot.
If carbon brakes are used like steel brakes (only below 60 kts) they spend little time in their optimal operating temperature zone and wear is increased.
The newest procedures for airplanes equiped with carbon brakes is to bring the engines into idle reverse, and use auto braking to slow the aircraft. This puts the brakes in the optimal heat zone quickly minimizing wear.
If anything other than the proposed procedures are used the modern planes will rat you out to ops for too low break temps, or using reverse above idle. This info is compiled in to a unique profile for each pilot recording his or her flying habits. Letters are sent out regarding aircraft operations outside the prescribed parameters. Big brother knows all.
Delta73Spilot From , joined Dec 1969, posts, RR:
Reply 9, posted (14 years 7 months 2 weeks 3 days 21 hours ago) and read 6834 times:
On the 737, most runways we operate are well beyond what we need to stop! I always arm the reversers just to have them handy but slow the airplane down on brakes, I find that it provides a much more comfortable landing to the passengers without all this extra noise. Now if operational needs dictate the use of them then by all means they will be used!
YXDfan From Canada, joined Dec 2000, 193 posts, RR: 0
Reply 10, posted (14 years 7 months 2 weeks 3 days 21 hours ago) and read 6827 times:
Idle reverse is a pretty common practice, they did it once when I was riding in the jumpseat of an AC DC-9. There are also a few smaller jets that have no reverse thrust at all, such as the F-28 and the BAe-146. Mind you, the landing on the F-28 is about the only thing thats quiet!
Jetguy From , joined Dec 1969, posts, RR:
Reply 14, posted (14 years 7 months 2 weeks 3 days 20 hours ago) and read 6804 times:
Thrust reversers are NEVER necessary to make "book" stopping distances. Book distances are based upon the use of wheel brakes only. Basically, the use of T/Rs provides the crew with a cushion or extra margin. It costs money to use the brakes (brake overhauls are big $$$) and T/Rs cost more or less nothing to use so they make sense from an economic point of view. Are they mandatory - never, nice to have - yes.
Red Panda From Hong Kong, joined Jun 2000, 1521 posts, RR: 0
Reply 16, posted (14 years 7 months 2 weeks 3 days 18 hours ago) and read 6780 times:
Thrust Reversers should not be ineffective by any mean. Even tho the air is thin, the engines can compress the inflow of air to 1:40 (when cruising). So I don't think thin air is a reason why thrust reversers are ineffective. The thinness of air is only a matter to propellers, but not Jet. (a/c w/ jet engines).
Cedarjet From United Kingdom, joined May 1999, 8409 posts, RR: 54
Reply 20, posted (14 years 7 months 2 weeks 3 days 10 hours ago) and read 6751 times:
Air-India didn't use them at JFK a few months ago in one of their 744s when I was over there in Spring. Nor did British Meditteranean in an A320 at Beirut a few years ago, which was more surprising cos the runway isn't an alternative landing site for the Space Shuttle (as the long runway at JFK is). Quite short in fact.
Whoever said reverse thrust is less costly than wheel brakes is mental - changing brake pads (not really "$$$" at all) is a fraction of the cost in significantly shortened engine life from the rigours of reverse thrust, and of course fuel used spooling up to 80%-odd power.
fly Saha Air 707s daily from Tehran's downtown Mehrabad to Mashhad, Kish Island and Ahwaz
Advancedkid From United States of America, joined Jun 2000, 762 posts, RR: 2
Reply 21, posted (14 years 7 months 2 weeks 3 days 5 hours ago) and read 6729 times:
A heavier plane needs more breaking power than a lighter one because of a greater inertia.
The use of reverse thrusts is mostly left to the
pilot's logical decision at any particular airport.
Several airports and or runways almost always require
the use of thrust reversers on some airplanes.
With some others it is hardly required.
I hope that helps.
Cfalk From , joined Dec 1969, posts, RR:
Reply 22, posted (14 years 7 months 2 weeks 3 days 4 hours ago) and read 6717 times:
I was told not long ago that in order to recieve civil transport certification from the FAA, the aircraft must be able to land safely using either only wheel brakes or only reverse thrust, so that if there is a problem with either system, you don't have a major problem. I suppose a "standard" runway length is specified for this, but I don't know how that is calculated. Anybody know?