regarding aircraft
2007-03-02 21:43:17 · 8 answers · asked by seshu 1 in Cars & Transportation ➔ Aircraft
They can provide more stopping power than the brakes... they are much more effective than the spoilers... and they cant really go out on you... Brake failures are not all that uncommon, airplanes are built so that the brakes can take the abuse of stopping on an aborted takeoff at more than 150 mph, but they heat up to over 5000 degrees Celcius, in the case of the 777 anyway... The reversers dont abuse any part of the airplane as long as they are disengaged before the airplane comes to a complete stop...
2007-03-03 03:01:00 · answer #1 · answered by ALOPILOT 5 · 0⤊ 0⤋
I wouldn't say efficient, but more effective. Overheating the brakes can cause problems. They will not heat up to 5000 deg C like one answer said. Steel and titanium melt somewhere around 1600 C and aluminum, I think around 700 C. If that happened everything attached would melt and the gear would collapse. In other words nothing would have time to heat that high, it already would have melted. There is a brake temp monitor on the EICAS display in the cockpit. Jets generally always land with full flaps, they increase lift at slow speeds, and spoilers reduce lift and increase drag. Reversers are cut out before a complete stop mainly to prevent anything on the ground from being blown into the air and sucked into the engine. This is not so much a problem with tail mounted engines as with the low hung wing engines. When we do maintenance on the reversers we operate them to make sure they work, which is done at a stop or while moving slowly ( under 15 kts). When you pull on the levers for the reversers two main things happen. One, the translating cowl on the engine slides to the rear to expose the cascade vanes and close the blocker doors. Two, a linkage also connects the lever to the throttle gearbox on the engine, and acting as the throttle lever, increases engine rpm, N1 and N2. The engine is not at idle when the reversers are in operation like many think.
2007-03-03 14:45:59 · answer #2 · answered by JET_DOC 2 · 0⤊ 0⤋
Thrust reversers are more effective at high speed due to the amount of air flowing through them. As the aircraft slows the air flow reduces and the likelihood of compressor stall increases. Many aircraft reversers have to be cancelled at around 70-80 kts pr cavitation/stalling occurs.
2007-03-03 07:34:50 · answer #3 · answered by Ranjeeh D 5 · 0⤊ 0⤋
i agree with, well the no namer. its not a matter of efficiency. its just a matter of safely bring an aircraft to a taxiing speed. brakes could have a chance to go out. they also deploy spoilers, which would easily be described as upside down flaps. do let guy above lead you in wrong direction. while flaps do help slow down aircraft, there main purpose is to help create lift at slow speeds.
2007-03-03 09:33:23 · answer #4 · answered by cparkmi331 3 · 0⤊ 0⤋
it helps the plane slow down to save wear and tear on the brakes. it is used like brakes but only provids about 15 - 20 percent breaking power. the spoilers, thrust reversers, wheel brakes, and flaps all help the plane come to stop or slow taxi speed in a hurry
2007-03-03 20:42:09 · answer #5 · answered by Jeffrey B 1 · 0⤊ 0⤋
the engines can produce much more opposing force, than braking force provided by the brakes.also the brakes cant handle such a heavy load,the pads will melt. in a no power ( no engines ) situation the craft will come in on full flaps ( all flaps are pointed down ) this creates drag to help slow the aircraft.some pilots when landing on a short runway will use a combination of reverse thrust,and full flaps and save the brakes for taxiing
2007-03-03 08:11:42 · answer #6 · answered by yankeegray_99 5 · 0⤊ 2⤋
Not a question of efficiency, but a question of slowing down the aircraft.
2007-03-03 05:46:43 · answer #7 · answered by Barry auh2o 7 · 0⤊ 0⤋
Because it eliminates the thrust of the engines by directed it forward.
2007-03-03 16:06:53 · answer #8 · answered by solara 437 6 · 0⤊ 0⤋