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january

Reverse Thrust in Flight

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Many years ago (1962 to be precise if you must!) I was aboard an Air Canada DC8 from Calgary to Toronto. We had just nicely started our descent into CYYZ when there was, suddenly, very loud engine noise and heavy vibration shaking the whole aircraft. All passenger conversation stopped and there were many pale faces looking nervously at each other. By way of emphasis, Air Canada DC8s were equipped with Rolls Royce engines- which definitely were not whisper quiet!After perhaps a minute- seemed much longer, a voice on the PA announced- " This is the Captain- we apologize for the noise and vibration but due to late clearance into Toronto, we have been using reverse thrust to descend more rapidly than normal."------Having recently tried this, for curiosity, with the QOS- with no result, would I be correct in assuming this is no longer an approved or even possible manoevre?Alex Reid

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In flight reversers were stopped some years back after it was implicated as the probable cause in one or more accidents. I believe in at least one of them, their use was unintentional. Now they only use the spoilers as a supplemental method to slow the aircraft down in flight, as such reversers are now inhibited from engaging in flight.

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No not ever..... If this ever happened with todays airliners you would be dead. Look up the Lauda air 767 accident, poor guys had only seconds before the aircraft broke up. I think there is a military transport that is capable.Ok before I get flamed the Lauda 767 broke up due the thrust being asymmetrical.If you run through the Abnormal checlist you will see that a failure of one of the four HYD systems can cause a inadvertent thrust reversor deployment among other things... proberbly the one thing that scares me the most about flying.http://aviation-safety.net/investigation/c...s/cvr_ng004.phpRob

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The DC-8 was approved for inflight reverse on the inboard engines only.I believe that the IL62 is as well. Both use clamshell reversers to block the full flow of the engines (think 737-200).Concorde was as well- but there were no speedbrakes there! In fact, no drag inducing devices except for teh landing gear. The only movable control surfaces were the elevons and the rudder(s)- there were two movable panels with separate actuators.im

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All moder airliners I am aware of have a mechanizm to bring the throttles to idle if a thrust reverser deploys in flight. The Fokker 100 has a cable. I was told about a TAM crew that had a thrust reverser deploy jsut after takeoff which causes the throttle to slam back to idle. The crew pushed forward on the trottle so hard that they broke the cable and moved the throttle back to takeoff power resulting in the loss of the aircraft. Planes are equipped with a lock out that will not allow reverse thrust if the throttles are not at idle. There are usually other criteria having weight on wheels that are required before reverse thrust can be used.

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