if autobrakes, why not autoreversers

[Guest delsimflyer]

Almost all modern jets offer autolanding capabilities right to touchdown and autobraking using wheel brakes. But apart from everything being auto the reversers are still deployed by the pilot even on the newer planes. why dont any aircraft offer an option for something like autoreversers?

[Chock 17,769]

I suspect there might be a few reasons, here's my guesses: First it would add largely unecessary complexity to the throttle and reverser system, when you can simply have the monitoring pilot pull the throttles into reverse for you, which is something most virtual co-pilots can do in FS too.Then there is the fact that reverse thrust increases the possibility of FOD ingestion, so I suspect the airlines would prefer pilots to use it manually when they felt they had to, rather than making it a part of the procedures on approach checklist, which might make crews overuse it.Lastly, I reckon airliner manufacturers are a bit leery about doing that because of what has happened to several airliners in fatal accidents. Most famously, the Lauda Air Boeing 767 which disintegrated in mid-air over Thailand when a thrust reverser deployed accidentally whilst it was at cruise altitude. Boeing actually altered the mechanism after that accident to prevent it from happening again. So adding automatic systems to the reversers comes back to the first point I made about 'more things to go wrong'. I think I'm correct in saying that accidental reverse thrust was the cause of the Spanair MD-82 crash at Madrid too, and I believe there have been other incidents of this nature.Al

[gman! 1]

I suspect there might be a few reasons, here's my guesses: First it would add largely unecessary complexity to the throttle and reverser system, when you can simply have the monitoring pilot pull the throttles into reverse for you, which is something most virtual co-pilots can do in FS too.Then there is the fact that reverse thrust increases the possibility of FOD ingestion, so I suspect the airlines would prefer pilots to use it manually when they felt they had to, rather than making it a part of the procedures on approach checklist, which might make crews overuse it.Lastly, I reckon airliner manufacturers are a bit leery about doing that because of what has happened to several airliners in fatal accidents. Most famously, the Lauda Air Boeing 767 which disintegrated in mid-air over Thailand when a thrust reverser deployed accidentally whilst it was at cruise altitude. Boeing actually altered the mechanism after that accident to prevent it from happening again. So adding automatic systems to the reversers comes back to the first point I made about 'more things to go wrong'. I think I'm correct in saying that accidental reverse thrust was the cause of the Spanair MD-82 crash at Madrid too, and I believe there have been other incidents of this nature.Al

He makes a valid point. Malfunctions and intentions of pilots may make automatic thrust reverses dangerous, and not needed. First there is the problem with planes doing touch and go's. Even 747s and A380s do touch and go's (google and youtube are your friends ;)) and automatic thrust reverses, would make it very hard, or even impossible to get back off the tarmac into the air. Then there is a problem if the systems malfunctioned (Which VERY rare) then, reverses could be applied in the air, depending on the logic of throttle positioning on the plane. Autoreversers will just be a big problem for pilots, and would be very annoying. The first officer, or flight engineer might not have anything to do controlling the plane as well either :(, which might make him or her very bored :(. The first officer will often handle thrust reversers on the plane after touchdown so he can do it more efficently than then an automatic system, such as in cases of an emergency landing, or something like that. There are also problems with certain planes where only a certain amount of reversers should be used, unless there is an emergency. An example is the A380, which has reversers on all engines, but reverses are only used on Engines 2 and 3, because the outer ones are so powerful, they could rip grass off areas next to the runway. Autoreverses would not be able to know when to use 2 reversers or all 4, depending on the situations. So the best thing to do, is let the crew do it. Most things on takeoff, approach, and landing are done manually anyway. (Except for CATIII autolands)

[tasmanet 0]

here are also problems with certain planes where only a certain amount of reversers should be used, unless there is an emergency. An example is the A380, which has reversers on all engines, but reverses are only used on Engines 2 and 3, because the outer ones are so powerful, they could rip grass off areas next to the runway. Autoreverses would not be able to know when to use 2 reversers or all 4, depending on the situations.

My understanding is there are only 2 reverser's on the A380Originally they were not going to have any to keep down the weight butcommon sense prevailed and they ended up with 2http://www.flightglobal.com/articles/2006/...irbus-a380.htmlIn regards to Auto everything the interim report on the Boeing NG atAmsterdam makes good reading on what can happen with a simplealtimeter failurehttp://www.taipeitimes.com/News/world/arch...3/06/2003437688Tas