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Being slightly off in adjustment of brakes when landing an airliner results in dead passengers. It's not as visible for manual braking, but that's because the b

by p_l 2y ago

Being slightly off in adjustment of brakes when landing an airliner results in dead passengers. It's not as visible for manual braking, but that's because the brakes have been "brake by wire" for some time. The scope of inputs in brake control loop is also much wider in aircraft than in typical car, at times including calculated mass, calculated ground speed, brake temperatures, tire temperatures, pressure on gear, etc. Now consider that the same network used to control the brakes also is sufficient to control every other sensor and servo on the aircraft s well.

wakawaka28 2y ago
That is all pretty interesting but I think we've gotten far away from my original comment, which was that planes don't need brakes to be as responsive as cars do. The typical application you're describing is in landing, not in puttering around in the airport. Landing involves executing some braking program continuously until the plane is on the ground. What I'm really getting at here is that the pilot is not going to be taken by surprise and have to apply the brakes in the same way as a driver would. It stands to reason that despite the lower speeds that cars go, they need to brake spontaneously in all kinds of conditions (on worse surfaces than the typical runway, in many cases). I don't know why this point matters anymore but that's what I was trying to say. I would like to add, brake by wire may be more reliable on planes than cars because planes are maintained very well by experts. Automobile design should strive for simpler and more failsafe options because owners are usually clueless people with limited budgets, who want to do as little maintenance as possible. The fact that hydraulic brakes work so well even in very old cars says a lot about how good they are. When they do get blamed for poor performance, it's usually due to something stupid like the owner not replacing worn out hoses after 20+ years of heavy use. I only found out about that one recently. Old hoses start breaking down and they gradually get congested.

by p_l 2y ago

wakawaka28 2y ago

That is all pretty interesting but I think we've gotten far away from my original comment, which was that planes don't need brakes to be as responsive as cars do. The typical application you're describing is in landing, not in puttering around in the airport. Landing involves executing some braking program continuously until the plane is on the ground. What I'm really getting at here is that the pilot is not going to be taken by surprise and have to apply the brakes in the same way as a driver would. It stands to reason that despite the lower speeds that cars go, they need to brake spontaneously in all kinds of conditions (on worse surfaces than the typical runway, in many cases). I don't know why this point matters anymore but that's what I was trying to say. I would like to add, brake by wire may be more reliable on planes than cars because planes are maintained very well by experts. Automobile design should strive for simpler and more failsafe options because owners are usually clueless people with limited budgets, who want to do as little maintenance as possible. The fact that hydraulic brakes work so well even in very old cars says a lot about how good they are. When they do get blamed for poor performance, it's usually due to something stupid like the owner not replacing worn out hoses after 20+ years of heavy use. I only found out about that one recently. Old hoses start breaking down and they gradually get congested.