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With Travel Halted, What Happens To The Planes?
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langwadt:

--- Quote from: jogri on August 12, 2020, 07:01:24 am ---
--- Quote from: langwadt on August 11, 2020, 12:49:12 pm ---afaik thrust reversers are never a requirement for safe landing, it just saves on brakes and might help a bit if it is very wet
the A380 doesn't even thrust reversers on all it's engines

I think I've read some where that the glide ratio on a wingsuit is ~2 .5:1

--- End quote ---

Yes, technically thrust reverser are optional on a dry runway and you can land without them, but you shouldn't do it... This is what it looks like when you try to stop a 747 with worn out brakes without thrust reversers:



--- End quote ---

that's not a landing that is an aborted takeoff

jogri:

--- Quote from: langwadt on August 12, 2020, 08:43:56 am ---that's not a landing that is an aborted takeoff

--- End quote ---

Yeah, and a nominal V1 (maximum speed at which a start can be aborted) is around 160 knots while a landing with MTOW will get you in the same range (usual landing speeds are in the 130-150 knots range)... So the only main difference is that the tires never left the ground for the aborted takeoff, but other than that a fast landing produces a similar strain on the aircraft than an aborted takeoff.
langwadt:

--- Quote from: jogri on August 12, 2020, 04:45:10 pm ---
--- Quote from: langwadt on August 12, 2020, 08:43:56 am ---that's not a landing that is an aborted takeoff

--- End quote ---

Yeah, and a nominal V1 (maximum speed at which a start can be aborted) is around 160 knots while a landing with MTOW will get you in the same range (usual landing speeds are in the 130-150 knots range)... So the only main difference is that the tires never left the ground for the aborted takeoff, but other than that a fast landing produces a similar strain on the aircraft than an aborted takeoff.

--- End quote ---

at an aborted takeoff there probably much less runway left to stop on, braking is much much harder

afaik thrust reversers are not even on the minium equipment list

jogri:
Well, every airplane with a certificate of airworthiness is capable of slowing down to a stop without thrust reversers... Albeit with significant damage to the landing gear, especially the tires.

Btw, i just checked the MMEL for the A320, this is what it says about thrust reversers being inoperative:


--- Quote ---(M)(O) One may be inoperative provided: a)   Inoperative reverser is deactivated and secured in the stowed position, and no operations or procedures require its use,
b)   All stow and deploy switches on the inoperative reverser operate normally (CFM only), 
c)   Both LVDT on the inoperative reverser are checked operative (IAE only),   
d)   ENG 1 (2) REV INHIBITED caution is displayed on ECAM E/WD after deactivation (PW only),   
e)   ENG 1 (2) REV UNLOCKED caution is not present on ECAM E/WD after deactivation (PW only)     
f)    ENG 1 (2) REV PRESSURIZED caution is not present on ECAM E/WD after deactivation,
g)   Wheel brake tachometers operate normally, 
h)   Main wheel braking system operates normally
--- End quote ---

Sounds like a "technically you can fly with only one reverser, but get it fixed ASAP". I'll take a bet and say that the airline uses this exception to get the plane to a workshop as soon as possible because every additional failure in the propulsion/breaking system is going to get the plane grounded.
langwadt:

--- Quote from: jogri on August 12, 2020, 06:54:59 pm ---Well, every airplane with a certificate of airworthiness is capable of slowing down to a stop without thrust reversers... Albeit with significant damage to the landing gear, especially the tires.

Btw, i just checked the MMEL for the A320, this is what it says about thrust reversers being inoperative:


--- Quote ---(M)(O) One may be inoperative provided: a)   Inoperative reverser is deactivated and secured in the stowed position, and no operations or procedures require its use,
b)   All stow and deploy switches on the inoperative reverser operate normally (CFM only), 
c)   Both LVDT on the inoperative reverser are checked operative (IAE only),   
d)   ENG 1 (2) REV INHIBITED caution is displayed on ECAM E/WD after deactivation (PW only),   
e)   ENG 1 (2) REV UNLOCKED caution is not present on ECAM E/WD after deactivation (PW only)     
f)    ENG 1 (2) REV PRESSURIZED caution is not present on ECAM E/WD after deactivation,
g)   Wheel brake tachometers operate normally, 
h)   Main wheel braking system operates normally
--- End quote ---

Sounds like a "technically you can fly with only one reverser, but get it fixed ASAP". I'll take a bet and say that the airline uses this exception to get the plane to a workshop as soon as possible because every additional failure in the propulsion/breaking system is going to get the plane grounded.

--- End quote ---

sure brake pads and the time to change them cost money, but

https://youtu.be/NkrozyWKCHY

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