737-700 Speedbrake question
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737-700 Speedbrake question
Hi guys,
I have a small question from a certain 'quiz' that has produced different answers from different sources... Input appreciated!
In order for the speedbrake to automatically deploy on landing the following condition(s) must be satisified:
a) Speedbrake lever in the armed position
b) Both thrust levers retarded to IDLE
c) Wheel spinup > 60 knots
d) Both a) and b)
Cheers,
Screwballs
Ps. I've already handed my answers in and had them corrected so just looking for different opinions on the answer.
I have a small question from a certain 'quiz' that has produced different answers from different sources... Input appreciated!
In order for the speedbrake to automatically deploy on landing the following condition(s) must be satisified:
a) Speedbrake lever in the armed position
b) Both thrust levers retarded to IDLE
c) Wheel spinup > 60 knots
d) Both a) and b)
Cheers,
Screwballs
Ps. I've already handed my answers in and had them corrected so just looking for different opinions on the answer.
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Speedbrake lever in the armed position
Flight spoilers come up at wheel spinup on any 2 main wheels
Ground spoilers come up when mechanical squat switch on right gear is compressed
If wheel spinup is not detected speedbrake lever will move to the up position and all spoilers will deploy after squat switch is compressed
Flight spoilers come up at wheel spinup on any 2 main wheels
Ground spoilers come up when mechanical squat switch on right gear is compressed
If wheel spinup is not detected speedbrake lever will move to the up position and all spoilers will deploy after squat switch is compressed
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I can't remember if it's the case in the NG (I think it is) but in the 3/4/500 the speedbrake (or should I say ground spoilers) will also automatically deploy on the ground if the reversers are unlocked, even if it is not armed.
TS6
TS6
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I agree with you, Topslide6, even if the Speedbrake lever is in the down position the auto speedbrake system operates when you get:
So with that info, which answer is the best fit?
Screwballs
- main landing gear wheels spin up (more than 60 knots)
- both thrust levers are retarded to IDLE
- reverse thrust levers are positioned for reverse thrust
So with that info, which answer is the best fit?
Screwballs
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Originally Posted by Topslide6
I can't remember if it's the case in the NG (I think it is) but in the 3/4/500 the speedbrake (or should I say ground spoilers) will also automatically deploy on the ground if the reversers are unlocked, even if it is not armed.
TS6
TS6
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Originally Posted by Screwballs
...
b) Both thrust levers retarded to IDLE
...
b) Both thrust levers retarded to IDLE
...
TRA must be <44
TLA (thrust lever resolver angle)
- Maximum reverse thrust =TRA 8
- Idle reverse =TRA 24
- Idle = TRA 36 to 38
- Maximum climb = TRA 72
- Maximum take-Off/go-around = TRA 78
- Maximum certified thrust = TRA 82.5
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Screwballs,
Personally, I would have said A and C are both correct but given that you can't choose both of those there isn't really a correct answer!! Maybe a typo on behalf of the question setter for answer 'D' perhaps?!
TR4A,
This is from memory and not from the manual but I believe that the action of pulling the reverser handles from their stowed position raises a 'switch' that lifts the speedbrake out of its down detent thereby deploying it. I think
Funny one!
TS6
Personally, I would have said A and C are both correct but given that you can't choose both of those there isn't really a correct answer!! Maybe a typo on behalf of the question setter for answer 'D' perhaps?!
TR4A,
This is from memory and not from the manual but I believe that the action of pulling the reverser handles from their stowed position raises a 'switch' that lifts the speedbrake out of its down detent thereby deploying it. I think
Funny one!
TS6
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From the 800 FCOM
Ground Operation
During landing, the auto speed brake system operates when these conditions occur:
SPEED BRAKE lever is in the ARMED position
SPEED BRAKE ARMED light is illuminated
radio altitude is less than 10 feet
landing gear strut compresses on touchdown
Note: Compression of any landing gear strut enables the flight spoilers to deploy. Compression of the right main landing gear strut enables the ground spoilers to deploy.
both thrust levers are retarded to IDLE
main landing gear wheels spin up (more than 60 kts).
The SPEED BRAKE lever automatically moves to the UP position and the spoilers deploy.
If a wheel spin-up signal is not detected, when the air/ground system senses ground mode (any gear strut compresses) the SPEED BRAKE lever moves to the UP position and flight spoiler panels deploy automatically. When the right main landing gear strut compresses, a mechanical linkage opens the ground spoiler bypass valve and the ground spoilers deploy.
If the SPEED BRAKE lever is in the DOWN position during landing or rejected takeoff, the auto speed brake system operates when these conditions occur:
main landing gear wheels spin up (more than 60 kts)
both thrust levers are retarded to IDLE
reverse thrust levers are positioned for reverse thrust.
The SPEED BRAKE lever automatically moves to the UP position and spoilers deploy.
After an RTO or landing, if either thrust lever is advanced, the SPEED BRAKE lever automatically moves to the DOWN detent and all spoiler panels retract. The spoiler panels may also be retracted by manually moving the SPEED BRAKE lever to the DOWN detent.
During landing, the auto speed brake system operates when these conditions occur:
SPEED BRAKE lever is in the ARMED position
SPEED BRAKE ARMED light is illuminated
radio altitude is less than 10 feet
landing gear strut compresses on touchdown
Note: Compression of any landing gear strut enables the flight spoilers to deploy. Compression of the right main landing gear strut enables the ground spoilers to deploy.
both thrust levers are retarded to IDLE
main landing gear wheels spin up (more than 60 kts).
The SPEED BRAKE lever automatically moves to the UP position and the spoilers deploy.
If a wheel spin-up signal is not detected, when the air/ground system senses ground mode (any gear strut compresses) the SPEED BRAKE lever moves to the UP position and flight spoiler panels deploy automatically. When the right main landing gear strut compresses, a mechanical linkage opens the ground spoiler bypass valve and the ground spoilers deploy.
If the SPEED BRAKE lever is in the DOWN position during landing or rejected takeoff, the auto speed brake system operates when these conditions occur:
main landing gear wheels spin up (more than 60 kts)
both thrust levers are retarded to IDLE
reverse thrust levers are positioned for reverse thrust.
The SPEED BRAKE lever automatically moves to the UP position and spoilers deploy.
After an RTO or landing, if either thrust lever is advanced, the SPEED BRAKE lever automatically moves to the DOWN detent and all spoiler panels retract. The spoiler panels may also be retracted by manually moving the SPEED BRAKE lever to the DOWN detent.
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The answer?
So to AUTO deploy ....MUST be
a) Speedbrake lever in the armed position..... Must YES
b) Both thrust levers retarded to IDLE Must YES as even if you use reverse thrust that requires thrust to idle
c) Wheel spinup > 60 knots NO ( strut compression will deploy them)
d) Both a) and b) YES
So A B and D are correct and I would chose D as it is "more correct"
a) Speedbrake lever in the armed position..... Must YES
b) Both thrust levers retarded to IDLE Must YES as even if you use reverse thrust that requires thrust to idle
c) Wheel spinup > 60 knots NO ( strut compression will deploy them)
d) Both a) and b) YES
So A B and D are correct and I would chose D as it is "more correct"