Question for 737 NG Drivers

[wooferdog]

To you NG drivers out there:

1. What conditions must be met for the reversers to deploy?

2. What conditions must be met for the spoilers to deploy?

No sarcasm, please.

Thanks.

 

[Zdriver]

1. Radio altimeter <10' altitude or air/ground safety sensor in the ground mode.

2. I'm assuming you mean ground operation...
auto speedbrake:
-lever armed
-speedbrake armed light illuminated
-both thrust levers retarded to idle
-main landing gear spin up <60kts
-right main strut compressed opening the mechanical linkage to the ground
spoiler shutoff valve
-radio altitude <10'

 

[GuppyWN]

I've seen where the above were met and the T/R's did not deploy. I'll wait until the NTSB does a prelim.

Without mitigating factors I'd be pretty hard to use an entire 8900 foot runway with enough residual energy to break apart the airplane.

Gup

 

[Green Banana]

1. Radio altimeter <10' altitude or air/ground safety sensor in the ground mode.

2. I'm assuming you mean ground operation...
auto speedbrake:
-lever armed
-speedbrake armed light illuminated
-both thrust levers retarded to idle
-main landing gear spin up <60kts
-right main strut compressed opening the mechanical linkage to the ground
spoiler shutoff valve
-radio altitude <10'

Actually, not true. The speedbrake will deploy automaticly when you deploy the thrust reverse.

 

[Homer Jay]

actually, not true. The speedbrake will deploy automaticly when you deploy the thrust reverse.

what?!?!

 

[Green Banana]

what?!?!

What?!?! , What?!?!
If you forget to arm the speed brake, Boeing designed it to auto deploy. It is the same system that deploys them on a rejected takeoff without the lever in the ARM position.

 

[Homer Jay]

What?!?! , What?!?!
If you forget to arm the speed brake, Boeing designed it to auto deploy. It is the same system that deploys them on a rejected takeoff without the lever in the ARM position.

I don't recall ever reading that. What's the point of arming them then if they'll auto-deploy anyway? I'm trying to find it in my manual. If it's true, just goes to show you learn something new everyday!

 

[ImbracableCrunk]

Speed Brake Lever DOWN During Landing or RTO
If the SPEED BRAKE lever is in the DOWN position during landing or rejected
takeoff, the Automatic 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, and
- reverse thrust levers are positioned for reverse thrust
The SPEED BRAKE lever automatically moves to the UP position and spoilers
deploy.

I guess we arm the SB just in case there's a problem with the T/Rs. They'll deploy sooner if you arm them, too, I suppose.

 

[CMRJetDriver]

Apparently the Space Shuttle only needs around 9000' as well. Granted they don't land it in the rain and some distances were longer.


STS-1

April 14, 1981, 10:20:57 a.m. PST, Runway 23, Edwards Air Force Base, Calif. Rollout distance: 8,993 feet. Rollout time: 60 seconds. Landing Weight: 194,184 lbs.

STS-2

November 14, 1981, 1:23:11 p.m. PST, Runway 23, Edwards Air Force Base, Calif. Rollout distance: 7,711 feet. Rollout time: 50 seconds. Landing Weight: 204,262 lbs.

etc, etc...

 

[flyboyike]

I don't recall ever reading that. What's the point of arming them then if they'll auto-deploy anyway?

Well, I can see it being beneficial if either or both reversers don't deploy.

 

[Whataburger]

Apparently the Space Shuttle only needs around 9000' as well. Granted they don't land it in the rain and some distances were longer.


STS-1

April 14, 1981, 10:20:57 a.m. PST, Runway 23, Edwards Air Force Base, Calif. Rollout distance: 8,993 feet. Rollout time: 60 seconds. Landing Weight: 194,184 lbs.

STS-2

November 14, 1981, 1:23:11 p.m. PST, Runway 23, Edwards Air Force Base, Calif. Rollout distance: 7,711 feet. Rollout time: 50 seconds. Landing Weight: 204,262 lbs.

etc, etc...

The year 1981 was way different than 2009.
Atmosphere, global warming, break pads, dirt runway, etc, etc...

 

[GuppyWN]

I don't recall ever reading that. What's the point of arming them then if they'll auto-deploy anyway? I'm trying to find it in my manual. If it's true, just goes to show you learn something new everyday!

Let's back up just a second. There are TWO types of spoilers - Ground and Flight (speedbrakes).

The ground spoilers will deploy upon right main gear squat switch.
The flight spoilers will deploy upon main gear wheelspin.

Right crosswind landings are always rougher because you're getting all the spoilers to deploy at the same time. And old hat taught me to slip the aircraft in the flare to get the left main to touch juuuuuuuust a touch before the right.

The reason to ARM them is so they will auto-deploy upon landing and kill lift BEFORE the T/R's are activated. The T/R deploy is just a backup.

Gup

 

[Homer Jay]

Let's back up just a second. There are TWO types of spoilers - Ground and Flight (speedbrakes).

The ground spoilers will deploy upon right main gear squat switch.
The flight spoilers will deploy upon main gear wheelspin.

Right crosswind landings are always rougher because you're getting all the spoilers to deploy at the same time. And old hat taught me to slip the aircraft in the flare to get the left main to touch juuuuuuuust a touch before the right.

The reason to ARM them is so they will auto-deploy upon landing and kill lift BEFORE the T/R's are activated. The T/R deploy is just a backup.

Gup

I found it, too. Makes sense now. Thanks guys!

 

[Be 23]

The year 1981 was way different than 2009.
Atmosphere, global warming, break pads, dirt runway, etc, etc...

Yep, way different. Alternate runways need to be at least 7,000' if the orbiter weighs over 220,000 lbs. Not that it matters because there is usually a 10,000' runway available for an overshoot. For example, depending on approach direction overshoot alternate for EDW could be either Moses Lake WA, Lincoln NE or Halifax.

 

[Quimby]

The year 1981 was way different than 2009.
Atmosphere, global warming, break pads, dirt runway, etc, etc...

What's the pay & schedule?

 

[airplane wizard]

Apparently the Space Shuttle only needs around 9000' as well. Granted they don't land it in the rain and some distances were longer.


STS-1

April 14, 1981, 10:20:57 a.m. PST, Runway 23, Edwards Air Force Base, Calif. Rollout distance: 8,993 feet. Rollout time: 60 seconds. Landing Weight: 194,184 lbs.

STS-2

November 14, 1981, 1:23:11 p.m. PST, Runway 23, Edwards Air Force Base, Calif. Rollout distance: 7,711 feet. Rollout time: 50 seconds. Landing Weight: 204,262 lbs.

etc, etc...

The space shuttle also lands like around 100 knots faster than a 737 too.

 

[Captain X]

The space shuttle also lands like around 100 knots faster than a 737 too.

Actually we're talkin' about NGs here, so probably only like 50 knots.

 

[airplane wizard]

Maybe they will start putting drag chutes on the NG's.

 

[flyboyike]

Let's back up just a second. There are TWO types of spoilers - Ground and Flight (speedbrakes).

The ground spoilers will deploy upon right main gear squat switch.
The flight spoilers will deploy upon main gear wheelspin.

Right crosswind landings are always rougher because you're getting all the spoilers to deploy at the same time. And old hat taught me to slip the aircraft in the flare to get the left main to touch juuuuuuuust a touch before the right.

The reason to ARM them is so they will auto-deploy upon landing and kill lift BEFORE the T/R's are activated. The T/R deploy is just a backup.

Gup

While we're on the subject of spoilers, what would happen to them if they were deployed and hydraulic pressure was removed. Would they stay up for some period of time, stay up forever or drop more or less right away?

 

[airplane wizard]

While we're on the subject of spoilers, what would happen to them if they were deployed and hydraulic pressure was removed. Would they stay up for some period of time, stay up forever or drop more or less right away?

Drop down, I would think, if they lost HYD pressure. I am not a seven three pilot though.