spoilers on go around- survey

seagull

seagull

Well-Known Member
For transport aircraft equipped with auto ground spoilers:

If, after initial touch down you advance the throttles to as a result of a bounce or to go around, do the autospoilers stow, but remain armed, so will deploy immediately upon closing the throttles when on the ground, or do they disarm?

Please state your aircraft type.

Thanks-
 
We have an auto-spoiler service kit installed on our Lear 55. There is a 2 second delay after the squat switches are made on landing. Also, whenever the thrust levers are off the idle stop, they are stowed. There is a "slam down" check done after engine start to ensure proper operation. The only way that they would remain extended is if the switch was moved from ARM to EXT.

Basically, there are two layers of protection to ensure the spoilers retract on a go around, even if you do actually touch down.
 
They are armed when the speedbrake/spoiler handle is pulled straight up out of it's disarmed detent. To auto extend you need the following:

• Mainlanding gear compressed
• Both throttle levers at idle
• Main landing gear aft wheel speed is greater than 85 knots

If the ground spoilers are not armed, and the three above conditions are met, they will deploy automatically when one thrust reverse lever is selected to the reverse thrust position.

If the aircraft should bounce during landing, the ground spoilers will remain extended provided both throttle levers remain at idle and all other arming conditions are met. System book doesn't specifically say but I'm assuming that if you bouce and then apply GA power they will retract but remained armed for the next landing attempt.

A300-600
 
On the CRJ200 the spoilers (considered part of the Ground Lift Dumping system) will stow after landing deployment if either engine spools to more than 79% N1 and then are armed for redeployment as long as either engine is above 79% and the wheel speed is >45 knots.

The 700 is similar but controlled differently.
 
Specifically, if the spoilers have extended, and you bounce and apply some power so they stow, and then subsequently touch down and close the throttles, will they extend with no other actions, or do they require manual extension at that point?
 
seagull said:
Specifically, if the spoilers have extended, and you bounce and apply some power so they stow, and then subsequently touch down and close the throttles, will they extend with no other actions, or do they require manual extension at that point?
Click to expand...

Embraer E170.

Upon touchdown, the spoilers will deploy when the following three conditions are met:

1. Weight on Wheels
2. Wheel speed above 40 knots OR airspeed above 65 MPH
and
3. Thrust Lever Angle.

The spoilers will retract if the Thrust Lever Angle goes beyong 35 degrees after landing, but will deploy again once the three conditions listed above are met.
 
EMB-145

Groud spoilers automatically deploy when either condition is met:

-Weight on all wheels (taxiing out if moving faster than 25kts wheelspeed)
-Main landing gear on ground with a wheelspeed +25kts, low thrust lever angle

On the go around, the ground spoilers will retract automatically once the thrust levers are are past a certain angle.

If you bounce a landing and add power to soften the next touchdown, the spoilers will stow (if thrust levers are pushed past the required TLA) and then automaticly redeploy provided the above criteria are met.
 
BobDDuck said:
On the CRJ200 the spoilers (considered part of the Ground Lift Dumping system) will stow after landing deployment if either engine spools to more than 79% N1 and then are armed for redeployment as long as either engine is above 79% and the wheel speed is >45 knots.

The 700 is similar but controlled differently.
Click to expand...

...your spoilers look like small tabs!
 
I forgot. But I *think* they automatically go back up when you advance the throttles.

757-200/767-300
 
On the 757/767 they will stow and DISARM after advancing the thrust levers. So, in Seagull's scenario, the spoilers would have to either be manually deployed or re-armed.
 
Like Capt Caucasian said....

757/767 when you go-around after deployment they automatically stow to the full forward and disarmed position.

They must be either re-armed or subsequently manually deployed. If you follow the checklist, you won't forget to re-arm them.
 
Capt. Caucasian said:
On the 757/767 they will stow and DISARM after advancing the thrust levers. So, in Seagull's scenario, the spoilers would have to either be manually deployed or re-armed.
Click to expand...

Thanks. I ought to know this stuff.

ER atrophy :(

Staplegun knows what I'm talking about. I think he barely remembers how to log on the website! :)
 
Capt. Caucasian said:
On the 757/767 they will stow and DISARM after advancing the thrust levers. So, in Seagull's scenario, the spoilers would have to either be manually deployed or re-armed.
Click to expand...

PeanuckleCRJ said:
Like Capt Caucasian said....

757/767 when you go-around after deployment they automatically stow to the full forward and disarmed position.

They must be either re-armed or subsequently manually deployed. If you follow the checklist, you won't forget to re-arm them.
Click to expand...

Doug Taylor said:
Thanks. I ought to know this stuff.

ER atrophy :(

Staplegun knows what I'm talking about. I think he barely remembers how to log on the website! :)
Click to expand...

Am I the only Douglas guy left?????
 
Citations without FADEC use a 85% N2 switch which will auto stow the spoilers no matter what else is happening. The 85% switch also starts pre-pressurization. Need to recycle the switch to deploy spoilers, and have WOW in ground mode. FADEC airplanes use TLA to coincide with N2 at 85%. The 650(III), 750(X) and 680(Sovereign), are different because they use a handle for speedbrakes with full travel being ground spoilers. Those airplanes might try to retract spoilers if WOW input is lost, I forget. I don't think the spoilers would retract in a bounce on any of the airplanes with spoiler switches.

Oops I just read the part when you asked about AUTO ground spoilers which no Citations have. Duh
 
seagull said:
For transport aircraft equipped with auto ground spoilers:

If, after initial touch down you advance the throttles as a result of a bounce or to go around, do the autospoilers stow, but remain armed, so will deploy immediately upon closing the throttles when on the ground, or do they disarm?

Please state your aircraft type.

Thanks-
Click to expand...

seagull said:
Specifically, if the spoilers have extended, and you bounce and apply some power so they stow, and then subsequently touch down and close the throttles, will they extend with no other actions, or do they require manual extension at that point?
Click to expand...

Excellent questions!

On the 88/90 DC-9, if you advance the throttles to go around after the spoilers deploy, they will retract AND disarm. It it based on throttle position. If you touch down again after you advanced the throttles the spoilers will have to be manually deployed. Up back, and up.

If you become airborne again after the spoilers deploy, they will STAY deployed unless you advance the throttles to go around, approx. 1/3 travel.

If you go around PRIOR to touchdown, they will stay armed.

Now, a Southernjets crew found out the hard way one strange caveat.

Imagine the bottom drops out on a approach and you cob the power a bit to catch the sink. You save it, but touch down with the throttles still above 1/3 travel, and bring them quickly to idle.

The spoilers will deploy and IMMEDIATELY stow and disarm; so fast it's hard to see the handle move aft and back forward. It has the same zip-zip sound of the normal spoiler deployment so if you're not looking at the handle, you may THINK they are deployed when they are not.

At Southernjets, you are required on the the 88/90 to LOOK at the handle to see that it is back, and staying back, before you say "spoilers up". Just hearing the sound of the handle is not enough.
 
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