Speedbrake Do Not Arm B737

[speedbird37]

Hi.

What triggers the SPEEDBRAKE DO NOT ARM light to come on after landing?

any ideas?
thankx

[NSEU]

The 737NG book says...

The SPEEDBRAKE DO NOT ARM light comes on when the automatic operation of the speedbrake system does not arm correctly. This occurs when the speedbrake lever is in the ARMED detent OR either thrust lever is in reverse, and one of these occurs:

Antiskid system inoperative
Auto speedbrake actuator not retracted
Disagreement between the wheel spin speeds and air/ground signals
Internal faults in the auto speedbrake module.

Have you looked at the Fault Isolation Manual?

[Flight Detent]

Purely off the 'top of the head' since my manuals are not with me...

But I thought the "Do Not Arm" light comes on when the speedbrake lever is in the fully down position and one or more spoiler panels are not down, with the airplane on the ground.

I guess I will have my memory tested this day!

Cheers...FD...:bored:

[Capt Apache]

Thats the Speed Brake Extended light Flight detent.The manual says Speed Brake Do NOt Arm indicates an abnormal conditon or test inputs to the automatic speedbrake system

[JammedStab]

After auto-spoiler deployment when the main wheel speed decreases below 60 knots until the speedbrake lever is positioned to DN perhaps?
That is how it works on the 727 anyways with the system operating normally or at least some 727s as I have heard that there are 3 different types of auto-speedbrake deployment that have been used on this aircraft type.

[speedbird37]

I think it has to be the 60 kts wheelspinn! Though I cann't find anything in the manuals what happens to the speedbrake system after landing!

It' s not unimportant to know why an amber light illuminates during landing roll!

[speedbird37]

no its not the thrust levers!

i watched it yesterday and the light illuminates passing 60 kts, reverse still on!
so it has to be 60 kts wheel spin