B757-200 receives brief stall warning when flaps are selected with speed brakes still extended.

Attributes
ACN	782922
Time
Date	200804
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mggt.airport
State Reference	FO
Altitude	msl single value : 12000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tower : lal.tower
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 250 flight time total : 12000
ASRS Report	782922
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : less severe non adherence : published procedure
Independent Detector	aircraft equipment other aircraft equipment : stall warning other flight crewa
Resolutory Action	flight crew : overcame equipment problem
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Flight Crew Human Performance

Narrative:

Approaching the guatemala city airport; we experienced a momentary stall warning activation. It occurred after a hand flown turn while slowing and extending flaps. We had just leveled at 12000 ft. As the aircraft slowed to flaps up speed; I called for flaps 5 degrees. We slowed to within 10 KTS of the flaps 5 speed; and momentarily heard the stall warning activate. At approximately the same time; the first officer observed the speed brake handle extended and immediately stowed it. I started to increase thrust in accordance with the approach to stall recovery; but observed that we were stabilized. The remainder of the flight was uneventful.

Original NASA ASRS Text

Title: B757-200 RECEIVES BRIEF STALL WARNING WHEN FLAPS ARE SELECTED WITH SPEED BRAKES STILL EXTENDED.

Narrative: APCHING THE GUATEMALA CITY ARPT; WE EXPERIENCED A MOMENTARY STALL WARNING ACTIVATION. IT OCCURRED AFTER A HAND FLOWN TURN WHILE SLOWING AND EXTENDING FLAPS. WE HAD JUST LEVELED AT 12000 FT. AS THE ACFT SLOWED TO FLAPS UP SPD; I CALLED FOR FLAPS 5 DEGS. WE SLOWED TO WITHIN 10 KTS OF THE FLAPS 5 SPD; AND MOMENTARILY HEARD THE STALL WARNING ACTIVATE. AT APPROX THE SAME TIME; THE FO OBSERVED THE SPD BRAKE HANDLE EXTENDED AND IMMEDIATELY STOWED IT. I STARTED TO INCREASE THRUST IN ACCORDANCE WITH THE APCH TO STALL RECOVERY; BUT OBSERVED THAT WE WERE STABILIZED. THE REMAINDER OF THE FLT WAS UNEVENTFUL.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.