B737-300 crew allows speed to get low when autothrottle becomes disengaged during approach.

Attributes
ACN	478089
Time
Date	200001
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : iah.airport
State Reference	TX
Altitude	msl single value : 4000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : san.tower
Operator	common carrier : air carrier
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : n/s other
Flight Phase	descent : approach
Route In Use	approach : instrument precision arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : multi engine pilot : instrument pilot : flight engineer pilot : cfi
Experience	flight time last 90 days : 170 flight time total : 8400 flight time type : 700
ASRS Report	478089
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe non adherence : company policies non adherence : published procedure other anomaly
Independent Detector	aircraft equipment other aircraft equipment : auto throttle warning other flight crewa
Resolutory Action	flight crew : regained aircraft control
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Flight Crew Human Performance

Narrative:

CAT IIIA autoland visual approach briefed. On arrival, on an intercept heading to the localizer, the second autoplt was turned on per procedure. ATC was keeping us tight and issuing speed and altitude reductions as quickly as they could. Slowing through 170 KTS, gear was called for and flaps 15 degrees. Also landing checklist. ATC requested 150 KTS, so I bugged it (reference was 151). While bugging, verifying checklist items, maintaining visual separation with traffic to follow, I noticed the autothrottle red annunciator flashing. Looked up at the airspeed and noticed 145 KTS and slowing, autoplt trimming nose up to maintain altitude. I immediately threw the thrust levers full forward and pushed forward on the yoke with about 20-30 pounds of pressure (entered control wheel steering). The aircraft remained on the GS and reference +10 was recovered about 4-5 seconds later. No shaker or buffet. Requested flaps 30 degrees and landed without incident. Somehow, somewhere the autothrottles disengaged and the airspeed was lost. Both the captain and the captain jump seater noticed no failure. The captain did help overcome the pitch forces after I began the recovery.

Original NASA ASRS Text

Title: B737-300 CREW ALLOWS SPD TO GET LOW WHEN AUTOTHROTTLE BECOMES DISENGAGED DURING APCH.

Narrative: CAT IIIA AUTOLAND VISUAL APCH BRIEFED. ON ARR, ON AN INTERCEPT HDG TO THE LOC, THE SECOND AUTOPLT WAS TURNED ON PER PROC. ATC WAS KEEPING US TIGHT AND ISSUING SPD AND ALT REDUCTIONS AS QUICKLY AS THEY COULD. SLOWING THROUGH 170 KTS, GEAR WAS CALLED FOR AND FLAPS 15 DEGS. ALSO LNDG CHKLIST. ATC REQUESTED 150 KTS, SO I BUGGED IT (REF WAS 151). WHILE BUGGING, VERIFYING CHKLIST ITEMS, MAINTAINING VISUAL SEPARATION WITH TFC TO FOLLOW, I NOTICED THE AUTOTHROTTLE RED ANNUNCIATOR FLASHING. LOOKED UP AT THE AIRSPD AND NOTICED 145 KTS AND SLOWING, AUTOPLT TRIMMING NOSE UP TO MAINTAIN ALT. I IMMEDIATELY THREW THE THRUST LEVERS FULL FORWARD AND PUSHED FORWARD ON THE YOKE WITH ABOUT 20-30 LBS OF PRESSURE (ENTERED CTL WHEEL STEERING). THE ACFT REMAINED ON THE GS AND REF +10 WAS RECOVERED ABOUT 4-5 SECONDS LATER. NO SHAKER OR BUFFET. REQUESTED FLAPS 30 DEGS AND LANDED WITHOUT INCIDENT. SOMEHOW, SOMEWHERE THE AUTOTHROTTLES DISENGAGED AND THE AIRSPD WAS LOST. BOTH THE CAPT AND THE CAPT JUMP SEATER NOTICED NO FAILURE. THE CAPT DID HELP OVERCOME THE PITCH FORCES AFTER I BEGAN THE RECOVERY.

Data retrieved from NASA's ASRS site as of July 2007 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.