Air carrier widebody transport unable retract gear after takeoff. Return and land overweight.

Attributes
ACN	101063
Time
Date	198901
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : lax
State Reference	CA
Altitude	msl bound lower : 100 msl bound upper : 2000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : lax
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	climbout : initial climbout : intermediate altitude
Route In Use	departure other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 240 flight time total : 9800 flight time type : 1100
ASRS Report	101063
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 120 flight time total : 13700 flight time type : 1300
ASRS Report	101354
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency none taken : unable other
Consequence	faa : investigated
Supplementary
Primary Problem	Aircraft

Narrative:

Takeoff lax landing gear would not retract, gear handle would not go past mid position and gear would not retract. Performed abnormal checklist and no help. Returned to lax and landed overweight. Performed overweight checklist. Also had a buffet at speed above 220 KTS. Kept speed below 210 KTS. Returned for landing. No further problem! Callback conversation with reporter revealed the following: problem was caused by double failure of both the primary and backup channel in electronic lock box that is in the circuit to prevent gear handle retraction if it senses something wrong. Could not determine what caused buffet. As cabin attendant felt it at their seats which are about over nose gear, suspect it was something to do with nose gear, possibly gear door partly open, but all appeared normal when back on ground.

Original NASA ASRS Text

Title: ACR WDB UNABLE RETRACT GEAR AFTER TKOF. RETURN AND LAND OVERWEIGHT.

Narrative: TKOF LAX LNDG GEAR WOULD NOT RETRACT, GEAR HANDLE WOULD NOT GO PAST MID POS AND GEAR WOULD NOT RETRACT. PERFORMED ABNORMAL CHKLIST AND NO HELP. RETURNED TO LAX AND LANDED OVERWEIGHT. PERFORMED OVERWT CHKLIST. ALSO HAD A BUFFET AT SPD ABOVE 220 KTS. KEPT SPD BELOW 210 KTS. RETURNED FOR LNDG. NO FURTHER PROB! CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: PROB WAS CAUSED BY DOUBLE FAILURE OF BOTH THE PRIMARY AND BACKUP CHANNEL IN ELECTRONIC LOCK BOX THAT IS IN THE CIRCUIT TO PREVENT GEAR HANDLE RETRACTION IF IT SENSES SOMETHING WRONG. COULD NOT DETERMINE WHAT CAUSED BUFFET. AS CABIN ATTENDANT FELT IT AT THEIR SEATS WHICH ARE ABOUT OVER NOSE GEAR, SUSPECT IT WAS SOMETHING TO DO WITH NOSE GEAR, POSSIBLY GEAR DOOR PARTLY OPEN, BUT ALL APPEARED NORMAL WHEN BACK ON GND.

Data retrieved from NASA's ASRS site as of August 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.