Mechanic fails to install nose gear door attachment bolt while performing maintenance on own aircraf...

Attributes
ACN	178401
Time
Date	199105
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : avo
State Reference	FL
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	ground : preflight landing other other
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : atp pilot : private
Experience	flight time last 90 days : 234 flight time total : 12000 flight time type : 10
ASRS Report	178401
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	none taken : unable
Consequence	other
Supplementary
Air Traffic Incident	other

Narrative:

After preforming maintenance on aircraft and replacing cowling, I apparently forgot to insert bolt that attaches nose gear door pushrods to brackets on nose gear. During pleasure flight following this, the nose gear failed to fully extend. After 3 1/2 hours of efforts to extend the nose gear, a landing was made on 2 mains and partial nose gear resulting in minimal damage to the aircraft. The cause of this incident was that the pushrod bolt was not installed after the cowling was replaced. If I had followed my normal maintenance SOP of putting up my tools and closing the too chest after working on the aircraft, I would have noticed the bolt (uninstalled) laying in the parts bin. The nose gear door appearance is identical whether the pushrod is attached or not. This leaves it undetectable during a walk-around inspection unless the door is physically handled by the person doing inspection. Also, SOP's should be strictly adhered to in maintenance activities.

Original NASA ASRS Text

Title: MECHANIC FAILS TO INSTALL NOSE GEAR DOOR ATTACHMENT BOLT WHILE PERFORMING MAINT ON OWN ACFT AND DISCOVERS THE ERROR DURING THE SUBSEQUENT GEAR UP LNDG.

Narrative: AFTER PREFORMING MAINT ON ACFT AND REPLACING COWLING, I APPARENTLY FORGOT TO INSERT BOLT THAT ATTACHES NOSE GEAR DOOR PUSHRODS TO BRACKETS ON NOSE GEAR. DURING PLEASURE FLT FOLLOWING THIS, THE NOSE GEAR FAILED TO FULLY EXTEND. AFTER 3 1/2 HRS OF EFFORTS TO EXTEND THE NOSE GEAR, A LNDG WAS MADE ON 2 MAINS AND PARTIAL NOSE GEAR RESULTING IN MINIMAL DAMAGE TO THE ACFT. THE CAUSE OF THIS INCIDENT WAS THAT THE PUSHROD BOLT WAS NOT INSTALLED AFTER THE COWLING WAS REPLACED. IF I HAD FOLLOWED MY NORMAL MAINT SOP OF PUTTING UP MY TOOLS AND CLOSING THE TOO CHEST AFTER WORKING ON THE ACFT, I WOULD HAVE NOTICED THE BOLT (UNINSTALLED) LAYING IN THE PARTS BIN. THE NOSE GEAR DOOR APPEARANCE IS IDENTICAL WHETHER THE PUSHROD IS ATTACHED OR NOT. THIS LEAVES IT UNDETECTABLE DURING A WALK-AROUND INSPECTION UNLESS THE DOOR IS PHYSICALLY HANDLED BY THE PERSON DOING INSPECTION. ALSO, SOP'S SHOULD BE STRICTLY ADHERED TO IN MAINT ACTIVITIES.

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.

Mechanic fails to install nose gear door attachment bolt while performing maintenance on own aircraft and discovers the error during the subsequent gear up landing.