A B747 on takeoff lost a large pylon panel that was not correctly installed and fastened.

Attributes
ACN	351528
Time
Date	199610
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz
State Reference	US
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B747-400
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	351528
Person 2
Affiliation	Other
Function	other personnel other
Qualification	other other : other
ASRS Report	351413
Events
Anomaly	aircraft equipment problem : critical non adherence : published procedure non adherence : far other anomaly other
Independent Detector	other other : unspecified
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

Aircraft departed dtw on oct/xx/96. On takeoff a passenger noted a large panel departed the aircraft. The aircraft continued to YYY. The pilot determined that the missing panel did not affect flight characteristics. The afternoon lead mechanic had instructed 2 mechanics to install the panel over #1 engine pylon. The aircraft was pushed out of the hangar and the lead thought the panel was installed and signed the work card.

Original NASA ASRS Text

Title: A B747 ON TKOF LOST A LARGE PYLON PANEL THAT WAS NOT CORRECTLY INSTALLED AND FASTENED.

Narrative: ACFT DEPARTED DTW ON OCT/XX/96. ON TKOF A PAX NOTED A LARGE PANEL DEPARTED THE ACFT. THE ACFT CONTINUED TO YYY. THE PLT DETERMINED THAT THE MISSING PANEL DID NOT AFFECT FLT CHARACTERISTICS. THE AFTERNOON LEAD MECH HAD INSTRUCTED 2 MECHS TO INSTALL THE PANEL OVER #1 ENG PYLON. THE ACFT WAS PUSHED OUT OF THE HANGAR AND THE LEAD THOUGHT THE PANEL WAS INSTALLED AND SIGNED THE WORK CARD.

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.