First officer conducting walkaround inspection of an air carrier medium large transport discovered a...

Attributes
ACN	181588
Time
Date	199106
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sjd
State Reference	FO
Altitude	agl bound lower : 0 agl bound upper : 0
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 8000
ASRS Report	181588
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

During my initial preflight inspection, I found the tailcone catwalk jammed in the up position. Maintenance was called and the problem was fixed. A small roller bearing, between the 2 fairings on the left side of the catwalk, that pushes the fwd fairing in when the catwalk raises up, popped to the wrong side of the fwd fairing. I moved the fairing by hand to simulate the raising of the catwalk and the roller popped out again. I popped it back in and raised and lowered the catwalk many times and it operated normally. The aircraft is less than 6 months old and none of the parts are worn or bent, and it is not any different than any of our other aircraft. It is my opinion that this is a poor design and this problem could easily happen on an medium large transport of this make and model at any time. Had this happened on a through flight (the tail compartment is not normally inspected on a through flight), it may have gone unnoticed, and if an emergency occurred that exit would be unusable.

Original NASA ASRS Text

Title: FIRST OFFICER CONDUCTING WALKAROUND INSPECTION OF AN ACR MLG DISCOVERED A PROBLEM WITH THE MECHANISM OF THE TAIL CONE EMERGENCY EXIT. NOTING THAT THE ACFT IS ONLY 6 MONTHS OLD, THE REPORTER ALLEGES THAT THE MECHANISM DESIGN MAY BE DEFECTIVE.

Narrative: DURING MY INITIAL PREFLT INSPECTION, I FOUND THE TAILCONE CATWALK JAMMED IN THE UP POS. MAINT WAS CALLED AND THE PROB WAS FIXED. A SMALL ROLLER BEARING, BTWN THE 2 FAIRINGS ON THE LEFT SIDE OF THE CATWALK, THAT PUSHES THE FWD FAIRING IN WHEN THE CATWALK RAISES UP, POPPED TO THE WRONG SIDE OF THE FWD FAIRING. I MOVED THE FAIRING BY HAND TO SIMULATE THE RAISING OF THE CATWALK AND THE ROLLER POPPED OUT AGAIN. I POPPED IT BACK IN AND RAISED AND LOWERED THE CATWALK MANY TIMES AND IT OPERATED NORMALLY. THE ACFT IS LESS THAN 6 MONTHS OLD AND NONE OF THE PARTS ARE WORN OR BENT, AND IT IS NOT ANY DIFFERENT THAN ANY OF OUR OTHER ACFT. IT IS MY OPINION THAT THIS IS A POOR DESIGN AND THIS PROB COULD EASILY HAPPEN ON AN MLG OF THIS MAKE AND MODEL AT ANY TIME. HAD THIS HAPPENED ON A THROUGH FLT (THE TAIL COMPARTMENT IS NOT NORMALLY INSPECTED ON A THROUGH FLT), IT MAY HAVE GONE UNNOTICED, AND IF AN EMER OCCURRED THAT EXIT WOULD BE UNUSABLE.

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.

First officer conducting walkaround inspection of an air carrier medium large transport discovered a problem with the mechanism of the tail cone emergency exit. Noting that the aircraft is only 6 months old, the reporter alleges that the mechanism design may be defective.