Mechanic is informed the B757-200 aircraft he previously worked; would not pressurize and required a...

Attributes
ACN	806377
Time
Date	200807
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	ground : maintenance
Person 1
Affiliation	company : air carrier
Function	maintenance : technician
ASRS Report	806377
Person 2
Affiliation	company : air carrier
Function	oversight : supervisor
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper maintenance non adherence : far non adherence : published procedure
Independent Detector	other other : 2
Resolutory Action	flight crew : diverted to another airport
Consequence	other
Factors
Maintenance	contributing factor : work cards contributing factor : briefing performance deficiency : repair performance deficiency : non compliance with legal requirements performance deficiency : inspection
Supplementary
Problem Areas	Aircraft Maintenance Human Performance
Primary Problem	Maintenance Human Performance

Narrative:

I was informed by management that aircraft X had an air turn-back in july because it was unable to pressurize. I came in on early call and was told to change out the nose gear steering valve that had already been started. The cover (panel) over the nose gear steering valve ahd been partially removed when I took over the job. I finished removing the cover (panel) and found that the towing bypass lever was sticking. Myself and another amt replaced the seals on the bypass lever and operations check leak check ok. I reinstalled the cover (panel) over the nose gear steering valve and signed off the open items on the write-up. I misunderstood that the nose gear steering valve cover (panel) that I found partially removed and reinstalled was the one that was written up on the write-up. The actual panel that was partially removed is in the forward l-hand side of the nosewheel well. There was no maintenance manual reference paperwork to show a location of this panel. Not thinking that a panel so far away from the problem with the steering valve was partially removed I signed off the nose gear steering valve cover (panel) thinking that this was the panel written on the write-up. When panels are partially removed there should be a maintenance manual picture showing the location of what panels are removed or partially removed. This will avoid confusion when signing off the work. I will pay more attention to the items that are written up on write-ups and will look up in the maintenance manual and items in question to avoid confusion in the future. Callback conversation with reporter revealed the following information: reporter stated he was called in on early overtime. Their normal shift had not started; so he did not have a lead. The turnover given to the on-shift supervisor and then relayed to him seems to be where the misunderstanding about a partially removed panel on their maintenance write-up began. Reporter stated their leads usually enter the maintenance and signoff data in their maintenance aircraft history and logbook. He believes if one of the leads was on duty; they may have caught the discrepancy in the signoff of the maintenance write-up.

Original NASA ASRS Text

Title: MECHANIC IS INFORMED THE B757-200 ACFT HE PREVIOUSLY WORKED; WOULD NOT PRESSURIZE AND REQUIRED AN AIR TURNBACK. A FORWARD LEFT HAND NOSE WHEEL WELL BULKHEAD PANEL WAS NOT FULLY SECURED.

Narrative: I WAS INFORMED BY MGMNT THAT ACFT X HAD AN AIR TURN-BACK IN JULY BECAUSE IT WAS UNABLE TO PRESSURIZE. I CAME IN ON EARLY CALL AND WAS TOLD TO CHANGE OUT THE NOSE GEAR STEERING VALVE THAT HAD ALREADY BEEN STARTED. THE COVER (PANEL) OVER THE NOSE GEAR STEERING VALVE AHD BEEN PARTIALLY REMOVED WHEN I TOOK OVER THE JOB. I FINISHED REMOVING THE COVER (PANEL) AND FOUND THAT THE TOWING BYPASS LEVER WAS STICKING. MYSELF AND ANOTHER AMT REPLACED THE SEALS ON THE BYPASS LEVER AND OPS CHK LEAK CHK OK. I REINSTALLED THE COVER (PANEL) OVER THE NOSE GEAR STEERING VALVE AND SIGNED OFF THE OPEN ITEMS ON THE WRITE-UP. I MISUNDERSTOOD THAT THE NOSE GEAR STEERING VALVE COVER (PANEL) THAT I FOUND PARTIALLY REMOVED AND REINSTALLED WAS THE ONE THAT WAS WRITTEN UP ON THE WRITE-UP. THE ACTUAL PANEL THAT WAS PARTIALLY REMOVED IS IN THE FORWARD L-HAND SIDE OF THE NOSEWHEEL WELL. THERE WAS NO MAINT MANUAL REF PAPERWORK TO SHOW A LOCATION OF THIS PANEL. NOT THINKING THAT A PANEL SO FAR AWAY FROM THE PROB WITH THE STEERING VALVE WAS PARTIALLY REMOVED I SIGNED OFF THE NOSE GEAR STEERING VALVE COVER (PANEL) THINKING THAT THIS WAS THE PANEL WRITTEN ON THE WRITE-UP. WHEN PANELS ARE PARTIALLY REMOVED THERE SHOULD BE A MAINT MANUAL PICTURE SHOWING THE LOCATION OF WHAT PANELS ARE REMOVED OR PARTIALLY REMOVED. THIS WILL AVOID CONFUSION WHEN SIGNING OFF THE WORK. I WILL PAY MORE ATTN TO THE ITEMS THAT ARE WRITTEN UP ON WRITE-UPS AND WILL LOOK UP IN THE MAINT MANUAL AND ITEMS IN QUESTION TO AVOID CONFUSION IN THE FUTURE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED HE WAS CALLED IN ON EARLY OVERTIME. THEIR NORMAL SHIFT HAD NOT STARTED; SO HE DID NOT HAVE A LEAD. THE TURNOVER GIVEN TO THE ON-SHIFT SUPERVISOR AND THEN RELAYED TO HIM SEEMS TO BE WHERE THE MISUNDERSTANDING ABOUT A PARTIALLY REMOVED PANEL ON THEIR MAINT WRITE-UP BEGAN. REPORTER STATED THEIR LEADS USUALLY ENTER THE MAINT AND SIGNOFF DATA IN THEIR MAINT ACFT HISTORY AND LOGBOOK. HE BELIEVES IF ONE OF THE LEADS WAS ON DUTY; THEY MAY HAVE CAUGHT THE DISCREPANCY IN THE SIGNOFF OF THE MAINT WRITE-UP.

Data retrieved from NASA's ASRS site as of May 2009 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 is informed the B757-200 aircraft he previously worked; would not pressurize and required an air turnback. A forward left hand nose wheel well bulkhead panel was not fully secured.