Mechanic describes how his efforts to meet a turn around departure schedule contributed to his installing the wrong air data computer (air data computer); even though the amm test procedure passed on a B757-200 aircraft.

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Attributes
ACN	788029
Time
Date	200805
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Aircraft 1
Controlling Facilities	tower : lax.tower
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	ground : parked ground : preflight
Person 1
Affiliation	company : air carrier
Function	maintenance : technician
Qualification	technician : powerplant technician : airframe
ASRS Report	788029
Events
Anomaly	aircraft equipment problem : less severe maintenance problem : improper maintenance non adherence : published procedure non adherence : far
Independent Detector	other other : 1
Resolutory Action	none taken : detected after the fact
Consequence	other
Factors
Maintenance	contributing factor : schedule pressure contributing factor : manuals performance deficiency : non compliance with legal requirements performance deficiency : testing
Supplementary
Problem Areas	Environmental Factor Maintenance Human Performance Aircraft Chart Or Publication
Primary Problem	Maintenance Human Performance

Narrative:

Events to the best of my knowledge: aircraft X arrived on ferry flight. Aircraft ferried with open maintenance item X. Captain's airspeed indicator reads 60 KTS not moving; aircraft copilot's was 90 KTS and increasing. Aircraft also required daily check; had additional write-up on left wing navigation light and what was thought to be damage by jetway. Operations wanted aircraft turned in approximately 30 mins. In the rush of things; I installed wrong air data computer. Wrong effectivity; should have been Y. Although wrong effectivity installed; a complete check was accomplished in accordance with amm with no faults indicated. Part was subsequently changed with correct one. Aircraft records/quality assurance discovered. I should not have felt pressure to get aircraft out. Had I slowed down and took time to verify part number; this could have been avoided. Also; I was multi-tasking; had more than 1 thing at a time on my mind; with the additional work on aircraft.

Original NASA ASRS Text

Title: MECHANIC DESCRIBES HOW HIS EFFORTS TO MEET A TURN AROUND DEPARTURE SCHEDULE CONTRIBUTED TO HIS INSTALLING THE WRONG AIR DATA COMPUTER (ADC); EVEN THOUGH THE AMM TEST PROCEDURE PASSED ON A B757-200 ACFT.

Narrative: EVENTS TO THE BEST OF MY KNOWLEDGE: ACFT X ARRIVED ON FERRY FLT. ACFT FERRIED WITH OPEN MAINT ITEM X. CAPT'S AIRSPD INDICATOR READS 60 KTS NOT MOVING; ACFT COPLT'S WAS 90 KTS AND INCREASING. ACFT ALSO REQUIRED DAILY CHK; HAD ADDITIONAL WRITE-UP ON L WING NAV LIGHT AND WHAT WAS THOUGHT TO BE DAMAGE BY JETWAY. OPS WANTED ACFT TURNED IN APPROX 30 MINS. IN THE RUSH OF THINGS; I INSTALLED WRONG ADC. WRONG EFFECTIVITY; SHOULD HAVE BEEN Y. ALTHOUGH WRONG EFFECTIVITY INSTALLED; A COMPLETE CHK WAS ACCOMPLISHED IN ACCORDANCE WITH AMM WITH NO FAULTS INDICATED. PART WAS SUBSEQUENTLY CHANGED WITH CORRECT ONE. ACFT RECORDS/QUALITY ASSURANCE DISCOVERED. I SHOULD NOT HAVE FELT PRESSURE TO GET ACFT OUT. HAD I SLOWED DOWN AND TOOK TIME TO VERIFY PART NUMBER; THIS COULD HAVE BEEN AVOIDED. ALSO; I WAS MULTI-TASKING; HAD MORE THAN 1 THING AT A TIME ON MY MIND; WITH THE ADDITIONAL WORK ON ACFT.

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.