A B737-300 incurred a delay when it was discovered a B737-200 nose tire was inadvertently installed.

Attributes
ACN	444879
Time
Date	199907
Day	Fri
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Environment
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	ground : maintenance ground : parked
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	maintenance : technician
Qualification	technician : airframe technician : powerplant
Experience	maintenance technician : 16
ASRS Report	444879
Person 2
Affiliation	company : air carrier
Function	maintenance : technician
Qualification	technician : powerplant technician : airframe
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper maintenance non adherence : published procedure non adherence : far
Consequence	other
Factors
Maintenance	contributing factor : schedule pressure contributing factor : lighting performance deficiency : installation performance deficiency : unqualified personnel performance deficiency : training
Supplementary
Problem Areas	Maintenance Human Performance Aircraft
Primary Problem	Maintenance Human Performance

Narrative:

On jul/xa/99, while working my regular shift at air carrier in ZZZ, I was involved in a safety infraction. I was working by myself on a B737-300 and found it necessary to change a main tire and a nose tire. Having done the main I went on to change the nose tire, at which time I inadvertently placed a B737-200 tire on the airplane. Fortunately this fault was noted by another mechanic before the plane left the gate and nothing other than a flight delay occurred. I would cite unfamiliarity with the task, fatigue, and haste as the primary factors contributing to this event. I am new to the line environment and had not changed a nose tire on this particular airplane before. Having the knowledge that the main tires are interchangeable, I then made the false assumption (or just plain forgot) that this was not also the case with the nose tire. Fatigue played a role as I had not slept prior to this event for a period of time approaching 22 hours. Given the poor lighting at that time of night, I didn't observe the discrepancy prior to proceeding.

Original NASA ASRS Text

Title: A B737-300 INCURRED A DELAY WHEN IT WAS DISCOVERED A B737-200 NOSE TIRE WAS INADVERTENTLY INSTALLED.

Narrative: ON JUL/XA/99, WHILE WORKING MY REGULAR SHIFT AT ACR IN ZZZ, I WAS INVOLVED IN A SAFETY INFRACTION. I WAS WORKING BY MYSELF ON A B737-300 AND FOUND IT NECESSARY TO CHANGE A MAIN TIRE AND A NOSE TIRE. HAVING DONE THE MAIN I WENT ON TO CHANGE THE NOSE TIRE, AT WHICH TIME I INADVERTENTLY PLACED A B737-200 TIRE ON THE AIRPLANE. FORTUNATELY THIS FAULT WAS NOTED BY ANOTHER MECH BEFORE THE PLANE LEFT THE GATE AND NOTHING OTHER THAN A FLT DELAY OCCURRED. I WOULD CITE UNFAMILIARITY WITH THE TASK, FATIGUE, AND HASTE AS THE PRIMARY FACTORS CONTRIBUTING TO THIS EVENT. I AM NEW TO THE LINE ENVIRONMENT AND HAD NOT CHANGED A NOSE TIRE ON THIS PARTICULAR AIRPLANE BEFORE. HAVING THE KNOWLEDGE THAT THE MAIN TIRES ARE INTERCHANGEABLE, I THEN MADE THE FALSE ASSUMPTION (OR JUST PLAIN FORGOT) THAT THIS WAS NOT ALSO THE CASE WITH THE NOSE TIRE. FATIGUE PLAYED A ROLE AS I HAD NOT SLEPT PRIOR TO THIS EVENT FOR A PERIOD OF TIME APCHING 22 HRS. GIVEN THE POOR LIGHTING AT THAT TIME OF NIGHT, I DIDN'T OBSERVE THE DISCREPANCY PRIOR TO PROCEEDING.

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.