A B737-700 aircraft two each nose tire replacement were found to be a mismatch of one bias tire and ...

Attributes
ACN	749911
Time
Date	200708
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Person 1
Affiliation	company : air carrier
Function	maintenance : technician
Qualification	technician : powerplant technician : airframe
ASRS Report	749911
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 other anomaly other
Resolutory Action	none taken : detected after the fact
Consequence	other
Factors
Maintenance	contributing factor : briefing performance deficiency : scheduled maintenance performance deficiency : installation performance deficiency : non compliance with legal requirements
Supplementary
Problem Areas	Company Maintenance Human Performance Aircraft
Primary Problem	Maintenance Human Performance
Situations
Publication	Stores IPC Tire Pins

Narrative:

Aircraft (cabin visit) needed 2 new nose tires. The nose tires on it were worn out. I walked and picked up 2 new tires. I rolled both items to the aircraft (-700 tires). Both tires I picked up from the same row. I proceeded to change the right side nose tires with no problem. I started to prepare the left side nose tire when I saw it wasn't svcable yet. It doesn't have ZZZ svcable parts tag. So I rolled it back to the tire rack. I put the tire aside and separated it from the svcable ones. I picked up another tire that's from the same row where I picked up both tires earlier. I proceeded then; to change the left side tire; not knowing it was different from the right side tire. The part numbers were the same on both tires. I was notified by supervisor that they suspected aircraft nose tires were a mix (radial and bias). ZZZ maintenance changed both tires at that point to the proper match. Upon my recollection; I might put on mixed tires that night.

Original NASA ASRS Text

Title: A B737-700 ACFT TWO EACH NOSE TIRE REPLACEMENT WERE FOUND TO BE A MISMATCH OF ONE BIAS TIRE AND ONE RADIAL TIRE.

Narrative: ACFT (CABIN VISIT) NEEDED 2 NEW NOSE TIRES. THE NOSE TIRES ON IT WERE WORN OUT. I WALKED AND PICKED UP 2 NEW TIRES. I ROLLED BOTH ITEMS TO THE ACFT (-700 TIRES). BOTH TIRES I PICKED UP FROM THE SAME ROW. I PROCEEDED TO CHANGE THE R SIDE NOSE TIRES WITH NO PROB. I STARTED TO PREPARE THE L SIDE NOSE TIRE WHEN I SAW IT WASN'T SVCABLE YET. IT DOESN'T HAVE ZZZ SVCABLE PARTS TAG. SO I ROLLED IT BACK TO THE TIRE RACK. I PUT THE TIRE ASIDE AND SEPARATED IT FROM THE SVCABLE ONES. I PICKED UP ANOTHER TIRE THAT'S FROM THE SAME ROW WHERE I PICKED UP BOTH TIRES EARLIER. I PROCEEDED THEN; TO CHANGE THE L SIDE TIRE; NOT KNOWING IT WAS DIFFERENT FROM THE R SIDE TIRE. THE PART NUMBERS WERE THE SAME ON BOTH TIRES. I WAS NOTIFIED BY SUPVR THAT THEY SUSPECTED ACFT NOSE TIRES WERE A MIX (RADIAL AND BIAS). ZZZ MAINT CHANGED BOTH TIRES AT THAT POINT TO THE PROPER MATCH. UPON MY RECOLLECTION; I MIGHT PUT ON MIXED TIRES THAT NIGHT.

Data retrieved from NASA's ASRS site as of January 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.

A B737-700 aircraft two each nose tire replacement were found to be a mismatch of one bias tire and one radial tire.