A mechanic reports about a B737-300 air turnback after hanger maintenance due to captain's airspeed ...

Attributes
ACN	843984
Time
Date	200906
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	Parked
Component
Aircraft Component	Air Data Computer
Person 1
Function	Technician
Qualification	Maintenance Airframe Maintenance Powerplant
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Procedural FAR Deviation - Procedural Maintenance Deviation - Procedural Published Material / Policy

Narrative:

Aircraft originated flight after hangar maintenance. Flight had air return; due to captain's airspeed abnormalities. I found the quick disconnect loose on #1 air data computer. I reconnected loose line and checked others for security. I then tested the #1 air data computer and pitot system per amm. I failed to recall our new maintenance procedures manual (mpm) section that requires a CAT III upgrade for any write-up or maintenance action that affects a CAT III system. I thought; that since the unit was not removed; a CAT III upgrade was not necessary. I feel that particular phrase should be emphasized more in our training. Aircraft was CAT III upgraded at a later date.

Original NASA ASRS Text

Title: A Mechanic reports about a B737-300 Air Turnback after hanger Maintenance due to Captain's Airspeed abnormalities. Quick disconnect hose found loose on # 1 ADC. Mechanic was informed later he failed to upgrade the aircraft to a Category-III Status.

Narrative: Aircraft originated flight after Hangar Maintenance. Flight had Air Return; due to Captain's Airspeed abnormalities. I found the Quick Disconnect loose on #1 ADC. I reconnected loose line and checked others for security. I then tested the #1 ADC and Pitot System Per AMM. I failed to recall our new Maintenance Procedures Manual (MPM) section that requires a CAT III upgrade for any write-up or maintenance action that affects a CAT III system. I thought; that since the unit was not removed; a CAT III upgrade was not necessary. I feel that particular phrase should be emphasized more in our training. Aircraft was CAT III upgraded at a later date.

Data retrieved from NASA's ASRS site as of April 2012 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 mechanic reports about a B737-300 air turnback after hanger maintenance due to captain's airspeed abnormalities. Quick disconnect hose found loose on # 1 air data computer. Mechanic was informed later he failed to upgrade the aircraft to a category-III status.