Commuter light transport reverse inoperative after maintenance activity.

Attributes
ACN	141766
Time
Date	199003
Day	Sat
Place
Locale Reference	airport : iah airport : lch
State Reference	TX
Altitude	agl bound lower : 0 agl bound upper : 0
Aircraft 1
Controlling Facilities	tower : lbb
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	141766
Person 2
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
Events
Anomaly	aircraft equipment problem : critical non adherence : published procedure
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Airport
Air Traffic Incident	other

Narrative:

On 3/sat/90 aircraft #2 engine's hydromechanical metering unit (hmu) required changing for parameter fluctuations. The hmu is rigged on the bench prior to installation on the engine. After installation on the right-hand engine, the engine run proved to require further rigging of the hmu. After numerous adjustments and engine runs, the hmu was finally rigged, operations and leaked checked good. Maintenance finished the safety wiring of the arm adjustments, cotter pinning of 3 linkage connected to the hmu. I was the rii inspector for the hum work on aircraft right-hand engine inspected the work and signed the work as being complete and satisfactory, approved for return to service. 4/sun/90 aircraft landed at lch. Upon landing the aircraft had no beta light or reverse on the right-hand engine. The aircraft landed west/O any other incident. Maintenance was dispatched from iah to troubleshoot the discrepancy. On inspection of the # engine it was found that the linkage at the hmu to the PCU had come off. It appears that I had missed the cotter pin on the hmu connection. This incident has made me aware of the thoroughness responsibility of the meticulous inspection of any aircraft system or subsys. Only a more strident look at any and all work I am inspecting can assure nothing like this will ever happen in the future.

Original NASA ASRS Text

Title: COMMUTER LTT REVERSE INOPERATIVE AFTER MAINTENANCE ACTIVITY.

Narrative: ON 3/SAT/90 ACFT #2 ENG'S HYDROMECHANICAL METERING UNIT (HMU) REQUIRED CHANGING FOR PARAMETER FLUCTUATIONS. THE HMU IS RIGGED ON THE BENCH PRIOR TO INSTALLATION ON THE ENG. AFTER INSTALLATION ON THE RIGHT-HAND ENG, THE ENG RUN PROVED TO REQUIRE FURTHER RIGGING OF THE HMU. AFTER NUMEROUS ADJUSTMENTS AND ENG RUNS, THE HMU WAS FINALLY RIGGED, OPS AND LEAKED CHKED GOOD. MAINT FINISHED THE SAFETY WIRING OF THE ARM ADJUSTMENTS, COTTER PINNING OF 3 LINKAGE CONNECTED TO THE HMU. I WAS THE RII INSPECTOR FOR THE HUM WORK ON ACFT RIGHT-HAND ENG INSPECTED THE WORK AND SIGNED THE WORK AS BEING COMPLETE AND SATISFACTORY, APPROVED FOR RETURN TO SVC. 4/SUN/90 ACFT LANDED AT LCH. UPON LNDG THE ACFT HAD NO BETA LIGHT OR REVERSE ON THE RIGHT-HAND ENG. THE ACFT LANDED W/O ANY OTHER INCIDENT. MAINT WAS DISPATCHED FROM IAH TO TROUBLESHOOT THE DISCREPANCY. ON INSPECTION OF THE # ENG IT WAS FOUND THAT THE LINKAGE AT THE HMU TO THE PCU HAD COME OFF. IT APPEARS THAT I HAD MISSED THE COTTER PIN ON THE HMU CONNECTION. THIS INCIDENT HAS MADE ME AWARE OF THE THOROUGHNESS RESPONSIBILITY OF THE METICULOUS INSPECTION OF ANY ACFT SYS OR SUBSYS. ONLY A MORE STRIDENT LOOK AT ANY AND ALL WORK I AM INSPECTING CAN ASSURE NOTHING LIKE THIS WILL EVER HAPPEN IN THE FUTURE.

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.