Reporter confesses inadvertently utilizing improper deferral procedures.

Attributes
ACN	286404
Time
Date	199410
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : dtw
State Reference	MI
Altitude	agl bound lower : 0 agl bound upper : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Dash 8-100
Operating Under FAR Part	Part 121
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	286404
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	non adherence : published procedure other anomaly other
Independent Detector	other other : unspecified
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

The pilot of a dash 8-102 aircraft wrote up the APU vent door stuck open. I went to the aircraft and discovered the vent door dampener at fault. It was determined that we had zero in stock. After consulting with maintenance control, and my supervisor, it was thought this vent door (located on the aft fuselage belly access door) was only opened and closed when selecting the APU bleed air on. I closed the door by hand and verified it stayed closed. I went ahead and deferred the APU bleed air. After more discussion with our maintenance control supervisor, the aircraft was then allowed to taxi out. In the meantime, our technical representative was consulted and it was then discovered this door could open (only on the ground) if the heat exchangers required more cooling. The aircraft was brought back to the gate never having flown, and a part was cannibalized from another aircraft, thus, the deferral was cleared. This aircraft was in a 'quick-turn' status which may have affected extensive trouble-shooting time. Since then I have been properly recurrently trained on proper deferral procedures and trouble- shooting system and interrelationships with other system. This item used to be on our cdl list and is on dehavilland's master MEL list. It's been recently removed from ours.

Original NASA ASRS Text

Title: RPTR CONFESSES INADVERTENTLY UTILIZING IMPROPER DEFERRAL PROCS.

Narrative: THE PLT OF A DASH 8-102 ACFT WROTE UP THE APU VENT DOOR STUCK OPEN. I WENT TO THE ACFT AND DISCOVERED THE VENT DOOR DAMPENER AT FAULT. IT WAS DETERMINED THAT WE HAD ZERO IN STOCK. AFTER CONSULTING WITH MAINT CTL, AND MY SUPVR, IT WAS THOUGHT THIS VENT DOOR (LOCATED ON THE AFT FUSELAGE BELLY ACCESS DOOR) WAS ONLY OPENED AND CLOSED WHEN SELECTING THE APU BLEED AIR ON. I CLOSED THE DOOR BY HAND AND VERIFIED IT STAYED CLOSED. I WENT AHEAD AND DEFERRED THE APU BLEED AIR. AFTER MORE DISCUSSION WITH OUR MAINT CTL SUPVR, THE ACFT WAS THEN ALLOWED TO TAXI OUT. IN THE MEANTIME, OUR TECHNICAL REPRESENTATIVE WAS CONSULTED AND IT WAS THEN DISCOVERED THIS DOOR COULD OPEN (ONLY ON THE GND) IF THE HEAT EXCHANGERS REQUIRED MORE COOLING. THE ACFT WAS BROUGHT BACK TO THE GATE NEVER HAVING FLOWN, AND A PART WAS CANNIBALIZED FROM ANOTHER ACFT, THUS, THE DEFERRAL WAS CLRED. THIS ACFT WAS IN A 'QUICK-TURN' STATUS WHICH MAY HAVE AFFECTED EXTENSIVE TROUBLE-SHOOTING TIME. SINCE THEN I HAVE BEEN PROPERLY RECURRENTLY TRAINED ON PROPER DEFERRAL PROCS AND TROUBLE- SHOOTING SYS AND INTERRELATIONSHIPS WITH OTHER SYS. THIS ITEM USED TO BE ON OUR CDL LIST AND IS ON DEHAVILLAND'S MASTER MEL LIST. IT'S BEEN RECENTLY REMOVED FROM OURS.

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.