Commuter mdt failed to comply with minimum equipment list requirement.

Attributes
ACN	133837
Time
Date	199001
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : ase
State Reference	CO
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Transport
Flight Phase	climbout : takeoff ground other : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 5000 flight time type : 2000
ASRS Report	133837
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 155 flight time total : 2700 flight time type : 160
ASRS Report	134466
Events
Anomaly	aircraft equipment problem : less severe non adherence : published procedure
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

Taxiing for departure in aspen, the #3 AC gen hot caution light illuminated. After consulting the MEL and the afm, the gen was switched off-line, deferring and the flight proceeded uneventfully. Reviewing the incident on arrival and after a closer look at the MEL, I found the gen had been deferring in error. MEL did not include a crew procedure for deferring on aircraft gen when only 1 was inoperative, but did include a crew deferrable procedure with 2 inoperative. The aircraft flight manual also contains a procedure to resolve an AC gen hot caution light indication. AC gens with mod XXXX (all our mdt aircraft AC gens have this mod) have a bearing wear detector in addition to a heat detector. Both can turn on the AC gen hot caution light. The procedure determined our situation to be preliminary bearing wear and the gen need not be removed until the end of the flying day. The MEL does not mention the afm procedure. Having gotten involved with the afm procedure, I lost track of the MEL's lack of a crew procedure to defer an AC gen. The mle appears to conflict with itself and is not in agreement with the flight manual.

Original NASA ASRS Text

Title: COMMUTER MDT FAILED TO COMPLY WITH MINIMUM EQUIPMENT LIST REQUIREMENT.

Narrative: TAXIING FOR DEP IN ASPEN, THE #3 AC GEN HOT CAUTION LIGHT ILLUMINATED. AFTER CONSULTING THE MEL AND THE AFM, THE GEN WAS SWITCHED OFF-LINE, DEFERRING AND THE FLT PROCEEDED UNEVENTFULLY. REVIEWING THE INCIDENT ON ARR AND AFTER A CLOSER LOOK AT THE MEL, I FOUND THE GEN HAD BEEN DEFERRING IN ERROR. MEL DID NOT INCLUDE A CREW PROC FOR DEFERRING ON ACFT GEN WHEN ONLY 1 WAS INOP, BUT DID INCLUDE A CREW DEFERRABLE PROC WITH 2 INOP. THE ACFT FLT MANUAL ALSO CONTAINS A PROC TO RESOLVE AN AC GEN HOT CAUTION LIGHT INDICATION. AC GENS WITH MOD XXXX (ALL OUR MDT ACFT AC GENS HAVE THIS MOD) HAVE A BEARING WEAR DETECTOR IN ADDITION TO A HEAT DETECTOR. BOTH CAN TURN ON THE AC GEN HOT CAUTION LIGHT. THE PROC DETERMINED OUR SITUATION TO BE PRELIMINARY BEARING WEAR AND THE GEN NEED NOT BE REMOVED UNTIL THE END OF THE FLYING DAY. THE MEL DOES NOT MENTION THE AFM PROC. HAVING GOTTEN INVOLVED WITH THE AFM PROC, I LOST TRACK OF THE MEL'S LACK OF A CREW PROC TO DEFER AN AC GEN. THE MLE APPEARS TO CONFLICT WITH ITSELF AND IS NOT IN AGREEMENT WITH THE FLT MANUAL.

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.