MEL requirement deficiency at flight crew interpretation of MEL allows unauthorized operation of air...

Attributes
ACN	183911
Time
Date	199107
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : ewr
State Reference	NJ
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Transport, High Wing, 2 Turboprop Eng
Navigation In Use	Other Other
Flight Phase	ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : commercial pilot : instrument
Experience	flight time last 90 days : 230 flight time total : 2700 flight time type : 230
ASRS Report	183911
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe non adherence : published procedure non adherence : far
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

We erroneously believed that the aircraft had a waiver for operation without the slip/skid indicator and operated the aircraft without same. We had been removed when two CRT's had been swapped out, which they did. The indicators are installed at the base of CRT's. We later discovered that the MEL required at least one indicator in the aircraft. A more careful reading of the MEL might have prevented the problem.

Original NASA ASRS Text

Title: MEL REQUIREMENT DEFICIENCY AT FLC INTERP OF MEL ALLOWS UNAUTHORIZED OPERATION OF ACFT.

Narrative: WE ERRONEOUSLY BELIEVED THAT THE ACFT HAD A WAIVER FOR OPERATION WITHOUT THE SLIP/SKID INDICATOR AND OPERATED THE ACFT WITHOUT SAME. WE HAD BEEN REMOVED WHEN TWO CRT'S HAD BEEN SWAPPED OUT, WHICH THEY DID. THE INDICATORS ARE INSTALLED AT THE BASE OF CRT'S. WE LATER DISCOVERED THAT THE MEL REQUIRED AT LEAST ONE INDICATOR IN THE ACFT. A MORE CAREFUL READING OF THE MEL MIGHT HAVE PREVENTED THE PROB.

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.

MEL requirement deficiency at flight crew interpretation of MEL allows unauthorized operation of aircraft.