Inspection hatch on engine cowling tore off aircraft in flight.

Attributes
ACN	109907
Time
Date	198904
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : 7d2
State Reference	MI
Altitude	msl bound lower : 2500 msl bound upper : 2500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : det
Operator	general aviation : corporate
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	cruise other
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 160 flight time total : 9000 flight time type : 850
ASRS Report	109907
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	none taken : unable
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

We had just leveled off after departing det (altitude 2500' MSL, 160 KIAS). We were on the second flight of the day. A loud bang was heard and the aircraft shuddered. We reduced airspeed to 130 KTS and checked flight controls. The aircraft felt smooth and responsive. The bang was caused by the right engine inboard accessory inspection hatch separating from the airframe and taking part of the top cowling with it. We returned to pontiac and landed west/O incident. We later discovered that a safety communication had been issued on this subject prior to our taking over operation of this aircraft. The aircraft logs were searched and no mention was made of any compliance with the communication. A copy is included with this report. An FAA form 8010-4 malfunction or defect report was filed by our maintenance indicating that the communication had been complied with based on inspection of the other 3 remaining inspection hatches, all of which were found in need of adjustment. The safety communication does not stress the 'leading edge protruding' into the slipstream enough. The design is poor to start with and the adjacent surfaces and not just the fastener fit adjustment. Fortunately no personal injury or damage was caused.

Original NASA ASRS Text

Title: INSPECTION HATCH ON ENGINE COWLING TORE OFF ACFT IN FLT.

Narrative: WE HAD JUST LEVELED OFF AFTER DEPARTING DET (ALT 2500' MSL, 160 KIAS). WE WERE ON THE SECOND FLT OF THE DAY. A LOUD BANG WAS HEARD AND THE ACFT SHUDDERED. WE REDUCED AIRSPD TO 130 KTS AND CHKED FLT CONTROLS. THE ACFT FELT SMOOTH AND RESPONSIVE. THE BANG WAS CAUSED BY THE RIGHT ENG INBOARD ACCESSORY INSPECTION HATCH SEPARATING FROM THE AIRFRAME AND TAKING PART OF THE TOP COWLING WITH IT. WE RETURNED TO PONTIAC AND LANDED W/O INCIDENT. WE LATER DISCOVERED THAT A SAFETY COMMUNICATION HAD BEEN ISSUED ON THIS SUBJECT PRIOR TO OUR TAKING OVER OPERATION OF THIS ACFT. THE ACFT LOGS WERE SEARCHED AND NO MENTION WAS MADE OF ANY COMPLIANCE WITH THE COMMUNICATION. A COPY IS INCLUDED WITH THIS RPT. AN FAA FORM 8010-4 MALFUNCTION OR DEFECT RPT WAS FILED BY OUR MAINT INDICATING THAT THE COMMUNICATION HAD BEEN COMPLIED WITH BASED ON INSPECTION OF THE OTHER 3 REMAINING INSPECTION HATCHES, ALL OF WHICH WERE FOUND IN NEED OF ADJUSTMENT. THE SAFETY COMMUNICATION DOES NOT STRESS THE 'LEADING EDGE PROTRUDING' INTO THE SLIPSTREAM ENOUGH. THE DESIGN IS POOR TO START WITH AND THE ADJACENT SURFACES AND NOT JUST THE FASTENER FIT ADJUSTMENT. FORTUNATELY NO PERSONAL INJURY OR DAMAGE WAS CAUSED.

Data retrieved from NASA's ASRS site as of August 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.