Engine cowl came loose and hit helicopter rotor blade.

Attributes
ACN	99333
Time
Date	198812
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : gls
State Reference	TX
Altitude	agl bound lower : 0 agl bound upper : 900
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air taxi
Make Model Name	Helicopter
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	company : air taxi
Function	flight crew : single pilot
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 6000 flight time type : 200
ASRS Report	99333
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	none taken : unable none taken : detected after the fact other
Consequence	other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

During the second leg of a 1+40 offshore flight, I had been circling a platform (right turn) 10 mins awaiting a helicopter that was refueling to depart so that I could land. I received a call to go to another platform for a passenger pickup. I rolled into a left turn to head for the other platform when I felt a sudden vibration of about 2 seconds duration. Immediately, I turned back to the first platform to land. The refueling aircraft was departing. Landing was uneventful. Post flight inspection revealed that the left hand engine cowling had opened in flight striking the rotor blades. Both latches were missing off the cowling. The rotor blades were scratched but repairable. These older cowling latches have a reputation for failing. We've had one previous fall off an aircraft. Post-flight revealed a cracked latch on the left side transmission cowling. There is an improved version latch made. We've had these latches back-ordered for 7 months. Manufacturer needs to increase production to get these latches to the operators.

Original NASA ASRS Text

Title: ENGINE COWL CAME LOOSE AND HIT HELICOPTER ROTOR BLADE.

Narrative: DURING THE SECOND LEG OF A 1+40 OFFSHORE FLT, I HAD BEEN CIRCLING A PLATFORM (RIGHT TURN) 10 MINS AWAITING A HELI THAT WAS REFUELING TO DEPART SO THAT I COULD LAND. I RECEIVED A CALL TO GO TO ANOTHER PLATFORM FOR A PAX PICKUP. I ROLLED INTO A LEFT TURN TO HEAD FOR THE OTHER PLATFORM WHEN I FELT A SUDDEN VIBRATION OF ABOUT 2 SECS DURATION. IMMEDIATELY, I TURNED BACK TO THE FIRST PLATFORM TO LAND. THE REFUELING ACFT WAS DEPARTING. LNDG WAS UNEVENTFUL. POST FLT INSPECTION REVEALED THAT THE LEFT HAND ENG COWLING HAD OPENED IN FLT STRIKING THE ROTOR BLADES. BOTH LATCHES WERE MISSING OFF THE COWLING. THE ROTOR BLADES WERE SCRATCHED BUT REPAIRABLE. THESE OLDER COWLING LATCHES HAVE A REPUTATION FOR FAILING. WE'VE HAD ONE PREVIOUS FALL OFF AN ACFT. POST-FLT REVEALED A CRACKED LATCH ON THE LEFT SIDE XMISSION COWLING. THERE IS AN IMPROVED VERSION LATCH MADE. WE'VE HAD THESE LATCHES BACK-ORDERED FOR 7 MONTHS. MANUFACTURER NEEDS TO INCREASE PRODUCTION TO GET THESE LATCHES TO THE OPERATORS.

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.