Rotary winged aircraft loses engine cowling while descending to helipad on first flight of the day.

Attributes
ACN	149095
Time
Date	199006
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : bed
State Reference	MA
Altitude	msl bound lower : 1500 msl bound upper : 2200
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : bed
Operator	common carrier : air taxi
Make Model Name	Helicopter
Flight Phase	cruise other descent other
Route In Use	approach : visual arrival other
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument pilot : commercial pilot : cfi
Experience	flight time last 90 days : 90 flight time total : 4500 flight time type : 800
ASRS Report	149095
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
Events
Anomaly	aircraft equipment problem : critical non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	other other

Narrative:

After washing helicopter and preflting, I departed minuteman airfield at am:50 for our boxboro helipad. I had our agent load 3 passenger. I departed boxboro at am:00 for burlington. At approximately am:12 I was descending out of 2200' MSL when the aircraft began to shake. At 1500' MSL, roughly 15 seconds, a loud bang was heard and the helicopter stopped shaking. During the shaking my attention was inside the aircraft for any sign of engine or transmission problems. All indications were fine. I was already in a descent with my helipad in sight. I continued to the pad where I got out to board my passenger. As I looked at the helicopter, it was very apparent that the pilot side engine cowling had departed the aircraft. I shut down and called maintenance.

Original NASA ASRS Text

Title: ROTARY WINGED ACFT LOSES ENGINE COWLING WHILE DESCENDING TO HELIPAD ON FIRST FLT OF THE DAY.

Narrative: AFTER WASHING HELI AND PREFLTING, I DEPARTED MINUTEMAN AIRFIELD AT AM:50 FOR OUR BOXBORO HELIPAD. I HAD OUR AGENT LOAD 3 PAX. I DEPARTED BOXBORO AT AM:00 FOR BURLINGTON. AT APPROX AM:12 I WAS DSNDING OUT OF 2200' MSL WHEN THE ACFT BEGAN TO SHAKE. AT 1500' MSL, ROUGHLY 15 SECS, A LOUD BANG WAS HEARD AND THE HELI STOPPED SHAKING. DURING THE SHAKING MY ATTN WAS INSIDE THE ACFT FOR ANY SIGN OF ENG OR XMISSION PROBS. ALL INDICATIONS WERE FINE. I WAS ALREADY IN A DSNT WITH MY HELIPAD IN SIGHT. I CONTINUED TO THE PAD WHERE I GOT OUT TO BOARD MY PAX. AS I LOOKED AT THE HELI, IT WAS VERY APPARENT THAT THE PLT SIDE ENG COWLING HAD DEPARTED THE ACFT. I SHUT DOWN AND CALLED MAINT.

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.