Narrative:

Shortly after takeoff on runway 33 at bur, I noticed an unusual airframe vibration (around 75-100 ft vertical), while in a left 30 degree angle of bank turn, passing through 1500 ft MSL. As it was still dark, I was unable to see much outside the cockpit. I leveled the wings and upon being able to see the silhouette of the right engine against the city lights below, noted that the right engine cowling was open or loose and moving vigorously in the slipstream. I immediately reduced power and leveled the aircraft. This stopped the cowling from moving. I was roughly on a downwind for runway 33 at this time and lowered the gear and completed landing checks. At this time I also experienced transmitter difficulties. The heads-up tower controller suspected a problem and cleared me to land on runway 33. Landing was uneventful, however, on rollout as I applied reverse thrust, the cowling again began to move vigorously. I came out of reverse and coasted to the end of the runway, applying gentle braking. The cowling was still attached and not moving at idle power, so I taxied back to the hangar. Upon shutdown, the ground crew noted a significant fuel leak from a line which had been cut by the flapping motion of the cowling, which could have resulted in an engine fire at any stage of the flight. While closing the cowling on preflight, I may have been distraction by the fueler asking for verification of the amount on the right side while closing the latch. Also, I had a small degree of difficulty catching the forward latch and suspect that the combination resulted in not ensuring the aft latch hook was properly engaged. Older and wiser, I now ensure multiple inspection of all latches opened and/or closed on preflight.

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Original NASA ASRS Text

Title: R COWLING BECAME LOOSE AFTER TKOF CAUSING AIRFRAME VIBRATION. UNABLE TO CONTACT TWR DUE TO XMITTER PROB, PLT CONTINUED ON DOWNWIND WHEREUPON AN ALERT TWR OPERATOR SUSPECTED PROBS AND CLRED HIM FOR AN UNEVENTFUL LNDG.

Narrative: SHORTLY AFTER TKOF ON RWY 33 AT BUR, I NOTICED AN UNUSUAL AIRFRAME VIBRATION (AROUND 75-100 FT VERT), WHILE IN A L 30 DEG ANGLE OF BANK TURN, PASSING THROUGH 1500 FT MSL. AS IT WAS STILL DARK, I WAS UNABLE TO SEE MUCH OUTSIDE THE COCKPIT. I LEVELED THE WINGS AND UPON BEING ABLE TO SEE THE SILHOUETTE OF THE R ENG AGAINST THE CITY LIGHTS BELOW, NOTED THAT THE R ENG COWLING WAS OPEN OR LOOSE AND MOVING VIGOROUSLY IN THE SLIPSTREAM. I IMMEDIATELY REDUCED PWR AND LEVELED THE ACFT. THIS STOPPED THE COWLING FROM MOVING. I WAS ROUGHLY ON A DOWNWIND FOR RWY 33 AT THIS TIME AND LOWERED THE GEAR AND COMPLETED LNDG CHKS. AT THIS TIME I ALSO EXPERIENCED XMITTER DIFFICULTIES. THE HEADS-UP TWR CTLR SUSPECTED A PROB AND CLRED ME TO LAND ON RWY 33. LNDG WAS UNEVENTFUL, HOWEVER, ON ROLLOUT AS I APPLIED REVERSE THRUST, THE COWLING AGAIN BEGAN TO MOVE VIGOROUSLY. I CAME OUT OF REVERSE AND COASTED TO THE END OF THE RWY, APPLYING GENTLE BRAKING. THE COWLING WAS STILL ATTACHED AND NOT MOVING AT IDLE PWR, SO I TAXIED BACK TO THE HANGAR. UPON SHUTDOWN, THE GND CREW NOTED A SIGNIFICANT FUEL LEAK FROM A LINE WHICH HAD BEEN CUT BY THE FLAPPING MOTION OF THE COWLING, WHICH COULD HAVE RESULTED IN AN ENG FIRE AT ANY STAGE OF THE FLT. WHILE CLOSING THE COWLING ON PREFLT, I MAY HAVE BEEN DISTR BY THE FUELER ASKING FOR VERIFICATION OF THE AMOUNT ON THE R SIDE WHILE CLOSING THE LATCH. ALSO, I HAD A SMALL DEG OF DIFFICULTY CATCHING THE FORWARD LATCH AND SUSPECT THAT THE COMBINATION RESULTED IN NOT ENSURING THE AFT LATCH HOOK WAS PROPERLY ENGAGED. OLDER AND WISER, I NOW ENSURE MULTIPLE INSPECTION OF ALL LATCHES OPENED AND/OR CLOSED ON PREFLT.

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.