A pc-12 flight crew reported an unusual flapping noise on approach that turned out to be caused by a...

Attributes
ACN	866526
Time
Date	200912
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	PC-12
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Route In Use	Vectors
Flight Plan	IFR
Component
Aircraft Component	Engine Air
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 50 Flight Crew Total 2400 Flight Crew Type 1200
Person 2
Function	First Officer Pilot Flying
Qualification	Flight Crew Commercial Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 87 Flight Crew Total 1500 Flight Crew Type 800
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy

Narrative:

Flying a pc-12 pilatus; after opening the inertial separator on the PT6-67B engine; we experienced a 'flapping' noise coming from the area by our feet. We closed the separator to determine if that was causing the problem; which it wasn't. After re-opening the separator; we advised ATC that we would like priority handling into our destination. Asked if we are declaring an emergency; we indicated in the negative. As we were turned over to tower control; we were advised that the tower would be treating it as an emergency; with trucks awaiting our arrival. We landed without incident and advised ground control that no further assistance would be required. Upon inspection; we found the engine air inlet cover protruding halfway out the separator door. This was subsequently removed and mechanics looked over the inlet; the engine and other parts that may have been affected. With a valid sign off from the mechanics; we proceeded to fly the aircraft back to our home base. The oversight of the cover not being removed was compounded by an early morning show time in which we discovered the aircraft heavily frosted over with no available de-icing. We requested the plane be put in a warm hangar to assist us in removing the frost. In a hurried situation and a hectic morning; we simply overlooked a very important part of our job. To help others learn from this; I would suggest that all pilots; in addition to a preflight; do a thorough walk around the aircraft prior to departure to ensure the aircraft is airworthy and clear of covers; doors closed; cones removed from the vicinity; etc. Distractions are everywhere and we cannot let them get in the way of our daily duties.

Original NASA ASRS Text

Title: A PC-12 Flight Crew reported an unusual flapping noise on approach that turned out to be caused by an engine air inlet cover that had not been removed before flight.

Narrative: Flying a PC-12 Pilatus; after opening the inertial separator on the PT6-67B engine; we experienced a 'flapping' noise coming from the area by our feet. We closed the separator to determine if that was causing the problem; which it wasn't. After re-opening the separator; we advised ATC that we would like priority handling into our destination. Asked if we are declaring an emergency; we indicated in the negative. As we were turned over to tower control; we were advised that the tower would be treating it as an emergency; with trucks awaiting our arrival. We landed without incident and advised ground control that no further assistance would be required. Upon inspection; we found the engine air inlet cover protruding halfway out the separator door. This was subsequently removed and mechanics looked over the inlet; the engine and other parts that may have been affected. With a valid sign off from the mechanics; we proceeded to fly the aircraft back to our home base. The oversight of the cover not being removed was compounded by an early morning show time in which we discovered the aircraft heavily frosted over with no available de-icing. We requested the plane be put in a warm hangar to assist us in removing the frost. In a hurried situation and a hectic morning; we simply overlooked a very important part of our job. To help others learn from this; I would suggest that all pilots; in addition to a preflight; do a thorough walk around the aircraft prior to departure to ensure the aircraft is airworthy and clear of covers; doors closed; cones removed from the vicinity; etc. Distractions are everywhere and we cannot let them get in the way of our daily duties.

Data retrieved from NASA's ASRS site as of April 2012 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.

A pc-12 flight crew reported an unusual flapping noise on approach that turned out to be caused by an engine air inlet cover that had not been removed before flight.