A cozy iv suffered engine roughness approaching their final destination. The pilot/owner declared pa...

Attributes
ACN	844951
Time
Date	200907
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Experimental
Operating Under FAR Part	Part 91
Flight Phase	Descent
Route In Use	Direct
Flight Plan	VFR
Component
Aircraft Component	Engine
Person 1
Function	Single Pilot
Qualification	Flight Crew Private
Experience	Flight Crew Last 90 Days 35 Flight Crew Total 250 Flight Crew Type 150
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

Aircraft is an experimental cozy mk iv; with ~50 hours total time on it. I was concluding a VFR flight with 4 aboard. At approx 50 miles south of our destination; approach was contacted and the letdown started from 8500 feet. During the descent; the engine started to run roughly. Full throttle and full rich mixture only gave about 2200 RPM; enough to sustain altitude but; with the threat of engine cut out at any moment; I elected to declare a 'pan'. I requested to land at the nearest airport. Approach vectored me to the field and I executed an uneventful landing. No investigation has been conducted yet; but I suspect either icing occurred as the aircraft descended into warmer humid air; causing the throttle body air intake to ice over; or turbulence during the flight caused tank debris from the build process to enter the filters and cause blockage. No one was hurt.

Original NASA ASRS Text

Title: A Cozy IV suffered engine roughness approaching their final destination. The pilot/owner declared Pan Pan Pan and diverted to the nearest suitable airport for an uneventful landing.

Narrative: Aircraft is an experimental Cozy Mk IV; with ~50 hours total time on it. I was concluding a VFR flight with 4 aboard. At approx 50 miles south of our destination; Approach was contacted and the letdown started from 8500 feet. During the descent; the engine started to run roughly. Full throttle and full rich mixture only gave about 2200 RPM; enough to sustain altitude but; with the threat of engine cut out at any moment; I elected to declare a 'Pan'. I requested to land at the nearest airport. Approach vectored me to the field and I executed an uneventful landing. No investigation has been conducted yet; but I suspect either icing occurred as the aircraft descended into warmer humid air; causing the throttle body air intake to ice over; OR turbulence during the flight caused tank debris from the build process to enter the filters and cause blockage. No one was hurt.

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 cozy iv suffered engine roughness approaching their final destination. The pilot/owner declared pan pan pan and diverted to the nearest suitable airport for an uneventful landing.