A PA32 pilot declared an emergency during climb after takeoff because of a rough running engine and ...

Narrative:

After departure at approximately 900 MSL the engine began running rough at full climb power. At low altitude and low airspeed I reported the problem to departure control; they asked if we could make it back to the departure airport which would require 180 degree turn and flying over water 6 miles. I declared an emergency and asked for permission to land at an air force base; the runway directly off the nose which would only require reducing power and landing straight ahead. Approach turned me over to the tower which cleared us to land on the runway. The landing was an unauthorized landing and required to be reported. The aircraft was checked by an a and P mechanic and cause of the rough running engine was determined to have been caused by water ingestion. Fuel system was sumped and cleared of all water. Pre-incident: the aircraft was fueled just prior to takeoff. During the pre-flight the tanks were sumped and no water was found and the run up all checked good. The only explanation we could determine was the water had not had time to settle to the sumps prior to take-off. In the future I will demand the tanks to be topped after landing and not wait until the next departure to insure water has adequate time to settle in the sumps.

Original NASA ASRS Text

Title: A PA32 pilot declared an emergency during climb after takeoff because of a rough running engine and landed at a nearby Air Force base. Maintenance determined that water had accumulated in the recently fueled tanks and had not settled out before the tanks were sumped.

Narrative: After departure at approximately 900 MSL the engine began running rough at full climb power. At low altitude and low airspeed I reported the problem to Departure Control; they asked if we could make it back to the departure airport which would require 180 degree turn and flying over water 6 miles. I declared an emergency and asked for permission to land at an Air Force Base; the runway directly off the nose which would only require reducing power and landing straight ahead. Approach turned me over to the Tower which cleared us to land on the runway. The landing was an unauthorized landing and required to be reported. The aircraft was checked by an A and P Mechanic and cause of the rough running engine was determined to have been caused by water ingestion. Fuel system was sumped and cleared of all water. Pre-incident: The aircraft was fueled just prior to takeoff. During the pre-flight the tanks were sumped and no water was found and the run up all checked good. The only explanation we could determine was the water had not had time to settle to the sumps prior to take-off. In the future I will demand the tanks to be topped after landing and not wait until the next departure to insure water has adequate time to settle in the sumps.

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.

Attributes
ACN	905859
Time
Date	201008
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	PA-32 Cherokee Six/Lance/Saratoga/6X
Operating Under FAR Part	Part 91
Flight Phase	Takeoff
Route In Use	Direct
Flight Plan	IFR
Component
Aircraft Component	Fuel Storage System
Person 1
Function	Single Pilot Pilot Flying
Qualification	Flight Crew Private Flight Crew Instrument
Experience	Flight Crew Last 90 Days 25 Flight Crew Total 350 Flight Crew Type 250
Events
Anomaly	Aircraft Equipment Problem Critical

A PA32 pilot declared an emergency during climb after takeoff because of a rough running engine and landed at a nearby air force base. Maintenance determined that water had accumulated in the recently fueled tanks and had not settled out before the tanks were sumped.