Flight crew reported heavy rains during an extended ground sit resulted in water entering the engine...

Narrative:

The airplane was last flown 2 1/2 days ago. Everything was normal on the taxi out and on the takeoff. When we were cleared for takeoff the first officer set the standard power with the auto throttles on and I took control of the throttles and noted the both eprs were 1.90 and both N1s at 90.5%. The takeoff roll was normal with reduced thrust and flap 6 on a heavier aircraft and warmer day. However; it was slow climbing and the higher we went the slower the rate of climb was. We started comparing eprs; N1 and N2s. We got out our performance charts and the books. Found out the N1s were low for the EPR settings. Both the left and right engines were reading the same. We used N1s for power setting. After talking to maintenance control we determined both eprs were giving false reading. We then continued to destination at FL230 after talking to dispatch about the fuel burn needed to do so. After landing maintenance decided to blow out the EPR lines. We did a full power run up and all engine readings were normal. Maintenance control said that water during the heavy storms earlier must have gone down the lines and was giving a false reading to both of the EPR gages.

Original NASA ASRS Text

Title: Flight Crew reported heavy rains during an extended ground sit resulted in water entering the engine EPR probes of a commuter aircraft and resulted in incorrect EPR readings on the first flight following the rains.

Narrative: The airplane was last flown 2 1/2 days ago. Everything was normal on the taxi out and on the takeoff. When we were cleared for takeoff the First Officer set the standard power with the auto throttles on and I took control of the throttles and noted the both EPRs were 1.90 and both N1s at 90.5%. The takeoff roll was normal with reduced thrust and flap 6 on a heavier aircraft and warmer day. However; it was slow climbing and the higher we went the slower the rate of climb was. We started comparing EPRs; N1 and N2s. We got out our performance charts and the books. Found out the N1s were low for the EPR settings. Both the left and right engines were reading the same. We used N1s for power setting. After talking to Maintenance Control we determined both EPRs were giving false reading. We then continued to destination at FL230 after talking to Dispatch about the fuel burn needed to do so. After landing Maintenance decided to blow out the EPR lines. We did a full power run up and all engine readings were normal. Maintenance Control said that water during the heavy storms earlier must have gone down the lines and was giving a false reading to both of the EPR gages.

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	951033
Time
Date	201105
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Component
Aircraft Component	Pneumatic System
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	First Officer
Events
Anomaly	Aircraft Equipment Problem Less Severe

Flight crew reported heavy rains during an extended ground sit resulted in water entering the engine EPR probes of a commuter aircraft and resulted in incorrect EPR readings on the first flight following the rains.