Cpr small aircraft suffers magneto failure after takeoff from N87. Subsequent performance on remaini...

Narrative:

Immediately after takeoff with full power, aircraft (small aircraft) experienced substantial engine power loss passing about 100' AGL in climb out. Conditions were MVFR due to haze with an OAT of about 80 degrees F. The airport elevation is 120' MSL. With 5 souls on board and 60% fuel, aircraft was about 100 pounds under maximum gross takeoff weight. Engine power loss was later discovered to be attributable to the failure of 1 of the magnetos. Aircraft performance on the remaining magneto was extremely marginal. I was able to climb to about 500' AGL at vy with a climb rate of perhaps 100 FPM; however, the engine cylinder head temperatures reached the never exceeded red line in the process. It was later determined that the magneto had failed due to corrosion from water ingestion. Both magnetos were fairly new, having about 300 hours total time each. The manufacturer recommends inspecting the magnetos after 500 hours. Both magnetos at 300 hours showed extreme corrosion. Both magnetos had to be replaced. The magnetos in the small aircraft apparently are positioned in such a way that water corrosion occurs relatively quickly. Pilots of piston aircraft generally expect minimal engine performance loss in the event of a magneto failure in a dual magneto system (after all, each cylinder should still fire). The performance deterioration in the small aircraft was critical, however. Small aircraft pilots should be instructed to expect this under gross weight/hot day conditions. In my case, I was able to return and land at the departure airport by flying a pattern altitude of 500' AGL. Had the WX conditions been IFR, I suspect I would have damaged the engine through overheating in an effort to clear obstacles (assuming I would have been able to clear obstacles at all). Callback conversation with reporter revealed the following: callback conducted to determine if a pre-departure magneto check was conducted. Reporter claimed that he did conduct a magnetic check, and that the RPM drop for both magnetos was within limits. There was nothing in the before takeoff engine check that appeared significant, either before departure or upon post-flight review. Reporter further suggested that aircraft performance on 1 magneto approximated that of a light twin with 1 engine failed.

Original NASA ASRS Text

Title: CPR SMA SUFFERS MAGNETO FAILURE AFTER TKOF FROM N87. SUBSEQUENT PERFORMANCE ON REMAINING MAGNETO SO POOR THAT ONLY MARGINAL PERFORMANCE RESULTED. SOURCE OF FAILURE SAID TO BE CORROSION IN MAGNETO DUE TO WATER ACCUMULATION.

Narrative: IMMEDIATELY AFTER TKOF WITH FULL PWR, ACFT (SMA) EXPERIENCED SUBSTANTIAL ENG PWR LOSS PASSING ABOUT 100' AGL IN CLBOUT. CONDITIONS WERE MVFR DUE TO HAZE WITH AN OAT OF ABOUT 80 DEGS F. THE ARPT ELEVATION IS 120' MSL. WITH 5 SOULS ON BOARD AND 60% FUEL, ACFT WAS ABOUT 100 LBS UNDER MAX GROSS TKOF WT. ENG PWR LOSS WAS LATER DISCOVERED TO BE ATTRIBUTABLE TO THE FAILURE OF 1 OF THE MAGNETOS. ACFT PERFORMANCE ON THE REMAINING MAGNETO WAS EXTREMELY MARGINAL. I WAS ABLE TO CLB TO ABOUT 500' AGL AT VY WITH A CLB RATE OF PERHAPS 100 FPM; HOWEVER, THE ENG CYLINDER HEAD TEMPS REACHED THE NEVER EXCEEDED RED LINE IN THE PROCESS. IT WAS LATER DETERMINED THAT THE MAGNETO HAD FAILED DUE TO CORROSION FROM WATER INGESTION. BOTH MAGNETOS WERE FAIRLY NEW, HAVING ABOUT 300 HRS TOTAL TIME EACH. THE MANUFACTURER RECOMMENDS INSPECTING THE MAGNETOS AFTER 500 HRS. BOTH MAGNETOS AT 300 HRS SHOWED EXTREME CORROSION. BOTH MAGNETOS HAD TO BE REPLACED. THE MAGNETOS IN THE SMA APPARENTLY ARE POSITIONED IN SUCH A WAY THAT WATER CORROSION OCCURS RELATIVELY QUICKLY. PLTS OF PISTON ACFT GENERALLY EXPECT MINIMAL ENG PERFORMANCE LOSS IN THE EVENT OF A MAGNETO FAILURE IN A DUAL MAGNETO SYS (AFTER ALL, EACH CYLINDER SHOULD STILL FIRE). THE PERFORMANCE DETERIORATION IN THE SMA WAS CRITICAL, HOWEVER. SMA PLTS SHOULD BE INSTRUCTED TO EXPECT THIS UNDER GROSS WT/HOT DAY CONDITIONS. IN MY CASE, I WAS ABLE TO RETURN AND LAND AT THE DEP ARPT BY FLYING A PATTERN ALT OF 500' AGL. HAD THE WX CONDITIONS BEEN IFR, I SUSPECT I WOULD HAVE DAMAGED THE ENG THROUGH OVERHEATING IN AN EFFORT TO CLR OBSTACLES (ASSUMING I WOULD HAVE BEEN ABLE TO CLR OBSTACLES AT ALL). CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: CALLBACK CONDUCTED TO DETERMINE IF A PRE-DEP MAGNETO CHK WAS CONDUCTED. RPTR CLAIMED THAT HE DID CONDUCT A MAG CHK, AND THAT THE RPM DROP FOR BOTH MAGNETOS WAS WITHIN LIMITS. THERE WAS NOTHING IN THE BEFORE TKOF ENG CHK THAT APPEARED SIGNIFICANT, EITHER BEFORE DEP OR UPON POST-FLT REVIEW. RPTR FURTHER SUGGESTED THAT ACFT PERFORMANCE ON 1 MAGNETO APPROXIMATED THAT OF A LIGHT TWIN WITH 1 ENG FAILED.

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.

Attributes
ACN	152207
Time
Date	199007
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : n87
State Reference	NJ
Altitude	agl bound lower : 100 agl bound upper : 500
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Operator	general aviation : corporate
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	climbout : takeoff climbout : initial other
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : atp pilot : instrument
Experience	flight time last 90 days : 60 flight time total : 8000 flight time type : 500
ASRS Report	152207
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency flight crew : overcame equipment problem other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Cpr small aircraft suffers magneto failure after takeoff from N87. Subsequent performance on remaining magneto so poor that only marginal performance resulted. Source of failure said to be corrosion in magneto due to water accumulation.