|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1201 To 1800|
|Locale Reference||airport : sdm.airport|
|Altitude||msl bound lower : 526|
msl bound upper : 2000
|Controlling Facilities||tower : sdm.tower|
|Operator||general aviation : instructional|
|Make Model Name||Skyhawk 172/Cutlass 172|
|Operating Under FAR Part||Part 91|
|Navigation In Use||other|
|Flight Phase||climbout : intermediate altitude|
landing : touch and go
|Function||instruction : instructor|
|Qualification||pilot : multi engine|
pilot : instrument
pilot : commercial
pilot : cfi
technician : powerplant
technician : airframe
|Experience||flight time last 90 days : 30|
flight time total : 8500
flight time type : 1000
|Function||instruction : trainee|
|Anomaly||aircraft equipment problem : critical|
|Independent Detector||other flight crewa|
|Resolutory Action||flight crew : declared emergency|
flight crew : landed in emergency condition
The student and I departed myf to conduct touch and go operations at sdm. The student pilot was pre-solo. Our plan was to do several touch and goes at sdm, then proceed to see for more touch and go operations, and then return to myf for several more. We arrived at sdm, did 3 touch and go operations and were departing to the northeast en route to see. At approximately 2000 ft MSL and approximately 2.5 NM northeast of sdm, the engine quit without any warning. It was as if the ignition had been turned off. I quickly went through cockpit checks and determined nothing was out of place or had been turned off. I called a mayday to sdm and advised them I would be making an off airport landing on a dirt road about .5 NM north of the pgy VOR. I successfully landed the airplane on the dirt road. The student and I were unharmed and the aircraft sustained no damage. Upon exiting the aircraft, we observed significant amounts of oil on the belly stretching all the way back to the tail and oil was also now running down onto the nosewheel pant. In a subsequent conversation with the mechanic who maintains this aircraft, he surmised that a magneto seal had failed, allowing engine oil to enter the magnetos which shorted them out. Apparently this cessna 172 has one of the lycoming engines that has 2 magnetos that are driven off one drive, unlike a standard aircraft engine where each magneto has its own drive. In my opinion, the lycoming single magneto drive engine is a ticking time bomb. It should be recalled. It is a mystery on how this engine got certified, there is no ignition redundancy.
Original NASA ASRS Text
Title: A C172 CFI WITH A STUDENT EXPERIENCE AN ENG FAILURE RESULTING IN AN OFF ARPT LNDG ON A ROAD.
Narrative: THE STUDENT AND I DEPARTED MYF TO CONDUCT TOUCH AND GO OPS AT SDM. THE STUDENT PLT WAS PRE-SOLO. OUR PLAN WAS TO DO SEVERAL TOUCH AND GOES AT SDM, THEN PROCEED TO SEE FOR MORE TOUCH AND GO OPS, AND THEN RETURN TO MYF FOR SEVERAL MORE. WE ARRIVED AT SDM, DID 3 TOUCH AND GO OPS AND WERE DEPARTING TO THE NE ENRTE TO SEE. AT APPROX 2000 FT MSL AND APPROX 2.5 NM NE OF SDM, THE ENG QUIT WITHOUT ANY WARNING. IT WAS AS IF THE IGNITION HAD BEEN TURNED OFF. I QUICKLY WENT THROUGH COCKPIT CHKS AND DETERMINED NOTHING WAS OUT OF PLACE OR HAD BEEN TURNED OFF. I CALLED A MAYDAY TO SDM AND ADVISED THEM I WOULD BE MAKING AN OFF ARPT LNDG ON A DIRT ROAD ABOUT .5 NM N OF THE PGY VOR. I SUCCESSFULLY LANDED THE AIRPLANE ON THE DIRT ROAD. THE STUDENT AND I WERE UNHARMED AND THE ACFT SUSTAINED NO DAMAGE. UPON EXITING THE ACFT, WE OBSERVED SIGNIFICANT AMOUNTS OF OIL ON THE BELLY STRETCHING ALL THE WAY BACK TO THE TAIL AND OIL WAS ALSO NOW RUNNING DOWN ONTO THE NOSEWHEEL PANT. IN A SUBSEQUENT CONVERSATION WITH THE MECH WHO MAINTAINS THIS ACFT, HE SURMISED THAT A MAGNETO SEAL HAD FAILED, ALLOWING ENG OIL TO ENTER THE MAGNETOS WHICH SHORTED THEM OUT. APPARENTLY THIS CESSNA 172 HAS ONE OF THE LYCOMING ENGS THAT HAS 2 MAGNETOS THAT ARE DRIVEN OFF ONE DRIVE, UNLIKE A STANDARD ACFT ENG WHERE EACH MAGNETO HAS ITS OWN DRIVE. IN MY OPINION, THE LYCOMING SINGLE MAGNETO DRIVE ENG IS A TICKING TIME BOMB. IT SHOULD BE RECALLED. IT IS A MYSTERY ON HOW THIS ENG GOT CERTIFIED, THERE IS NO IGNITION REDUNDANCY.
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.