Yesterday was the second time (after several weeks of normal operation in between) that the following symptoms arose:
After approx one hour in flight, the low voltage lamp lighted up, EFIS showed 12,1 v, hence the light. The voltage slowly decreased to 12,0, 11,9 V at a rate of 0,1V ~ every 5sec.
All of a sudden, voltage regained its normal in flight lelvel of 13,7v. This voltage drop reappeard every now and then for periods of 3 secs to 30 secs for approx 1% of the remaining flight time.
Switching the transponder off didn't prevent the sudden voltage drop, but after the inital drop from 13,7 to eg 12,2, the further decrease of voltage was very much slowed down to ~0,1V very 20 s.
System: Rotax 912 S, no additional alternator, EFIS+EMS, Transponder, Radio on. Voltage drop while actuating the electrically driven flaps is known and normal.
Conditions: 75%, OAT 15°C, oil temp 9x deg.C, 5000ft
My question: this temporary error points to the regulator in my opinion. As I will almost certainly find no anormaly while test running the engine on the ground and there is therefore no possibility to immediately verify the success of my work, I want to make sure that I am curing the right disease.
Could this error be caused by improper/broken/loose electrical connections (between whom)? Or is it the regulator for sure?
The plane is a MCR01. The cooling is rather too effective, I have to block 60% of the coolant air intake in winter and never see oil temps above IIRC 110deg C at 75% and OAT of 25 deg C. This however doesn't say anything about the temps at the back of the engine where the regulator sits ...
Thanks for reading
After approx one hour in flight, the low voltage lamp lighted up, EFIS showed 12,1 v, hence the light. The voltage slowly decreased to 12,0, 11,9 V at a rate of 0,1V ~ every 5sec.
All of a sudden, voltage regained its normal in flight lelvel of 13,7v. This voltage drop reappeard every now and then for periods of 3 secs to 30 secs for approx 1% of the remaining flight time.
Switching the transponder off didn't prevent the sudden voltage drop, but after the inital drop from 13,7 to eg 12,2, the further decrease of voltage was very much slowed down to ~0,1V very 20 s.
System: Rotax 912 S, no additional alternator, EFIS+EMS, Transponder, Radio on. Voltage drop while actuating the electrically driven flaps is known and normal.
Conditions: 75%, OAT 15°C, oil temp 9x deg.C, 5000ft
My question: this temporary error points to the regulator in my opinion. As I will almost certainly find no anormaly while test running the engine on the ground and there is therefore no possibility to immediately verify the success of my work, I want to make sure that I am curing the right disease.
Could this error be caused by improper/broken/loose electrical connections (between whom)? Or is it the regulator for sure?
The plane is a MCR01. The cooling is rather too effective, I have to block 60% of the coolant air intake in winter and never see oil temps above IIRC 110deg C at 75% and OAT of 25 deg C. This however doesn't say anything about the temps at the back of the engine where the regulator sits ...
Thanks for reading
