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This is in Rants and Raves because it happened to me on a Spam Can. If anyone else has seen this malfunction I would like to hear from you.
Scenario: An annual inspection on a Beech Sundowner. Battery condition was at very low charge to just plain dead. The airplane had been sitting for 17 months without flying and the Lycoming O-360 was probably never started during that time.
A&P Actions: Charge battery for several hours and then attempt an engine start.
It took several tries, but the engine finally coughed to life. The engine instruments were allowed to stabilize and then I performed maintenance checks for five to ten minutes
taking readings and checking magneto drop. Then the engine was shut down.
No further engine starts were done that day.
Two days later I went out to work on the plane and intended to taxi it to a maintenance
location. Engine start sequence was rather standard; mixture rich, prime several
strokes, leave fuel pump off to conserve the weak battery, put key into the ignition slot
in the OFF position, master switch ON.
Surprise! The prop began spinning when the master was turned on!
I immediately shut off the master switch. Did that really happen? Blip the master
on again – same result!
Hmmm. Two lessons learned.
First, the starter solenoid can stick in the on position. Although the problem has not
been fully diagnosed yet, the solenoid is almost assuredly the problem.
Quite possibly it welded itself in the ON position during the attempted engine starts.
Second, Check the prop is clear before turning on the master switch.
Consider calling out “Clear Prop” should be done before actuating the master switch
instead of just before turning the key.
Scenario: An annual inspection on a Beech Sundowner. Battery condition was at very low charge to just plain dead. The airplane had been sitting for 17 months without flying and the Lycoming O-360 was probably never started during that time.
A&P Actions: Charge battery for several hours and then attempt an engine start.
It took several tries, but the engine finally coughed to life. The engine instruments were allowed to stabilize and then I performed maintenance checks for five to ten minutes
taking readings and checking magneto drop. Then the engine was shut down.
No further engine starts were done that day.
Two days later I went out to work on the plane and intended to taxi it to a maintenance
location. Engine start sequence was rather standard; mixture rich, prime several
strokes, leave fuel pump off to conserve the weak battery, put key into the ignition slot
in the OFF position, master switch ON.
Surprise! The prop began spinning when the master was turned on!
I immediately shut off the master switch. Did that really happen? Blip the master
on again – same result!
Hmmm. Two lessons learned.
First, the starter solenoid can stick in the on position. Although the problem has not
been fully diagnosed yet, the solenoid is almost assuredly the problem.
Quite possibly it welded itself in the ON position during the attempted engine starts.
Second, Check the prop is clear before turning on the master switch.
Consider calling out “Clear Prop” should be done before actuating the master switch
instead of just before turning the key.
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