Question about Starters

ScoutFlyer

ScoutFlyer

Well-Known Member
Hello everyone! I have been flying a Cessna 150 and the airplane has been in maintenance several times during the past few weeks. Each time the problem turns out to be a bum starter. I was "lucky" enough to be the guy to write it up the last time it went in maintenance:panic:. The airplane sat on the ramp for about 2 hours in -20°C weather without an engine cover. I attempted to start it up and the prop turned very slowly. I wrote it up for what I thought was a dead, or close to dead, battery. It turns out that maintenance is throwing a new starter on it. When I wrote the airplane up, the prop was turning, just not very fast. If a starter is busted, wouldn't that result in the prop not turning? I'm just curious to know the symptoms of a bad starter I suppose.
 
Depends on how broken the starter is and what the problem is. If your airplane is burning out starters repeatedly, either there is another system problem causing it or your pilots need to be taught how to not burn up a starter.
 
"I'm just curious to know the symptoms of a bad starter"

We had one C-150 that when the starter would not line up, you would have to go out and push or pull on the prop to get the starter to work. I don't know if that was something with the starter, but it worked without putting the plane down.

The other starter problem that I've had was when the entire bottom case of if blew off, (made a "that ain't good) noise).

I too am curious what others have experienced.
 
We have the Sky-Tec high speed starters on our 172s. The failure mode that I saw in the shop was basically a hand-grenading of the starter motor. Essentially, the base of the starter motor case sheared off from the rest of it, and pieces of the commutator fell out. I'm not sure, but I suspect that it's caused by pilots leaving it engaged for too long. If I understand correctly, the starter motor is geared down quite a bit to get enough torque to spin the engine. So if you leave it engaged after the engine starts, the motor goes way too fast and BOOM. Don't treat it like a turbine-don't have to keep the starter engaged while the engine winds up to 50% N1.
 
Hey, Roger, has your maintenance shown you the fantastic, unshielded position of the Twin Star's starters? I love flying that plane, but am I ever glad I don't have to maintain it.

As to the OP, what you're describing indeed sounds more like a weak battery than a bad starter, but a messed-up starter can manifest in a number of ways, and in many cases the prop will still turn. It's also entirely possible that your write-up was accurate, but when maintenance pulled off the cowling they decided to do some work on the starter, as well. Out of curiosity, did you preheat the engine before attempting to start it?
 
ScoutFlyer said:
Hello everyone! I have been flying a Cessna 150 and the airplane has been in maintenance several times during the past few weeks. Each time the problem turns out to be a bum starter. I was "lucky" enough to be the guy to write it up the last time it went in maintenance:panic:. The airplane sat on the ramp for about 2 hours in -20°C weather without an engine cover. I attempted to start it up and the prop turned very slowly. I wrote it up for what I thought was a dead, or close to dead, battery. It turns out that maintenance is throwing a new starter on it. When I wrote the airplane up, the prop was turning, just not very fast. If a starter is busted, wouldn't that result in the prop not turning? I'm just curious to know the symptoms of a bad starter I suppose.
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That's not a bum starter, that's a cold airplane. Make sure the airplane has heat before it starts otherwise it will be difficult. The battery is too cold to be able to supply power normally. Happens all the time with our airplanes if we forget to plug em' in. Remember, batteries are chemical in nature and don't supply constant power, and are vastly effected by things that effect chemical reactions (e.g. temperature).

If the starter is busted (e.g. bendix won't engage, etc) then it probably won't turn over. To me, an airplane that turns over really really slowly is an electrical power issue. Your starters are fine. Don't write that up, just warm the airplane up.
 
ILS37R said:
Out of curiosity, did you preheat the engine before attempting to start it?
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Thanks for the responses everyone.

I did have the engine preheated before attempting to start, but after it didn't fire in the right away, I think it cooled down pretty quick. There was a 15kt wind blowing right in the cowling. Probably not the best conditions for trying to start an older aircraft.
 
ILS37R said:
Hey, Roger, has your maintenance shown you the fantastic, unshielded position of the Twin Star's starters? I love flying that plane, but am I ever glad I don't have to maintain it.
Click to expand...
In fact, I helped with a starter change on it. It was a lot of fun :sarcasm:
 
In the case of your 150, there is no starter bendix. There's a starter drive adapter with an overrunning clutch.

If there is a problem with the starter motor windings, it could indeed turn very slowly and act like a dead battery. If that's been happening a lot I would suspect that people are being very hard on the starter, or whatever overhauler your school uses has some issues.
 
Our clubs Cherokee will often kick the prop about 180-degrees and stop dead. You have to keep releasing the starter switch and pushing it until the engine finally spins over normally. Kind of odd, and always looks good in front of worrisome passengers.
 
Today our Landing Light fuse in our C-150 needed to be replaced, which meant our starter did not work, which made me think, "topical".
 
We used to have an RG Cardinal on the field that would have a heck of a time engaging the starter bendix. Sometimes the owner would move the prop a little bit and try again, or mx would spray a little lubricant on the starter and it would start right up. I always thought, get off your wallet and buy a new starter...

I do remember once or twice having a new student start a 172 and the starter would not fully disengage. Right after they finally release the key you think to yourself, "huuummm, what is that weird metal on metal sound?" One or two of the mx personnel would come running out of the hangar motioning you to shut it down.

Oh the joys of starters...
 
I know a lot of you have some great websites to read up on different things. Anybody have one about the intricacies of the starter? Im not particularly sure what a starter bendix is...
 
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