TSIO-360-LB Starting Issue

[FlyWalt]

Good Morning All,

I have a bit of a brain teaser here. I'd like to see what you think.

Subject aircraft was flown on Saturday for a total of 5.5 hours on two flights with no issues. And this starting system has NEVER given me an issue till yesterday. Yesterday she started fine and flew for 2.5 hours. We stopped for rest break and refuel. About 30 minutes later we boarded and tried to start. The blade made one rotation and then stopped. I tried again, this time the blade would not move. Upon pushing the start button you could tell there was plenty of juice in the battery. Yet when the button was pushed you could see a power drain going on yet no prop movement.

A check of the volt meter shows 11.7 volts on the battery. Interesting as she was charging for the past 2.5 hours.

The Concorde battery had been installed on 01-01-2020, according to the markings on it. So it is only 3.5 years old. We changed it out with a new one right there on the ramp. Same exact result. So the shop I left it with reinstalled my old battery. They now can get the prop to turn.

Any thoughts? I'd hate to take it with an iffy starter or solenoid. Or could something else be happening?

Thank you in advance,
Walt

[Fly Boomer]

7 minutes ago, FlyWalt said:

Good Morning All,

I have a bit of a brain teaser here. I'd like to see what you think.

Subject aircraft was flown on Saturday for a total of 5.5 hours on two flights with no issues. And this starting system has NEVER given me an issue till yesterday. Yesterday she started fine and flew for 2.5 hours. We stopped for rest break and refuel. About 30 minutes later we boarded and tried to start. The blade made one rotation and then stopped. I tried again, this time the blade would not move. Upon pushing the start button you could tell there was plenty of juice in the battery. Yet when the button was pushed you could see a power drain going on yet no prop movement.

A check of the volt meter shows 11.7 volts on the battery. Interesting as she was charging for the past 2.5 hours.

The Concorde battery had been installed on 01-01-2020, according to the markings on it. So it is only 3.5 years old. We changed it out with a new one right there on the ramp. Same exact result. So the shop I left it with reinstalled my old battery. They now can get the prop to turn.

Any thoughts? I'd hate to take it with an iffy starter or solenoid. Or could something else be happening?

Thank you in advance,
Walt

The one metric you mention, 11.7 volts suggests it either was not charging for the past 2.5 hours, or the battery (despite its age) is unable to take and hold a charge, or some load was able to drag it down between shutdown and voltage check.

[FlyWalt]

So the same results on a brand new battery do not negate that diagnosis? What about the fact that they could then turn the prop on the old battery when it was reinstalled?

[Fly Boomer]

3 minutes ago, FlyWalt said:

So the same results on a brand new battery do not negate that diagnosis? What about the fact that they could then turn the prop on the old battery when it was reinstalled?

No idea what the condition of the "new" battery was, and no idea why the engine will turn over at one point and not another.  All I'm saying is that if the voltage was 11-something, that is a very strong clue.

[FlyWalt]

I forgot to mention that this is an Energizer Starter, Part No. 646238.

[jlunseth]

My guess is the new battery was not charged either. Just because it is new does not mean that it is charged up. You should see a buss voltage in at least the mid to high 12’s and 13-something is better. 11.7 is pretty low and low enough to be the problem. You would see some kind of low voltage indication in your instruments. If you don’t have particularly sensitive instruments, like an engine monitor, you probably at least saw a low voltage indicator light at start up. If the mechanic has an APU the mechanic should plug that in and use it to start the plane. I bet it starts right up. Suspicious to me that the mechanic can now get it to turn over, I will bet the battery was put on a charger and then reinstalled, which would temporarily solve your voltage problem until the battery gets discharged again.

Sounds to me as though the battery was not charging in flight, but was in fact being discharged to run the electrical system. Do you have an amp meter in the plane? Do you remember what the amp meter was showing in flight before the failure to start?

In the LB engine, the alternator is direct drive and is connected to the engine via a coupler, which is a sort of clutch. The purpose is to prevent damage to the engine should the alternator freeze while the engine is running. The coupler is a well known point of failure. The result is that although the engine is running, the alternator is not charging. That is the first thing I would check, but there are certainly other possible issues, like an alternator going bad, voltage regulator, etc.

[FlyWalt]

Thank you for all of the insights. I need to mention that the low voltage lights were extinguished after start up. The Am meter was in the positive at all times during the flight. There was never a point, at which, either indicator showed a lack of charging.

One electrician friend has suggested to check all of the grounds associated with the system. I am also going to have the shop check the alternator and alternator clutch to eliminate those.

 

[FlyWalt]

Update:

Old / Current 3 year old battery shows 12.3 volts on external volt meter. Whereas the JPI voltage indicator was low at 11.7.

New Battery on the shelf shows 12.85

Proceeding with solenoid troubleshoot. Also calling JPI regarding the voltage misreading.

[jlunseth]

There is an AD for the starter switch. It has been around forever. Pilot can do the check and log it. 

 

[PT20J]

I would capacity test the battery if it’s 3.5 years old.

Sounds like it might be a voltage drop due to a poor connection. I’d check all the connections between the battery and starter and if that doesn’t fix it, I’d measure the voltage drop across the starter solenoid. 

From the Concorde manual:

[PT20J]

4 minutes ago, jlunseth said:

There is an AD for the starter switch. It has been around forever. Pilot can do the check and log it. 

 

Yes, but that is related to not killing the mags, not starting.

[PeteMc]

Did you happen to notice the voltage during all of your flights?  Was it in the high 13 or low 14 range?

Did the JPI keep stopping on the Voltage display?  (pending which JPI you have)

 

[FlyWalt]

I have the 830. So it is showing all the time. I didn't notice the voltage in flight but there were no red alarms showing.

[kortopates]

It’s not clear from your description if you could hear the starter was running yet the prop not moving. If so, it’s not a battery issue but the starter adapter slipping. If you’re aware of the issue when an adapter is slipping, it should be easy to recognize the difference.
The mooney annunciator will also show when the starter is getting power which makes it easy to tell if the starter relay is closing.

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