Cessna 172SP Wouldn't Start

Cessna310

Member
I attempted to go flying last night and as I was ready to start, nothing happened. When I would turn the key everything eletrical would turn off. I could hear this slight spinning when turning the key ( I don't think it was the mags) After each attempt of starting it would take 2 minutes or so for all the panel lights etc to fully restore.

It was about -3C last night but the plane was in a heated hanager for the past 3 hours. I went over my checklist 10 different time to ensure I missed nothing, then I realized it wasn't me.

Any ideas what could have been wrong?
 
Probably weak battery, when you engaged starter the amp load to spin the starter caused a voltage drop hence the dim lights. The spinning sound was the starter but there wasn't enough speed to throw it forward into the ring gear to actually turn over the engine.
 
Thats what I thought. Do you think it needs a new battery? I left a note in the book...I don't want to look like a complete idiot if the plane is fine today :o
 
Probably weak battery, when you engaged starter the amp load to spin the starter caused a voltage drop hence the dim lights. The spinning sound was the starter but there wasn't enough speed to throw it forward into the ring gear to actually turn over the engine.
:yeahthat:

One thing that I've had happen a few times is when there's a big change in temperature or humidity - or both - and there's some corrosion on the terminals, you will get enough current to turn the lights on and energize the starter solenoid, but not enough current to actually turn the starter. Turn key, receive "CLICK" and nothing happens. You can literally come back a few hours later if there's another change in temperature or humidity and start it right up.
 
Probably just needs to be charged. If the starter isn't engaging with the propeller, try turning the prop by hand a few times and trying again. It's worked for me in the past on older models.
 
What was happening was the starter was trying to engage and took all the power from the battery.

Also, read up on how the magnetos work again. They only turn when the engine is turning because they are geared directly to the back of the engine on the accessory case. Was this a solo flight for you or was there going to be an instructor on board?
 
Charge battery first, if that's fine give a few good whacks on the starter nose with a screwdriver handle, if it still doesn't work replace the starter.
 
Something somewhat similar happened to me on my last check ride, DPE got out and hand propped it for me :)
 
Mr. Kim had to tinkle after his third failed single-engine NDB.

Yes, I was a sadist, but my students found their ME-I checkride to be a delightful respite from my training creativity.
 
IF you still can't get it started, hook it up to a glider, have it drag you to 60 or so knots, and engage the mag with the mixture rich and throttle just above idle. Should start right up.
 
IF you still can't get it started, hook it up to a glider, have it drag you to 60 or so knots, and engage the mag with the mixture rich and throttle just above idle. Should start right up.



Just to be the police here, I don't see how a glider could tow his Cessna to 60 knts or so... Just saying lol.


Next time, if you have one available, have a ramper hook you up to a GPU. Start up and you will be fine.
 
^^ Not if you're going IFR. I'd get the battery checked out before you go IFR in the thing with a bad battery.
 
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