Engaging starter while propeller is turning

Discussion in 'Lessons Learned' started by Pilot27, Aug 2, 2017.

  1. Pilot27

    Pilot27 Guest

    A question about engaging the starter while the propeller is turning. I went to start the airplane and I was having a little difficulty getting it started. I turned the key which obviously engaged the starter at that point and as the engine acted like it was starting to catch I released the starter (but it hadn't quite started) it was still trying to light so I opened the throttle a little bit trying to get it started. As I was doing this, I turned the key for just a second to try to bring the starter back in for assistance. It eventually started after I opened the throttle a little more. The question is, is there anyway that by turning the key for literally just a second to engage the starter while the propeller was already spinning (but before the engine was started), could have caused any damage? The aircraft is a Cessna 172.
     
  2. Pilot27

    Pilot27 Guest

    Btw, the reason I didn't keep the starter engaged until it completely started, was because this 172 has the Skytec Fast starter and you're only supposed to crank for 10 seconds with a 20 second test period between cranks. So I try to use the starter for as short as I can. The airplane has had some trouble starting which is why it didn't light immediately but it acted like it was getting close so I'll open a throttle a bit to assist.
     
  3. coloradobluesky

    coloradobluesky En-Route

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    If the starter tries to engage while the engine is moving the gear of the starter is very likely to not be line up with the gear of the engine that it engages. So it is likely to either not engage, engage with clashing but no damage or engage in a damaging way. There usually isn't damage, but it can damage the starter cog or the engine cog. Some engines prevent it from trying to engage. So you're not supposed to do it.

    If the starter works ok and cranks the engine reliably all the way around, there probably isnt any damage.
     
  4. GRG55

    GRG55 En-Route

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    Engaging the starter when the engine is already turning is a classic way to chip or break a tooth on the starter ring.
     
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  5. unsafervguy

    unsafervguy Line Up and Wait

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    if it had not quite fired up the bendix could have still been engaged in the flywheel, it takes a bit of inertia for it to retract. if it was retracted you should have heard it grind just like in a car when you do that.

    bob
     
  6. GlennAB1

    GlennAB1 Ejection Handle Pulled

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    They don't call it "crash engagement" for nothing.
     
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  7. TRocket

    TRocket Line Up and Wait

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    Yeah, I would definitely not do that.
     
  8. eman1200

    eman1200 Final Approach

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    Can't u see the starter ring thingy from the front cowl opening?
     
  9. mtuomi

    mtuomi En-Route

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    Depends on the engine. O-200/300 starter is in the back.
     
  10. Ryanb

    Ryanb En-Route PoA Supporter

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    On most Lycomings it sits right at the front, next to the flywheel.
     
  11. James331

    James331 Touchdown! Greaser!

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    Shouldn't need anywhere near 10 seconds, look into why its having a hard time starting, might be you, might be the priming system, might be plugs, ?
     
  12. CJ Rader

    CJ Rader Pre-takeoff checklist

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    Had the same thing happen to me in a 172 and in a 152. In my case, I was so focused on trying to get it to turn over that when it did, I neglected to turn loose of the starter. Noob mistakes on my part.