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I have a full feathering prop on my
IVP.
....but there are some holes in my understanding I
wonder if someone has a definitive understanding of.
I believe the following are true:
- on this prop oil pressure pushes it to fine pitch
and springs push to coarse pitch
- if you lose oil pressure, it will go to
feather
- if you pull the prop control all the way out it
will go to feather
- if you do an air start from feather and you have
a strong battery and starter, you can get it out of feather in about 25
seconds.
- it has prop locks which prevent it from going to
coarse on a normal shut down.
Here's what I dont' understand:
- EXACTLY how do the prop locks work? It
seems that if you get rpm below 1200 but haven't lost oil pressure, somehow the
prop locks will keep it from going to full feather when you finally lose all
pressure.
- If the engine were at 1100 rpm when you lost
power, what would happen? I assume the prop locks keep it from
feathering.
- If the prop is windmilling, you have oil
pressure. If you slowly pull the prop back til it's below 1200rpm and then
continue all the way back, how is this different than a normal shut down, as far
as the prop is concerned?
In other words, are there scenarios where the prop
locks can bite you in the air and what are they?
Colyn
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