What happens if my engine quits with a CS prop in flight?

Kooshball · #1 02-09-2020, 04:45 PM

Yes, it will get quieter. But with an IO360 running std. compression pistons on an MT 3-blade prop will the prop keep spinning or stop? Is the sink rate likely to be more than what I see with the prop full forward and engine power at idle? I don?t really want to practice this one for real but would like to know what to expect with that combo on an RV4.

Thx!

mike newall · #2 02-09-2020, 04:52 PM

Not a lot will happen.

We did trials on our RV7 - IO-360 with an MT 3 blade prop.

Pulled the mixture in fine and coarse. No, the prop didn't stop. As there is rotation, there is oil pressure, so the prop stayed where it was set. Marginally less drag when fully coarse.

Settled at about 700fpm at best glide around 70kts.

There are videos on YouTube if you look of others doing the same.

DeeCee 57 · #3 02-10-2020, 01:09 AM

Had a conrod failure with total oil loss on a O-320 with a 2 bladed Hartzell... prop kept turning and went into lo pitch acting as a very effective speed brake, resulting in a high ROD...

Snowflake · #4 02-10-2020, 07:40 AM

If you maintain oil pressure, nothing happens.
If you lose oil pressure, if it's an aerobatic prop, it will go to full coarse, RPM will drop, and you'll descend "sort of" normally.
If it's not an aerobatic prop, it will go full fine, RPM will increase, and you'll be descending like a streamlined grand piano with the extra drag.

Finley Atherton · #5 02-10-2020, 11:56 AM

Also depends on the brand of prop governor.
On my O 320 with a windmilling Hartzell prop at idle cutoff the MT governor still works whereas a Hartzell governor does not (insufficient rpm for the Hartzell governor).

Fin
9A

elev666 · #6 02-10-2020, 12:04 PM

Good to know varying governors make a difference ! any opinions on what my McCauley. ( it came with my 0 time engine) governor might generate? I plan on putting a hartzell two blade BA on my project

no7rosman · #7 02-10-2020, 08:03 PM

I am considering converting from FP to CS and worried about the same thing. Does anyone use electric instead of hydraulic for this? I saw they don't recommend electric for aerobatics but I have a 9A so that isn't an issue.

I have never seen or heard of anyone using electric pitch control...but it seems like a good solution to this concern.

TS Flightlines · #8 02-11-2020, 01:02 PM

'What happens if my engine quits with a CS prop in flight?"
well I had a different thought--some of which was what cleaning solution to use on the seat?

LOL not funny though
Tom

mike newall · #9 02-11-2020, 01:21 PM

VG indeed !!!

FORANE · #10 02-11-2020, 01:25 PM

Quote:

Originally Posted by no7rosman

I am considering converting from FP to CS and worried about the same thing. Does anyone use electric instead of hydraulic for this? I saw they don't recommend electric for aerobatics but I have a 9A so that isn't an issue.

I have never seen or heard of anyone using electric pitch control...but it seems like a good solution to this concern.

I have an electric MT prop. I run it in manual mode so the pitch wouldn't change if the motor stopped running or if the prop stopped spinning. If run in auto mode the pitch would adjust to attempt to maintain the set RPM's and would stop when it reached the stop limit.