Light Twin Feather Detent

[KingAir1985]

If it is direct drive it stays in low pitch at shutdown. If it is fluidic coupling it goes to feather upon shutdown. I have been told that is one of the main ways you can tell the difference between a PT-6 and a Garrett just looking from a distance.

 

[A Squared]

If it is direct drive it stays in low pitch at shutdown. If it is fluidic coupling it goes to feather upon shutdown. I have been told that is one of the main ways you can tell the difference between a PT-6 and a Garrett just looking from a distance.

One big exhaust stack in the rear of the engine vs. two smaller ones at the front of the engine is a pretty good way to differentiate

 

[KingAir1985]

One big exhaust stack in the rear of the engine vs. two smaller ones at the front of the engine is a pretty good way to differentiate

Gotcha, thanx.

 

[Blueliner]

Yep...gotta shut one down on the ride. I'm surprised you haven't shut one down in training...very surprised.

-mini

I dont have a PTS nearby, but I am pretty sure a full shutdown is not required. It is not for a pt. 135 ride.

 

[timeoff]

I don't have my multi yet, but the PTS states simulated below 3000agl. Above that I believe your DE can have you shut one down.

page 2-28:

http://www.faa.gov/education_research/testing/airmen/test_standards/pilot/media/FAA-S-8081-12B.pdf

 

[IP076]

Yep...gotta shut one down on the ride. I'm surprised you haven't shut one down in training...very surprised.

-mini

I too am surprised you haven't done this in training. The PTS doesn't technically say you have to do one on every checkride, it says something along the lines of "If you are using an aircraft in which an engine can be safely shutdown, and restarted, you do a complete shutdown." So, its up to the examiner. I do believe a PA-44 to be in this category. We do engine shutdowns during the training, and on practical tests, above 9000' msl. (Airport elev. of 5000).

You're description of the prop system is pretty accurate. However, I don't see the need to rush. I'll have to take another look next time I go flying, but at 88kias with an engine shut down and the prop windmilling, I do believe the RPM is higher than 950...but I'll have to double check that!

 

[minitour]

However, I don't see the need to rush. I'll have to take another look next time I go flying, but at 88kias with an engine shut down and the prop windmilling, I do believe the RPM is higher than 950...but I'll have to double check that!

Absolutely. I just want the original poster and any other multi students that may be reading this to see how many people have said this...don't rush.

You can take your time to make sure you're doing it correctly and still get it done quick. Just go through your procedures. The prop won't come to a complete stop from just windmilling...unless you've got no oil or something else going on in the engine. Then all bets are off....

But yeah, with one windmilling at Vyse (88), the RPM in the seminole is well above the 950 needed...you should have no problems what-so-ever.

Good luck with the rest of the training & have fun!

-mini

 

[CalifDan]

I once had an instructor ask me what was the first thing I would think about if an engine failed. I went through the throttles, props, mixtures, dead foot checklist stuff and he told me that was incorrect. He said the first thing you think about is "What is this going to cost me?". He said if you have the presence of mind to consider that, you will be slowed down enough to do everything else right.

 

[Tonala2k]

I have often wondered why some turboprops are designed to be feathered on normal shutdown, and some not.
Is there any advantage in one system over the other?

As mentioned, a turbo-prop that maintains high RPM at shut down has a geared connection from the N1 shaft. Like with a piston direct drive, you would otherwise have to work against the air resistance on start up. Bad Idea.

Turbo-Prop Engines only shut down in the feathered position when there is not a geared connection. Instead, the engine uses exhaust gas pressure to turn a turbine connected to the prop. This takes the load off the engine during start up. Allowing the the engine to start in this way with a feathered prop allows for a simple auto-feather design in the event of a failed engine.

 

[SPilot]

I didnt hack the simulated engine failure until my instructor told me "make it look boring", and he incorporated a few seconds delay before I was allowed to start with the checklist. First priority is airspeed and aircraft control, and not until you have the aircraft under control should you begin thumbling inside the cockpit. Of course after lots of practice you can do it at the same time because flying the airplane becomes second nature...but at least during training: take your time and trim the aircraft for Vy/Blue line, put your corrections in, and then take a deep breath before you start the checklist.