Starting a PT-6

[satpak77]

not being a smart aleck (Avbug that was good info) but me personally, I just stick to the checklist. My fancy B-350 "Before Engine Starting" checklist states

Power Console and Pedestal

a. Power Levers - IDLE
b. Prop Levers - FULL FORWARD
c. Condition Levers - FUEL CUTOFF

etc etc

I am not smart enought to recite all that A & P stuff above. I just do what the checklist says. That is good info above tho, but some guys eat that up, I am just not one of them.

Some of the guys you fly with want to read the POH in flight, and find "wow, I didn't know that" stuff buried in there. I am not in that crowd however. Thats all nice and all, but I tend to read USA Today or Maxim at cruise and my thoughts are on if Sally is working the counter at the my favorite FBO, and not why does convection fog occur.

The factory wrote the checklist....I stopped trying to be smarter than them a long time ago!

 

[avbug]

You're not being a smark alec. I don't think anybody is suggesting anything to the contrary, and I agree with you whole heartedly. I also believe you can never know enough about your airplane.

Bear in mind when looking at the checklist, it was written by the airframe manufacturer, not the engine manufacturer. That doesn't mean you shouldn't follow it; clearly it's there to be used. Just means you should think.

Most all of us have flown Cessnas and pipers with continental and lycoming engines. How many checklists did you see that included post flight runups and idle mixture checks? Probably none, because it's never included in the checklist, and in most cases in the pilot operating handbooks. But it is included in the engine manufacturers literature and publications, and doing it enhances safety, engine longevity, and catches problems before they become problems. One example of many where knowing more about the airplane than what's in the short book, pays off.

Specifics such as harmonic ranges and operational limitations aren't always on the checklist, but the pilot must know them anyway. Sometimes these are reflected in color codings on the airspeed indicator, but not always. A number of things need to be known, rather than just read, in order to fly the airplane, in fact, from turbulence penetration speeds to landing gear speeds, and much of what we do is still pilot discretion...such as when to drop the gear...or when to push up the prop. Again, different airframes have different needs, as do different types of operations. If you're starting over loose gravel, starting in feather is a wise idea, as is taxiing with the ice vanes/inertial separators deployed for PT6 installations. That may, or may not be in the checklist, but it's certainly important to the life of the engine and the propeller.

My previous point wasn't use or non-use of the checklist, but rather that the pilot was applying technique based on a misunderstanding of the basic operating principle of the engine. Any time one operates the airplane according to a myth, it's time to seek better training and understanding of the machine.

 

[BGSkyGuy]

Good info Avbug! You always get me thinking...

 

[satpak77]

excellent thread

i agree about the gravel/rough strips, it is not on the checklist per se, but is in micro-fine print under limitations or performance, I can't remember, for the B-350.

 

[Cstyle]

Let me interject my $.02.

In my experience with the King Air and the Shorts their starting sequences are vary similar. Not surprising, considering they are both running PT6's.

The main difference is in the position of the prop levers during starting. The reason for starting the Shorts with the props in feather was well covered by avbug.

My understanding for the reason to start the King Air with the props forward is an electrical issue.

The oil pressure gauges in the King Air are AC powered. The static inverter is not brought on line until after both engines are started. Starting with the props forward will give you an indication of engine oil pressure, as the props move from feather to flat pitch. This of course assumes the engine was shut down in feather, which is what is called for on the checklist.

In any case, my philosophy has always been to operate the A/C the way I was trained. If it’s your airplane, do it however you want. Otherwise, follow the checklist.


FYI: The King Air info above is for the 1904 A90 I have flown. Your mileage may vary.

 

[MauleSkinner]

My understanding for the reason to start the King Air with the props forward is an electrical issue.

The oil pressure gauges in the King Air are AC powered. The static inverter is not brought on line until after both engines are started. Starting with the props forward will give you an indication of engine oil pressure, as the props move from feather to flat pitch.

FYI: The King Air info above is for the 1904 A90 I have flown. Your mileage may vary.

This is correct...for the 1904 A90, although I'm not sure they had static inverters until the 1906 models came out

Later versions went to DC gages, and this isn't an issue any longer.

I would eliminate this statement, though...

This of course assumes the engine was shut down in feather, which is what is called for on the checklist.

Regardless of propeller lever position, the propellers WILL go to feather upon shutdown, as they are spring-driven that direction, and the loss of oil pressure will allow the springs to do their things.

Fly safe!

David

 

[MauleSkinner]

Some of the guys you fly with want to read the POH in flight, and find "wow, I didn't know that" stuff buried in there. I am not in that crowd however. ...

The factory wrote the checklist....I stopped trying to be smarter than them a long time ago!

Not to hijack the thread, but there are a LOT of things in the POH that aren't in the checklist...f'rinstance...in Hawkers, the book tells you not to hold the nose off the ground for aerodynamic braking, lest you screw up the main gear something awful (and trust me...the shaking IS awful). Never heard it at school, and it's not in the checklist, but it IS in the book.

A couple of our guys were trying to troubleshoot an engine indication for a long time...DoM came up with a form to fill out that was largely engine parameters. I found out about this when I got in that particular airplane, having not been in it for over a year. Had the engine issue at cruise, pulled out the form, and thought "why am I filling this out? I just push this little button here, and the engine computer takes a picture of all this stuff for a fair amount of time on either side." Not in the checklist, as the computers were a mod and the checklist was never changed to reflect the fact that the vast majority of the airframes HAVE been modded...but it's in the AFM supplement. Care to guess how many people in the company HAD read that supplement?

Long story short, I strongly recommend reading ALL of your aircraft's manuals and supplements...whether you do it at cruise or on your own time is your business. I like to do it on company time

Fly safe!

David

 

[7777]

Noise and ice are the two reasons I start in feather. If I am close to a FBO and they don't want the noise, I start in feather. If I am on ice and think I might slide, I start in feather. Other than that, I start out of feather. Just my 2 cents.

 

[satpak77]

Not to hijack the thread, but there are a LOT of things in the POH that aren't in the checklist...f'rinstance...in Hawkers, the book tells you not to hold the nose off the ground for aerodynamic braking, lest you screw up the main gear something awful (and trust me...the shaking IS awful). Never heard it at school, and it's not in the checklist, but it IS in the book.

A couple of our guys were trying to troubleshoot an engine indication for a long time...DoM came up with a form to fill out that was largely engine parameters. I found out about this when I got in that particular airplane, having not been in it for over a year. Had the engine issue at cruise, pulled out the form, and thought "why am I filling this out? I just push this little button here, and the engine computer takes a picture of all this stuff for a fair amount of time on either side." Not in the checklist, as the computers were a mod and the checklist was never changed to reflect the fact that the vast majority of the airframes HAVE been modded...but it's in the AFM supplement. Care to guess how many people in the company HAD read that supplement?

Long story short, I strongly recommend reading ALL of your aircraft's manuals and supplements...whether you do it at cruise or on your own time is your business. I like to do it on company time

Fly safe!

David

good points...I kinda exagerrated (sp?) to make my point, I do read everything I can get my hands on, but I am not up at cruise working on my Riddle Phd thesis on airflow and stall speed changes when the ice boots are inflated either.

One thing we do (that is us, not necessarily everybody out there) is put windshiled heat "ON" at 10K in the King Air and 10K turn it off coming back down. Beech claims it will "be in the next edition" of the POH but they have said that for years now.

It is not "in the book" but is something we do.

However, in most all situations, we stick to the book and try not to outsmart it (not too much...)

FLY SAFE

good thread, keep it going

 

[Striptyler]

I may be mis-understanding this, but i was under the impression in the 1900D, that, the boosted oil will always flow into the prop, and that the govoner regulates blade angle by regulating how much oil leaves the hub... Thus, ensuring a fresh, warm supply of oil at all times, during all phases of flight.

That being said, during start it wouldn't the oil be circulating through the prop dome?

eh, could be our training materials