Turbo Commander: Engine Start Deep Dive

#turboprop #turbocommander #aircraft #engines
So you are probably wondering why my finger is on the HP limiter switch during the start sequence. This is something you will not find in the operating manual. By bumping or holding the HP LIMITER switch in the TEST position we can reduce the fuel supply to the engine thus controlling temps that may be trending to the hot side. This is very useful during a quick turn when the engine is close to the maximum start temperature of 300 Celsius.
It is not uncommon for an already warm engine to want to exceed max start temperatures, this presents as a normally moving ITT gauge needle that just wants to keep going up the scale. To control this type of start the HP limiter can be blipped or held to manually stop fuel from entering the burn cans and halting the temperature increase until the compressor can spool up enough to supply adequate air flow to keep combustion temperatures within limits.

[@ErikFigueroa]

Someday, hopefully this year, there will be a Turbo Commander in MSFS. :) I'm sure this video will become popular once that happens!

[@FlyingWildAZ]

Did you ever fly the Carenado Turbo Commander in X-Plane 11?

[@mysteryY2K]

i enjoyed the Carenado one in P3D. hope to see it in MSFS as well! love the Aero Commander 500 as well

[@anac3652]

Incredible video, makes me really want to get into these old twins before they are inevitably retired... gotta build them hours

[@bernardanderson3758]

I always love flying in these types of Aircraft and this is a great way to see how it’s all done

[@mikemiller659]

My Dad was a draftsman for Aero Commander..Rockwell in OKC from 1963 through 1972 when he passed . He took me & my sister to the plant one evening and saw the plane Arther Godfrey flew around the world in.

[@1212CRMD]

Thank you so much for teaching this Start Procedure for the Turbo Commanders. I flew a 681 back in 1994, now with your instructions I am able to get it started. Please, if possible making other videos about taxing rudder and steering wheel typical Turbo Commander's control and other Ops procedures. Thank you a lot.

[@Michael-iw3ek]

omg the visibility in it is amazing

[@erice9536]

Wowsa, trip down memory lane there. I used to work at the factory (flight line) in Bethany a long time ago. I guess I am calling your airplane old. :)

[@FlyingWildAZ]

Well look at the legacy you have left Eric!

[@jimdavis1939]

Well, this one brought back a lot of memories, man I loved that airplane! Flew one for 2 years. Marvelous airplane!!

[@tanabi]

Brings back memories of the SC 7 and the Do 228 days

[@gilamonsterfab3438]

I did not realize that you were out of KSAD till I watched this video that is where i fly out of and want to get to fly one of those someday.

[@garypugh1153]

Wow im 71 rented cessna 152's 40 years. Remove wheel ckocks and tie down. Turn the start key, taxi for takeoff ! Nice😊

[@ivoryjohnson4662]

This is an amazing video!!!

[@jim5870]

They say that whenever a TPE 331 engine starts a baby is born deaf. I used to work on Swearingen Merlin II

[@FlyingWildAZ]

OMG you are killing me! I always love pulling into the FBO and seeing all the Biz Jet folks running for their lives.

[@ericm333]

Thanks for sharing

[@jeff95050]

Great video. Love the guages on screen during switch manipulation. A lot to take in, but pause and replay makes it all perfect and very instructional. Very nice job!!! Thank you.

[@john-lb5fu]

Great stuff.... keep it coming!!!

[@matiasmerono]

Great video to enjoy - Long, long time ago I was seventeen and I started a Garret but a TFE731 for the first and last time🙃🙂

[@FlyingWildAZ]

Oh do tell that story please!

[@matiasmerono]

@@FlyingWildAZ Difficult to do shortly and still painful almost forty years later.

[@zachhering5809]

I love Garretts so much.

[@mw7440]

No NTS test?? On the MU-2 We did that test on every start. Fail was a no go item.

[@ADAPTATION7]

Very well explained. One question if I may: What exactly are the differences between power levers and fuel condition levers? Do thrust levers act on the propeller pitch as the power is increased?

[@FlyingWildAZ]

Power lever from flight idle to max thrust is going to control the metering valve in the fuel control unit, Condition lever is only going to set the prop governor, for the commander the permissible RPM range in flight is 96% to 100%. To give RPM % context the Garrett turbine spool turns at 41,730 max rpm with a 26:1 gear reduction to the prop for a max RPM of 1,591.

[@ndenise3460]

The condition. Lever sets the underscored and primary prop control. The power lever acts as a manual fuel valve and the prop governor controls engine speed@ 96-100% the over speed will hydraulically govern the prop above 101%, and the hp limiter will dump fuel above 717hp. Other garretts have a TTL temp/torque limiter

[@ndenise3460]

Underspeed governor

[@Captndarty]

Perfect video for Horizon underwing employees

[@azspotfree]

Dang, starting that thing is an ordeal.

[@dr62220]

Have overhauled many, many of these turbines along with the 731's Worked on as many Commanders, both piston and turbine. Anyone needing schooling, let me know. 74 yr A&P

[@pascalcoole2725]

Seems a procedure simular to other free turboprop engines. one advice, during startup not only carefully monitor the ITT, TGTR, JPT (whichever yopu have) but alsno monitor the FuelFlow... A high fuel flow may indicate a faulty fuel controller and surely result into a hot start. Also time your startup to prevent running into a hung start.

[@FlyingWildAZ]

good advice!

[@ndenise3460]

Our callouts. Rotation,10%, fuel flow, ignition, light off ,egt, 50/50, stabilized ,70%, stable start, parallel,gen on

[@maxcfi7718]

awesome video, thanks! would love to fly one

[@Critter145]

It’s only confusing bc I’m not a pilot. Happy flying!

[@ndenise3460]

No NTS test, no checking overspeed or underspeed governors.. Considering that most TCs only get a few hundred hours a year. These are critical. Also didn't discuss parallel vs series starts

[@FlyingWildAZ]

We fly our Commanders on a daily basis, the checks you described are done at the start of the week, they are not daily checks. The base NTS check is done every startup and there is no reason to discuss parallel vs series starts because the conditions requiring it are rare.

[@ndenise3460]

Well maybe my company takes it seriously because we spend 90% of our time below a 1000' ago and a lot of it at 200'. Every start.

[@FlyingWildAZ]

@@ndenise3460 Nothing wrong with that.

[@stkbkr1]

love it brother

[@alex14franklin]

ah the good ol garrett grenade

[@pilotdane1]

COOL !!!!

[@mysteryY2K]

so i have a question. so in a normal turboprop (with no autofeather/feather lock start), say a Cessna Caravan, would you start the engines with the prop lever full forward, then bring it back after start? just wanted to make sure i'm understanding this right.

[@ndenise3460]

The pt6 requires 10c prior to taking it out of feather. Above that you can start either in feather or ground/flight. If you don't have the power lever up it will settle at ground range.

[@mysteryY2K]

@@ndenise3460 thanks for the reply!

[@calvinnickel9995]

@ndenise3460 Negative. You can start it in fine pitch. This is the PT6-20, PT6-114, PT6-140, PT6-60A, and PT6-67. In fact most plane will not allow you to keep it in feather for any length of time due to hot exhaust gases damaging the airframe. The only PT6 I know that they tell you to keep in feather is the PT6-67AG on the Air Tractor 802.

[@waynec369]

One has to wonder why the controls in an airplane are always beat to hell...

[@wasimakhtar2625]

💞Good 💞

[@rowleywalsh]

Are you still flying jets?

[@FlyingWildAZ]

I went back to Turbo Commander after I did my year commitment and recently transitioned to Super King Air 200

[@ThomasMarcotte-jt9od]

What are the FM radios for?

[@FlyingWildAZ]

This aircraft is configured as a Fire Attack Command and Control Aircraft. They talk on a ton of frequencies.

[@sledawgpilot]

NTS check?

[@FlyingWildAZ]

I debated about going into NTS and the checks required during start but decided that subject deserves a dedicated video for a later date.

[@sabinasabine4122]

Hoped for the same ! Is that video out ? This is the best start up video I have seen. Thank you.

[@Booosting]

95% of the switches and instruments on the airplane are completely useless just to make it look complicated and hard to operate.

[@sylkelster]

Name a couple of useless switches so I can remove them.

[@Booosting]

@@sylkelster all except the starter

[@jjkrmain]

Cool! Now I can steal....er.....properly start a Turbo Commander if I happen across one that is "unattended". Good Vid. Newer pilots just press buttons without actually understanding what is happening.

[@FlyingWildAZ]

New pilots conduct maneuvers without knowing what is actually happening as well.

[@calvinnickel9995]

@jjkrmain Older pilots too. They are the reasons for dumbing things down as well as higher insurance rates.

[@andreaseckert8683]

Nice video! Brings back some momories. I worked on the twin commander the last time about 15years ago. Always loved the unique looks and sound of it. Now they become quite rare over here in europe.

[@Breenild]

Interesting video! Thank you for that! 😃

[@ndenise3460]

Wrt the PT6, the oil temps come up fairly quick, however in my environment of you take the blades out of feather prior to 10degrees oil temp you'll blow prop seals. In the Arctic you either tether the prop on the start, or make the F/O hold it until temps come up. Yes helfansayftie loses there shit

[@TerrySmith-em4ph]

Excellent presentation !!!

[@maheralazzawi7814]

Very good

[@iainmillar1532]

I flew survey in a turbo commander for a couple of years around 2005-2007. The sounds brought back good memories!

[@AZCubDriver]

My dad was an engineer at Garrett and extremely involved in the development of that engine. Your seeya at the end makes me wonder if you worked at Great Lakes at some point?

[@FlyingWildAZ]

"See yaaaaa" is pretty ubiquitous across the industry

[@AZCubDriver]

@@FlyingWildAZ I’m retired ATC at Phoenix Tracon and they were kind of notorious for it.

[@bernardanderson3758]

Love the sound of the Garett engines and especially when you have to go in BETA

[@crazyhumpy]

Awesome video! Thanks for making it!

[@grafhilgenhurst9717]

Great video! Can anyone explain why the Garrett and the Pratt and Whitney PT-6 are so different, yet both accomplish the same goal?

[@ndenise3460]

They both burns jet fuel, I e is easier to start.

[@LightningSpeed64]

I’ve spent many years around U.S. Forest Service air attack turbo commanders, and they are by far the most obnoxious sounding airplane ever invented.

[@ndenise3460]

You haven't been around a Rolls Royce Dart then. The original two finger salute.........One in each ear

[@OVTraveller]

Loved, loved It!