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Left prop is feathered which is unusual on the ground for a Garrett engined a/c. But the R/H prop is in the usual flat (very fine) pitch which reduces starting loads.
Chris, your photo and comment fascinate me and I have been trying to find an answer for years, which is, all turboprops I see when on the ground and starting up, all have their props pitched flat to the air as shown in the left prop, which I would gather would have the most air resistance which doesn't make sense to me.
You indicate and mention that such a flat pitched prop is unusual yet that is how I see them all, when parked and when starting up.
I am obviously not a pilot, but could you or someone explain why they are the way they are when I see them and I assume that is the correct way even though you say it is unusual.
Confused I am. ;-)
I would have thought being flat to the wind would provide a lot of wind resistance to the start-up and make it harder on the starter motors.
You indicate and mention that such a flat pitched prop is unusual yet that is how I see them all, when parked and when starting up.
I am obviously not a pilot, but could you or someone explain why they are the way they are when I see them and I assume that is the correct way even though you say it is unusual.
Confused I am. ;-)
I would have thought being flat to the wind would provide a lot of wind resistance to the start-up and make it harder on the starter motors.
First off, Chris Robey is referring to the left engine, NOT the engine in the left side of the photo.
Garretts are normally shut down with the the prop blades in the flat or fine pitch setting.
Pratt and Whitney PT6's are shut down in the feathered setting. It has something to do with the different way they operate and whether it's a free shaft or something.
I only flew Pratts on the King Airs and never flew Garrett turboprops.
Apparently you can shut down a Garrett TPE331 either way though.
Garretts are normally shut down with the the prop blades in the flat or fine pitch setting.
Pratt and Whitney PT6's are shut down in the feathered setting. It has something to do with the different way they operate and whether it's a free shaft or something.
I only flew Pratts on the King Airs and never flew Garrett turboprops.
Apparently you can shut down a Garrett TPE331 either way though.
Thanks, Jim and I assumed the attention was given for the port (left) engine.
I am just curious why such turboprops always seem to be started up with the blades feathered flat to the wind, not just when shutting down, and doing that actually makes sense.
What doesn't make sense to me is having the blades feathered flat against the wind that would increase the spinning resistance. And is there any reason for doing so???
Or are the props just freewheeling during startup and there isn't any actual resistance on the starter motor engines involved???
I am just curious why such turboprops always seem to be started up with the blades feathered flat to the wind, not just when shutting down, and doing that actually makes sense.
What doesn't make sense to me is having the blades feathered flat against the wind that would increase the spinning resistance. And is there any reason for doing so???
Or are the props just freewheeling during startup and there isn't any actual resistance on the starter motor engines involved???
Hi Patrick. The Garrett TPE331 engines in this Skyvan are fixed shaft turboprops. So there is a direct physical connection between compressor section, turbine and propeller. So this will mean that the lowest starting load will occur with the blades in the normal (for a Garrett) fine pitch (like the actual R/H prop in this shot of N196WW). The PWC PT6A turboprop which is widely used (including on MOST, but not on all Beech King Airs) is a free turbine design where there is only a gas connection between the compressor section and the turbine section and the propeller. These blades normally start out slowly from the feathered position, which has the benefit of being safer for ground personnel.
Thanks, Chris and others, who supplied my brain with some more information it can use,
in the air as we "speak" 09:18 EDT August 28, 2020
NICE pic!
NICE pic!
Unkind folks used to say that the Shorts was "the box that the Dornier 328 came in!"
Love the fat boy short...looks like it just ate 3 little planes
The Skyvan can carry a vehicle driven up the rear ramp.
The Irish Concorde :)
運航表
1998年のN196WWに関する全資料を検索しますか? 今すぐ購入。1時間以内に入手できます。
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日付 | 機種 | 出発地 | 目的地 | 出発 | 到着 | 時間 |
---|---|---|---|---|---|---|
2025年05月 9日 | Unknown | Bishop Airfield (1AZ0) | Coolidge Muni (P08) | 09時08分 MST | 09時29分 MST (?) | 0:21 |
2025年05月 9日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 07時46分 MST | 08時37分 MST (?) | 0:50 |
2025年05月 9日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 06時26分 MST | 07時03分 MST | 0:37 |
2025年05月 9日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 05時42分 MST | 05時56分 MST (?) | 0:13 |
2025年05月 9日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 04時08分 MST | 04時33分 MST | 0:25 |
2025年05月 9日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 03時34分 MST | 03時58分 MST | 0:24 |
2025年05月 9日 | Unknown | Coolidge Muni (P08) | Bishop Airfield (1AZ0) | 03時08分 MST | 03時24分 MST (?) | 0:16 |
2025年05月 8日 | Unknown | Bishop Airfield (1AZ0) | Coolidge Muni (P08) | 11時04分 MST | 11時22分 MST | 0:18 |
2025年05月 8日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 09時38分 MST | 10時30分 MST (?) | 0:51 |
2025年05月 8日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 08時17分 MST | 09時08分 MST (?) | 0:50 |
2025年05月 8日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 06時48分 MST | 07時40分 MST (?) | 0:51 |
2025年05月 8日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 06時02分 MST | 06時17分 MST (?) | 0:14 |
2025年05月 8日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 05時42分 MST | 05時56分 MST (?) | 0:14 |
2025年05月 8日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 05時19分 MST | 05時35分 MST | 0:16 |
2025年05月 8日 | Unknown | Coolidge Muni (P08) | Bishop Airfield (1AZ0) | 04時54分 MST | 05時11分 MST (?) | 0:17 |
2025年05月 7日 | Unknown | Bishop Airfield (1AZ0) | Coolidge Muni (P08) | 13時19分 MST | 13時41分 MST | 0:21 |
2025年05月 7日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 11時46分 MST | 12時43分 MST (?) | 0:57 |
2025年05月 7日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 10時20分 MST | 11時17分 MST (?) | 0:57 |
2025年05月 7日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 08時22分 MST | 09時22分 MST (?) | 0:59 |
2025年05月 7日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 06時54分 MST | 07時50分 MST (?) | 0:56 |
2025年05月 7日 | Unknown | Coolidge Muni (P08) | Bishop Airfield (1AZ0) | 04時51分 MST | 06時17分 MST | 1:26 |
2025年05月 2日 | Unknown | Bishop Airfield (1AZ0) | Coolidge Muni (P08) | 09時23分 MST | 09時42分 MST (?) | 0:19 |
2025年05月 2日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 08時07分 MST | 08時58分 MST (?) | 0:51 |
2025年05月 2日 | Unknown | Bishop Airfield (1AZ0) | Bishop Airfield (1AZ0) | 06時50分 MST | 07時42分 MST (?) | 0:52 |
2025年05月 2日 | Unknown | Coolidge Muni (P08) | Bishop Airfield (1AZ0) | 04時55分 MST | 06時25分 MST (?) | 1:30 |
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