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Thread: Approach speed for a turbine beaver

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    Member algonquin's Avatar
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    Default Approach speed for a turbine beaver

    Anybody got a bunch of turbine beaver time , the 11 seat version, PT 6-20? I'm flying one and just curious what speed you use when light 2-3 people 1/2 fuel for example . Also we are on wheels. Thanks Tom

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    Member avidflyer's Avatar
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    11 seat version??? would that not be an Otter??

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    Maybe it is a modified Beaver for hauling 11 little Texans around.

    Quote Originally Posted by avidflyer View Post
    11 seat version??? would that not be an Otter??

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    I've read about the new Viking Air DHC-2T Beaver that is essentially a stretched turbine beaver (not an Otter) certificated for 9-11 pax. From what I've read those are all powered by a PT6A-34. Have never heard of one with a PT6A-20. Maybe there were a few transitional mods built? Have only read about them and seen a few pictures. Sure sounds like a VERY cool plane! Sure would love to see one up close and personal!
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    Quote Originally Posted by Cresent Hills View Post
    Maybe it is a modified Beaver for hauling 11 little Texans around.
    A Super Cub will carry 25 of them, but you first have to boil the BS from them . . . . .

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    I would think 1.3 x Vso would work, then again reading the POH might help. 1.3 it the multiplier for the Approach speed. So if your airplane stalls at say 60 knots with full Flaps and gear down, then your approach speed would be 78 Knots, and since I can't read 78 Knots on an Airspeed indicator, I would just round up to 80 Knots. For bumpy and gusty conditions, I would add another 5 to 10 knots for a fudge factor. This stuff should be in the POH for the airplane. And since you are new to the airplane a good check out and flying it a bit, increase your landing and take off distances a bit till you get enough operational time and a good comfort level. Around a 100 hours in time is good number buy that time you should have a handle on the airplane and what you can or can not do with it.

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    There was an early conversion that used the old twin otter engine (PT6-20)... Straight 500 SHP...

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    Seating is 2,3,3,2, small jump seat in the rear . Just curious what others were doing was all. The airplane has a barons stol kit and flys fantastic. Just laughing a bit my last job you would have been fired for flying as loose as you recommend there 206.

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    I don't get the flying loose comment... What 206 says makes perfect sense...specially the part about reading the POH....

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    Well I asked for some general infro from beaver pilots and got a bunch of smart axx comments by people that don't fly beavers. A dissertation aimed at the pvt. Pilot level. And piper cub, at my last job before I retired we had formulas to get a speed and you flew that speed , within a kt or 2, it was rare to have someone off over 5 kts. You ever here the old saying aim small. Thanks I'm out of here.

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    Quote Originally Posted by algonquin View Post
    Well I asked for some general infro from beaver pilots and got a bunch of smart axx comments by people that don't fly beavers. A dissertation aimed at the pvt. Pilot level. And piper cub, at my last job before I retired we had formulas to get a speed and you flew that speed , within a kt or 2, it was rare to have someone off over 5 kts. You ever here the old saying aim small. Thanks I'm out of here.
    Formulae are "standards", just as are building codes. If you're flying "standards", you're not flying the airplane, it's flying you.

    And I apologize for offending you with my "smart axx comment" about Super Cubs and Texans. Didn't mean to offend you . . . . .

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    What is the formula for ********* pilot?

    Well I have an ATP and thousands of hours flying behind Turboprops both single and twin. What 206 said is perfectly legit. What is strange is some yahoo coming on this site asking for speeds that he should damm well already know if he is doing what he says he is doing.
    You don't fly an aircraft by the numbers, you fly it for the conditions you are in...if you can't adjust the numbers to match the conditions. You are in the wrong business. Which tends to straighten itself out over time, being in the wrong business that is...

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    OK, this has gotten a little out of hand, sorry to all that I have offended, I should have been more tempered in response . Please let me simply restate in a better way my intent of this post: I was only trying to open dialog , looking for some tips, with some experienced Beaver guys. Not to run thru my experience , but for instance I flew a DC 9 for fifteen years and would like to think I could offer some tips and insights into flying one. That's all I intended.
    One thing is flying in hi or low idle, what do experienced guys do, as it effects lots of thing like spool up time, reverse, approach etc. . I'm sure there are lots of thing experience has taught guys that have fifteen years in a Beaver.
    Again my apology to anyone I offended.

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    You might look at backcountry pilot forum. The site looks new has some pictures of K2 and their turbine otters. Maybe someone over there could give you some straight answers.

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    What outfit out of Talkeetna runs the Turbine Beavers in Healy during the summer?

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    Quote Originally Posted by pipercub View Post
    What outfit out of Talkeetna runs the Turbine Beavers in Healy during the summer?
    Talkeetna Aero Sevices/Fly Denali, Eric Denkewalter, I believe.

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    Yep. Those are Eric's planes. K2, nor Talkeetna Air Taxi fly turbine beavers. My son works in K2's shop.
    Bunny Boots and Bearcats: Utility Sled Mayhem

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    I would be curious to know about hi or low idle too. All ag pilots I know operate in low idle. The biggest thing for me is I like to adjust my prop so that when prop lever is forward and power lever is pulled back I can feel a fair amount of speed reduction. If a prop guy tries to set the prop according to king air specs, an air tractor will float for ever. If needed I will pull a little beta but try to keep ng above 60ish. I just never have thought the PT lag to be much of an issue.

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    ​I was kinda watching this thread as the topic plane sounds very cool. I am intrigued by the fact that you are getting acceptable performance in a plane of that size with a -20. This is really a
    C-206 sized engine! I would have 'guestimated' that it would require a -27, on the marginal end, and
    probably fit best with a -34 or -34ag, but then again I have no experience in that aircraft. Surely a
    testament to the wing!
    I have no Turbo Beaver experience, but have a few hours in similar sized 'overwieght' turbo props
    running Pratts in sizes varying from -11 thru -65's, as well as a few hours in Garretts of varying
    sizes and even the odd ball Walters.


    I think the questions involve too unique of an aircraft to be addressed in such
    a broad interest forum. I also agree with others that if you are the caliber of pilot that
    flies approaches to 1 KT, you probably are ahead of anyone who may speculate at answering
    your question here. If you don't know the answer or where to find it already, all the 1 kt
    approach stuff is moot…


    Having said all that, I have a couple opinions on PT-6s, (though none on the Beaver specifically)
    whether or not they are of value to you is up to you.


    Like Goose, I believe the whole song and dance about spool lag in a PT-6 is over rated hog wash.
    I suspect this song and dance comes from in experienced ramp rats, or Garret (only) drivers who watch a
    Garret on the ramp go from beta (flat pitch) to something taxiable, (fine pitch) with not much movement
    needed (all while spinning at close to 100%) and then they watch a Pratt go from full feather into fine
    pitch (while at 50 +/- %) all the while thinking that this is what's taking place any time you advance
    the throttle. Phooey…. All equal, free turbines have less spool up time than a shaft driven prop! Simple physics
    dictates this, because it has less mass to 'wind up'. Ever see how fast a hot start happens? In the Pratt
    the only time there is *significant* lag is when you have allowed the power section speed to diminish
    unacceptably. Consequently, if you are the type of pilot that can keep an approach nailed to 1 kt, you will
    never see an appreciable difference in spool up time between either engine. And the first time you transition
    form a Pratt to a Garrett you will be severely disappointed, because of all the hype you have heard about
    how much more responsive the Garrett is.


    As proof of this concept, I offer SEAT operations. The vast majority of which are now powered by big Pratts.
    In a heavy downhill drop, airspeed management becomes such that having the fuel lever at the gate is common
    place. In fact having the fuel lever over the gate and tickling reverse is very common. Never the less the prop
    (read; power section) is still spinning quite quickly, consequently there is no appreciable lag in throttle response
    at the round out and departure. This is the sole reason for the flight idle position on the Pratts, to keep the thing
    spooled up! which BTW does not function the same as the Garretts.


    Flight Idle vs. Ground idle…. what's really going on? In a smaller Pratt, the easiest way to look at this lever is
    to compare it to a gate that only allows you to pull the throttle back so far. Period…. it has no bearing
    on what the engine is doing once the engine is spooled up beyond that point. The notion that flight idle
    changes anything in flight (or on the ground) only exists if you let your engine wind down that far.
    It's true that most aggies fly in ground idle. It is also true that if you ask a green one why, he will say
    because it doesn't float that way. As an advanced pilot you should recognize that there are plenty of
    ways to control float, so where it's idling (barring an insanely high setting) has little relevance. The
    real skinny behind not flying in flight idle is because;
    A) we have already established that in a PT-6 that is spooled up, it is adding nothing. And..
    B) as a general rule an agpilot tends to run very short / frequent cycles lending to the possibility
    of an inadvertent flame out when there is enough cable stretch, a broken set screw, etc.ect.. that
    leads to the condition lever retarding just back enough to enter the ICO position. K.I.S.S..... that is the
    reason for leaving the lever alone... Period


    My personal habit is to advance the condition lever to flight idle and back to ground once while taxing
    to the pad, just to exercise the cable and assure that the gate is still operating correctly. Just as if one
    was exercising the prop on the roll.


    None of this is applicable to the Garret / Walters / or larger turbo props, and flying one like this will
    leave you looking for more power as you approach the departure end of the strip in a gutless fashion.



    Food for thought!
    Take care, Rob

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