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Navajo ("Kodiak" Shakes and Jiggles: Maybe found the pr...

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Guest Allan Jones

Fire up the Navajo, and select Weigh & Balance with CG info showing. It's much too nose-heavy with the default loadout, reading about -7 (an impossible (?) value).I removed the front luggage, the co-pilot and the first row of passengers, added 200-pound passengers to each of the rear seats and 200 pounds to the rear cargo. The resulting CG reading was 35 -- more reasonable. The plane took off better and, when at cruise at 186TAS, the "jiggles" never showed up when I engaged autopilot.Prehaps with an unrealistic weight/balance condition, the AP is fighting to do the impossible. Try using loadout to correct the CG issue and see if the Navajo is better behaved.

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Guest Allan Jones

Steve,Did another test late yesterday, and the CG numbers were different (?) under the same loadout conditions. The modified loadout produced a CG value of 54 instead of 35 as I previously noted. Still, shifting the CG toward the tail seems to help. I can't help wondering if there is something wrong "deep down" in this aircraft's definition files.In Fly! 1/2K, the Navajo (speciifically, Rob Young's v88 version) was my favorite twin. Now they seem like completely different planes! In the II version, the Nav needs every bit of KLWSs 6512 feet of runway 26. and then just barely clears with lots of protests from the stall horn. I'm not a "real pilot," so I don't know if the real plane is so sluggish close to the ground.

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Allen,The Navajo isn't even close - this plane needs to be worked over big-time by someone with the skills of a Rob Young. The rest of the Fly! II aircraft are really pretty good, and the Rob Young corrections for the 'Flyhawk' and the Pilatus are a big help.I've found the initial loadout on the Navajo to be improper, so your approach certainly helps. I can verify that the aircraft is way underpowered (the v88 version was spot-on) and takes some special handling, but I have been able to get it off a 3000' runway. What flap setting are you using and when are you rotating? I can also verify that you'll need to "clean up" shortly after takeoff, level off for acceleration, then continue your climb-out.


Randall Rocke

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Guest Dean

Alan,Interesting discovery. I'll check it out and see if helps the autopilot problem.

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Guest Allan Jones

Randall,Thanks. Your procedure is quite close to what I do on take-off, including the low-angel initial climb. I set one click of flaps at power-up. I've tried getting to ~70 knots and then deploying the flaps, but it doesn't make much difference. Unless I tweak the W/B, the plane never seems to want to fly itself off the ground. I have to yank it up and that usually overcorrects and I hear that lovely stall horn.I found yesterday that the odd CG numbers are caused by the CG window needing to be re-opened to update. It doesn't update automatically when I change loadout. The -7 number is with stock loadout, inboard tanks full, outboard empty. I still get the best "feel" when the front-back CG number is about 35.I'm raising the gear as soon as I can, often with only a few feet of air between me and oblivion. I'm also going wing-smooth as soon as I feel I have control. Still makes for a slow climbout compared to the excellent v88.I, too, wish that someone could overhaul this model.

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Guest Bart

Just open the svh file and kick the CG back some, under the (CofG) tag, the last number is the front to back setting, a negative setting will move the cg toward the tail...or open the loadout file (.vld) and set what you are setting for loadout as the default, save you having to adjust it everytime.If it has a forward CG it'll take a lot to get the nose up on the takeoff run, if it'll come up at all.c ya :-waveBart flyhelp@zoomtown.comhttp://bartsflyplace.tripod.com/pics/ryans...ight/flight.gif http://bartsflyplace.tripod.com/bart_logo3.jpg

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Guest Allan Jones

Thanks Bart!I wasn't sure where those settings were hiding.As for getting the nose up, I was thinking a couple of bricks of C4.....

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>In Fly! 1/2K, the Navajo (speciifically, Rob Young's v88>version) was my favorite twin. Now they seem like completely>different planes! In the II version, the Nav needs every bit>of KLWSs 6512 feet of runway 26. and then just barely clears>with lots of protests from the stall horn. I'm not a "real>pilot," so I don't know if the real plane is so sluggish close>to the ground.Five days late with the reply, but yes, this model is sluggish and underpowered. Needs far too much attention to climb..... when even possible. About 10 years ago, I flew multi-lessons in a Piper Seminol which doesn't have the power of a real Navajo. Even a takeoff out of Afton, Wyoming with three adults & a child at over 6000' with the Seminol had much more power & climb than the FLYII Navajo/Kodiak.Like everyone else, I agree that the V88 model was far superior. It was my favorite for FLY1.

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Guest Dean

I must be the only one without issues with the Fly II Navajo, other than the autopilot jiggles. Since I don't have the real world experience of Larry or Randall, ignorance must be bliss! I have never heard the stall horn on climb-out with the Fly II Navajo and when I check the A/C specs, 1200 fpm rate of climb at 101 knots, I can hit them exactly all the way to 24,000 ft with the default loadout.

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Guest Dean

Just to add to my confusion, here is a shot of my default loadout information with C/G showing. It's the same everytime.

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Guest Colins2

RandallMany years ago when I did my multi rating in a Seneca 11, we had to carry some weight in the aft baggage compartment to get the cg within limits. I seem to recall that with just 2 front seat passengers it was outside the envelope.This was something the FAA examiner was really keen on.No surprise, as he was in the front with me!Maybe the (real) Navajo is similar? I'm not sure.Colin

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>Randall>>Many years ago when I did my multi rating in a Seneca 11, we>had to carry some weight in the aft baggage compartment to get>the cg within limits. I seem to recall that with just 2 front>seat passengers it was outside the envelope.>It's interesting to note the different flight characteristics regarding passenger weight, that you might not normally think about. For instance, in a RV6A experimental like mine, which is side by side seating in which your legs overlap the main spar (CG), but your body is slightly behind the CG...........................If flown solo with a heavier C/S prop & depending on pilot weight, you might have to carry or add some slight power during the final moment of touchdown to keep the nose from dropping to quickly. With a passenger & more weight behind the CG to compensate, you might not even have to think of it.L.Adamson

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Are you starting the flight at sea-level or something. :)Beginning at 4200'msl and engines leaned, my Kodiak/Navajo tries to fly like a "one legged dog". Just never seems to have enough power & un-normal stick forces are required to even rotate. I'm using the default loadout --- same as yours. I'd never use this bird out of Bountiful, Skypark which is just north of KSLC. Too many oil refinery towers less than a mile from the runway, for a plane that can't climb!! :)L.Adamson

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Guest Dean

>Are you starting the flight at sea-level or something. :)I never really thought about it but now that you mention it, yes. Most of my Kodiak flights have been out of sfo, dal, iad or phl. All under 700'msl. I also use auto mixture and auto fuel grade so I don't know if that would make a difference. It doesn't climb nearly as quickly as the Pilatus which I've been flying lately, but I can hit the above numbers in it. This may be the dumb question of the week but, are you guys retracting the cowl flaps on climb out? Once I'm trimmed for a steady climb I close them to the first notch.

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