Twin Engine PT6 rigging

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silverjack18
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Twin Engine PT6 rigging

Post by silverjack18 »

Can anyone recommend a facility or someone (in Canada or the USA) that is proficient in rigging twin engine PT6 powered aircraft for power lever matching? (King Air series preferably) Where in take off, cruise, and reverse, the power levers are even and the aircraft doesn't want to veer off the runway because of the mismatched rigging between the engines?
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ahramin
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Re: Twin Engine PT6 rigging

Post by ahramin »

The only guys I have found in all of North America that can rig a King Air to my satisfaction are the ones at Jet Aviation, Dallas Love Field. Every single King Air that goes through that place comes out with perfect rigging.
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L382Medman
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Re: Twin Engine PT6 rigging

Post by L382Medman »

is this a joke!
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kilpicki
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Re: Twin Engine PT6 rigging

Post by kilpicki »

Yes it is, how many shops in N America have twin engine pt6s in them, 100? 200? probably 1000 and 1 pilot has been to them all and decided 1 is best.
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ahramin
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Re: Twin Engine PT6 rigging

Post by ahramin »

Lol, learn to read kids. That's the only place I've found, from a sample of about 15 shops.

Obviously there are more, so why don't you post the name of one, and then we'll be up to two.
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2550
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Re: Twin Engine PT6 rigging

Post by 2550 »

Even levers in TO, cruise, AND reverse? That would make things way to easy.
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kilpicki
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Re: Twin Engine PT6 rigging

Post by kilpicki »

Shouldn't that procedure be in the MM? Or get the last maint person to go on course and get their notes from class.
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rigpiggy
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Re: Twin Engine PT6 rigging

Post by rigpiggy »

Your assuming that you have 2 perfectly matched engines, even identical twins are different, so are engines. Give it a warm start or 2, and several hundreds of hours, and you'll be bitching again. It isn't FADEC learn to fly it.
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Heliian
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Re: Twin Engine PT6 rigging

Post by Heliian »

Sure the levers probably could be perfectly rematched at every check by any king air wrench, how much are you willing to pay for this service? It requires several runs and adjustments to get the settings perfect for power output and like said above may fall out of perfectness within a short time. If you think that the levers are so bad that it becomes a flight safety issue, then snag it in the logbook. It may also be "slop" in the linkages that is within acceptable limits but would require much time and parts to make perfect again.
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ahramin
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Re: Twin Engine PT6 rigging

Post by ahramin »

There's no reason to accept poorly rigged engines because it will cost money. Cost of owning the aircraft and money well spent, especially with our winter conditions.

It's like fuel guages, I don't know how many King Air drivers I've run into that when the fuel guages are out by a couple hundred pounds say: "They are all like that". Costs money to empty out the tanks and calibrate the guages, but then you know how much fuel you have.

Don't accept poor aircraft maintenance people.
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Heliian
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Re: Twin Engine PT6 rigging

Post by Heliian »

Most a/c are hand built and no 2 are exactly alike, even if they have sequential serial numbers. If it's within acceptable limits as outlined by the FM and MM then it's not poorly rigged, if you can't one hand the throttles there is obviously a problem. A fuel gauge out a couple hundred! pounds is cause for adjustment, duh. Complaining that the #2 throttle is a mm out is just being picky. If you think that all the mechanics out there are just incompetent or lazy then rig it yourself and see how that goes.

As said by an earlier poster, a fadec system will take into account the myriad of factors for fuel scheduling and be perfect, 2 independent engines running a hydro/pnuematic mechanical fuel system will never be perfectly matched through all ranges. Even rigging 2 seperate single engine pt6 powered aircraft will yeild different results on the quadrant.

So, next time you are talking to your wrenches, ask them nicely if they could rig it to be more even in the range you want.
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ahramin
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Re: Twin Engine PT6 rigging

Post by ahramin »

My car mechanic calls it Cadillac Owner's Syndrome. I just call it Wanting Shit To Work Correctly. If I own it or have to deal with something on a regular basis, it better work right.

Having fuel guages that work properly may be a duh for you and me Heliian, but most of the 703 pilots I've met don't know that.
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torquey401
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Re: Twin Engine PT6 rigging

Post by torquey401 »

Don't accept poor aircraft maintenance people.
I agree 110%. And the process should start with the driver of the bus. How would anyone know that the power levers in your aircraft need to be adjusted?

If it is a safety of flight issue (ie really bad), then snag it and get it fixed. If it is an annoying issue (not really bad and you can live with it and it is within limits) then talk with the maintainers and get it fixed at the next inspection. If it has come out of inspection like that, don't accept to fly it as is and get it fixed BEFORE blasting off. Maintenance and flight ops both have jobs to do to make the company successful and safe.

Inaccurate fuel indicating is rarely a calibration issue and requires time to troubleshoot. Calibration usually comes after the fix.
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Pat Richard
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Re: Twin Engine PT6 rigging

Post by Pat Richard »

The biggest issue I found over the years with Kingair engine rigging was with the ctrl cables/linkage from the quadrant to the engines.
If the position(lever quadrant) of the power lever changes for a given power setting on the return leg to idle, or vice versa, I'd suspect the cable.

Shouldn't be a huge deal to almost 100% match them otherwise, but like it was mentioned, it's not fadec, and they all will have some stagger. Anything more than half a knob was usually when we were asked to start looking. I can't remember the actual allowable limit, but its been many years.


Pat
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sprayrail
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Re: Twin Engine PT6 rigging

Post by sprayrail »

Pat's partly right but the biggest single issue I've encountered over the years with nearly all King Air/B99 models is stretched cables. Now I'll confess I have never had any experience with new or low time aircraft, they have all seen better days but if you're careful to adjust some of that extra play out, the rig up is a lot easier. Remember there are alot of little adjustments you can make initially on the engines themselves to make the controls at the quadrant behave the way you want.
Like anything else though you can only make honey out of horses**t for so long before new parts are required.

Regards
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Pat Richard
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Re: Twin Engine PT6 rigging

Post by Pat Richard »

Pat's partly right but the biggest single issue I've encountered over the years with nearly all King Air/B99 models is stretched cables
The biggest issue I found over the years with Kingair engine rigging was with the ctrl cables/linkage from the quadrant to the engines.
So Im partly right/mostly wrong??? You just repeated what I said, which is the cables are a problem. :roll:
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KISS_MY_TCAS
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Re: Twin Engine PT6 rigging

Post by KISS_MY_TCAS »

Stretched cables are common, but I have found if the same AME doesn't rig both engines, it turns into a goose chase. Tell your maintainer you want BOTH engines rigged. Far easier to rig a mechanical fuel system as a pair on a PT6 twin than trying to match one to someone elses rig, and often faster to accomplish. It will also tell you right away if you have a cable problem after the AME beats his head against the nacelle for a xouple hours trying to rig it out.
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roscoe
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Re: Twin Engine PT6 rigging

Post by roscoe »

IMHO when it comes to arriving at peace and quiet over power lever stagger/mismatch the journey starts at the power lever to firewall quadrant rigging. Get that right, and by right I mean travel and cable tensions as per the MM, not TLAR methods, and the firewall forward will be a lot easier to get right.
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T44-CDI
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Re: Twin Engine PT6 rigging

Post by T44-CDI »

Sorry to add to such an old post, but here it goes. Currently I work for a United States Navy contract in South Texas maintaining 52 King Air, flight training aircraft. We have insanely tight tolerances on every aspect including twin engine rigging. A few of us are branching out to start our own mobile repair business with a start up focus on rigging. I will guarantee our rigging to meet or exceed the top shops out there. Try us, you will not be sorry!
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GA MX Trainer Dude
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Re: Twin Engine PT6 rigging

Post by GA MX Trainer Dude »

This is still there.

viewtopic.php?t=86178

Regards,
MX
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You can train a monkey to ride a bicycle but you can't train it to fix it!!!
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