OK new guy here
If one needed a prebuy on a 30 by a good shop near ATL, where might one go? Say north through SE of ATL 100 miles.

Hi Cliff and welcome to the ICS Forum,

 

I live too far west to know the shops in you area so you might try contacting your tribe Rep - she can be found under the ICS Reports Tab from the home page or click here and scroll down. http://www.comancheflyer.com/NS/bod_list.php

or you might try under the members Tab, click Pathfinder and use GA as a search criteria - 45 hits. If you don't already know, N numbers ending in Y are usually twins - this is more hit or miss but lets you know there are a bunch of Comanche owners close-by.

Glad you are using ICS to find a qualified person for the pre-buy. If you don't find a local shop, I'd pay to fly in one of the ICS tech directors or Tim Talley from Clifton Aero to do the pre-buy - that expense would be small compared to a first really expensive annual. Don't know if 400 owner Matt Kurke from Naples, FL would be interested at www.Comanchegear.com - he'll tell you if not.

Hope this helps.

I rhink Paul New is in Jackson, TN, I don't thonk you will find anyone that close to ATL that knows enough about Comanches to do a proper pre-buy.

Cliff,

 

Kristin and Pat know much more about maintenance than I do. As a new ICS member near Atlanta your Tribe Chief is Sally Williams, and ICS president is Bernie Mazurek, both live in Florida and could likely suggest a Comanche specialist near you. Sally's phone is 561 625 0313 and she can put you in touch with Bernie. Actually they are meeting today in Palm Beach with tribe members to celebrate New Years and plan for the 2011 ICS convention in Savannah. If convenient let me know the TC you are considering. I try to keep track of Comanches for sale. I'm in Houston.

Dave Pyle • dap8@comcast.net • ICS 730

Thanks folks for the quick replies.
I currently own and fly a Mooney C model and need to move to a TC for a variety of reasons. Have been looking and studying for 2 years so I know them fairly well. I am also a 40 yr+ A&P and retired corp and airline driver. I guess I should have offered a little more info in my first post. I live out west in AZ and am looking at one near ATL so I can't attend to the inspection myself. Can anyone tell me if there is a codified prebuy inspection item list for TCs? Not just a normal annual list but something geared to just TCs and specific items that are problematic? Like the #12 inspection panels on the bottom of each wing for spar corrosion issues and the tail yoke and tube issues. I have all the ADs of course. Just want to check it against what I have been recording for a while.
Again thanks for all the helpful ideas.

Cliff,
There is no "official" prebuy list, however the most obvious items are usually the items that cause the most damage, when improperly attended too. These are the Landing gear system, and the fuel system. Twin Comanches are pretty robust and don't have many issues with the airframe (other than possible firewall cracking where the engine mount attaches). There will probably be some small cracks in the upper wing skins. They will not grow once the stress has been relieved (stringers weren't attached to some ribs), and general practice is to leave them alone. Pitch Horn cracking is a non issue with the thick walled torque tube (all twins/400s were built with the thick walled tube). The lower spar corrosion has not been found to be an big issue on the Comanche series due to extensive corrosion proofing at the factory. Pitch trim tab actuation system should have no play in it. Set trim to neutral. Stand aft of the stabilator, push down on trailing edge of stab just in front of trim tab and deliberately move the trim tab up and down with the other hand. A small bit of linkage lash is acceptable, but any large movement, including translation of the jack screw spool (trim drum) in the cage is not acceptable. Also check the solidity of the tail attachment by standing at the tip of the stab, and moving it up down, forward and back while feeling for any movement, listening for any squeek, clunk or grind. This should be done in a quiet atmosphere, as this is very subtle sometimes. Any of these would need to be investigated further. Check the control cable tension. This is often a neglected item.

 

Landing gear needs to be rigged correctly with no perceptable slop in any bushings or linkages. It needs to be properly rigged with the correct preload set. Limit switches must be set correctly, wiring in good shape and properly routed. The transmission needs to be smooth, serviced and not loose. The AD 77-13-21 is a 3 part AD. Many do not realize this and simply sign it off as complied with when the bungees are replaced. Beware of para. C that requires 1000 hr interval inspection of the entire system. Check that all of the springs are in good condition (many have not been changed in a while. Service manual says to change main gear springs when bungees are changed). All of this is easy to do, but it is best done by someone who knows what to look for.

Fuel system. Bladders leak becuase most people don't fill the tanks all the way up! Capacity is only accurate if the aircraft is leveled (aircraft does not sit level), AND the tank is filled all the way up, as in overflowing. The bottom of the filler neck is about 4 gallons short of full. Fill the tanks up, and you will find the leaks. If you have tip tanks, check the fuel valve solenoid for proper operation. Also check to see if the flexible fuel line from the tip to the hard line in the wing is leaking or has been changed since install (many haven't and leak or will colapse once the tank is about half full and begins to suction feed vs gravity feed). Take very thorough fuel samples. If you find ANY black specks, you will need to change the bladders, and possibly have other fuel system problems such as fuel servo malfunction, and plugging injectors. Rubber dust can find its way through every screen and filter on the plane. Fuel valves. These have a good service history, but after 40 yrs the cad plating is somewhat sketchy. Many have shown internal corrosion where the plating is worn off. You can inspect them by removing the sump bowl, and bypass valve. If you see any corrosion, send them to webco for service. They will replate, rebuild, and it will be almost like new. Also new PMA units made from stainless are available from Parker Hannifin.

These are the biggies. The rest is pretty straight forward Lycoming, Hartzell, and AC-43-13 stuff.

-Zach

Zach,

 

Wow! That is some list. If you were doing the prebuy inspection how long might that take...assuming that no major issues are found?

About 15 minutes once the plane was on jacks....The inspection is easy and quick. Fixing the problems found take a bit longer. When we do "tech" inspections, it takes about 1 hr per aircraft, roll in to roll out. A thorough prebuy is about 4-6 hrs depending on documentation, plus an inflight operational verification check.
-Zach

Most prebuys look exclusively at the airframe. After my last purchase I decided "if I ever do that again"... I would also spend a couple hundred bucks and have an avionics tech give it a check out too. Autopilots, etc... are expensive repairs... having a knowledgeable Avionics tech check out the systems would be a good thing!
Jim

Avionics is one of the big reasons that I do a flight test wtih every pre-buy inspection that I do, assuming of course that the buyer doesn't walk away based on what is found before that. All the avionics should be checked for functionality. Beyond that, you are looking at a bit more money to have an avionics shop bench check everything.

 

My typical pre-buy starts out with a debate over whether it wouldn't just be better to do an annual. But an annual, even by a knowledgeable Comanche mechanic, doesn't check the avionics or flight test the plane. Once we get by, I usually have the seller telling me that it has been maintained by a mechanic who has been maintaining Comanches for 40 years and has owned them himself. The implication is that this is a waste of time. Almost invariably, I walk over to the tail and check the tab free-play, which is out of spec, often by a whole lot. About a third to half the time, I find blue stains under the wings, or in the wing root area. You gotta know where to look if the seller has cleaned the blue stains off the underside of the wing.

I commonly find bearings loose in the Dura landing gear transmissions and varying amount of slop in some of the bushings/bolts in the gear. The landing gear assist springs are usually a horror show, even when maintained by a so-called 40 year "Comanche Expert".

You should get someone who really knows the aircraft to look at it even if you have to bear the cost of flying someone in or flying the aircraft somewhere. 99.99% of the mechanics will miss big stuff on a Comanche. Unless you are working with them all the time and flying them yourself, and I might add keeping up with the latest developments in the fleet (think rudder hinge brackets) you will almost surely miss significant stuff.

These considerations would appear to narrow the field for those facilities one could trust for a buyer inspection. No debate. Do you or ICS or anyone have an "approved" list? If not, wouldn't this be a good project for the ICS Fleet Airworthiness Committee. I believe Zach is on that committee as are others who have a good Comanche inspection reputation.

im not the technical person that zach and kristin are, but i have found the guide that Bill Creech put together to be a pretty good buy and informative. i believe it is still for sale on this web site.

 

good luck, the pa-30 is a great plane. i own one.

best regards,

scott ducey

Dave,
We have not published an "approved" list for a variety of reasons including liability, consensus etc. Instead ICS has and is continuing (no doubt some day may change) to follow the path of allowing members and owners to make their recommendations good or bad, available through sights such as this and COF. We all have opinions, and it is much easier to credit or discount a singular oppinion than to blame an entire Society one way or the other. I beleive the folks that are on here helping others are very concious of not being self serving. I have not seen any cases of free advertising abuse on this sight. Usually only a mention of good faith help is profered. SO, it is tough for us to recommend any specific shop, though one of the most asked question is "whats a good shop near XYZ...). We can give you some options of those shops others have had good luck with if they have given feedback, or shops that are the only ones that do a specific function, or are a regional "hub" of Comanche activity. Other than that there are way too many variables to keep track of for all the independents and shops in this world.
-Zach

Zach,

 

I get it. Problem is no one has answered Mr. Biggs initial question either here, or at COF. Seems like short of a "recommendation" someone should.

I think he got his answer. No one knows of a good facility close to ATL.