VG-21 SQUADRON

NEWSLETTER

ISSUE # 28

NEWS: I have just received a copy of FAA Advisory Circular AC43-16 General Aviation Airworthiness Alerts, Alert No. 217 dated August 1996. This advisory circular included the following report.

------------------------------------------------------------------------------------------------------------------------------------------------------

VARGA

Information for the following article was furnished by the FAA's Aircraft Certification Office (ACE-117A), located in Atlanta, Georgia.

"There have been several incidents of near fuel exhaustion involving these aircraft. This situation occurs when the aircraft is parked on a sloping ramp with one wing lower than the other and both fuel valves are left in the "on" position.

The fuel will drain from the high wing to the low wing and may begin to siphon when the fuel reaches the level of the fuel vent outlet. Fuel siphoning will continue until the fuel is drained below the level of the outlet, fuel pressure in the tank builds up too much for the fuel to allow venting, the aircraft is moved to a level surface or at least one of the fuel valves is closed, and a tank cap is loosened to relieve the pressure. Fuel loss may range from a fraction of a gallon to several gallons (depending on the circumstances). In addition to the loss of fuel, this condition represents a very serious fire hazard.

Owners, operators, and maintenance personnel should ensure that both fuel valves are placed in the "off" position when the aircraft is parked. A thorough preflight inspection, including verification of fuel quantity, will alleviate the possibility of operating the aircraft with unknown fuel quantity."

Part total time not reported.

------------------------------------------------------------------------------------------------------------------------------------------------------

The italics in this report are mine. The italicized part was taken from a more thorough explanation of the problem that I wrote to local FAA representative, John Eller. I think it would have been more accurate and more helpful if the FAA had published more of my letter but I guess it doesn't matter much at this point. I changed the vent system on my airplane and it looks like the problem has gone away. I've filled the tanks to the brim several times and, so far, haven't lost a drop from the vent tee. I sent sketches of my changes to Bill Morrisey and he is helping me with a less complicated vent design for Varga owners. If someone wants to volunteer to change their airplane and get FAA approval, let me know and I'll send you sketches of what we come up with.

Cleave Murdock asked what I know about recent Airworthiness Directives that affect Varga engines. One had to do with periodic inspection of Bracket air filters, the other involved Bendix magnetos and the third is related to oil pump impellers. I have a copy of the oil impeller AD and the way I read it, although both the O-320 and O-360 Varga engines are affected, nothing needs to be done until the "...next engine overhaul,...next oil pump removal, or 5 years after the effective date of this AD, whichever occurs first.". Will someone let me know about the other 2 AD's?

Henry Freixas said he talked to Curt LoPresti of LoPresti Speed Merchants when he was at Oshkosh. While Varga Aircraft was still in business, Curt developed a fiberglass nose cowl for the model 2150A and got an STC. He claimed that it added 10MPH to the speed of the 150HP airplane. He now has the STC and tooling for sale. If you're interested, you can probably reach him at (800) 859-4757.

MESA, ARIZONA: Copperstate Regional EAA Fly-In at Williams Gateway Airport. Thursday, October 10 through Sunday October 13. There were 8 Vargas at last years event. I will fly over from Falcon Field on Friday and Saturday and I hope to see you there. Call (800)283-6372 if you want a fly-in brochure that will include information about the event and transportation and lodging. The motel I suggested to Del Lutz and the Beerys last year turned out to be less than desirable so at least I can tell you where not to stay if you want to call me for information.

Clare Weidman has his Shinn 2150A for sale at $29,500. It has 1860 hours TT on the airframe and 500 hours SMOH with an extensive annual in 1995 and a June 1996 annual. He says it is in excellent condition with new paint in 1994. I don't have a phone number but his address is Rt#1 Box 116, Eagle Rock, VA 24085

FOR SALE: VARGA 2150A N4618V VAC83-78 Asking $36,900 OBO to VG-21 Member. 1030 TTAE, Full Gyro Panel, King KX155 W/LOC, Apollo 604 Loran, Narco Transponder, 3 Lite Genave Marker Beacon, Intercom, David Clark Headsets. Tanis Winter Heater. September 1995 Inspection, All Ad's Complied with, New Side And Front Glass, New Pointer 3000 ELT, New Main Tires, Always Hangered, Original Airplane Excellent Condition In & Out.

Ray Hancsak, 3676 Forbes Trail Dr., Murrysville, PA 15668 (412) 327-6743 or Co-owner Phil Stango at (412) 372 2620. Ray sent photos and I will send them to you if you're interested. It has a Navy paint job with a blue fuselage and yellow wings and tail.

John Ellis of Jackson, MO has VARGA 2150A N7066T VAC105-78 For Sale for $30,000.It has been converted to a taildragger with a 210hp Continental engine. John says he has a taildragger STC but it is certified Experimental (Exhibition Catagory) due to the engine change which he was unable to get STC'd. He says it is a 10/10 In and Out and he will send details upon request. His phone is (523) 243-3502.

-----------------------------------------------------------------------------------------------------------------------------------------

TRADE-A-PLANE, SECOND AUGUST ISSUE, 1996:

1982 VARGA 2180, 1560TT, 40 SMOH, KX170B, KT78A w/Mode C, excellent condition, $39,900. 423, 428-2336. au2

1979 VARGA, 1090TTSN, COLLINS Microline Nav/Com, KI206 Indicator (glideslope), Collins GLS350 glideslope receiver, KT76A transponder, Apollo 618 loran, asking $38,500. J.M. Aircraft, 704, 326-8900; Fax 8902.tf

78 2150A, 1500TT, 50-SMOH, by Mattituck, new Imron paint by R&B, new leather interior, Nav/Com, xponder, Mode-C, intercom, headsets, Hooker harnesses, hangered, fresh annual, excellent condition. $44,500. 505, 986-1968. s2

1978 VARGA, 938TTA&E, KMA20 audio, King KR86 ADF, FOH King KX170B w/GS, cyl. temp. and EGT, 6/1/97 annual, $38,900. 602, 582-9867;602, 897-1799. au3

------------------------------------------------------------------------------------------------------------------------------------------------------

VG-21 Membership: A $20 annual donation will cover all the printing and mailing costs for at least four issues a year and will help pay for return phone calls, letters and postage when you have questions or comments that require a quick or personal response. Beery VG-21 Newsletters: $10 covers most of the printing and mailing costs for all issues. Old Bishop VG-21 Newsletters: $2.00 per issue (includes postage).

For those of you who don't know, I am the former Varga Aircraft Corporation engineering manager (1975-1982) and may be able to help you with a problem. I can be reached at:

2062 West Gila

Chandler, Arizona 85224

(602)786-3578 (evenings)

(602)891-6152 (days)

You may also be able to find me at hanger A9 at Falcon Field in Mesa.

Timothy Keith-Lucas of Sewanee, TN is a new member who just bought Varga 2150A N4614V from former member, Rick Phillips.

Claiton & Joyce Jordan from right here in Phoenix bought George Geottl's Model 2180, N8463J.

While I was at Varga Aircraft, we had lots of requests from potential customers for a taildragger version of the airplane. We could barely afford to build the tricycle gear airplanes let alone spend the time and money required to develop and certify a taildragger. We were very glad when Norm and Joyce Hibbard decided to design and build one with their own money. We were eventually able to buy their Supplimental Type Certificate (STC) and design documentation, but the cost of the STC, the cost of updating the drawings, developing production tooling, making new parts and incorporating the new model in the production line probably helped contribute to the demise of the company.

I had to recertify Hibbard's Aviation's STC (Supplimental Type Certificate) for production and I could do it again, but it is an awful lot of work for one person to do as a multiple STC. Not including their own time and effort, I think it took almost a year and cost the Hibbard's over $35000 for development and certification of their tail dragger more than 15 years ago. In today's aircraft market and financial climate, I think it might cost at least as much to do it again, even though the FAA might accept a little less testing if you could show that much of the design was duplicated from the original STC. There are also several improvements that should be made which would add even more to the required work and cost. The original Taildragger STC now belongs to Loren Perry and, as far as I know, unless he transfers the production rights, he is the only one legally allowed to use that STC number to convert Varga's to taildraggers. There's nothing magic about converting airplanes to taildraggers so patents are not allowed and there are no legal restrictions that I know of to duplicating the Hibbard design, but even if duplicated exactly, the FAA would (and should) require an application for a new STC. That is what would cost so much. Again, it might be nice if Loren Perry would release his STC for production and make the necessary parts.

Beginning with the Hibbard conversion there have been several Varga taildraggers.

Hibbard Taildragger: As noted above, Norm and Joyce Hibbard were Varga dealers who spent much time and money converting a tricycle gear Model 2150A to a taildragger configuration and obtaining a Supplimental Type Certificate (STC) for it.

Varga Taildragger: The Hibbards sold their STC to Varga Aircraft. We redid the design data to make the parts more suitable for production and added a larger rudder. I think we made three 180hp Taildraggers before we went out of business.

Bill Morrisey's Bravo Taildragger: Several years ago, Bill sent a picture of his single place Bravo Taildragger that he was trying to market as a kit airplane. From the picture I have, it looks like the main gear is a flat spring type from a Cessna which are attached to the fuselage truss. I can't tell from the picture what type of tail wheel and spring assembly he used. Bill would probably tell you what he did and how he did it if you gave him a call.

Montanair Taildragger: After I left Montanair they built a taildragger version of the 180hp tricycle gear airplane that I designed for them. They changed the shape and location of the vertical tail from my original tail and I think they changed the tail wheel from a Scott model 3400, which uses a round spring, to a model 3200, which uses a flat spring. Ernie Smith said it had softer landing characteristics and didn't shimmy like the round spring gear. The Montanair airplane also had a fuselage truss that was stretched 3" forward and 1 1/4" aft and used a 180hp engine.

Aerospec Taildragger: When I bought a ship set of parts, along with a special fuselage truss that I had built while Varga was still in business, I took a set of taildragger components and a larger rudder. This airplane has many differences from a regular Varga but the tail wheel conversion is the same as the production airplane.

Don Tate Taildragger: Don Tate's airplane was originally a wrecked tricycle gear model 2150A that was rebuilt as a taildragger by Mr. J.A. Humphrey. It appears to have the original design Hibbard type main gear but the tail gear assembly is from a Cessna 180. Lots of other differences include moving the oil cooler to the left front air intake of what appears to be an early Piper nose bowl, moving the battery forward of the firewall to where the oil cooler used to be, a sliding canopy and a flush riveted aft fuselage and vertical tail. Although the airplane is certified as Experimental, many of the changes were done by FAA form 337.

John Ellis Taildragger: I recently learned that John Ellis and a partner built a taildragger from two crash damaged airplanes. John said that they were able to get a taildragger STC but were unable to get an STC for the 210HP Continental engine that they installed. It is currently certified as an experimental and is for sale at $30,000.

George Banks Taildragger: I have two photos of George's 2150ATG, N8294J. George says it was a tri-gear that was converted to a taildragger but, in his letter, he didn't say how it was done. From the pictures it looks like it has a factory built larger rudder and factory built landing gear.

Perhaps the best way to get a tail dragger conversion for your Varga is if the current Varga Aircraft Co. would release their STC for production and aftermarket sale. You can write or call Loren Perry and ask him if he will do that. He might not do it for you right now, but if he gets enough calls and/or letters he might consider it.

The most common way to make major changes to a production airplane is through your local FAA FSDO (Field Service District Office) using standard aircraft repair techniques authorized in FAR 43, shown in Advisory Circular 43.13 and documented on an FAA 337 MAJOR REPAIR AND ALTERATION form. Unfortunately, making a tricycle gear airplane into a taildragger is a little too "major" for a 337. Although J.A. Humphrey had several 337 approvals relative to his taildragger conversion, he still had to have it classified as an "Experimental".

The easiest way for you to make a taildragger on your own is to get the parts or drawings to make parts from, make the necessary changes to your airplane and ask the FAA for an Experimental Type Certificate (TC). However, an Experimental Certificate does have some problems and risks.

One of the problems is with the kind of Experimental Type Certificate you can get. Experimental TC's are classified as "Amateur Built", "Exhibition" and "Research and Development". The best Experimental TC you can get is Amateur Built but, unless you have a real liberal FAA guy, you probably can't have one of those because, with a Type Certified production airplane, you're not starting from scratch and building at least 51% of the airplane.

A Research and Development TC is what manufacturers usually use while developing a new product or making major changes to an already Type Certified one. The FAA restricts flights to within a specified test area (at least for a while) and they also expect that you will eventually certify the product or changes so they limit it's duration to one year. It's renewable every year but, along with the flight restrictions, that is a nuisance that most people don't want to live with for very long.

An Exhibition class TC means to the FAA that your airplane is for show like aerobatic airplanes and warbirds and you will only fly it to and from aviation events and to maintain proficiency. Although the TC doesn't have to be renewed annually, the FAA will restrict you to flying in a designated airspace and expect you to submit an itinerary if you choose to leave that airspace.

One risk of an Experimental TC is that you need make sure you know what you're doing because, as an experimental change, if it doesn't look too unsafe, the FAA will let you do almost anything. It is often amazing how one small change can lead to another, and the effects of that change can have unpredictable consequences. It's really not too hard to get in over your head. If it's an experimental, the FAA won't check to see that you got all your nuts and bolts at Ace Hardware or that you had your welding done at Joe's Auto Salvage. They will only check to see that all the parts appear to be fastened together, you have done a weight and balance check and that all the required paperwork is properly completed. After they give you that "Pink Slip", you're on your own.

Another way to make changes to a production airplane is with a Supplimental Type Certificate (STC). An STC allows the airplane to be operated as a standard category aircraft with no restrictions other than those specified in the original TC and in the STC.

The two classes of STC that I know of are "One Time" and "Multiple". A "One Time" STC means just that. You only expect to certify the changes on one (usually your own) airplane (although sometimes you can get away with using the same paperwork to do more than one plane). The advantage of a one time STC is that documentation (photo's will usually do) and testing (load and demonstration flight tests) are limited to the minimum required to prove that the change is safe on that one airplane. A "Multiple" STC means that the design changes are documented well enough that if the approved design data is used to modify any airplane of that type, it can be returned to service as a standard category aircraft.

A sometimes difficult (and expensive) thing about a multiple STC taildragger conversion is making "FAA approved" parts. If you're doing an experimental project you can use the "cut to fit, beat to shape, paint to match and use as is" approach and save a lot of time and money. You don't even have to show the FAA that it flies well, only that it won't fall apart in the first 20 to 40 hours of flight. You will also always have an "Experimental" airplane with some restrictions that you may or may not be willing to live with. If you do a one time STC just for your airplane, you will eliminate any restrictions but you will have to show that you used the proper materials and processes in making the parts, give them some pictures and sketches for their files and demonstrate that it has acceptable flight characteristics so that the guy or gal who eventually buys it from you won't find out that you are the only one in the world capable of flying the darn thing. You will also spend more money than you spent on a strictly "experimental" conversion.

Most people don't have the skills, time or money to do any of the above. That's why multiple STC's were invented. If you can afford the development costs and there are enough airplanes out there (and people who want to convert them) to amortize your investment, you MAY (I repeat "MAY") make several people happy with your STC and not lose your shirt in the process.

Approval for a multiple STC requires that you make adequate drawings, quality parts with adequate control of all materials and processes used to make and assemble those parts, and have adequate procedures and records to insure that the finished product is, and will remain, flightworthy after it leaves your hands. As the designer and/or manufacturer you must also accept the responsibilities and risks associated with FAA Type and/or Production Certification. Sometimes you can find someone who has an aircraft parts production facility and can have them make your parts with a FAA PMA (Parts Manufacturing Approval?) and share the investment costs and risks (and the profits?). Univair has FAA PMA's for many production parts.

STUB WING MODIFICATION: These are extensive. The outer wings must be removed first and then the fuselage must be supported so that the main gear can be removed. The rivets from the entire lower skin should be removed along with the rib rivets in the leading edge. The top skin and the rivets in the leading edge upper spar attachment can be left in place. It is then easy to remove the attach bolts from the main gear and take it out. The next step after you have made all the necessary parts is to install them. In addition to the new or modified upper main gear, these parts include two forward spar and two aft spar truss mounting channels along with the square steel tubes that go between them to reinforce the main gear attachment. You'll probably have to trim the leading edge skin at least part of the way out for room to install the main gear. If all the parts have been made well, they should cleco in place so that all the attach holes can be drilled to the proper bolt size. There are also some aft spar reinforcing angles that are installed where the old main gear used to be. You'll also need to reroute the brake lines and fittings. After doing all the appropriate FAA approved things like deburring and corrosion treatment, the parts can be installed. Once the new gear parts are installed, the skin can be put back on. It's best to trim the leading edge skin around main gear a little at a time to get a close fit. There is also a hole required in the leading edge for access to the lower strut attach bolt and the oil hole. After the gear root fairing is installed, the lower main gear, the brake lines and fittings and the gear and wheel fairings can be attached. This part of the conversion requires the purchase of steel and aluminum sheet, steel tubing, brake line and fittings and assorted bolts, nuts and rivets and the fabrication of parts.

MAIN GEAR: After removal from the airplane, the tri-gear upper strut attachment flanges need to be carefully cut and ground away. The cadmium plating will have to be sanded or stripped away with muratic acid so that the new taildragger attach flanges can be welded on. After you've had the taildragger flanges made according to the drawing, you'll have to make some sort of fixture (one left and one right) to hold all the parts in alignment while they are being welded. This alignment is very important if you want all the attach holes to line up and you don't want to taxi down the runway sideways. Each upper gear assembly requires the purchase of some sheet metal and weld and fabrication of parts. Except for the addition of wheel pants, the lower gear is unchanged.

TAIL GEAR: The Hibbard tail gear includes a Scott model 3400 (round spring) tail wheel and a Hibbard designed spring, pivot, spring snubber and attaching hardware all of which are a little tedious but relatively easy to install to existing aft fuselage bulkheads. This part of the conversion requires the purchase of some steel tube, sheet metal, aluminum blocks and assorted bolts, nuts and rivets and the fabrication of parts.

TAIL WHEEL STEERING: The Hibbard conversion runs a separate tail wheel cable from the tail wheel to the rear rudder pedals and requires modification and installation of three pairs of pulley assemblies and the fabrication and installation of their attaching parts.

NOSE GEAR MODIFICATION: Hibbard's modification removed the lower nose wheel/gear assembly and all the attaching hardware including the steering parts and cut the upper strut off nearly flush with the lower cowl.

NOSE COWL MODIFICATION: The Hibbard modification to the nose cowl requires the fabrication and installation of an aluminum patch to cover the U shaped cut out in the fiberglass lower cowl where the gear strut goes through. Stainless steel patches are also made and installed to cover the holes in the firewall left by removing the nose wheel steering rods.

WEIGHT AND BALANCE: I don't remember what Hibbard had to do to demonstrate weight and CG limits but when FAA pilot Carl Jacobsen did flight tests on our first model 2180 taildragger, we got an interesting result at the most forward CG limit. If I remember correctly, I had to pile more than 100 pounds of lead on the battery box just to get to the most forward CG limit of 10.4 inches aft of the wing leading edge. During the flight test, the airplane flew just fine but on landing Carl found that he didn't have enough elevator authority to get the tail wheel on the ground before the main wheels touched. On every landing with full flaps, he could get the tail wheel no closer than 6 to 8 inches above the ground until the airplane slowed down enough for the tail to drop. It wasn't hard to land that way but it was unacceptable for certification as far as Carl was concerned. Carl and I went back to the office and he calculated that with a normal pilot, and no fuel, a taildragger would never have a most forward CG of less than 12 inches aft of the wing leading edge, so we changed the CG range in the taildragger flight manual to 12 to 17.5 inches instead of the 10.4 to 17.5 inch range on the tricycle gear airplane. Unfortunately, we also learned that the CG range had moved so far aft on the taildragger that with pilot, passenger and full fuel, we could no longer load anything in the baggage compartment without exceeding the aft CG limit. Since loading the airplane was the responsibility of the pilot, this CG shift didn't affect certification but, in my opinion, it did significantly affect the utility of the taildragger version of the airplane.

Lots of people have asked about it and it might be nice to make a taildragger conversion available but it seems that whenever I discuss a potential cost of $5,000 to $10,000, most Varga owners say either "that's too much" or "that may be reasonable but I can't afford it."