Insight on Rebuilding Falcon UL

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kool69sporty

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May 12, 2019
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Just found a Falcon mfg 1985, last flown 1991 and stored since. Winds are complete with no damage I've found, but no Tedlar. Pod is intact except for crack at nose wheel attach. Rotax 277 will need rebuild but leaning to Polini anyway. It will take some work to clean it up and make flyable but I'm taken to the 36' double surface wings and canard arrangement. Can't find much information beyond Wikipedia but described as fun to fly. Should I make the investment in this old bird? Anyone with first hand knowledge or even 2nd hand, I'd welcome your insight.
 

TFF

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Apr 28, 2010
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I had a friend that had a flyable project years ago. The Tedlar was starting to lift up. He flew it once I know. He had the carb come off and ended up in a field with minimal damage. It needed a recover despite the off field landing. I think his had a crack too. I don’t know if he ever did finish it. Elegant in the air.
 

Protech Racing

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Jul 10, 2020
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There's a reason the carbs are safety wired on. Many fell off of the rubber booty . Or the rubber broke. Support the carb some how.
 

simflyer

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Moravia
Great flyer and easy to fly as it is a canard. ...
It is sad that Falcon czech designer Romuald Drlik, haven't drawings. It deserve next development and building for actual pilots. Here in Romualds fatherland we have only one Falcon UL.
 

reo12

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Jan 15, 2021
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It is sad that Falcon czech designer Romuald Drlik, haven't drawings. It deserve next development and building for actual pilots. Here in Romualds fatherland we have only one Falcon UL.
I have a Falcon UL and a later higher performance model known as a Falcon Safety Craft. There is no reason to make plans available. The wing's aluminum D cell spar is made in a purpose built hydraulic press. The pod (fuselage) is made in a mold. It is made of Kevlar and molded using a vacuum bag process. A builder would not have a press nor the mold.
Romuald is of German decent.
I'm searching for a source of Tedlar and appropriate tapes to recover my planes.
 

kool69sporty

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May 12, 2019
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reo12, what do you make of the guy on ebay that has Tedlar, located in Elkhart, IN? I'm looking to recover a Falcon UL, too. If my calcs are right, 0.002 Tedlar is 0.23oz/ft^2. Oratex 600 is 0.4 oz/ft^2 at 0.0047 thickness. Difference should be less that 2# total to cover the canard and wings. Why not use Oratex other than cost?
 

Victor Bravo

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I would strongly support the Oratex option as well. Wrapping the Oratex around the leading edge like a conventional aircraft covering job will eliminate the Tedlar peeling issues. You will more than make up the weight difference using the Polini engines.
 

slevair

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I covered my Falcon XP wing with Polyfiber and it turned out great. I have full confidence in it. Has never had any problems. Leading edge is fully covered. I wouldn't do it any other way. Avoid the chance of peel. They are great flyers, but have low wing loading so bumpy days are not fun for the pilot. The plane doesn't seem to care. Four pedals takes a bit of getting used to. They easily T/O and land in less than 1000'.
 

reo12

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reo12, what do you make of the guy on ebay that has Tedlar, located in Elkhart, IN? I'm looking to recover a Falcon UL, too. If my calcs are right, 0.002 Tedlar is 0.23oz/ft^2. Oratex 600 is 0.4 oz/ft^2 at 0.0047 thickness. Difference should be less that 2# total to cover the canard and wings. Why not use Oratex other than cost?
Do you mean the guy on ebay with the 24" wide TTR20SG4? That is the wrong type and too narrow. Mike Fithian from Falcon East posted on UltralightNews back in 1997 that it was the proper grade - it is not. Why in the heck he did not get that corrected is beyond me. He was selling that grade and even the slow flying Lazair folks were having it separate from the tapes. The proper grade is TUT20BG3 and needs to be 64" wide TUT20BG3 is 2 mil thick and etched on both sides as the tape on the ribs has to stick to the inside and the finishing tapes have to stick to the outside.

Fithian claimed at least 20lb weight for fabric and paint - minimum. A person familiar with Lazairs's stated I needed to figure 10lbs per coat for paint. He's seen a Lazair wing go from weighing 35lbs with Tedlar to nearly 60lbs with fabric and show quality paint finish.
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Here is Fithian's list of the materials needed to recover the wings, canard elevators, and the rudders. The actual footage of tapes are my estimations. His write up can be found at http://www.ultralightnews.ca/articles/tedlarinformation.htm

100ft PVF film 64" - Each wing will have a total of about 148sq/ft of film on them.

4rolls Seamstick Tape - I believe this is the double sided tape with acrylic adhesive. I do not know if it was Tedlar film. Requires about 170ft

2roll PVF - This is likely the finishing tape used on the edges of the Tedlar. Requires about 60yds total.

2rl Silver Mylar - This is optional for U/V protection of the tape adhesive. Carlos Pereyra used an aluminum foil tape with an acrylic adhesive on the Solaris.

1rl Foam Tape - 3/4" wide double sided foam tape made by 3M with an acrylic adhesive. Requires about 170ft. I think it requires more than 1 roll to get this many feet.

Oh - I forgot to figure the winglets(rudders)
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Your figure of 0.23 oz per sq/ft for the film would total 34 oz of film per wing. I do not know if this is accurate. I can't determine the weight of the various tapes used.

Here are the spec sheets for some grades of Tedar. They only provide the specs for 1 mil TUT10BG3: https://s3.amazonaws.com/fellers/production/documents/Signgold_-_Tedlar_Spec.pdf

TUT10BG3 has a specific gravity of 1.37. Note - this is 1mil not 2 mil as needed. I would presume that it would be reasonable to determine the actual weight for 1 mil based on specific gravity and multiply the result by 2 for an actual weight. They use ASTM D-1505-68 to determine specific gravity. I am attaching the ASTM test method.
A calculator for determining weight from specific gravity is here: specific gravity - calculator.org
 

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reo12

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Jan 15, 2021
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40
I covered my Falcon XP wing with Polyfiber and it turned out great. I have full confidence in it. Has never had any problems. Leading edge is fully covered. I wouldn't do it any other way. Avoid the chance of peel. They are great flyers, but have low wing loading so bumpy days are not fun for the pilot. The plane doesn't seem to care. Four pedals takes a bit of getting used to. They easily T/O and land in less than 1000'.
Hi Bill,
I honestly do not know for certain what model my plane is. It is NOT a Falcon UL. It is a later model. I've been told 2 different names. Falcon Safety Craft and Falcon Phoenix. I was told that Paul McShane was involved with it's manufacture. https://www.sec.gov/litigation/aljdec/1992/id19920214jks.pdf

Since my plane is a single seat I'm trying to keep it looking like a UL. Additionally - the main gear location results in only about 10 - 12 lbs of weight on the nosewheel when parked. Additional wing cover weight would increase the amount of weight behind the main gear - reducing nose wheel weight even more. I had made a retractable prod that stuck out the back to enable me to not have to hold the nose down while getting fuel or talking a walk.

I had over 400 hours in Pterodactyls so the response in thermals was not unexpected. What I did have issue with was this version has a pod made as a sandwich construction of kevlar, foam, kevlar. The beams that are on the sides of the pod of the XP and UL versions are not present. The pod twists in thermals. The nose twists separate from the aft portion. It is disconcerting to see the canard ends move up an down much as it does and pedals move about under you feet. Mine has hand grip operated hydraulic brakes with nose wheel and rudders controlled by the 2 pedals.

It was built with a 277. This is adequate engine to enable speeds in excess of 70mph. The rotation speed of 47mph was an issue with the runway I was using as it was 1300ft but will full grown trees all about. I was not certain the 277 would get the plane safely out of that field. I had an entire powerplant from one of my Pterodactyls. A Cuyuna ULII-02, 2:1 belt reduction drive and 54x27 wood prop. I made mounts and fitted that powerplant to the plane and brought it to a familiar airport to assemble and test fly. The 54x27 prop was insufficient. Climb exceeded 1400ft/pm. The engine overspeeded just at minimal flight speed. We put an Ultraprop from a T-bird with a 503 on it. That worked. The plane was capable of 87 mph in level flight without wheel pants, strut fairings or winter canopy. The designer - Romuald Drlik told me I should be able to get over 105mph with those improvements and an efficient propeller with 35hp

I rebuilt the plane after finding many deficiencies in how it was built. Later I was to find that it had left the factory incomplete and was finished by someone who really didn't know what they were doing. I was able to fly it under 12 hours before a powered parachute ran into it on the ground - damaging a wing. It has sat the 23 years since.

Sadly - few folks that had knowledge of this version were ever known to me. Mike Fithian was secretive. I have what is left of 2 of these. Romuald thought that roughly 7 could have been made with components that were made. Possibly someone reading this has information to share.
 

kool69sporty

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May 12, 2019
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Reo, I used 1.37 sp. gr. for the TVF. Water @ 62.4 #/ft^2 * 1.37 = 85.5#. 12" tall cube a ft square = 6000 sheets at .002". 85.5#/6000=.01425#=.23oz/ft^2.
I used 144ft^2 per wing, 17 ft^2 canard, but nothing for the tape and forgot the rudders, too.
Great info you provided. Way more than I've been able to find. Thnx.
Mine is a true Falcon UL, S/N: 500317. My plan to counter any weight gain on the cover is offset with a Polini 202, 12 lb. lighter, same power as 277, water cooled, internal PSRU and counter weight. Penalty - short mean TBO ~ 250hr.
Joe
 

reo12

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Jan 15, 2021
Messages
40
Reo, I used 1.37 sp. gr. for the TVF. Water @ 62.4 #/ft^2 * 1.37 = 85.5#. 12" tall cube a ft square = 6000 sheets at .002". 85.5#/6000=.01425#=.23oz/ft^2.
I used 144ft^2 per wing, 17 ft^2 canard, but nothing for the tape and forgot the rudders, too.
Great info you provided. Way more than I've been able to find. Thnx.
Mine is a true Falcon UL, S/N: 500317. My plan to counter any weight gain on the cover is offset with a Polini 202, 12 lb. lighter, same power as 277, water cooled, internal PSRU and counter weight. Penalty - short mean TBO ~ 250hr.
Joe
Hi Joe,
I forgot to mention I measured the Phoenix wings for the dimensions I gave. They are slightly thinner and the root end ribs are longer. They lean against each other in the building. Below is a photo with the UL wing on the left. The wingtip rudder/stabilizer is upturned on the Phoenix/Safety Craft. The main Tedlar covered portion is stationary. Only the rudder/dragger is moving. Here is a photo of that also.

The Polini 202 looks interesting. I'd be willing to try one if I was given the chance. I wonder what has to be replaced at 250 hours? That is a short - glorious life. Using it could get costly if much has to be replaced at 250 hours.

Here is some information on the development of the Falcon UL. I just found this today. When I talked to Romuald back in 1997 he said he had designed a number of versions of the Falcon. I didn't understand quite what he meant. This article gives some insight. American Aircraft Falcon
 

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