# The Lazair Ultralight

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#### Tiger Tim

##### Well-Known Member
The Lazair has had as many as (4) Engines put on it.
I wonder how many Fox .35s you’d need to line up along the leading edge to get a Lazair airborne. Enough that I bet you’d probably never notice if one quit…

#### n3puppy

##### Well-Known Member
I wonder how many Fox .35s you’d need to line up along the leading edge to get a Lazair airborne. Enough that I bet you’d probably never notice if one quit…
Calculated Thirty eight Fox 35's required, each swinging a 10x6 prop.

38 ten inch props plus clearance will fit on Lazair 36 ft wing span.

#### Armilite

##### Well-Known Member
I wonder how many Fox .35s you’d need to line up along the leading edge to get a Lazair airborne. Enough that I bet you’d probably never notice if one quit…
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I wouldn't try to Fly with the (2) 5.5hp Chain Saw Engines let alone Fox .35 RC Engines. The Rotax 185's were 184.2cc, and if they had just talked to some Snowmobile Race Shops, they could have made the Improvements to make a lot more hp. 184.2cc/7cc= [email protected]! The Lazair really only needed 13.7hp per Engine to Fly Well. Just a Carb Change, CR Bump, and maybe some Trail Porting would have probably made 13-15hp. If Stock CR is 8.0 a +3cr Bump = 3hp + 9.4hp = [email protected] A +2mm Carb bump can make 10% more hp = +1.24hp = 13.64hp, a +4mm Carb bump can make 20% more hp. So +2.48hp = 14.88hp. Put a Belt Drive on it and you can turn it Higher rpm and use bigger props. (4) Stock Engines = 9.4 x 4 = 37.6hp total. (2) 185 Engines fully modified with a Tuned pipe at 26.3hp x 2 = 52.6hp. (4) Engines at 37.6hp/2= 18.8 hp needed per engine. Not too difficult to do at 6500rpm.

Today, these Honda/Clone GX200/212 Engines are the way to go on a Lazair.

Stock Predator 212 [email protected] on a Dyno. When on Sale $99.99. Episode 1. We put a$99.00 Predator engine in our Honda Insight. 39mph on 6.5hp.

Episode 3. We build a Stage 1 Predator 212 cc engine [email protected]

These Honda/Clones with a Belt Drive similar to what Peter Harrison used would be ideal. (1) 4 Groove Micro Vee Belt is go for 20hp, but for redundancy use (2) Belts, so 8 Groove Pulley. I paid $8.50 for this 8 Groove Pulley off eBay. It looks like he used 1.0" for the Back Plate which is overkill for 9.4 to 15hp. 3/4" is more than you need for up to 35hp. Still working on the Design. First concept. PTO Hole and Bolt Pattern is correct. At 5000rpm/2750rpm= 1.81 Ratio, so if Small Pulley is 2.370" x 1.8 = 4.266" for the Big Pulley. 5500rpm/2750rpm = 2.0 Ratio. 2.370 x 2.0 = 4.74" for Big Pulley. Rotax's Prop Bolt Pattern is based on a 75mm = 2.952747" Bolt Circle so you probably need a Big Pulley at least 4.0+" OD. #### Attachments • 53.2 KB Views: 21 • 29.6 KB Views: 20 • 30.7 KB Views: 18 • 19.8 KB Views: 17 • 35.6 KB Views: 17 • 16.5 KB Views: 18 • 44.1 KB Views: 18 • 24.2 KB Views: 17 Last edited: #### Armilite ##### Well-Known Member (4) 4 Groove Mico Vee Belts are good for 80hp on another Belt Drive Design. So (2) are good for 40hp. (1) for 20hp. One 4 Groove Belt is actually good for like 25hp, but you never go up that far for AirPlane use. 25hp - 20% = 20hp. #### Attachments • 43.3 KB Views: 12 #### REVAN ##### Well-Known Member IMO: If you want to power a Lazair, there are a couple options that make the most sense. 1) If you want 4-stroke and are looking for economy over performance, go with Tillotson engines. - For less than$1000 you can power it with 2 stock 212cc engines and Xoar 36x14 propellers.
This will deliver about 19 hp and about 100 pounds of static thrust.
- For $1500, use 2 Stage1 Tillotson 212cc and get maybe 21 to 22 hp total. - For about$2000, get 2 Tillotson 225cc performance engines and derate them with 36x16 props.
This should deliver about 27 to 28 hp at 4800 to 5000 RPMs.

Tillotson Engines @ GoPower Sports

These are all direct drive setups. Be cautious of heat dissipation issues. The Tillotson engines have more cooling fin area than a Predator engine, and the 225, more than the 212. However, it is still something to watch out for. Just because you can get up to 17.5 hp from a Tillotson 225 doesn't mean that it can sustain that without overheating. I would not consider using these engines with a redrive. Direct drive, the disk power-loading is about right. With a re-drive, the engine will get expensive, heavy and may exhibit poor cruise performance with the lower powered engine options. With the added weight of a re-drive, these 4-stroke engines may very well push a Lazair over the US 254 pound weight restriction of Part-103 and throw the CG too far forward.

2) If you want the acceleration and climb performance of a big propeller, I'd recommend powering the Lazair with Radne Raket 120 Aero engines. The cost is similar to using performance Tillotson engines with redrive systems, but I think Rakets will work much better on a Lazair, having reduced cooling and CG issues. These engines are lightweight, already come with a reduction drive that is set up to accept a propeller, have the right power for a Lazair and they are pretty affordable (about $1500 each with electric start). With propellers and a tuned exhaust, it would likely end up costing around a total of about$4000 to maybe \$4500, depending on prop selection and how much you spend on motor mounts. For this, expect to achieve a total of 27 to 28 hp on your Lazair, while turning props in the 120 cm (47 inch) range. I would expect a Lazair to have reasonable single engine performance with these engines, so low level flying, flying over water, or mountain flying should be both fun and relatively safe. It should perform well on floats as well.

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#### plncraze

##### Well-Known Member
HBA Supporter
I like their cute little damper! Light and simple!!

#### bmcj

##### Well-Known Member
HBA Supporter
====================

The Lazair has had as many as (4) Engines put on it.
Lazair’s are decent flying craft. I have flown both a two engine and a four engine Lazaro… both flew similarly.

#### PagoBay

##### Well-Known Member
Does anyone know what Gene Yarbrough is up to? Gene was upgrading the Lazair air frame to handle heavy pilots. Last post and other details are in 2019.

Gene was planning to offer a kit. Maybe health issues?

Gene's BLOG:
and a nice PowerPoint on Lazair history:

#### toucan

##### Member
Although Dale Kramer's Super Floater hang glider eventually used a twin engine set-up provided by Ed Sweeney ( Partner chainsaw twin engine set-up designed for hang gliders), Ultraflight's Lazairs NEVER used Ed's later set-up you describe above. Ed Sweeney used those on his Hummingbird UL (sold under the Gemini International brand). Dale did not like reduction units, believing they were too heavy and less reliable than direct drive. Ultraflight's Lazairs always had direct drives. Several owners over the years built their own redrive units, not the factory. I was one of them, utilizing the original Pioneer engines on my series one Lazair. Chappy
Chappy, we meet again. Super.
Last saw you at Lubitz Field (anniversary?).
My C-IIII ended up in Saskatchewan.
(It was the Lazair that flew at the Paris Airshow had the only mixer with no aileron rods on wing struts - drool.)
###
I am almost considering another Lazair (offered a pair of wings).
Lucky enough to live in Canada, no Far 103...so considering e-power (slightly different configuration than Dale's which I saw at Oshkosh 2012).
(Drop me a note @
[email protected])
Dave

#### Armilite

##### Well-Known Member
Would love to see the E conversion further refined. STILL waiting on better batteries...
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With original (2) Rotax 185's and 5 Gallons about 2 hrs of Fight, approximately 60 lbs for the Engines! 210 lbs - 60 lbs = 150 lbs for Airframe! For Part 103 that only leaves 254 lbs - 150 lbs = 104 lbs for Electric Motor, Controller, and Battery Packs = about 25-30 Minutes of Flight! MTOW of 450 lbs - 254 lbs ls = 196 lbs for Pilot & Bags, don't leave room for more Battery's.
• Empty Weight: 210 lb (95 kg)
• MTOW: 450 lb (204 kg/10 kg = 20.4 kw needed = 27.35685hp = 13.678 hp each needed to Fly Well).
27.35685hp at 75% = 20.517 hp / 2= 10.258 hp.

It flew marginally on (2) 5.5hp engines = 11hp. It flew better with (2) 9.4hp Engines = 18.8hp. So would you give up Flight Time and Speed to go Electric? I believe he used a 22hp Electric Motor and only got 25-30 minutes under Part 103. With only 196 lbs to play with for Pilot, Bags, and that doesn't leave room for any extra Battery Packs to even bump it up to just 1hr of Flight, since the Avg Pilot Weight falls between 180-235 lbs. Not many People under 150lbs.

#### howardyin

##### Well-Known Member
The early series 1 shown in the first 2 photos above had a bit thinner skins on the spars, cables instead of push rods in the wings and didn't have rudder pedals. Without the instruments shown, gas and the non-standard extra metal on the wheels, only weighed 142 pounds! The engines (converted chain saw) were rated at 5 1/2 or 6 HP depending on the manufacturer's charts, but because the props limited the engines top rpm's, actually only produced about 4 1/2 HP each. Glide of that model was a bit better at 13:1. Some of the spec's in the posting were mixed up with later, more developed Lazairs. BTW, the gentleman flying that early plane was very tall. Most pilots aren't nearly as cramped looking. I still have mine I built in 1979/80. Mine has rudder pedal conversion, aileron pushrods, a 5 gallon gas tank (original was 2 1/2), a storage compartment behind the seat, a cut-down fiberglass dune buggy seat in place of the original bicycle or sling seat, a wide gear conversion, engine redrives and much larger props, and still weights 10 pounds less than 200. These are very light and strong aircraft.
what's the film of wing skin? thickness ?

#### Chappy

##### New Member
The prototype Lazair had light weight Dacron covering, but the early production kits came with 2 Mil (0.002") Polyester Mylar film (the wing tips remained in Dacron fabric). Mylar is not UV stable, so when Lazairs started operating in Southern climates (Ultraflight was a Canadian company) the covering became brittle and could fail. I was flying my Lazair behind another early Lazair here in the Mid-Atlantic region of the States when a wing panel behind an engine blew off. It looked like silver foil to me as it fell. However, the aircraft continued to fly normally with just the bottom surface intact. The pilot was not aware of it until I pointed it out. Most Lazairs are therefore covered in 2 Mil Tedlar, a Polyvinyl fluoride film that is very UV stable. Unfortunately, it is no longer available in large rolls suitable for wing covering (thank the lawyers at Dupont). David Legrand in North Carolina has covered dozens of Lazairs he has rebuilt in Dacron fabric. Dacron is fine but does add some weight, and Lazairs are all about light, and to many of us Lazair owners just doesn't look like a Lazair without the visible wings. I still use Mylar. Keep UV off the covering when in storage and get used to recovering as needed. Interestingly, Mylar in rolls is available for about what it cost 40 years ago! Mylar is usually applied with Mylar based tapes with rubber based adhesive. Tedlar tapes used acrylic adhesive. Both coverings (and also Dacron) are heat shrunk, although the techniques are a bit different. Dacron and Tedlar can be over shrunk if you don't know when to quit!

A fellow in Canada developed a system that used Boat Wrap. Seemed to work fine. It's a heavier film though, and kind of soft and easy to snag. A couple Lazairs have been covered in metalized Mylar. Very tough to shrink without cooking the tapes, and is even more susceptible to UV damage. Very cool looking though! I suspect that Tyvek, like they seal house exteriors with, might make a viable covering. I made up a test sample years ago (glued it a small frame with rubber based contact cement) and it heat shrunk. Never did find out how it held up to the sun. I lost the test sample.

Chappy

#### Woodenwings

##### Well-Known Member
Sorry if i havent read all the posts and if i am repeating another post.

Wayne Winters from Canada has his own version of a Lazair available for sale as plans (maybe a kit?). Other stuff too.

EZ Fun Flyer

I have seen it flying around at Oshkosh and looks really good.

He is a really nice guy.
1-403-936-5767
Blue Yonder Aviation, Inc.

Happy new year.

#### billyvray

##### Well-Known Member
Is he still in business? Website has been down a long time. They have some neat planes but they aren't promoted anymore. I know, I know, maybe I should just call them....

#### jedi

##### Well-Known Member
Like your post. It has several interesting planes but the links all go to "Kitplanes" and not to the model shown. Is his version of the Lazair still a FAR 103 ultralight?

A Canadian UL is different form a FAR 103 UL.

#### Armilite

##### Well-Known Member
Sorry if i havent read all the posts and if i am repeating another post.

Wayne Winters from Canada has his own version of a Lazair available for sale as plans (maybe a kit?). Other stuff too.

EZ Fun Flyer

I have seen it flying around at Oshkosh and looks really good.

He is a really nice guy.
1-403-936-5767
Blue Yonder Aviation, Inc.

Happy new year.
================================

The Twin Engine EZ Flyer isn't like a Lazair! Do you have a Link to these EZ Fun Flyer Plans, a Photo?

While I don't find a Working Website for Blue Yonder, there must be one similar to the Lazair called the EZ Fun Flyer. I found this Info:

Blue Yonder EZ Fun Flyer!

Even though it is a Canadian design, the aircraft was designed to comply with the US FAR 103 Ultralight Vehicles rules, including the category's maximum empty weight of 254 lb (115 kg). The aircraft has a standard empty weight of 251 lb (114 kg). It features a strut-braced high-wing, inverted V-tail, a single-seat, open cockpit, conventional landing gear and twin engines in tractor configuration. The EZ Fun Flyer closely resembles the Ultraflight Lazair in configuration and dimensions.

The aircraft structure is made from aluminum tubing, with foam wing ribs. Its 34 ft (10.4 m) span wing is supported by a single lift strut per side. The engines are Radne Raket 120 single cylinder, 120cc, air-cooled, two stroke powered hang glider powerplants of 14 hp (10 kW) each, which give a cruise speed of 50 mph (80 km/h) and a rate of climb of 400 ft/min (2.0 m/s).

The construction time from the supplied kit is estimated by the designer at 160 hours.

Specifications (EZ Fun Flyer):
General Characteristics:
Crew: one
Length: 15 ft (4.6 m)
Wingspan: 34 ft (10 m)
Wing area: 146 sq ft (13.6 m2)
Gross weight: 600 lb vs Lazair 450 lbs!
Empty weight: 251 lb vs Lazair 210 lbs!
Useful Weight: 349 lbs vs Lazair 240 lbs!
Fuel capacity: 6 U.S. gallons (23 L; 5.0 imp gal)
Powerplant: 2 × Radne Raket 120 single-cylinder, two-stroke, 120cc, air-cooled powered hang glider engines, 14 hp (10 kW) each.

Performance:
Cruise speed: 50 mph (80 km/h, 43 kn)
Stall Speed: 17 mph (27 km/h, 15 kn)
Range: 100 mi (160 km, 87 nmi)
Rate of climb: 400 ft/min (2.0 m/s)
===================================

The Raket 120 features electronic ignition and a Walbro carburetor. It weighs 6.8 kg (15 lb) and, due to its 13,000 rpm redline usually drives a propeller through a 3.6:1 reduction drive. The engine is equipped with a centrifugal clutch to allow running the engine without turning the propeller.

Specifications (Raket 120 Aero):

General Characteristics:
Type: two-stroke, single cylinder
Bore: 60 mm (2.4 in)
Stroke: 42 mm (1.7 in)
Displacement: 118.8 cc (7.2 cu in) = 113.1cc
Length: 219 mm (8.6 in)
Width: 234 mm (9.2 in)
Height: 171 mm (6.7 in)
Dry weight: 6.8 kg (15 lb)

Components:

Oil system: premixed 4% oil to fuel, 25:1
Cooling System: air-cooled
Reduction gear: 3.6:1 belt drive and centrifugal clutch.

Performance:
Power output: 14 hp (10 kW) at 9000 rpm! The Solo 210/Hirth F36 would be a better engine, or one of these Hoda/Clone 4 Stroke Engines.Compression ratio: 10:1
Fuel consumption: 1.15 to 2 litres (0.25 to 0.44 imp gal; 0.30 to 0.53 US gal) per hour.
===============================

The Blue Yonder EZ Fun Flyer is a Canadian twin-engined ultralight aircraft that was designed by Wayne Winters and is produced by Blue Yonder Aviation of Indus, Alberta. The aircraft is supplied as a kit for amateur construction.

I went on a Vacation in that area about 55 Years ago, a pretty cool area. The Calgary Stampede Rodeo is close by. Mountain Tram close by also.

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#### Woodenwings

##### Well-Known Member
He makes a version of the lazair...look a little more and you will find it. Call him and ask!

#### Woodenwings

##### Well-Known Member
Blue Yonder EZ Fun Flyer - Wikipedia

#### Armilite

##### Well-Known Member
He makes a version of the lazair...look a little more and you will find it. Call him and ask!
================================

I tried calling, got his Voice Mail, so left a message. Do you know what the Plans are Selling for today? Do you have them? Got an Example Page?

#### Armilite

##### Well-Known Member
This website shows Lazair's MTOW at 530 lbs vs most websites show it as 450 lbs. The Average Pilot Weight falls between 180 lbs and 235 lbs.

Empty Weight: 210 lbs + 30 lbs Gas + 235 lbs Pilot = 475 lbs!

MTOW 450 lbs = 204.1166 kg / 10 kg = 20.41166 kw needed to Fly Well = 27.37249 hp. 27.37249hp / 2 = 13.7 hp needed for each Engine to Fly Well.

MTOW 475 lbs = 215.4564 kg / 10 kg = 21.54564 kw needed to Fly Well = 28.89318 hp.

MTOW 530 lbs = 240.404 kg / 10 kg = 24.0404 kw needed to Fly Well = 32.23871 hp. 32.23871hp / 2 = 16.1 hp needed for each Engine to Fly Well.

A Honda/Clone GX200 can make [email protected].

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