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So I talked to Aerolite 103.

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Armilite

Well-Known Member
Joined
Sep 5, 2011
Messages
3,738
Location
AMES, IA USA
So by their Info, a 277UL with the right Prop should work also. They only show a 60" & 63" Prop. A Rotax 277UL (26hp@6250rpm) with a 2.58 Redrive at 77F using a 63" x 19 Pitched for 2,322.5 rpm = 227.83 lbs Static Thrust and needs 25.474 hp!

A Hirth F-33 (28hp@6500rpm) with a 2.5 Redrive at 77F using a 60" x 20 Pitched for 2,500 rpm = 217.18 lbs Static Thrust and needs 27.514 hp!

Just about any of these GX270+ Honda/Clones could also be used if upgraded to make 25hp+.

Prop Static Thrust Calc:
http://godolloairport.hu/calc/strc_eng/index.htm

Hi Rich.

So with what Engine is it 235lbs?
==> Hirth F-33(28hp).

What 50hp Engine does it make Part 103 254lbs?
Hirth F-23(50hp), manual start, reduction drive, no options/upgrades. It will meet the weight limit of 278 lbs with the F23(50hp), but it will zip right past the 63 MPH.

What is the Smallest HP Engine you have seen used?
==> Hirth F33(28hp)

Here is some additional info regarding weight:
If you use the F33 engine, the completed aircraft is 10-12 pounds under 254 without a parachute. With a chute, it is approximately 17 pounds under the 278. In either configuration, you can add pretty much whatever options/upgrades you would like and remain under 254/278.

Using the Hirth F23(50hp), and no options/upgrades, the aircraft will come in right about 278 with a parachute. If you are not familiar with the Part 103 language, it allows you 24 pounds for a parachute system. Since the parachute system only weighs 17, you pick up that other 7 pounds which will offset the additional weight of the F23.

Having said all that, about 98% of all UL’s are either a few pounds over the 254/278 weights, and/or go faster than 63 MPH, and nobody cares. I have personally asked guys from the FAA about a dozen times “What happens if my UL is over the weight limit.” Their response every single time has been “We have more important things to worry about.” Most owners of a single-seat UL type aircraft opt to install the engine and options they desire, and they still fly it as an Ultralight even if it is a few pounds over 254/278.


Please let us know if you have any additional questions or need any additional information.

Dennis

Aerolite 103, LLC

Magnum Parachutes, LLC

U-FLY-IT Light Sport Aircraft, LLC


386-738-4444 (Hangar)

740-407-4491 (Cell / Text)

www.fly103.com

www.ballisticparachutes.com

www.uflyit.com

[email protected]

[email protected]

[email protected]
===============================================

From: Rich Gillen
Sent: Thursday, July 25, 2019 11:28 PM
To: [email protected]
Subject: Spec's?

Hello:

So with what Engine is it 235lbs?

What 50hp Engine does it make Part 103 254lbs?

What is the Smallest HP Engine you have seen used?

IF with Hirth Engines, which Configuration.

F-33 28hp Weight: 35lbs including exhaust sys. - 40lbs W/re-drive - 45lbs W/elec. start

F-23 50hp Weight: 78lbs, including reduction unit, full exhaust, and electric start or 71lbs with recoil start reduction unit and full exhaust

Aerolite 103 Spec's.
http://www.uflyit.com/aerolite_103_specifications.htm
 
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