J.a.g.

[Jazzenjohn]

I've been reviewing Hornet plans because several people I know are in the process of building Hornets. I started making some parts for another gyro using common materials and building techniques with a focus on making it a legal UL using a Rotax 503 or MZ202. I'll use my HKS engine on it, but, I should be able to make it legal with a parachute exemption which, given that an HKS weighs at least 25-35 pounds more than those 2 stroke options, should make it easily legal with a 2 stroke engine. Basically I'm trying to make it like an Ultralight kit the way I think an Ultralight Gyro kit should be done....

 

[Jazzenjohn]

[No message]

 

[bugflyer]

I'll use my HKS engine on it, but, I should be able to make it legal with a parachute exemption which, given that an HKS weighs at least 25-35 pounds more than those 2 stroke options, should make it easily legal with a 2 stroke engine. Basically I'm trying to make it like an Ultralight kit the way I think an Ultralight Gyro kit should be done....

Part of Faa Advisory Circular AC 403-7:
18. POWERED VEHICLE WEIGHT. a. Items Excluded From the Computation of the Empty Weight of a Powered Ultralight Vehicle. ( 1) Safety Devices Which are Intended for Deployment in a Potentially Catastrophic Situation. Parachutes and some associated additional equipment necessary for their operation meet this criteria. Other devices, such as seatbelts, roll cages, instruments, or wheel brakes, are considered part of the airframe and are included in the empty weight. (i) Up to 24 pounds of weight associated with the parachute system may be excluded by the FAA without requiring a separate weighing of the system components. (ii) No weight allowance will be given for any component of the parachute system if, when it was operated, the parachute was not carried and attached to the ultralight at the reinforced points/fittings provided. This means you can't use the 24 pounds for anything BUT parachute. If you have a 10 pound parachute you get 264 pound vehicle weight. smiles, Charles

 

[Jazzenjohn]

I'm pretty sure it means you get the first 24 pounds for the parachute without it needing to be weighed separately, but, if the system weighs more, you may or may not be allowed to use the exemption for any additional weight by having it weighed seperately. It's worded exactly the same way for the float exemption that the Mosquito helicopter uses to give you the full body as an ultralight by adding the inflatable floats, and several other ultralight manufacturers have used in the past with either or both the chute or float exemption. John

 

[Alan_Cheatham]

Legal ultralight gyros have been done with the 503 and 202 (with belt reduction) but just barely. If the HKS is 25-35 lbs over the weight of the other engines then you will not make weight even with the parachute exemption as you must have the chute system installed, which must weight something itself.

 

[Jazzenjohn]

I've already built a legal ultralight gyro with an HKS 4 stroke engine Alan. It came in at 249 pounds including a prerotator.

 

[Kevin_Richey]

John: Would you post some photos of that bird? As well as a brief description of what you did to accomplish coming in under Part 103.

I imagine there are many who'd find it fascinating...

 

[Jazzenjohn]

Most of the build is here Kevin. Although I used a welded Titanium frame, the bulk of the weight savings were from the more mundane parts. Wheels, controls, rotorhead, prerotator, instruments, and tail. https://www.rotaryforum.com/forum/rotorcraft/builders-corner/17002-pile-o-parts