Two cycles, Boy some folks sure hate them

[radfordc]

There is no disrespecting ultralights here. They serve a purpose but they do have a higher risk. I don't think anyone will deny that.

I personally felt safer in my ultralights than I do flying my Sonex. Yes, I had 10 "emergency" landings in ultralights over the years, but because they land so slow and in such a short distance and because you only fly ULs over "safe" terrain there was never any fear of damage or injury. Basically, the engine quits and you land.

[steveinindy]

Likewise. I'd take an engine out in an UL aircraft any day over a Sonex.

[bwilson4web]

I finally got around to weighing the 60 hp, 1835cc, HAPI VW engine: 172.6 lbs. This is about 20 lbs heavier than the 'dry weight' in the Sport Aviation article. This weight includes the starter, cooling baffles, intake manifold, magneto, backup electric ignition, and second spark plugs. It did not include the 1.3 lb Ellision and 7.0 lb exhaust stacks for an all-up weight of 179.9 lbs. BTW, I will be selling the HAPI but not the Ellison, yet.

The BSR straps can run from the engine mount points along the fuselage and back to the wing cover. Replacing the VW engine means the 'side cheeks' are no longer needed or could be replaced by something more functional:

For example, ducts that carry radiator plumbing and BSR stainless steel cable.

One radical thought is the BSR might fit in front of the firewall. This improves the CG by moving it forward and putting the rocket on the other side of the firewall. In fact, a canister BSR might fit:

A lighter, 60 hp engine means the engine mount needs to extend forward to maintain CG. This increases the space between the firewall and engine and possibly allowing a BSR canister to fit. This space might compete with a radiator and ducting but there is a more radical solution.

The coolant hoses could route outside the sides of the fuselage back to a rear mounted radiator and ducting in the fuselage behind the wing drag bulkhead. This avoids running plumbing through the cabin and bulkheads. Jon Finley did this with his Subaru powered, Q2 running the pipes under the fuselage.

The radiator hoses could be encased in functional, external duct(s) on each side with a profile no worse than the 3" x 9" side cheeks. The side cheeks could be the front anchor for aluminum ducting. Run the BSR straps or stainless steel cable along the duct top and two problems are solved. A rear, P-51 style, radiator offers the possibility of reduced cooling drag. Both options need to be modeled.

Bob Wilson

[bwilson4web]

Good luck to you Bob.

Thanks Jeff,

I also noticed my Yahoo Dragonfly list membership was pulled. Fortunately N19WT is not dependent upon the Dragonfly list.

Too bad, I was going to share progress on my airframe and navigation light work.

Bob Wilson