I began initiation of a follow-on production Helio when I was in pursuit of Helio Aircraft in 1982. As an aeronautical engineer and pilot, my emphasis was on making the ultimate Helio.
1) Ultra-high strength plastic extruded roll cage
2) continuous spar eliminates wing carry-thru
3) Turbine power
4) 4400 pound max weight
5) 180 knot cruise
6) 44" wide cabin with true six-place seating..
I have the drawing somewhere and when I locate it, I'll scan and post..)
I've given your points some serious thought and I have some questions.
1) The only plastic like material I've heard of that rivals the strength of steel is a combination of kevlar and carbon fiber is their a way to extrude it? Obviously you know something I don't, please elaborate.
2) I'm only familiar with the H-295 spar and that's, because of missing paperwork for the carry through spar, when I contacted Clarence Brent, I asked him about the engineering that went into his STC he just kind of laughed and said that there wasn't much engineering to it that he used a bridge truss, made it
look hell for stout and used stronger materials. The Fed's took one look at it and signed it off. In a previous post there is mention of the 800 carry through is being made out of
stainless is that the only difference? You say you would use a
continuous spar how would it
connect to the fuselage and would it improve the
headroom? Maybe you could post a
drawing, I'm having trouble picturing it in my mind.
3) Everyone seems to want to put a turbine on their airplane. Wouldn't the initial cost of a turbine plus its high fuel burn, especially when using the airplane as most do, count against it? Range and loiter time is one of the pluses in the Helio. And what about turbine lag? I've always heard that in a STOL situation where you have gusty wind conditions and marginal landing area where at the last second you need to do a go around the
spool up time is a bad thing.
I've seen the Zoche Aero Diesel radial mentioned, Mistral rotary in previous posts, and other engines. Probably what we should discuss is the
most likely engine to reach
production status. With the fuel situation here and world wide the Helio needs a different engine preferably one that will burn anything. I think that's one of the reasons the Rotary is so attractive. I think the rotary has the most potential if you used a compounded
traction turbine on the exhaust you could quiet it down considerably (I believe noise is going to become a major issue) and increase its horse power. Direct injection using
Lorentz or Piezo coils seems to be the answer for fuel delivery, emissions and efficiency. There are some new alloys available one discovered by Nasa allows engines to run hotter in the combustion chamber and cylinders. Rotax is using it in one of their newer engines.
4) Gross weight seems achievable. Didn't I just read in an earlier post that the 800 was rated at 4000 lb gross.
5) I'd like to see 180 kt cruise without increasing the HP all that much. When I visited Jaars back in 1993 Jim Metzler or maybe another Jim showed me a Helio that they were using for
speed test mods. I didn't remember the numbers but I just read Frank Rowe's book
(worth reading) and he writes that the speed mods to "The Grey Goose" gave it 7-8 knot increase in cruise.
I do remember he said there was no penalty on the bottom end. You said in an earlier post that there was a
significant penalty. I wanted to get a copy of the fiberglass fairing above the windshield where wing intersects cabin but was never able to. I also thought there was potential to increase
upward visivbility although that might involve a whole new windshield. they also had a fairing at the bottom of the windshield for better aerodynamics.
6) How wide is the present cabin? I don't remember it being uncomfortably narrow, but I usually flew alone or with a skinny female passenger, at least for any long distance flights where you have the time to become uncomfortable.
I always wanted more cross wind capability, after reading the information at Zenith site on the Zenith, I wonder if an all movable vertical stabilizer wouldn't be a major help by cutting down on the size of the stabilizer. What does everyone think on that subject.
These 7 items should probably be discussed in 7 separate threads since they are each quite lengthy. I just did some searches I see that a lot of these things have already been discussed but maybe there's new thoughts and ideas.
I understand that most people believe that all aircraft are compromises but I don't want to give up any of the
go slow characteristics of the Helio. I just want to see a few improvements.
Did you find your
drawing?
Thanks, Doug