My HiMax


HiMax specifications
Engine - Rotax 277 25hp
Weight - 310 lb with chute
Stall speed - 30 mph
Climb - 700 fpm @ 48 mph
Cruise speed - 72 mph @ 5900 rpm
Top speed - 80 mph @ 6500 rpm


The HiMax is for sale, for the latest description, pictures and video clips go HERE

click to enlarge The kit(???) has just arrived, I don't think you can tell from the picture I'm crying - This was suppose to be an airplane ???, a bunch of sticks some plywood and tubing, the only thing resembling any kind of airplane part was the wheels.
click to enlarge The winter had passed and it does start to look like an airplane, the wings and tail are done, the fuselage well under construction, I'm about half way at this point.
click to enlarge The end of summer, time to take the plane to the airport, yes I did turn a few heads along the way, I had no trailer and the trip was only 8 miles.
click to enlarge So this is the original version, built exactly as the plans show, note the flat top.I wasn't trying to make a point of not modifying anything, I just didn't know any better. The plane went through many changes since, as I was getting more experience and new ideas
click to enlarge This is the second version, added spinner, nose cowling, strut fairing, drooped tips wheel pants, but still a flat top and the original landing gear, it gave me noticeable increase in performance but didn't do anything for the comfort level and I realized later on that was really needed to make this plane more practical and enjoyable
click to enlarge This is the latest version, many changes here were geared towards raising the comfort level and aren't visible on the picture, new instrument panel with GPS, radio, ANR headset, 10 gal fuel tank, interior upholstery/sound insulation, contoured seat, in flight trim, fiberglass landing gear and tail spring, new "lord type" engine mounts, openable (is this a real word ???) window, parachute, pull start inside the cockpit, internal pushrod aileron controls and round fuselage top.
click to enlarge Here is a good pic of the nose job, note that the bottom of the fuselage curves up decreasing the front fuselage profile, cut down (up ???) by 4 inches, good for drag reduction and improves the look as the desired cowling shape is much more manageable this way, compare the cowl pic above. I did the same on my new minimax and it was very easy done by cutting two slots into the bottom longerons the length of the bent, inserting pieces of flat stock into the cuts and glue up this laminate in a simple jig to desired shape.
click to enlarge Redesigned aileron controls, this system is cheaper, lighter, easier to build, eliminates the high static friction of the push-pull cables and enables differential aileron throw about 2:1 (the v shape angle of the lower horn does that). Basically the same as the Airbike. click to enlarge click to enlarge
click to enlarge Elevator pushrod control mod,
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click to enlarge Nose wheel conversion
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click to enlarge Fitting the new rear window over the new turtle deck, note the turtle deck doesn't look anything like the one on plans, this one is made out of 1.5 mm plywood bent around two ply formers, very easy and quick to build and very light weight, it goes only up to the rear window bottom, not all the way behind the pilot.
click to enlarge All finished back there, here you can see the chute instalation fiberglass top and botom window trims and aileron controls pushrod just behind the forward edge of the rear window
click to enlarge The interior finish, the material is from Wallmart auto department, it is sold in rolls of diffrent colors like blue, geay or black for use as truck beds liners. Very light waight and easy to work with, Installed with 3M super 77 contact spray adhesive (home depot) In the place of the wing root is a foam rib covered with same material
click to enlarge The bulkhead behind the pilot is 1 inch foam covered the same way. That bulkhead renders the transparency of the rear window rather useless but cuts down the noise level considerable by blocking that echo effect from the rear, This was suggested by a friend (smart one) when I mentioned to him the high noise level bothered me, it really worked.
click to enlarge It always amazes me to what effort, complication and expense some people are willing to go to build a trim system, with all kinds of pulleys bell cranks or electrical devices. I'm firmly convinced that every airplane should have an in flight adjustable trim and I would not have a plane without it but it doesn't need to be expensive or complicated, a simple "model airplane like" solid wire push pull control works great. The second "mixture" lever on the dual throttle quadrant is used to operate the trim. There is also a fixed spring hooked up to the stick that takes up the weight of the elevator
click to enlarge The fiberglass landing gear, I flew with the original solid gear for three years and its perfectly usable strong and relyable landig gear but changing to this fiberglass one was like going from riding a horse wagon to driving a Cadilac, not to mention the clean instalation
click to enlarge Off to Sun"n"fun we go, Here I finished the last rebuilt, not flown yet, I just put all the parts on and took it to the show. Check the piles of snow around the house
click to enlarge Sun"n"Fun, The ultimate reward for your work, you get to take your plane to the show, hang out with all the "Airheads" and talk about your plane. Thatís Paul Burns with his plane next to me.
click to enlarge And this is what it's all about.



Below I made a table with performance numbers for Maxes with different engines. The 6.5 sq ft flat plate drag HiMax and 7.5 sq ft MiniMax are about as clean as you can get them, engine cowling , spinner, enclosed cockpit and all the tubes streamlined including landing gear and tail braces. The Himax can be made about 1 sq ft cleaner because the wing on a Mini passes through the prop wash and the roots have big gaps in the rear and also the spring type landing gear is a lot cleaner. The regular Minimax is something like a 103 with the cowl and spinner , rounded top and turtle deck but open cockpit and no strut fairings. The speeds and range are in miles, fuel burn in gallons per hour. The range is calculated with 9.5 gallons assuming you have a standard 2 5 gal. tanks where about Ĺ of the gallon would be unusable and no reserve is considered.
These numbers are not to be taken at their absolute value, each airplane is rigged differently and each engine is tuned different with different prop and so on, They do work well for comparison, note how drastically the range goes down with the higher horsepower.
I hope this will help somebody to decide what to get and what to do

Top speed Cruise Fuel burn Range
Clean HiMax-6.5 sqft R 277-25hp 80 72 1.9 360
R 377-35hp 88 80 2.6 292
R447-40hp 92 84 3.0 264
R 503-50hp 100 90 3.8 213
Top speed Cruise Fuel burn Range
Clean MiniMax-7.5 sqft R 277-25hp 76 70 1.9 350
R 377-35hp 84 76 2.6 277
R447-40hp 88 80 3.0 252
R 503-50hp 94 86 3.8 203
Top speed Cruise Fuel burn Range
regular MiniMax-9.5 sqft R 277-25hp 70 64 1.9 320
R 377-35hp 78 70 2.6 256
R447-40hp 82 74 3.0 233
R 503-50hp 88 80 3.8 190