Motorfloater Storyboard  2

I tour the local area, just looking at whatever I find. In calm air I might be spiraling down and suddenly get solidly bumped by flying through my own wake. This can be alarming, it makes you look around for whatever it was that came close but was unseen, when, of course, there was nothing there at all.

Here's a nose up climb, "clawing" for altitude in the traditional two-stroke engine mode. The idea was to get up fast in case the engine quit so you would have some emergency landing options. This high a nose attitude might not be giving me my best climb angle, but I did seem to be going up, so I wasn't just wallowing on the back side of the power curve. At full power and full back stick the plane won't do a nose drop, it just keeps flying, so I can indulge myself in delusions of ascendance. This might not be true for heavier pilots, considering that the pilot is half the gross weight of a motorfloater. Adding fifty pounds might not be trivial.

If the engine stopped at low altitude I would put the nose down (to get extra airspeed, for good flight control), focus on flying the airplane (ignoring distractions), and make a plan for a simple landing (avoiding low turns or close proximity). I would not try to re-start the engine (it might not work) and I would not call the tower to declare an emergency (they'll figure it out). I wouldn't make any big effort to preserve the aircraft, I'd concentrate on pilot safety (me) and avoid pointing the nose at anything valuable.

Some pilots might dismiss a plane for being too draggy, having too many struts and cables strung out across the breeze.

Exposed struts and cables are draggy, but so what? Parasite drag will reduce your top speed and climb rate, but those need not be of high importance to a motorfloater. The effect of drag on local flying at slow speeds is: not much, since you are there to fly, not to go fast or far. Climb angle can be a safety issue with airplanes that cannot turn sharply, they may have to go over obstacles when a motorfloater might just make a tight turn  back into the clear airspace they just flew through.

Tubes that are mostly across the wind are faired and others not. You can fly with all bare tubes, as many ultralights do, but round tubes will drag in the breeze. You will have to run your engine harder to hold the same airspeeds.

 

The nose down landing is a safety feature that is intended to allow the pilot to land the plane in a strong wind. Once the plane stops, nose down, it can be held in place to allow the pilot to get out.

Full span vortex generators were applied to both the upper and lower wings of Bloop 4. Here they look like a row of small bumps from wing tip to wing tip on the tops of the wings. They worked as advertised, allowing smoother, better controlled slow flight and having no evident effects at higher speeds. They may have allowed slower flight, and they seemed to prolong floating in ground effect when landing. On the Bluebird monoplane I didn't use them because I didn't want a long float over the runway before setting down onto the ground.

Here's Floyd Fronius with Bloop 4 in his rustic hangar.

The previous operator has installed a 5 gallon fuel tank, that black box on top of the lower wing. Several Bloop operators have done something like this, bringing the plane up to the full Part 103 allowable fuel capacity, and allowing long flights with a good margin of reserve fuel. I still prefer the original 2.5 gallon tank, it's the right size for local flights and keeps you from flying with 15 pounds of unused gas. Also, I really like the translucency of the smaller tank, I can quickly see how full it is.

As of July 2023 Bloop 4 has a new owner and is flying in southern California with the original small fuel tank and a new tail skid.

 A lot of garage technology is in view here . Anything that is damaged can be quickly replaced or repaired, either by work in my shop or by an "off the shelf " purchase.

This wing structure is ready for fabric covering. Each rib is just a tube on the upper surface, there is no rib structure below that. The lower surface fabric is tensioned by being drawn upward using loops of stitching over the rib tube.The undercamber of the lower surface is incidental, it's just a result of tensioning the fabric.

My motorfloaters don't have welding, sheet metal, structural riveting, jigs or molds, spray painting, wood, windows, windshields, doors, walls, electrical or hydraulic systems, nor flight instruments. There is no circulation of water or oil, no dual ignition checks, no fuel valve, no fuel sample drain check, no ground steering system, no tail wheel, no main wheel brakes, no pyrotechnic rocket expiration date, and no access doors to open and close.

My current practice is not to bend any tubes larger than 1/2 inch diameter. I used to do this but I came to see it as a "special skill" which could be eliminated. Garage technology involves a minimum skill set and no specialized vendor parts or support.

Beach wheels! I flew with these slick balloon tires for a while and I liked them the most of all, more than the bicycle or kite buggy tires. They were soft and bouncy, and would skid sideways without much resistance (which I liked a lot). This property of weak side loads in response to a side skid puts less load on the landing gear when landing at a crab angle, and probably gives better steering control. (Crab angle means my course is down the runway but my heading is pointing off into the crosswind, so I touch down slightly sideways. Wheel dance!). I suppose most airplanes want strong tire tracking forces to keep the plane straight on the runway, but I want the opposite, the weakest possible tracking so I can slide a little.
 
These were big, fat wheels (19.3" x 9"). On final glide to landing at low power I noticed a steeper descent than with the bike tires, a noticeable increase in drag.

The beach tires are cute and fun to fly with, but they are just light urethane tubes and not very durable, so I doubt they would last long on runways. Durable balloon tires, with tubes, tend to be heavy, but these beach tires suggest they might be a lot of fun to fly with.

FAA Part 103 has provided us with a golden era of experimental flight. I have taken full advantage of it's freedoms for design, construction, modification,and test flying. I flew experiments with variations of wheels, controls, nose structure, nose and tail skids, ground brakes, parachute containers, line tensioning, wing angle and twist, rudder and horizontal tail plane shapes, and various ways of building foot pedals. 

The tubes were cut with a hacksaw, the holes were made with a hand held power drill, smoothing was done with a file. I have a 4" vice and a work table, I don't use a drill press and rarely use a grinder.