One of my favorite little airplanes. This is a bit on the way-back meter, but my recollection of the time was that the
Moni suffered the fate of nearly all motorgliders: Not fast enough for power-plane pilots, not "pure" enough for sailplane pilots, and in its original form it was really best at ridge-soaring. If you don't have a ridge nearby, well.... For a short time at the beginning it was offered only with the mono-wheel main gear, which put off a lot of the pilots who were looking at it anyway. There was a "short wing" version for power-plane pilots that had conventional gear that came out later in the production run for the kits, and while I believe that ended up being the best-selling model, it never did make a big splash. The weight of the gear cut strongly into the useful load, and added enough drag to reduce the performance. If Wiki is correct, the original version useful load was only 240 lbs to begin with. I dimly recollect a long-wing "enhanced soaring" model, but I'm not sure that got beyond the prototype stage.
I think there may have been some issue with the KFM engine, late in the game. I don't recall what it was. May have been that it was discontinued?
Pireps I read of the airplane said it was typical of small single-seat homebuilts, with light controls and simplifications compared to type-certificated aircraft, but that it flew well for what it was, and got decent performance out of the original 30hp engine. I remember one power-pilot complaint about the seating position - sailplane-like and too "laid back" for his taste. A lot of people liked the kit. Very simple, especially for the time.
Another factor is that this was full-bloom "Rutan-time", and the
Quickie 1 was considered a direct competitor by most, even though it couldn't soar at all. The
Quickie, by virtue of its looks and association with Rutan, got a lot more press.
The
Moni is the figurative and literal ancestor of the
Sonex family. John Monnett designed both.