Whelp, just like men with cars and grilling; as soon as men made things work, they started one-upping each other. The FAI (Fédération Aéronautique Internationale) kept track of aviation records since 1905. This is about their smallest powered aircraft category: C-1a/0
IT’s no secret I’m into the smaller and faster planes. I fly the big things but always think of the smaller stuff. So when It comes to breaking records on my own, a bit of research should be accomplished. C-1a/0 dictates a takeoff weight of under 300 kilograms or 661 pounds, with fuel and pilot. That’s not much seeing how a Cessna-150 weighs 1,000 pounds empty. This category also makes achieving records much easier for you and I. Just build a light single place airplane and get to work! Engines aren’t hugely expensive behemoths, and structures aren’t priceless warbirds. The advent of foam and fiberglass over spruce wood in the 1970’s made for a revolution in this area. Something inexpensive to build in our garages could be the next Collier Trophy or pulitzer aviation prize winner and holder of international records such as the 3km two-way course for top speeds, or perhaps long range closed courses.
Before the new fiberglass and foam construction technique evolved, we had lawn chairs strapped to rainbow nylon skinned hang gliders with lawn mower engines. The real birth of ultra-low-cost flying, but also flight in forms lighter than ever. At this point by 1982, the fastest airplane under 300kg was an ultralight. The UL Soaring Wizard set a 3km record of 56 mph. Yes, 56. Remember, the ultralight had to carry a pilot and gas; most likely 200 pounds combined which was almost the weight of the ultralight itself!
Once common aircraft construction was applied to the ultra-small concept, much sturdier and therefore faster aircraft came along. Suddenly, folks realized that true speed and range could be cheap. This yielded some very efficient designs like motor gliders that were light and aerodynamic at the same time. Such as the Monett Moni...
...that crushed the 3km record at 118mph in 1985, or in another direction, weight-conscious construction that allowed more speed like the Cri-Cri...
...which did 146mph in 1988. We were finally off to the races with combined light weight and speed. We’ll return to this concept.
On the other end of the spectrum, these planes could travel some distance as well but either not as reliably, or they simply didn’t have enough fuel on board to cover the range due to the weight of the airframe and engine. The longer range records weren’t even tried until outright aerodynamics applied made higher miles per gallon possible. Burt Rutan designed some incredibly efficient planes, but in this weight class, he penned the Quickie which not only did 110mph on 18hp but held the outright class distance record for five years at 845 miles.
Not bad economy for a winged fiberglass canoe, an Onan generator driving the prop, and a few gallons of gas. (Pictured is a model with a small Rotax fitted)
In 1982, favoring slick aerodynamics but doing everything possible to run big power as well, the Monnett Monex set the 100km and 500km distance records at 185 and 182 mph respectively, with the help of a direct-drive high compression Volkswagen flat-four. The 100km record stood until just a few years ago, the 500km record is still current after 35 years!
We can see visibility is not important. Pure Speed is.
Thirty-five years, huh? Is someone interested in breaking a few records yet? Well, let’s look at what has to be done to build such a thing.
Building a plane to do these things, from an engineering and conceptual viewpoint, will break down into three areas of concern: Aerodynamics, power, weight. All three play against each other. Of course, we want it as slick as possible to maximize speed for a given power or to maximize miles-per-gallon for the distance records. But to make it fast, we would need to build a heavier structure to withstand the forces. We would need a more powerful engine to go faster which adds weight, and we wouldn’t be able to carry much fuel for any distance at all if we go that route. Remember, 661 pounds is all we have to work with.
Returning to the 3km records, we left off at the Cri-Cri which did that 146 mph speed on a pair of 15+hp two-strokes; Over thirty horsepower and an empty weight of 172 pounds. Its maximum takeoff weight is near 400 pounds. So let’s say we need to go after the distance records too, but if we stack on 200 pounds of fuel (33 gallons) to take advantage of all 300kg of weight available, the structure won’t take it, and the wing area is too small to perform properly. So we’re adding more structure, and more wing and that means, more weight and not as much gas as we hoped to bring. That enters hodge-podge land of changes and overall, a clean-sheet design is the next step.
The next year after the 146mph record, we saw a VW powered Sonerai race plane top 186mph. Two years later, a 50hp two-stroke driven BD-5b at 201mph. The next year came Mike Arnold’s 65hp two-stroke AR-5 at 213mph, then the Bd-5 re-engined with red-bull support and a factory Rotax 618cc at 75hp and only went six mph faster. Ultimately the final speed was topped and stands today by a Brazilian engineering school and leading-edge teacher. Their wood, foam, and fiberglass design brute forced it’s way to 223mph with an 80hp flat-four engine that weighs 145 pounds installed. The CEA-308.
That plane, pictured at the very top of this article and just like the Monex of twenty years prior, sacrificed fuel weight for higher-power and could only set shorter range records (100km stands today at 203mph). Eying that, can wewe can think about long range records and perhaps a lighter engine, slower speed and the ability to carry the fuel necessary to really tackle the long range speed records? Enter Austria’s Willem Lischak.
All he wanted to do in the mid-1980’s was build a cheap to operate, and fun to fly motor glider styled airplane. What he and his good friend, an Airbus engineer, wound up with was the wood and fiberglass LW-02, a light and glider efficient plane that had enough strength to hold a monstrous volume of gas.
His engine came from an Austrian four-stroke Styer-Puch (used in their version of a Fiat 650) with big-bore VW cylinders making north of 36hp. Weighing under 370 pounds empty, he filled up with 19 gallons of gas and set the 1,000km, 2,000km speed records as well as the outright distance record of 1688 miles. All while taking off under 300 kilograms.
I don’t know about you, but how would you like to sit under a bubble canopy for over twelve hours? That’s what it took. In the list of records, there are some that haven’t been fulfilled but could easily be taken at the same time while breaking other records. I firmly believe the technology of small engines is there, aerodynamic science is also there and not too hard to obtain ourselves, and the cost? Honestly, in this category of aircraft, it’s not all that high.
I’ve got my own designs, and I’ll give it a shot sometime in the next few years. Look close enough and there’s a plane already designed that could make this happen, with a few more aerodynamic alterations. The trick is to do it safely. I’ll see where this takes me. I just have to get my butt down to 185 pounds so I can carry the gas.
3km: 223mph CEA-308
15km/25km straight course: 204mph CEA-308
100km closed course: 203mph CEA-308
200km closed course: no record
500km closed course: 186mph Monex
1000km closed course: 120mph LW-02
1500km closed course: no record
2000km closed course: 110mph LW-02
2500km closed course: no record
Outright distance: 1688 miles LW-02