John flew his latest F1D model in the EAA Eagle
Hangar during EAA’s Family Flightfest last
March. The plane, which weighs 1. 2 grams, has
an airspeed almost equal to a slow walking
pace. Spectators and modelers walk slowly so
they don’t create wake turbulence that can easily wreck one of these models.
RIGHT: John’s prized 2000 FAI World Championship medals.
A NEW CHALLENGE
The FAI changed its rules governing the prestigious and demanding F1D aero-model category a decade ago. Traditionally, an F1D airframe weight was limited
to 1 gram—equal to a dollar bill—while the size of the motor, a specially formulated rubber strip, was unregulated. Under the new standards, airframes could
balloon to 1. 2 grams, while the motor was restricted to 0.6 grams.
Microfilm itself was a major factor in the F1D rule change. By 2000 polymer
film had replaced microfilm for most aero-modeling applications. Polymer
comes on a roll, eliminating tedious microfilm manufacturing, and unlike microfilm, it is relatively strong and durable. Its one drawback—the polymer film, at
about 0.5 microns thick, is heavier in aggregate than properly made microfilm, at
about 0.27 microns. (Saran wrap, by comparison, is about 30 to 50 microns
thick.) Thus, F1Ds would not make the 1-gram weight limit with a polymer film
wing covering. That’s why the FAI increased the F1D’s maximum airframe
weight 20 percent.
The new rules cured another F1D problem: airline flight. The traveling cases
needed to protect fragile microfilm wings were too big for carry-on luggage.
With the maximum wingspan now limited to 55 centimeters, the wings were
now short enough to allow several F1Ds to fit in one carry-on case.
In the eyes of the FAI, the unlimited motor weight permitted prior to the rule
change enabled F1D flights to remain aloft too long for the good of the sport. The
motor weight limit of 0.6 grams was intended to reduce flight time to a more
competition-friendly length.
John recalls his reaction to the rule changes, “I didn’t think we needed
change. And the motor restrictions limiting how much rubber I could use
were traumatic.”
John realized the new standards would
take time for him to master. And he had
another free-flight goal, joining the assault on
what was seen as the rubber-powered world’s
ultimate milestone: cracking the one-hour
aloft barrier. Steve Brown, another noted
free-flight competitor, had broken the one-
hour mark with an official time of 1:00:01,
flying an unlimited hand launch (HL) stick
category model. John wanted to do better.
For more information about free-flight modeling, visit
www.FreeFlight.org. To watch a video of John’s F1D
