The Broadway Bod Busters

Happy Birthday F2D Proto!

Yes folks, it's true,

It's 2009 and thanks to the BBB, Mike Hazel and John Thompson, F2D Proto is one year old.  Those of you who hang around the speed circle may have noticed some of the attributes.

1.     They're fast!

2.     Easy to start, run, and fly.

3.     Engine and muffler are to a formula. (stock engines are very competitive)

4.     APC props work well. Range 7 x 3 to 7 x 4

5.     You don't need special lines or handles.

The variables turn out to be mostly head clearance and prop to push the speed into a faster bracket.

Like all one year olds, the proto event is making itself known, there have been several inquiries from around the country about our infant.

 Most are from fliers like you and me who want to try it out, most seem to like the formula and the high quality engines. There have been some critics suggesting that it is not a"real" speed event because it allows braided line and adjustable handles. The BBB's response is simply this: If the event becomes so popular that the need for uniform rules exists then they will likely morph to the AMA set of rules. In the meantime, it is still the same ol' user friendly and safe SPEED event that it was intended it to be.


Profile only, wing area of 100 square inches minimum, not counting the stabilizer and elevator.

It must have a canopy but a painted outlines will be allowed, a vertical fin, external controls but the centerline of the bellcrank can be inside the fuselage as long as it is exposed when deflected. This will allow you to use a pin through the fuselage to take the pull of the model instead of the wing. The model must be painted or trimmed colorfully ... no clear finishes. There must be two wheels at least 1" in diameter and separated by 2-1/2" min.


Must be a legal F2D engine as well as legal muffler, no modifications are allowed to the muffler or to the venturi i.d.

From the FAI Sporting Code:

Engines with glow plug ignition shall have their exhaust port(s) connected to silencer(s) (one or two),consisting of a simple chamber with one circular cross-section outlet aperture of 8mm (1) or 5.65 mm (2) diameter(s) opposing the exhaust port connection. The minimum total volume of the exhaust system shall be 12.5 cm 3. In the case of two exhausts, each silencer shall have a minimum volume of 6,0 cm 3. The maximum total length of the exhaust system from exhaust port(s) of the cylinder to and including outlet(s) is 15 cm. The motor shall have a maximum effective venturi diameter of 4,00 mm (see 4.4.6.d for field

Lines and handle:

.015 x 52 ft, same as F2D combat, Adjustable handles allowed, safety and pull test are patterned after the Clown racing event of 25 lbs. If you use metal buttons on the bellcrank you will be required to use double loop construction on the line terminations. If the lines contact a non metal surface then single loop is allowed. (if you have a nylon bellcrank single loop wire is okay to terminate.)

Complete rules:

PHEW! What a lot of stuff just to make a simple event! "What works for you guys? " you ask.

Here is a simple and effective formula.

Wing:               1/4" or 3/8 x 31" x 3.25" soft balsa (put some sort of short spar in it for wing) bellcrank mounting. You may get some flex with 1/4".

Airfoil:            OS1099_A.pngN.A.C.A. 63-008

Stabilizer :       1/8" or 3/16" med-hard balsa 20-30 sq" 10" x 3"

Fuselage :        3/8" med balsa             16-18" long

CG.                 25% wing chord

Motor mounts:           hard maple or buy aluminum F2D mounts from Jeffrey Rein.

Vertical fin:     1/16" plywood or sandwich 1/64 ply and 2 ea 1/16 blasa.

Finish:           4 coats of thin nitrate dope, light coat of primer, color or trim in either dope, epoxy or Lustre Coat.

Fuel Tank:    Any fuel system can be used, I use a small bladder tank that is stretched between two anchor points when it is empty. When you fill it the tension will ease but should be enough to keep the tank in place. The shape is very streamlined, I use 1/4" dia surgical tube cut about 1-1/4" long.


 Keep on your toes !   

When taking off, be 10 degrees ahead of the model, hold your arm up so you will force the outboard

Wing down when released. They can turn left and come visit you if you fall asleep, but you are allowed to whip to get the model airborne so take some advantage here.


The fun of this event is in the actual races you will encounter, they can be very close so learn all you can about props and how to modify them. Head clearance and what it does and doesn't do. ZZ Prop has a good news letter in circulation, you can also join the North American Speed Society for other engine tips and ideas. Flying Lines is another place for speed tips along with F2D sites such as Mark Rudner's For those who wish to learn how to set head clearance here is an excellent article by Mark at

Kenny-b  and The Bod Busters

This page was upated April 1, 2009

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