Market Harborough Model Aero Club


Free Flight Competitions – A Proposal


With the increasing popularity of free flight competitions over recent years and the upsurge of interest in “Nostalgia” models I propose a new competition to be adopted from January 2008.




That a new Free Flight Class be introduced from January 2008. The class will be a Rubber Duration Class based upon “One Model Type” only. This model will be the Senator as originally designed by Albert Hatful in the late 1940’s.




The “Vince Redfern Memorial Trophy for Free Flight” has been well supported in recent years and has lead to both renewed, and new, interest in free flight. Although the competition is an “Open Free Flight” class covering three disciplines, most entrants fly rubber duration models. Furthermore most models entered in this class are Keil Kraft Senators. This model was designed in the late 1940’s by Albert Hatfull and was later kitted by Keil Kraft. It is widely accepted as one of the best models that KK ever produced, has been copied by many manufacturers and is the subject of many “Nostalgia Free Flight” competitions world wide.

“One Model” competitions are becoming more popular, particularly in the United States where our hobby is taken far more seriously.

I propose an additional free flight competition be adopted from next year to be called “The Senator Rubber Duration Challenge”.

The Vince Redfern Memorial Trophy should be retained with the current rules. This will continue to promote interest in the free flight disciplines of:

  • Towline (and hand launch) glider.
  • Open Rubber Powered models.
  • Open ic Power models.





Proposed Rules


These are intended to promote discussion within the club and should not be seen as definitive.



1.       Construction


1.1               The BMFA builder of the model rule shall apply. The model must be built and flown by the entrant.

1.2              The model must be constructed from a commercially available kit or from scratch according to the Albert Hatfull or KeilKraft plans. Any modifications to these plans must be in accordance with published additions or modifications in the Aeromodelling Press and legal in FAI competitions for this type of model and shall be additions only. There must be no reduction in sheet thickness or omission of original parts except as specified below.

1.3              The propeller must be hand carved from wood and must not exceed 13” in diameter. It may have a freewheel mechanism and thrust bearings of any kind. It must not be of the folding type.

1.4              The rubber motor must be fully enclosed in the body of the model and must drive the propeller directly (no gearboxes).


2.     Flying


2.1              The model must be flown on the appointed day as published in the MHMAC competition calendar. This date may be altered at the discretion of the Competition Secretary if weather conditions dictate.  If the date and/or time are changed the changes must be notified to and agreed by all entrants.


2.2            The score will be the best aggregate time of 3 from 5 attempts.


2.3            An attempt will be defined as:


2.3.1                   A flight that has been notified to the Timekeepers and accepted by them as an attempt.


2.3.2                 A score which is at least 10 seconds.





3.     Timekeepers


There will be at least two timekeepers appointed by the Competition Secretary at the start of the competition. An entrant in the competition is ineligible as a timekeeper. Timekeeping rules will be in accordance with BMFA regulations.






Plans - I can provide email copies of plans (in Adobe Acrobat format) that will print on tiled sheets of A4 paper. I can also provide full size parts images (in TIFF format) that can be used to print directly on to balsa (if you have a laser printer or photocopier). See later article on this if it is accepted. I also have CAD files in dxf format.


Short Kits – Laser cut parts and plans – are available from Replikit - A short kit is a plan and laser cut parts only. You have to provide your own strip wood, covering and hardware etc. These short kits may seem a little expensive but the quality of wood and laser cutting are excellent. 01603 898474


Mick Bates kindly provided me with a reprint of an article entitled “Successful Senators” which gives some good info on Legal modifications to the kit. Mick is also a useful source of info as is Mike Hartop.




Mike Woodhouse - – a good source of rubber, tissue, thrust races etc.

Online and mail order supplies. 01603 457754


SAMs models – – another source of hardware and covering materials etc. Online and mail order supplies. 01763 287606


This is not an exhaustive list but a starting point. I personally have dealt with all companies mentioned so can recommend them.              John Wood