2026 SEFSD Aeroscout Endurance Challenge

This contest was proposed by Rob, a member of SEFSD who lives in Minnesota, but visits San Diego each year.     Mark then volunteered to fund the contest with a cash prize of 5 Billion Dollars (*), to be awarded at the 2027 holiday banquet (**).      The goal is to fly an Aeroscout as long as possible on a single battery.  The rules (which may change from time to time at the direction of The Voices in my head) are enumerated below:    

1. The Aeroscout must be stock except that the propeller may be changed to anything that fits without modifying the airframe.

2. The battery must be 3S and marketed as 2200mah.   If HV batteries are used, then the applicable capacity must be 2200mah.   For example, SMC gives different capacity ratings for the same battery, for 4.2v and 4.35v initial charge.   You may use these, but must charge to the voltage that is marketed as having 2200mah capacity.

3.  You must take off from and land on the same runway.    

4. You must have a timer/spotter.  Clock starts when the wheels leave the ground, and stops when the wheels touch the ground.

5. There is no limit to final voltage, you may torture your battery mercilessly.

6. You must fly over an approximately flat area.   Thermals are OK.  Slope soaring is not OK.

7. To enter, email a picture of yourself with your plane, and the timer showing your final time.  Also tell me some details about the flight.   Email to mdavis1863 (at) yahoo.com.    

(*) Dollars are Zimbawe dollars issued by the Reserve Bank of Zimbabwe

(**) Since the contest was posted on FB, we are getting submissions from other clubs in other states.    So we are now declaring this to be a solar-system-wide contest, and might end up with a winner who is not here next January.   If the eventual winner is outside of San Diego, we'll mail the prize  (non-earthlings may expect delivery within 1 to 2000 years).

The shaft of the Aeroscout motor shaft is 5mm,  but the thread is left-hand.  You can use the nut that comes with the stock propeller on other propellers, but it is shaped for the stock propeller and might not be ideal for others.    I have a bunch of M5x0.8 left-hand thread nuts and M5 washers, I'll give you one upon request.  I will also give a few to other people so that there should be somebody at the field with one at any given weekend.  

It seems a 6.5in diameter prop will barely fit, and you might even have to file the ends to make sure they don't hit (for example any mould flashing).

There is a useful video about testing various props for static thrust here:

https://www.youtube.com/watch?v=fnYv1KqfEuQ

If you use the DXS that comes with the Aeroscout, it has main battery telemetry.   The green lights will show 4, 3, 2, 1 dots, and then will start blinking.    An audible alarm goes off at very low voltage, and at that point it is pretty much "emergency landing" time.

Rob has confirmed experimentally (and inadvertently) that installing the prop backwards only serves to generate noise, and does not extend your flight time.

Place 1 :  R. Scott Page, 44:55

Place 2 :  Jim Bonnardel, 41:55

Place 3 :  Rob Jahnke, 36:55

 Place 4 : Josh Rodriguez, 33:17

Place 5 : Rob Jahnke, 20:35