SEN 2407 - Don Leath

Table of Contents – SEN 2407


  1. Acceleration sensor for control of F1A towhook:  (Sensor controlled models)
  2. Don Leath



Acceleration sensor for control of F1A towhook:  (Sensor controlled models)


From: Dave Edmonson


The acceleration sensor is an automatic control that is not a one time activated control!  It can latch and unlatch the hook multiple times during the flight!  The flyer can choose to launch on acceleration or decelerate to relatch the hook!  


The acceleration device, as a control device during tow to give advantage, not much different than a control system that senses atmospheric conditions and steers a model toward a thermal in the glide!


Going back in time, the swinging tow hook controlling the rudder/wing wiggler during tow should also have been seen as a control device, and disallowed it's use per the rules!


On another controversy, are you still able to RCdt to abort a bad flight under the attempt time?


Good luck on those issues!


Dave Edmonson.....



Editor’s Comment: Dave I believe it is permitted because the flight does not commence until the model comes off the line.  Neither of the comments from Ian or Allard explicitly mentioned or confirmed this. There are relatachable tow hooks in common use that use either a spring that trips a switch or a strain gage to open and subsequently  possibly close the hook if the launch is abandoned.  In this case the flight has not commenced.  If we go even further back the auto-rudder or even the flyer pulling the towline in one direction could possibly be interpreted as the flyer controlling or steering model but that is OK too because the flight has not started.


There is no penalty for using a RDT to terminate a model flight even if it causes an attempt.  This is a non-issue these days.  While I’m not sure when it was done and the exact reasoning but I believe the consensus was that safety  of people and avoiding damage to model or property means that sportsmen should be encouraged to use an RDT to avoid a crash.   For example model is going to crash, and RDT could stop it or lessen the impact but the flyer does not do it because that would make the flight  not an attempt.   


Don Leath

From: Jim Bradley


I regret to inform all that knew Don Leath of his recent passing.  Don was an active F1A flyer for many years in both Florida and then California after he moved there in the 1980's.  Don served in the US Navy before joining the FAA as an electronic technician where he stayed for his entire working career.


Those of us who knew Don during his years of flying knew him as a great competitor and good friend.  Don was always eager to help other modeler with their flying, especially if it involved chasing which he was very good at.


Cards of condolences can be sent to his wife at:


Fran Leath

3145 Paddle Boat Lane

Jacksonville Fl 32223


Jim Bradley


Editor’s comment: Don was a member of SCAT, the Southern California Aero Team while he was living and flying in California. He regularly took part in our events as both a flyer and organizer.  He is missed by all of us.