Background:

Safety is paramount.  There is an obvious need for an independent method of securing an autonomous flying vehicle when things go wrong.  Many of the vehicle entering the competition are heavy and energetic.  Many have exposed whirling rotor blades and/or propellers.  In short, without proper safety procedures, your memories of the competition could be unhappy ones.

The requirements are divided into two categories - general and specialized.  General requirements apply to all entries.  Specialized requirements vary by the type of propulsion used in the vehicle.  During the static judging and before the first flight in the competition arena, the flight termination mechanism will be inspected.  The team will be required to demonstrate the operation of its flight termination mechanism to the satisfaction of the judges.

General Requirements:

All vehicles MUST have a Flight Termination System (FTS).  The FTS shall immediately stop the engine, shall be activated by an independent communication link, and shall have an independent power supply.  The method of stopping engine will vary depending on the ignition source, (see Specialized Requirements).  It shall use an independent, reliable communication link with sufficient range to operate with reliability over the entire arena area.  It will have an independent power supply.  The FTS will be operated at the direction of a competition official.

Specialized Requirements:

Spark Ignition Engines shall be stopped by disabling the ignition and/or choking off the air supply to the engine.  Fuel cut-off may also be employed as part of the FTS but will not be sufficient to meet the FTS requirements.

Non Ignition Fueled Engines, glow ignition and diesel, shall be stopped by choking off the air supply.  A fuel cut-off may also be employed as part of the FTS but will not be sufficient to meet the FTS requirements.

Electric powered vehicle shall have an independent method of removing main electrical power from the vehicles propulsion motor.

Discussion:

The fuel cut off method is not sufficient, in any case because once the fuel is pinched off, the engine normally speeds up and then quits abruptly.  The air supply can be cut off with an independent device or a second independent actuator connected to the throttle arm.

Many teams in the past have employed a "manual back up mode".  Manual modes are useful for recovering a vehicle without causing much damage and working through development.  However, the "manual mode" does not supersede the requirement for an independent FTS.

If you have questions please forward them via E-MAIL to Don Lacey. It would be advisable to have your FTS design completed and approved as early as possible.