Flying Aids

Winders, Stooges And Retrieval Systems

Retrieval systems

For many years the radio direction finding system sold by Jim Walston was the gold standard retrieval system for free flight planes. A small transmitter attached to the plane sent a series of beeps and the pilot found the bearing to the plane using a directional antenna on a UHF receiver. Walston no longer supplies these systems, but they are still available according to an NFFS forum. Apparently, Walston got his systems from a supplier to Falconry hobbyists ( Systems are also available from Falconry transmitters weighing as little as 4 grams are available from
The transmitters are tuned to channels about 10 KHz wide in a HAM Radio band near 220 MHz. Walston systems used a WMI TRX-3S receiver with a frequency range of 148 to 222 MHz, which can be tuned to 3 channels.

Remote Dethermalizer Activation by Radio

In addition to on board Clockwork or Electronic Timers and fuses, it is now possible to activate a dethermalizer (DT), such as a pop-up stabilizer, from the ground via radio control. While for the biggest planes a battery, receiver and servo might weigh in excess of 20 grams using normal R/C plane gear, recently lighter gear based on garage door opener technology is becoming available. One source in the UK has a system to burn through a rubber band to activate the DT Eagles are testing this system for activation range. A longer range transmitter is also becoming available.