Receiving real-time information about the state and functioning of your airplane during flight enables the RC pilot to make informed decisions therefore contributing to overall safety and peace of mind. The current generations of radios provide various sorts of telemetry information such as speed, RF Quality, battery capacity, RPM altitude and much more depending on the radio vendor. Some radios provide such information via voice announcements and others will present data on the radio screen. RC pilots can configure a range of switches on their radio that can activate voice telemetry announcements during flight informing the pilot for example how much capacity is left in their main battery.
With so many new options available one should ask itself if telemetry adds unnecessary complexity and distraction when controlling an airplane or are there ways where telemetry data is given only when needed and relevant. When implementing telemetry the users should decide early on whether he wants a passive or active telemetry system.
With a passive telemetry setup, the user configures several switches on his radio that when toggled will give voltage, capacity or temperature data to make an informed decision when to land or avoiding a system malfunction. The benefit of such passive setup is that you can retrieve information at any given moment during flight. The drawback is that you will need to remember to monitor the telemetry risking distraction and potential loss of control when looking for your telemetry switches.
An active telemetry system is based on a range of preset user values that when any of such value has been reached the telemetry radio will notify the RC pilot so that he can make the a decision and action to take based on the information provided. The benefit of an active telemetry setup is that the pilot can focus on flying his model with little to no distractions unless there is something happening that needs his attention. The pilot can still configure a range of switches that will give on demand information but he does not rely only on his own actions since the telemetry is actively doing all the monitoring in the background informing when needed. It’s just like having a co-pilot with you.
So how does one setup an active telemetry system? What is needed is a beforehand strategy of what you require based on your personal preferences and RC model requirements. A good way to go about it is to compare with driving a car. When driving somewhere we factor in how long we want to drive before taking a rest, how much fuel we have and if there is enough oil to complete the trip. When setting up our active telemetry system we can apply the same thinking process. First we setup our flight timer to a value which we feel comfortable flying, second we configure the allowable discharge level of our battery or fuel tank, third the allowable low voltage level of our battery, fourth the maximum motor or ESC temperatures. Some telemetry systems will even allow you to setup maximum allowable altitude, model distance or speed.
When the pilot starts his flight the timer starts running and all is fine. Depending on flying style and conditions he may get no telemetry notifications as all is in the green. When the timer reaches zero the pilot can decide to land or continue flying until one of the telemetry notifications announces that the battery or fuel is getting low. During flight he may be notified of a certain RPM or temperature condition that may indicate an imminent system failure or when flying close to an airport an altitude warning will tell the pilot to descend.
Telemetry adds a whole new dimension to the RC pilot that when used and setup properly can take a lot of work load away and add to the overall peace of mind and safe operation of model airplanes and helicopters.
by: Model Airplane News