Communication Lost - All Data Links Lost

Owned by Matt Skelton
Last updated: Apr 04, 2023
2 min read

What triggered the failsafe?

The autopilot and the ground station have failed to communicate with each other during flight for more than the lost comms timer is set to.

The PHX defaults to a 30 second lost comms timer. The timer can be changed to be longer but needs to be changed before every flight. The default value resets after landing.

The loss of communications may be due to the following:

Cause

Info

Cause

Info

CommsBox

  • The CommsBox should be set up so that it has a clear line of sight to the aircraft while in flight.

  • The CommsBox should not be setup on the ground.

  • The CommsBox should be set up away from any large objects such as vehicles or buildings that may block signal.

  • Using the small antenna when flying more than 3/4 of a mile away may cause a poor connection.

  • Flying more than 1.5 miles away with the long range antenna may cause a poor connection.

  • If the CommsBox battery dies the connection will be lost.

  • A CommsBox that has been damaged may have degraded performance.

CommsBox Connection to Laptop/Tablet

A poor WiFi or Ethernet connection between the CommsBox and the Laptop/Tablet may cause communication issues. 

Laptop/Tablet

  • If the laptop or tablet overheats it may cause the Fly PHX application to perform poorly or crash, leading to a loss of communications.

  • If the laptop or Tablet dies during the flight the connection will be lost.

  • Exiting the application or locking the screen when using an iPad will cause the connection to be lost.

Environment 

  • High power transmission lines or towers can interfere with the datalink and degrade connection performance.

  • Thick woods can interfere with connection strength.

  • Tall corn can interfere with connection strength.

Flying directly overhead

The omni-directional antenna used on the CommsBox has a dead spot directly out of the tip of the antenna. Flying directly overhead of the CommsBox antenna can cause a momentary loss of communication. 

What will the aircraft do?

The aircraft will activate the Return To Land flight mode and will perform the planned landing pattern. 

What should the pilot do?

The pilot should visually find the aircraft in the sky and keep eyes on the aircraft. Try to reestablish connection with the aircraft if possible.