AD17 Motion Booting in Firmware 4.0.4 and previous (2017-1-25)

INTRODUCTION

This Airworthiness Directive (AD) is being issued to alert all Alta users of a bug associated with the Motion Booting function that could prevent the machine from booting and operating successfully. Use of the Motion Booting function is not recommended for firmware versions 4.0.4 and previous. No other functions are known to be impacted by this bug.

This AD is being issued to all Alta 6 and Alta 8 owners.

BACKGROUND

Alta flight control firmware includes an optional function to allow the machine to be booted on a moving platform such as on a boat. This boot process is “off” by default in the Alta App and must be selectively turned “on” to be used.

DISCUSSION

A bug was discovered that affects the stored gyroscope data on the Synapse flight controller. During the Motion Booting startup sequence, the Alta could pull old or incorrect gyroscope data or may revert to estimated values rather than the stored values. As a result, the machine may exhibit out of control behavior if booted with Motion Booting on.

The standard booting process is not affected by this bug.

RECOMMENDATION

Do not use the Motion Booting function available in the Alta App v1.6 (Synapse firmware version 4.0.4) until a new firmware version has been released for public use.