GM1 Article 2(22) Definitions

CAA ORS9 Decision No. 16

DEFINITION OF ‘MAXIMUM TAKE-OFF MASS (MTOM)’

The MTOM includes all the elements on board the UA, including the motors, propellers, electronic equipment and antennas, batteries /fuel, oil and all other fluids and the payload, including sensors and their ancillary    equipment.

Privately built UA, and some off the shelf UA do not have a MTOM defined. In this case, the mass of the aircraft at the time of take-off should be used instead, when interpreting the term ‘MTOM’ within the regulation.

Although the UAS Regulations refer to ‘maximum take-off mass’ (MTOM) throughout, this term creates some confusion when referring to home-built or other non-class marked UA where an MTOM has not been defined by the manufacturer.

Take-off Mass (Article 22)

The term ‘take-off mass’ is also used when referring to non-class marked aircraft, but only within one article (Article 22 – transitional arrangements) and the term is not specifically defined.

For these aircraft, any reference to ‘take-off mass should be taken to mean the mass of the UA at the point of take-off for that particular flight.