This AIC serves as Notice about the implementation of the extended CPDLC message set in ACC sectors in the LHCC FIR effective from 27th February 2019.

The following new CPDLC messages will be introduced:

Uplink messages: UM231 STATE PREFERRED LEVEL UM106 MAINTAIN [speed] UM108 MAINTAIN [speed] OR GREATER UM109 MAINTAIN [speed] OR LESS UM116 RESUME NORMAL SPEED

Downlink messages: DM106 PREFERRED LEVEL DM18 REQUEST [speed]. DM18 REQUEST [speed] can be sent alone or with DM65 DUE TO WEATHER or DM66 DUE TO AIRCRAFT PERFORMANCE messages.

Operational meaning of the messages:

Uplink messages: UM231 STATE PREFERRED LEVEL: Air traffic controller can ask for the requested level using this message. Please note that using this message cannot guarantee that the aircraft can be cleared later for that level and this message has a different meaning that the DM6 REQUEST [level] or the DM9 REQUEST CLIMB TO [level] or the DM10 REQUEST DESCEND TO [level] messages.

UM106 MAINTAIN [speed]: Indication of a speed clearance given by air traffic controller. UM108 MAINTAIN [speed] OR GREATER UM109 MAINTAIN [speed] OR LESS UM116 RESUME NORMAL SPEED

Downlink messages: DM106 PREFERRED LEVEL: Aircraft can indicate the planned cruise level using this message. DM18 REQUEST [speed]. Aircraft can request for a speed value. Aircraft can indicate a reason by using DUE TO WEATHER or DUE TO AIRCRAFT PERFORMANCE messages.

The AIP of Hungary will be modified according to the above described information at 25.04.2019.