Communication failure
Expect
VMC
squawk 7600
continue in VMC
land at nearest suitable airport
IMC
squawk 7600
maintain last assigned speed and level for 7 minutes OR minimum flight level, if the minimum flight altitude is heigher than the last assigned level
if being radar vectored or proceeding offset according to RNAV without a specified limit, proceed in the most direct manner possible to rejoin the CPL no later than the next significant point, taking into consideration the applicable minimum flight altitude
the aircraft will proceed to the designated navigational aid serving the destination aerodrome and hold until commencement of descend.
commence descend at, or as close as possible to the EAT last received and acknowledged, OR if not EAT received and acknowledged, commence descend at or as close as possible to, the ETA resulting from CPL
complete a normal instrument approach procedure as specified for the designated navigation aid
land, if possible, withinh 30 minutes after the ETA specified, OR within 30 minutes of the last acknowledged expected approach time, whichever is later.
Remember
A 'Acknowledge' - S 'Separate' - S 'Silence' - I 'Inform' - S 'Support - T 'Time'
failure of transmitter or receiver only
possible relay by other stations?