When did this change? (Not the 135..475 to 135.480 on going to 8.33.)
"VHF LOW-LEVEL COMMONFREQUENCY
‘VHF LL-Common’is being trialled as an information service on the VHF Frequency 135.475 MHz inorder to improve the situational awareness amongst, and aid deconflictionbetween, military and civilian aircraft operating in the same area. It is available for use by all aircrewoperating at or below 2000’ AGL in the UK Low Flying System whenoperating north of LatitudeN56·00°.
Aircrewshould apply their airmanship when considering the timing and content of theirtransmissions. The following is offeredas guidance:
Timing
· When safe and suitable to do so
· When operating north of Latitude N56·00°.
· At turning points or significantheading changes
· Approaching well-known and recognisablephysical features
· Any time it is considered beneficial tothe safety of the aircraft (such as approaching choke points or knownareas of high traffic density).
Content
· Ac callsign
· Ac type (and number, in the case offormations)
· Position in relation to reference pointsimmediately identifiable to other pilots (using cardinal or inter-cardinaldirections)
· Height
· Heading
· Next significant reference point
Exampletransmission:
“Spartan, Tornado, 8nm NE of Inverness,250’, heading 170° towards Aviemore"
“Python formation, 2 Hawks, 5 miles N of Perth,250', heading East towards Montrose”
Notes:
· Using this frequency should not takepriority over obtaining a Lower Airspace Radar Service.
· Transmissions should be kept short,simple and effective, and should not clog up the frequency.
· If you do not hear any transmissions,you should not assume there’s no aircraft nearby. Use all measures available to avoid MAC, andmaintain an effective lookout scan."