cossack,
Excellent news, adds evidence to those aspiring to the same.
We've increased the number of vehicles with VHF direct from Leader vehicles (Checker etc) through Engineering vehicles to grasscutters.
With increasing reliability of small VHF radios - we use the same kit fitted to aircraft - and improved training and recurrent testing of staff allowed on the Manoeuvring Area, the need for a UHF cross-coupled system is washing away.
The Odd One
ps, ground vehicles don't need FM immunity, 'cos they're not flying IFR in controlled airspace!