I've not on the other hand heard of calibrations being required following an accident.......
From CAP493 Appendix C:-
Flight Inspection of Radio Navigation Aids and Radar
2.1
Types of Flight Inspection
The flight inspection of radio navigation aids and radar can be divided into four basic
categories:
a)
A commissioning flight inspection to determine the state of a facility before it is
brought into operational service;
b)
Routine flight inspection at specific intervals to check that facilities are operating within tolerances;
c)
Special flight inspection in addition to routine flight inspection whenever the
performance of a facility is suspect and airborne measurement is required. This
may affect all or part of the facility;
d)
Accident/Incident flight inspections to determine the performance of all
equipment, used or considered to have been used by the aircraft concerned, which
could have contributed to the accident or incident.