What was found
(CAN) A/C HAD A DUAL ATC FAILURE AFTER DEPARTURE LHR. UK ATC WOULD NOT LET THE A/C PROCEED SO RETURNED TO LHR. OVERWEIGHT LANDING CHECK CARRIED OUT. ATC CONTROL PANEL CHANGED AND NO FURTHER FAULT
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
(CAN) A/C HAD A DUAL ATC FAILURE AFTER DEPARTURE LHR. UK ATC WOULD NOT LET THE A/C PROCEED SO RETURNED TO LHR. OVERWEIGHT LANDING CHECK CARRIED OUT. ATC CONTROL PANEL CHANGED AND NO FURTHER FAULT