Confidential Human Factors
Incident Reporting Programme
The Charity
Aviation
Maritime
ATC843
Initial Report
We are not a procedural unit and none of the controllers hold a Procedural licence. We don’t have procedural procedures, the best we have are contingency radar failure shut down procedures/training. However, according to [local instruction], when we’re SSR-only and an arriving aircraft has a transponder failure before or after establishing contact with us, we are now allowed, with the assistance of [Area Radar Unit], to provide the inbound aircraft with a procedural approach (again, not holding a procedural licence) whilst proving a radar service to our other aircraft. We don’t do regular training on radar failure. I have been radar valid on the unit since [many years] and haven’t so much as done a sim run on radar failure. Currently, MATS Pt2 Complete Radar Failure Inbound Procedures state that aircraft already under [ATCU] control and below MSA are permitted to conduct instrument procedural approaches. We shouldn’t be accepting a radar failure aircraft during SSR procedures if they aren’t on frequency already.
The biggest issue is that we’re expected to accept and then work an aircraft during SSR-only operations when the aircraft has had a transponder fail, isn’t on our frequency and is not in our airspace. If the aircraft was already on our frequency and in our airspace then I agree that we shouldn’t just send the aircraft away.
I believe we only have one or two controllers who have previously held a Procedural endorsement. There is no way to maintain currency on a Procedural endorsement at [ATCU] as we don’t do Procedural Control and for those of us that are dual-rated, we sometimes only just achieve our minimum hours in Radar and Tower, having to take hours from our RitT hours to get over the line.
CAA Comment
There have to be pragmatic solutions in place for such circumstances were the alternative of diverting a transponder-failed aircraft may well be more risky than continuing the approach on a rare one-off basis with a controller who is not formally procedurally endorsed. We will review the associated MATS Pt2 procedures with the unit concerned to ensure that they are appropriate for the resources and training available.
CHIRP Comment
This report generated much debate within the CHIRP Advisory Board because, essentially, the procedure of applying Procedural Control (PC) by controllers who are not PC-qualified is, superficially at least, troublesome. As background context, there are not many controllers who are PC-qualified these days at larger airports because modern practices, the increased use of RitT, and improved reliability of aircraft and ground equipment do not regularly require its employment. As a result, PC procedures often rely to a large extent on retained knowledge from initial controller training supplemented by emergency simulation.
Maintaining controllers with PC qualifications would come at a cost; the initial course is in the order of 6½ weeks to gain the qualification, although it is much simpler to revalidate someone who was previously qualified. However, controllers may not need to be fully PC-qualified in order to conduct one-off emergency responses to a radar-fail situation and so a safety risk analysis should have been completed to understand what mitigations were required to cope with the contingency procedure.
Accepting that some airports might be SSR-only for long periods if their radar was under maintenance, in effect, the situation equates to a double emergency of the airport radar not being available and the aircraft SSR failing; the likelihood of such a scenario was probably very small, and the airport’s procedure had already allowed for the fact that, although they would only have a primary return to work with, the area radar unit would be available to assist the airport controller in positioning and identifying the aircraft; transponders do not fail very often and so the mitigations in place probably only need to recognise the low likelihood of such circumstances.
As a similar example, some airports no longer have SRA-qualified controllers but contingency plans often recognise that an SRA might be given by a controller if required in extremis in order to guide an aircraft to land. All that being said, controllers should be given simulator training to allow them to understand the intricacies and nuances of PC approaches, and how they might interact with the area radar unit to achieve situational awareness; CHIRP controller members were surprised that the reporter had not done any radar-failure simulation even if they were not PC-qualified, and they felt that this should be a key part of all radar controller training and recurrency that the ATCU and CAA should focus on during their review of the ATCU’s MATS Pt2 and SMS risk mitigations.