On the side of caution

The RAF’s National Air Operations Centre team explains why aircrews should always monitor 121.5

“Air Europe 123, this is London Centre on 121.5 acknowledge or squawk ident.” A call we have heard all too often. Whilst the callsign is fictitious the rest of the transmission is unfortunately one we hear on a daily basis. We being the Royal Air Force National Air Operations Centre (NAOC) charged with the air policing of the UK and located deep underground somewhere west of London.
The RAF maintains a number of armed fighter aircraft on alert for air policing duties, both NATO and national. The crews are normally dismounted but are able to be in the air in an extremely short space of time.
For years, the threat was the Soviet Air Force and naval long range bombers and maritime aircraft and, indeed, we still have flights into the UK FIR by Russian long range aircraft.  Whilst they have every right to fly in the UK FIR, outside territorial waters, unfortunately they do not squawk and thus are invisible to civil ATC. Therefore we will scramble and escort these flights enabling civil ATC to ’see’ and avoid these flights preventing any flight safety hazards.
However, since 9/11 we have had to acknowledge that that there is a potential threat to the UK from terrorist organisations utilising civilian aircraft (most likely airliners) as weapons of mass effect with enormous human, economic and psychological consequences and that we must counter that threat.
24/7 Operations

Within the NAOC there is myself (an Air Defence Wing Commander ex-fighter type) and a small team on 12-hour shifts, day and night all year round. We are at the strategic level; it is not up to us to monitor the airspace continually. We have a much larger team at the Control and Reporting Centres (CRCs) compiling the air picture, watching the airspace continually and working hand in hand with civilian ATC at Swanwick and Prestwick.
However, we will always be monitoring 121.5 throughout the whole of the UK FIR and a call such as the above will start an immediate reaction.  The first call will get our attention but quite often, and some carriers are better than others, an immediate response will be heard and a new frequency allocated.  However, a second call and we are up and responding; the team will pull up the flight plan on the tote (we have access to all flight plans in the UK FIR) and we will highlight the route on the screen.  We will work out a rough expected position based on the filed flight plan but at the same time the CRC will have found the track and label it with the callsign.
We have exactly the same equipment and picture as the CRCs, thus as soon as it is highlighted we will see it, alleviating any need for the CRC to call us. Quite often at this stage it is obvious that there is nothing sinister with this incident, for instance the aircraft is outbound from the UK FIR and is too far away for radio communications. However, if the track is inbound or gives us any other cause for concern then we will be contemplating tactical action even at this early stage.
Changing tac
If the aircraft remains out of communications London/Scottish will contact the duty CRC on the dedicated line with the basic details. The CRC will change the tac label to highlight the track thus alerting all, including our NATO colleagues, that there is a potential incident in the UK FIR and will contact us with the details; the aircraft officially becomes a ’lost-comms‘ at this stage.
Depending on the location, routing and any other information I may have will dictate my reaction, but most likely I will order RAF fighters up to cockpit readiness; which is crew in the aircraft, power on and ready for immediate start (from this posture I would expect them to be airborne in about three minutes). Some may think that this is a bit of an over-reaction at this early stage but time is of the essence if we have to scramble and successfully intercept prior to any potential target being reached, and all we know at this stage is that for some reason these pilots are not responding to ATC instructions on the assigned frequency and also are not listening out on guard (121.5).
Whilst the fighter crews are ’coming to cockpit‘ I will contact the duty officer at Transport Security (Transec) within the UK Department for Transport requesting that they contact the airline operations concerned and have them attempt to raise their aircraft by any means of ‘secondary communications‘ (e.g. ACARS, SATCOM or mobile phone) and have them contact ATC immediately, normally on guard. Some are better than others at contacting their flight crew, and indeed some, even major carriers, have no secondary communications.
Additionally, in the case for instance of a bizjet or another general aviation aircraft, where there commonly is no 24/7 operational support centre, Transec may have difficulty raising the aircraft.  However, usually this, together with continuing attempts by ATC to raise the aircraft, will be sufficient and we will hear a somewhat chastened voice on 121.5 requesting a new frequency. Once ATC have re-established communications we will stand our crews back down
However, what if the company cannot contact their crew, and the flight is still not talking to ATC?  We will then most likely scramble a pair of fighters to intercept the aircraft as quickly as possible.  From our point of view we have to assume the worst and until I get evidence to the contrary I have to assume that this aircraft poses a potential threat to the UK.
Priority basis
Once airborne our fighters, and indeed the air-to-air refuelling tanker as well, have priority over all other aircraft, and thus a number may have to be rerouted out of our way, causing delays and expense to a lot of other flights and airlines. Additionally, depending on the location, departures may be stopped, arriving aircraft put in the hold or even diverted so the knock-on effect to an airline’s operations can indeed be extremely costly!
As we approach for the interception our fighters will be attempting to raise the suspect aircraft on 121.5.  If the aircraft answers our call we will remain well astern and once satisfied that nothing is amiss we will recover to base.  However, if assistance is required, we will readily give it, and indeed as in the instance of a recent bomb threat will escort the aircraft to an agreed diversion airfield.
Unfortunately, sometimes we have to continue and intercept the aircraft.  We will always approach from astern having completed a very wide intercept and with our mode C switched off (thus there will be no warning or sudden automatic manoeuvres from TCAS).
As we approach we are looking firstly to confirm the identity of the aircraft, and secondly whether there is anything unusual – all lights out may signify an electrical emergency which could explain why there has been no radio communication!
One aircraft will approach on the left hand side and forward of the cockpit so that they are easily visible to the captain. The fighter crew will again call on guard and we would expect an immediate acknowledgement on 121.5. If there is no acknowledgement we will attempt to ascertain by looking in the cockpit or visual signals what is the problem and whether there is an emergency or something more sinister.
By means of visual follow-me signals i.e. rocking our wings and turning to the left we will confirm that the flight crew or whoever is flying the aircraft is compliant with our instructions.  Whilst all of this is going on I will be in constant touch with the highest levels of government  Assuming that there is an emergency and we are required to lead aircrews someplace we will convey our intentions by visual standard ICAO signals. Suffice to say that if there is something more sinister then we have to have and do have procedures in place to deal with any situation
Worst assumed
Some may say this is an over-reaction. However, until we can positively ascertain that there is nothing sinister, that the flight crew or even cabin crew are not under duress and that the cockpit door is secure we must assume the worst and that this aircraft poses a threat and could be used as a weapon to devastating effect.
Thankfully we rarely get to the stage of an interception.  Indeed more often than not we can look at the situation early on and assess that this is not a threat but probably just a wrong frequency on handover or some other explanation. It is however a daily occurrence for us to have to bring our crews to a higher state due to a ‘lost-comms’ on guard. We do not scramble as often as our colleagues in some other European countries but we certainly will if we feel the situation dictates and a potential threat exists.  (Be warned, whilst there is currently no charge in this country for our time and costs, some of our European colleagues do indeed charge and in some countries it is not the airline but the flight crew who are fined!).
Where a lost comms occurs we would encourage the flight deck crew to report it, particularly exactly what happened and the reason why. Depending on the case, Transec will contact the airline concerned to ascertain what  happened and what steps, as appropriate are being taken to reduce the possibility of a recurrence. Transec and ourselves stand ready to help with this, e.g. by offering briefings, as required.
I have a number of ex-RAF friends who now fly for the airlines and they have explained their procedures and why sometimes, particularly when there are only two radios, aircrews may not be monitoring guard: for instance, when they are getting the weather or talking to the handling agent or operations. This is of course completely understandable and a few minutes off guard is acceptable.
However, a recent incident I had was a crew over Germany with Maastricht who had  ’lost comms’ and were inbound to an airfield in UK. They flew for 40 minutes prior to the UK FIR without talking to any ATC agency, failed to check in with London at the FIR boundary and flew for a further 30 minutes before we intercepted. So for over an hour they had flown through some of the busiest airspace in the world without talking to anyone and not monitoring guard.  All that time Maastricht, London and a host of other aircraft were calling them on guard.  Additionally they failed to acknowledge the calls of their operations centre who had been contacted by the Germans, Dutch and UK authorities and only selected guard when we were alongside!
Departures were stopped at Stansted, Heathrow and Luton and a great number of aircraft were moved out of the way.  The overall result was a huge amount of disruption to a lot of passengers and a great deal of extra costs incurred by a number of airlines, and all because a crew were not monitoring 121.5. Wg. Cdr. Davy Jones