ATC PROVISIONS
controlled airspace, this is still not guaranteed and, ultimately it remains the pilot’s responsibility to avoid a collision.
The trick is knowing what you really want and asking for it
you won't get it at all from an A/G service (Callsign 'Radio')
What you should not expect on a Basic
Service is specific traffic information. You might be told about generic stuff, like 'XXX gliding site is active' or intense activity in the vicinity of XYZ'. At best, you might be told if another pilot is estimating the same position at the same or a similar time and altitude, but if you want more you need a different service.
Here's where it gets a bit complicated, however. Some ATS units might identify you by giving you a squawk. This helps them monitor your progress but you shouldn't assume they will be, or that a different service is being provided. Furthermore, if an ATS unit is providing you with a Basic Service and the controller or FISO thinks that there's a definite risk of collision they must actually pass you specific traffic information after all. Why? Well, in addition to the vast amount of paperwork a mid-air collision creates, Controllers and FISOs have a legally defined 'Duty of Care' to you as their customer. It is, in fact, these legal obligations of individuals and companies that form the basis for the services. In an 'uncontrolled' environment, however, it is recognised that not every eventuality can be covered and they need to exercise their professional judgement to suit the circumstances. By its very nature, application of this is open to a fair amount of interpretation. While controllers are actively discouraged from passing specific traffic information under a Basic Service – so that the services are applied consistently – the interpretation of 'a definite risk of collision' can be somewhat subjective. Without radar, (e.g. Cranfield, Shoreham, Carlisle, Redhill) and sometimes those with radar (e.g. Gloucester, Cambridge, Exeter) they'll
probably be more inclined to tell you about aircraft at the same level. Lookout and avoiding action remain the pilot’s responsibility. You'll probably only be told once. Not comfortable with this? Traffic Service might be the answer.
TRAFFIC, TRAFFIC Similar to what used to be 'Radar Information Service', Traffic Service will only be provided by units with access to radar equipment. There's no point asking 'XYZ Information', they don't have the kit or qualifications to help you with this. The AIP will tell you which aerodromes have radar and the Notam will tell you when it's not available. Provided to both IFR and VFR flights, ATC will 'identify' you with a squawk or, in rare cases, a turn and generally give you traffic information on relevant aircraft coming within 3nm and 3000ft. If the other traffic is passing behind or diverging this might be omitted and, in theory, you'll be passed information that is pertinent to you in sufficient time for you to think about avoiding action. Here's the nub; if avoiding action is needed, it's still your responsibility. You will not be given avoidance advice on a Traffic Service. Hazy day, busy airspace, this is probably the safety blanket you need.
DECONFLICTION SERVICE Only available to IFR flights (in IMC or VMC), the controller will give you headings and levels with a plan to achieve the appropriate 'deconfliction minima'. It's their job to try to assist you in not bumping into other aircraft by generally keeping you 3 or 5nm laterally and/or 1000 or 3000ft vertically from everyone else. The distances will depend on what radar equipment they have. This is the only service under which avoidance advice is given. Outside
PROCEDURAL SERVICE Again, this is now the domain of IFR flights only. Usually provided by airfields without radar, or when radar is not available, the controller will allocate routes, timings and levels that provide standard deconfliction minima (most often 1000ft vertically) between other aircraft on a procedural service. You may also be given traffic information on other Basic Service traffic if a confliction exists but, as always, collision avoidance is your responsibility.
BENDING RULES? The basic premise of the services was that we all stick to the rules and no-one gets confused about what it is they're getting. In the 'bandit country' that is uncontrolled airspace however, this doesn't always work and the level of service you request and receive is the 'contract' between you and the controller. Sometimes, ATC might ask you to
take a particular course of action, such as 'not below/above' a level or to route via a particular point (e.g. north of the Danger Area) for co-ordination purposes – if you agree, you’ll be expected to stick to the agreement. These types of 'agreement' are generally for short-term tactical reasons.
SERVICE LEVELS
Controllers should endeavour to give you the service you request. Practicalities and pragmatism need to be considered, though. If it's a clear, cloudless day and it's taken you ten minutes to get your call in on the frequency, the controller's workload is likely to be too high for the more sophisticated service levels. By the same token, if you find yourself unexpectedly in the murk, you can request to change to a more appropriate service.
The trick for all parties is finding the balance. Know the services, know what the unit you're talking to is capable of providing and think about the situation you're in and you should have a reasonable chance of getting what you need. Your pre-flight planning really needs to include a thought process about the optimum service, and what your contingency is, if that's not available.
Darren Lewington is an ATC instructor at Global ATS.
SUMMER 2019 CLUED UP 19
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40
