GA1369

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7th August 2024

Pop-up TDAs

Initial Report

I fly from [Airfield], as well as other nearby airfields. A few days ago, a couple of NOTAM-ed [military] temporary danger areas appeared as well as other recently declared HIRTA areas (NOTAM-ed not charted). The areas obviously impinge on the airfield, the circuit and some of the local flying area. I was surprised on visiting our ATSU for further information (assuming that, like parachuting, the military would have co-ordinated this with them) to be told that they are given no notice of these areas, and all attempts to obtain further information about them are rebuffed by NATS – “we cannot tell you/ we don’t know.“

One assumes that these areas (up to FL200) have to be flown into by aircraft from elsewhere. So when selecting somewhere for local flying training, how do I know whether I am likely to be met by a four-ship of fast-jets without at least having some idea of from where and when they might arrive. Is the airfield supposed to effectively shut down for three weeks whilst these exercises take place? There are already numerous AIAAs over [Region] and many more areas away from airfields. On what basis does the military deem it acceptable to put these temporary DAs slap bang on top of an active civilian airfield? To me this generates an unacceptable level of risk of mid-air collision.

I’m not suggesting that the military should ask permission, just that they should liaise with [Airfield] ATSU before mapping out an area that encloses a busy GA airfield. The [Airfield] ATZ barely provides protection for the circuit (which is somewhat large due to noise abatement restrictions) and any GA training airfield will have a considerable amount of traffic flying locally nearby for training purposes – in fact exactly where one of these areas lies (by the way, they don’t have a great record of avoiding the area on a normal day either!).

Military low flying – or rather the unwillingness to publish routes of the basis that “we might be anywhere” has been an issue since the day I started flying.

CHIRP Comment

Ultimately, Class G airspace is a sharing environment in which neither military nor civil aviators have any priority over and above the Rules of the Air. We researched the NOTAMs mentioned and they were all ‘H’ series navigation warnings (which you just have to be aware of but don’t have to avoid) and not RA(T)s or TDAs (which you would have to avoid and would be ‘J’ series NOTAMs). Some useful links for understanding NOTAMs are the CAA Infringement Tutorial and UK AIP Gen 3.1 (Aeronautical Services) Table 3.6.3.4 which explains what each of the 18 NOTAM series types are (see below).

The specified locations of the 2 high-energy NOTAMs up to 20,000ft were applicable to operations at the reporter’s airfield, although [NOTAM 1] gave the blanket statement that associated military aircraft “…will avoid controlled airspace unless given permission to enter by appropriate ATSU” which implies that they would avoid the airfield ATZ. The reporter mentioned that their ATSU had tried to contact NATS to get further information but NATS would be unlikely to have any on a specific NOTAM and so that is probably why they received the response they did. In fact, the 2 high-energy NOTAMs had the same contact number within their Section E details where more information should have been available to the ATSU (our assumption was that this number gave access to the exercise controllers who would have details of when aircraft might be using the areas and at what heights).

All that being said, one wonders how much research into airspace usage is conducted before the decision is made to plan military low-flying exercises. Why these specific locations were chosen we don’t know, but we’re all well aware that there could be high-energy fast-jets flying at low-level without NOTAMs at any time in most parts of the UK Class G airspace and so at least these NOTAMs were a step up from that in warning that there will be a higher concentrations in the specified areas over the associated periods. We doubt that the military will consult with [Airfield] before deciding on their exercise areas and issuing the associated warning NOTAMs, and military crews will be well-versed in understanding that [Airfield] is there and to be avoided. But there is a valid argument that local airfields and their training areas could be taken into account during military exercise planning such that likely conflicts due to concentrated military activity might be reduced. Perhaps there is also a case for GA training airfields to publish their own favoured training locations (if such exist) so that this information is available to all – military and other civil aviators alike?

Key Issues relating to this report

Dirty Dozen Human Factors

The following ‘Dirty Dozen’ Human Factors elements were a key part of the CHIRP discussions about this report and are intended to provide food for thought when considering aspects that might be pertinent in similar circumstances.

Knowledge – awareness of NOTAM applicability; navigation warnings are not avoidances.
Communication – use of NOTAM contact information; liaison between military and civilian airspace users.
Complacency – NOTAM publication is but one part of risk-reduction and should not be assumed to confer any protection in their own right.

lack_of_knowledge, poor_communication, complacency