They probably have a better idea than they did before.
Under the old scheme you had to consider deaths per thousand of the population at risk per year. Which you averaged over a five year period. This works fine for any large industry with many thousands of people involved. However for your typical military aircraft the population at risk is normally in the low hundreds, if you're lucky. This meant any accident that caused death of a first party made the airframe intolerable for the next five years as you'd have to multiply the small population and the fatalities by whatever factor was required to reach 1000.
At the same time a logical reading of the 3rd party tolerability boundary, 1 death per million of the population at risk per year, meant you could happily kill 60 civilians a year and remain tolerable.
Not sure how DHs will have a better idea without guidelines as to what is tolerable. As I said before what is quoted in Issue 4 of RA 1210 is just a general statement lifted from HSE (R2P2). Also, not sure where the five year average came from as there is no mention of it in the HSE documentation. I suspect it is (was) a fudge in order to make the boundary data fit the needs of the day.
Your statement also exposes another flaw in the risk to life process, namely it can only be regarded as a risk to life if a death has already occurred; it is reactive rather than proactive. Risk assessment must be about determining the
potential of gaining or losing something of value. In his comments to the the Tornado SI Air Marshal Garwood said,
"bad luck has to be part of the explanation.......a few few feet difference in altitude of one aircraft would have created a near miss rather than this tragic accident". So would this near miss have been regard as a risk to life, or not. For me the risk to life occurred before the collision event, not after it. In my book every Class A/B near miss, confirmed by the AIRPROX body, is a risk to life (not machine)
I don't know that TCAS was ever considered. For aircraft that spend a lot of time at low level it doesn't really give you anything extra as the RAs are suppressed below a certain height.
The following is an extract from the MoD Helicopter Safety Enhancement Programme, dated Sept 2013,
"The UK MOD is actively considering installing systems on the majority of the helicopter fleet. For most types the decision in the short term is to fit a non-integrated system, most likely to be a TAS type unit. For the larger platforms (Chinook, Merlin and Puma) the fitment of fully integrated TCAS II systems is being considered."
We can continue to debate what the outcomes could have been with and without certain items of equipment, but the facts remain the same,
(1) The risks of collision and wire strike were the No.1 and No.2 Air Safety risk according to the Cdr JHC (ODH).
(2) The risks, at the time of the accident, were neither tolerable nor ALARP.
(3) The ODH had signed off to say they were.
According to RA1210, by reference,
”The Health and Safety Executive is responsible for making adequate arrangements for enforcement. In fulfilment of its duty the Executive provides guidance to its regulatory staff who have to judge whether measures put in place or proposed, by those who are under a duty to control and reduce risks "as low as is reasonably practicable" (ALARP), are acceptable.
The principles and guidelines set out [in HSE documentation]are based on what the courts have decided is required of duty-holders, and are intended to help HSE regulatory staff reach decisions about the control of risks and make clear what they should expect from duty-holders. Ultimately, it is for the courts to decide whether or not duty-holders have complied with the law.”
The final paragraph is very important and is the reason why it is covered in MAA RA1210. So far the MAA/MoD have avoided having the regulation tested in court.
DV