Operational and general risks

John Bradley is a retired flight test engineer with a long career in the flight testing of military aircraft at what was the A&AEE at Boscombe Down in England.  On his retirement he wrote of his experiences in At the Edge of the Envelope – A flight test engineer’s story. (Active Aviation Ltd, Bowdens Court, Urchfont, Devizes SN10 4SJ, England)

I took particular note of what he wrote about testing Harriers on an aircraft carrier at sea:  “I found it exciting to be involved in this potentially dangerous activity, undertaken in a hostile environment.  Below decks were all the modern trappings of the health and safety industry, warning you that ‘this tap produces hot water’ and the like.  On that flight deck, with the ship rolling and pitching and the wind gusting to 50 knots, it was the training, alertness and sheer professionalism of everyone from the pilot to the most junior rating that kept you alive.”

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This is a reminder of the great difference between operational risks and general risks, a distinction made in Chapter 5, see Table 5.4.

It also draws attention to aspects of the ‘health and safety industry’ that do it no credit – the provision of warning signs about hot water on domestic taps.  In days gone by it was sufficient to note which tap dispensed cold and which hot by the use of C or H on the tap itself, or blue and red colour codes.  Any tap which does dispense hot water should be connected to a hot water service which is not able to dispense water at greater than an allowable temperature or whose thermostat has been set to ensure this is the case.  Then, in the time taken for someone to realise that the tap water is hotter than they want, there is time for them to also remove their hands from the water without chancing a burn.  Anything able to dispense water of an injurious temperature needs to have a warning sign – for example a boiling water dispenser in the kitchen or (perhaps) water used in the wash down of food equipment.

It is not surprising that those involved in the engineering of or management of hazardous operations (be they aircraft, thermal power stations, ships, trains, mines etc.) do not take kindly to general safety people trying to influence them.

John also wrote: “Firstly, forget the old adage that ‘there can be no compromise with safety’.  Every time we take a car out on the road we are making a judgement that the benefit of the journey being undertaken is worth the small probability of having an accident.  Aviation is no exception, except that the risk of an accident is assessed numerically rather than subjectively as in the case of a private car journey.  The premise for (specified) commercial operations was that an overall fatal accident rate of 4 per million flight hours would be acceptable, (about ten times riskier than on a commercial flight in a large airliner) with the fatal accident rate following failure of the propulsion system being no more frequent than 1.3 per million flight hours;…”

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