The MOD has today published the report of the Board of Inquiry into the tragic loss of Nimrod XV230 in which 14 servicemen lost their lives on 2 September 2006.
Full story here.
Board of Inquiry available here (Adobe Acrobat required).
An excerpt -
Due to incomplete evidence arising from the nature of the crash and its hostile location, the Board was not able to identify with absolute certainty the cause of the fire on Nimrod XV230. The BOI has put forward the most likely scenario for the fire and the events and factors which led to the loss of the aircraft. The fire most likely resulted from escaped fuel igniting against a hot pipe in a compartment near the wing-fuselage attachment – the No 7 tank dry bay. The fuel probably gained access to the pipe through a gap between two types of insulation. The fuel most likely escaped from one of two possible sources: the action of a pressure-relief device in the main fuel tank, which led to an overflow of fuel during Air to Air Refuelling, or a leaking fuel coupling.
My wings are like a shield of steel.
POSSIBLE CONTRIBUTING FACTORS TO THE LOSS OF
NIMROD XV 230
The Board of Inquiry identified a number of factors which possibly contributed
to the loss of XV 230 as follows:
Age: While the Board considered that the Ministry of Defence had done all
that was required of it to cater for the increasing age of the Nimrod, the Board
was unable to discount the age of the seals as a possible cause of the
increase in leaks from fuel couplings and of the condition of the hot air pipes’
insulation. The Board acknowledged, however, that other factors might have
been responsible for their condition.
Maintenance Policy. The Board also considered that maintenance policy in
relation to the Nimrod’s fuel system was a possible contributory factor, as it
did not detect a gradual increase in fuel leaks over time, nor did it prevent that
increase. Maintenance policy for the aircraft’s hot air system was seen as a
contributory factor, due to a lack of guidance on the allowable condition for hot
air pipe insulation.
Failure of Hazard Analysis and Lack of a Fire Detection and Suppression
System. The Nimrod Safety Case identified the hazards associated with the
No.7 Tank Dry Bay but incorrectly quantified the SCP Duct hazard.
Consequently, the risk was underestimated. Had the risk been correctly
estimated it is almost certain that a range of risk-reduction options which
would have reduced the likelihood of fire would have been considered and
these may have included a redesign to fit fire suppression in the dry bay –
although it is more likely that action to mitigate the risk by removing the
potential ignition source would have been taken.
Not Identifying the Full Implications of Successive Changes to the Fuel
System and Associated Procedures. The Board also felt that the formal
incorporation of an air-to-air refuelling capability on the Nimrod in 1989 did not
identify the full implications of successive changes to the fuel system and
associated procedures.
Taken from Nimrod XV230 - Additional Briefing.
Great work Batfink in condensing the report for us so quickly, some very interesting information. For those that are interested there is more from Flightglobal here.
AirSpace - more than just hot air
I filed the attached on the Telegraph web site this morning.
Can anyone answer my questions?
Does my memory serve me correctly in stating that the Air-to-air refuelling capability was fitted to the Nimrod fleet as a "War Emergency" requirement for the Falklands campaign. If I am correct, then it would have been done by short-circuiting most of the normal MOD procurement mandated air worthiness checks, that cover operability, maintainability and all aspects of safety. Was the Air-to-air refuelling system on the Nimrods ever subsequently tested through the full set of checks, like any other new product procurement, after the Falklands campaign? If not, why not? The findings of the BoI indicate that the whole history since 1983 has been a fudge; latterly, severely constrained by lack of MoD funding.
Your correct it was a "war emergency" fitting, the AAR system on the Nimrod was apparently only formally ratified seven years after the Falklands conflict....