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
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:
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
The Nimrod Safety Case identified the hazards associated with the
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
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....