The following section regarding delays to introduction of new equipment is in many ways more disturbing, not that much of it hasn't been referred to here.
(I assume the C-17 figure refers to hours per airframe as the US fleet topped 4 million hours around the time as 99 Sqn hit 150K)
Enterprise Governance
Delays to the introduction of new capabilities to succeed legacy platforms and fill emerging
capability gaps extend legacy platforms in service and prolong the risks associated with
ageing aircraft. These delays have far ranging effects on these fleets, as well as across
broader Defence capabilities, and on the need to sustain aircrew and type-engineering
training pipelines. The risks are exacerbated by incrementally increasing Out of Service
Dates (OSDs), including long delays in safety modifications for a number of platforms[50].
The increases obsolescence and supply issues, adding pressure to platform capability
delivery, with legacy decisions either requiring or not being revisited correctly[51]. This is a
direct effect of late capability decisions resulting in a requirement for ageing platforms to
continue to deliver operational output long beyond their expected, supported, lifespan
instead of slowly reducing output as they approach OSD[52]. The introduction of RA120553
and the generation of ASSC has improved the ability of the ODHs to manage Air Safety
risks, albeit there are still a number of cases where the only option remains reduction in
output. This in turn increases pressures on other air systems as the respective demand
signal increases to compensate[54].
50 Long lead times for Puma2 modifications directly related to Service Inquiry recommendations and
continued requirement for long standing Hawk T1 modifications.
51 As part of any Out of Service Date (OSD) Extension Programme there should be a Safety Assessment
Report that revisits decisions. With multiple OSD extensions some of these may be missed as with Gazelle
AH Mk1. This error resulted in a flying pause that required 2* led recovery action.
52 For example, delays in delivering the range of A400M capabilities has resulted in the extension in service
of the C130J and significant additional tasking allocation C17. Of note, the UK C17 aircraft are now the world
fleet leaders in terms of hours flown.
53 RA1205 – Air System Safety Cases
54 Gazelle AH Mk1 OSD is currently 31 Mar 2025, but with any replacement still awaiting approval, the
forecast Full Operating Capabilty of the replacement in Q3 2024 is unlikely to be met. The complex
relationship in this example, which involves Special Projects MultiAir Platform DT, DComd Find, Army Cap, 1
Flying Training School, UK Military Flying Training School DT and Air Cap will need careful management by
the SRO and will need close MAA oversight. There is also a desire to maintain operational output by
continuing Gazelle task-lines, potentially across 2 x UK sites and in Canada, during the delivery of the new
capability, which presents an increased risk above that of extending the OSD further.