Managing fighter gaps

The audits identify the challenges for the Australian transition to F-35, the most significant of which is further delays to the F-35 acquisition, whether political or industrial in nature. The audit particularly notes the US delay in moving F-35 full rate production to 2019, saying: “ . . . the F/A‑8A/B fleet’s operational life is likely to be extended beyond the current planned withdrawal date of 2020. Defence is accordingly preparing options for Australian government consideration later this year. ” “Defence’s capacity to accommodate any further delays in the production and/or acquisition of F-35s through a further extension to the life-oftype of the F/A-18A/B fleet, beyond the limited extension currently being considered, has limits, is likely to be costly, and has implications for capability. ” But the ANAO also identifies that Defence’s approach to managing the RAAF’s ageing classic F/A-18A/B Hornet fleet to its planned withdrawal date at the end of this decade has been “effective thus far in identifying … the risks to their planned withdrawal dates” and noted Defence had been “active in putting in place mitigation measures for these risks”.

The same report also drew out the “significant” risks and future challenges, citing increasing airframe corrosion and fatigue; management of annual flying hours; managing a reduction in the rate the jets accumulate structural fatigue; and the likelihood the F/A‑8A/B fleet’s planned withdrawal date will be extended due to delays to the F-35.

More importantly perhaps is what the ANAO didn’t say. The ANAO reports were written before the August announcement of the RAAF’s EA-18G Growler acquisition, and consequently make no mention of its impacts on existing fleet sustainment.

Sustaining the classic fleet is made easier when you can run the temporary bridging capability Super Hornet fleet harder (and burn up valuable airframe hours earlier than normal) to compensate.

But now the Growler acquisition means 12 of those 24 jets will remain in service far beyond the original 2025 planned withdrawal date. Further, those jets will be taken off line for modification to Growler status mid and late this decade, just at the time the RAAF most needs that ‘bridging’ coverage between the classic Hornets and the F-35, leaving the 12 F/A-18Fs not to be modified taking up an even greater load.

Further, the cost of sustaining an ageing fleet should not be understated. The classic Hornet has a structural-fatigue safe life of 6,000 hours. As at May 2012, the RAAF’s classic jets had accrued between 4,000 and 5,000 hours each. “Once any aircraft exceeds its safe life of 6,000 airframe hours, it may need to be withdrawn from service, be made subject to additional inspections, or alternatively undergo refurbishment of the structures. ” The ANAO states: “Similar to other aircraft, Hornet aircraft suffer metal‐fatigue cracks that increase in size and numbers as load stresses are applied during flying operations. Consequently, in addition to airframe hours, stresses applied to the Hornet structures also need to be measured, and periodic fatigue assessments need to be conducted. These assessments may lead to limitations on flying manoeuvres that produce excessive structural stress, and to structural refurbishments that treat the cumulative effects of structural fatigue. ” Further delays to the withdrawal of the classic fleet past 2020 could require a more comprehensive inspection program that is likely to far outweigh the cost of introducing the F-35 earlier rather than later. “An extension past 2020 may well require an expanded, and hence more costly, safety‐by‐inspection regime, structural modifications and capability upgrades,” the ANAO report said.

At best, the ongoing sustainment of the classic Hornet fleet will require careful management to maintain the fine balance between allowing for further flexibility in the F-35 acquisition and not running the classic fleet until airworthiness concerns pulls them from the flightline. And this doesn’t take into consideration the need to park classic jets to make space for the newly-raised F-35 squadrons. A capability dip –if not a gap –seems inevitable.

But at worst, delays have created long-term planning headaches with the result that an air combat capability gap will be unavoidable.

More important is what the ANAO didn’t say.