The UK Royal Air Force’s (Raf) C-130J tactical transport aircraft have had a lower availability than their C-17 and A400M counterparts in 14 out of the past 19 months, beginning 1 March 2021 to 1 September 2022, including five months where the fleet availability rate dropped below 60%. 

Availability reached a peak of 71% in five separate months during the reporting period, with between eight and ten aircraft free to undertake operations. By comparison, the A400M strategic transporter, which is intended to undertake many of the roles and functions performed by the C-130J when the latter type leaves service in 2023, achieved rates of 65%-70% with either 13 or 14 aircraft available at any given time.  

Meanwhile, the C-17, the largest strategic transport aircraft in the RAF’s fleet, saw rates of 75%-88% with six or seven platforms available each month of the reporting period. The information came to light following a 14 November UK parliamentary written response, outlining air mobility availability rates.  

The UK maintains a fleet of eight C-17 aircraft, produced by US defence prime Boeing, in addition to 21 A400M platforms, procured from European aerospace giant Airbus. The 14-strong C-130J fleet, designated a tactical rather than strategic aircraft, is due to be removed from service in 2023, without a direct replacement.  

In October the C-130J fleet was added the list of military equipment that will be made available for sale through the Defence Equipment Sales Authority (DESA) from 2023, aligning with the expected out-of-service date.  

At the time of publishing, the UK Ministry of Defence (MoD) has not provided a comment to Airforce Technology regarding C-130J and A400M availability rates. 

DateC-17%C-130J%A400M%
Aircraft in fleet availableNumber as a % of fleetAircraft in fleet availableNumber as a % of fleetAircraft in fleet availableNumber as a % of fleet
1 Mar 20217889601470
1 Apr 20217889601365
1 May 2021 6758531470
1 Jun 2021 6758531365
1 Jul 2021 7889601365
1 Aug 202179601365
1 Sep 2021 78810711470
1 Oct 2021710711470
1 Nov 2021 7889641470
1 Dec 2021 7888571365
1 Jan 20227888571470
1 Feb 2022 7888571470
1 Mar 2022 78810711470
1 April 2022 7889641365
1 May 2022 67510711365
1 Jun 2022 67510711470
1 Jul 20226759641365
1 Aug 20227889641470
1 Sep 20227889641470
Credit: UK Parliament

A400M taking the lead 

With the C-130J fleet due to begin to leave service in the coming months, the A400M – of which 22 were ordered from manufacturer Airbus – will take on some of the roles previously performed by the departing aircraft, not least of which will be special forces insertion. 

However, it is unknown whether the A400M will be cleared to undertake the full range of these roles by the time C-130J leaves services, creating the potential for yet another capability gap to emerge in the UK military. One key area is parachute insertion, with the A400M still to be fully cleared on the performance of symmetric jumps from the port and starboard side of the aircraft. The UK MoD also has its own clearance protocols for capabilities being added to aircraft types.  

During a UK Defence Committee hearing on 29 November, a senior Airbus UK official said that UK military personnel parachuting off the rear platform of the “had been cleared”, as had the single static line method. 

Regarding availability of the A400M, Sir Kevin Leeson, Airbus UK director of Military Affairs, said that there had been some “difficulty in the summer” but that the platform was now “completely through that”.  

Issues with the A400M in the gearbox and other engine components have resulted in much lower availability rates for the platform that originally envisaged. To remedy this, in UK service Airbus has been working to introduce “Mod Pack 2” to the fleet, with all aircraft listed as “first line” now having been modified, according to Leeson.  

It is unclear by what range availability rates differ among UK A400Ms from those that have been fitted with Mod Pack 2 and those ‘non-first line’ platforms still awaiting such rectification work, nor the timescale required to update the original aircraft. 

The UK MoD’s 2022-2032 Equipment Plan, released on 29 November, reaffirmed the suggestion that the retirement of the C-130J would free up resources to procure additional A400 aircraft. However, according to the National Audit Office’s report into the Equipment Plan, released the same day, an option to purchase additional A400M aircraft was assessed as ‘unaffordable’.