Before taking a Christmas break in 2025, the Vulcan to the Sky Trust released new updates in its efforts to safeguard Vulcan XH558 for future generations as fundraising efforts continue. In its December 2025 newsletter, the Trust described 2025 as an “extremely busy year” for the team maintaining XH558 and outlined the aircraft’s winter maintenance schedule and out‑of‑phase work. The Trust reported that, during 2025, engineers completed a mix of minor and major jobs on XH558 alongside the 2025 winter servicing and the aircraft’s out‑of‑phase (OOP) maintenance tasks.
The OOP program was described as a set of aircraft‑specific tasks, inspections, and certifications that do not line up with major scheduled checks. According to the newsletter, these included boroscoping the engines to check for corrosion, damage, debris, and signs of wear, checking each engine’s magnetic chips for indications of internal wear, changing the aircraft battery, and servicing the Auxiliary Air Power Pack (AAPP). The update added that XH558’s 200‑volt distribution system received an in‑depth inspection and partial reconditioning during the year, while the team diagnosed and solved problems that had been experienced earlier.
The newsletter also confirmed that the team removed a faulty AAPP from the aircraft and tested a replacement unit on the AAPP test rig. The Trust reported that the new AAPP ran and “excited” correctly on the rig. Before refitting it to the aircraft as part of the winter maintenance programme, the oxygen relight system, fire bottle system, and cartridge casings were fitted to the new unit, and the exhaust pipe was rotated through 180 degrees to face downwards, as required for installation on the aircraft. The note explained that when AAPPs are removed from the aircraft, their exhausts are turned upward so they are ready to be serviced and tested on the rig.
According to the December newsletter, the team also replaced the No. 6 starboard fuel pump and inspected the fuel system, bringing it back into a “fully operational state” ready for engine runs. In addition to these three major tasks, work on the 200‑volt system, the AAPP and the No. 6 starboard fuel pump, the newsletter said the engineers bled the bomb doors and topped up the hydraulic oil to the required level, carried out lubrications and inspections, ran functional checks regularly, serviced and modified the aircraft’s pneumatic system and completed three successful engine runs.
The Trust added that work in 2025 extended to some of Vulcan XH558’s ground equipment. The Blackburn Commer turbo air starter truck was undergoing a major service after an engine issue was found at the end of the previous season. The H&S STAD Mk.12A air starter trolley received what the newsletter described as a deep service, which brought it back into use and allowed engine runs to commence again, although the unit still needed some attention to its electrical circuitry because it remained “a little temperamental.”
With a full year of engine runs planned, the Trust said that three new air starter units had been acquired, including a reconditioned Mk.12A engine (ECU), a Mk.12L trolley, which is described as a slightly later and more compact variant of the Mk.12A with better diagnostic circuitry, fault indications and a Lucas fuel system instead of a Dowty system, and a spare Mk.12L engine. The newsletter added that the spare engine would require “a fair bit of restoration and reconditioning” and that further updates would follow in the next year’s maintenance diary.
The December 2025 update concluded that 2025 had been an “excellent and unbelievably busy year” for the maintenance team. The Trust acknowledged the complexity of keeping a 65‑year‑old Vulcan in fully serviceable condition, adding that systems and subsystems can fail at short notice, and said the engineers carried out the work “for the love of it.” For more information, visit www.vulcantothesky.org
