The Ministry of Defence has issued an early notification for a forthcoming contract opportunity to replace the Tactical Air Navigation (TACAN) and Direction Finder (DF) systems on the Queen Elizabeth Class aircraft carriers as they face “obsolescence challenges”.

The contract, valued between £8,000,000 and £10,000,000, pertains to the air defence radar industry and is open to any region.

The procurement reference is tender_351487/1196915. Published on 31 March 2023, the approach to market date is set for 1 November 2024, with the contract starting on 1 November 2025 and ending on 31 October 2028.

The Maritime Combat System (MCS), Communications and Situational Awareness (CSA) Team is leading this In-Service Support (ISS) contract, which focuses on the replacement of the aging TACAN and DF systems.

  • TACAN System: Serves as a beacon, providing aircraft with crucial information on their bearing and distance relative to the ship.
  • DF System: Provides air traffic controllers with bearing information of aircraft based on their radio transmissions.

The MoD plans to invite bid applications starting 1 November 2024, with the contract expected to commence on 1 November 2025 and conclude on 31 October 2028.

Here’s the description.

“The Maritime Combat System (MCS), Communications and Situational Awareness (CSA) Team has responsibility for placing an In-Service Support (ISS) contract covering HMS Queen Elizabeth Class (QEC) Aircraft Carriers,’ Ship Air Interface (SAI) equipment (equipment used on board the QEC to maintain the aviation capability).

The current TACAN and DF systems are key components of the SAI and are also classified as Air Traffic Management (ATM) equipment, and therefore subject to the regulatory requirements of the Military Aviation Authority (MAA). The TACAN system acts as a beacon providing aircraft with information on relative bearing and distance to the ship. The DF system provides air traffic controllers with information on the bearing of aircraft from the ship based upon their radio transmissions.

At present, the capability is facing obsolescence challenges and replacement systems are sought for deployment from 01 November 2025. The requisite approvals under the Military Airworthiness Authority’s (MAA) Regulatory Articles under the Air Traffic Management (ATM) Equipment Approved Organisation Scheme (AAOS) will be required. A high-level Statement of Requirement (SoR) has been developed and agreed with Navy Command stakeholders defining the scope of support required to achieve the required levels of availability and provide the necessary specialist advice and support to meet legislative, regulatory and safety requirements.

Additionally, the provision of enduring support to meet this scope of requirement is a prerequisite for obtaining full ATM releases for the operational use of the systems on QEC.”

George Allison
George has a degree in Cyber Security from Glasgow Caledonian University and has a keen interest in naval and cyber security matters and has appeared on national radio and television to discuss current events. George is on Twitter at @geoallison

25 COMMENTS

    • I would prioritise 40mm Bofors turrets over missiles, but certainly then CAMM silos to add to a Task groups defensive screen.

      Also anti drone systems and Dragonfire as soon as possible….

      • And 7 marlets attached to the 30mm cannon. I think the new trainable decoy launchers can be have munitions attached as well.

    • Can’t put VLS on a carrier without risking efflux damaging aircraft on deck, or having to stop air operations every time a threat is possible (i.e all the time). Could add some 40 or 57mm, or even RAM, though.

      USN uses a combination of Mk 29 launchers for ESSM (like the old SeaWolf box launchers), Mk 49 RAM launchers and Phalanx on their carriers. All of them are point and shoot.

      • Just go to Naval News
        Article:
        OCCAR Progressing Towards Charles De Gaulle Carrier’s SAAM-FR Update

        Click in Aster being fired from Charles de Gaulle to see the whole image.

        • Well you can put them on a carrier, but you are putting ship out of action while you use them.

          There is a good reason why USN – the only carrier operator that really counts – does not fit them, and its the same reason that drives UK thinking.

      • Always amazed by the amount of crap on the flight deck, that came from the Phalanx live firings. Having broken cover after. Ark+Lusty. 🤔🙃🕳️

        • You should have seen the trial on Bulwark. Man sized plywood range targets. Ally plates to act as aircraft skins. Fired the Goalkeeper and looked at the mess afterwards. Holes punched through the range targets (12mm Ply) and ally plates. Damage was caused by the sabots and the pusher discs as they peel away from the penetrator core.
          After every single GK or Phalanx shoot we ended up FOD Ploding the upper deck, finding sabot and pusher disks.
          After SW VL shoots there was bits of glass from the cannister covers everywhere. It was like an old school car windscreen before laminates. Months afterwards little square bits of glass kept appearing!

          • Well Gunbuster, the addage of “no substitute for experience” once again applies. Even though some on here subscribe to the flat earth theory. 😶🙄🕳️.

      • Most navies with carriers operate SAMs aboard them, including past RN carriers, so I think the foreign debris issue is a red herring.

        I wonder wether TACAN could also provide a great way of enemy missiles homing onto our carriers?

        • I wonder wether TACAN could also provide a great way of enemy missiles homing onto our carriers?

          Certainly

        • Its not – the only operater that counts does not use them – for good reason. And it is the reason UK does not fit them either.

          • But the reason USN cited, at least what they told Congress, is more on the budget side of things rather than technical (Yes, surprising, US DOD does have problems with money).

            This question was raised and answered in Senate Appropriations Committee Hearings on CVN-77 back in early 2000s. The current no-VLS set up has simply been sufficient for the USN self-defense requirements for CVN, so they can avoid spending money on not only the VLS itself, but also the wirings and space to accommodate them.

            Yes, perhaps that was because redesigning a Nimitz to accept VLS might have cost a lot more than adding it into clean-sheet design like Ford, but every little “keeping the cost down” tricks still count when you ask legislative branch to fund programs that are far overbudget.

  1. I obviously know sod all here but what’s stopping then from just having a bunch of new laptops on the bridge with bespoke software they can change at will?

    They could even have them linked to a central server for more compute power if needed but it would make changing anything (even upgrading all the laptops) a breeze.

    Surely the computer parts should be the easiest to change and upgrade?

    • The laptops still need a piece of kit to talk to in order to track incomming aircraft and provide a signal for those aircraft to follow. I think it’s that particular piece of kit that this procurement is looking at rather than the internal control systems i.e. laptops/desktops

      • Fair enough.
        I wonder how much time was spent during the design of the carriers to make sure all that stuff is easy to get at as it was bound to need upgrading.

        Would making it easy to get at also make it more vulnerable to battle damage?

        • So from my limited understanding, the “box” will reside in a designated area within the ship with cables going outside to the transmitters and recievers rather than the box itself residing outside.

          Happy to be corrected by anyone who knows more detail.

          • TACAN is pretty low tech, basically a military VOR with additional features. They are probably being replaced due to parts obsolescence, which makes maintenance expensive. Thales is one of the world leaders in TACANs/VOR’s right now, so I expect them to win it.

  2. I am suprised these items are running into obcelence so early in the carriers life. Wasn’t it a consideration when the designs were fixed – or was it a way to reduce the overspend at the time knowing it would have to be done later when the ships were in service and the overspend was history.

    • These systems are not directly carrier specific so if they need replacing due to obsolescence is because the system has been in use elsewhere as well as the carriers. The carrier designs were confirmed at contract so even if the Tacan design was brand new it would have been specified as that available in 2005 – so already 20 years old or much more

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