An Independent Website Considering the Future Royal Navy and Promoting Naval Affairs

 

  Astute
  Carrier Strike
   Future Carrier - CVF
   CVF - Pre-Contract
   Pictures
   Design
   Deck Layout
   Propulsion
   CVF Statements
   JCA
   JCA Statements
   CVA-01
  FMCMC
  FRC (Lift)
  FRC (MSA)
  JCA
  JCTS
  JSF
  LPH(R)
  LSD(A)
  MARS
  MARS (FT)
  MASC
  Merlin CSP
  MUFC
  OMAR
  OPV(H)
  S2C2
  Type 45
  Vanguard(R)
  Site Index
  Email the Editor

 

Future Aircraft Carrier (CVF)

Queen Elizabeth Class
 

Part 24

             Article Parts 

 1. Current Project Status and
     Graphics

  2. Specification

  3. The Project and its Origins

  4. Role

  5. Smart Procurement

  6. Project Schedule

  7. Procurement Process I
      (until Jan 2003)

  8. Procurement Process II  
      (until July 2007)

  9. Procurement Process III
      (latest situation)

10. Management and Industry
       Structures

11. Aviation Operations

12. STOVL or CV F-35?

13. Platform Design ...

14. ... and Redesign

15. C4ISR Facilities

16. Operational Concepts

17. Crew, Accommodation &
       Habitability

18. Propulsion and Engineering

19. Manufacture

20. Build Problems and UK
      Content

21. Basing and Support

22. Costs

23. Air Group

24. Aviation Requirements and
       Facilities

25. Catapults and Arresting Gear

26. Armament and Armour

27. Operations

28. Names

29. CVF Links



 

 

Aviation Requirements and Facilities

There is no doubt over the importance of the so-called ship/air interface - for which Thales UK will have responsibility - although under the final management control of the platform design authority.  

According to Peter Fish, an ex-RN aviator and former Head of Aviation Systems and Interface for the now defunct BAE Systems' CVF team "The carrier air group is the CVF primary weapon system, and CVF exists to deliver offensive air capability.  The carrier is, therefore, critical to making sure we return the investment in FJCA."   

CVF video clip
A CVF in Action!  A short video clip from BAE Systems of an early STOVL CVF design operating aircraft.  Its in the .WMV Windows Media format and thus requires a supporting add-in such as MS Windows Media Player.

An excellent article by D Andrews in the International Journal of Maritime Technology implies that some of the significant factors and drivers affecting the aviation related design and architecture of CVF include:

  • Airgroup numbers and type;

  • Hangar type, size and aviation support facilities;

  • Aviation magazines and weapon routes;

  • Length and width of launch area, including number and length of catapults (even only "fitted for");

  • Length and width of recovery area, both VL spots and - for arrested landing - the number and strength of arrestor wires and angled runway;

  • Safe parking area including refuelling/servicing and  stowage);

  • Primary operational concept (i.e. sortie generation rate / simultaneous launch and recovery / maintenance of combat air patrol / multi role operations – Combat Air Patrol (CAP)/ASW Helicopters/Airborne Early Warning (AEW));

  • Aircraft lifts, number, location and type (i.e. internal or deck edge), governed by hangar design as well as flight deck logic;

  • Island position and size (usually to minimise its footprint on the flight deck), with essential aviation features such as Flying Command position (Flyco), Carried Onboard Delivery (COD) and deck stores,  but also significant ship facilities such as bridge, radars/Electronic Warfare (EW), often leading to significant ship and Force Command and Control facilities. Machinery uptakes demand further encroachment on precious deck stowage;

  • Sponsons and walkways.  These are important features providing not just aircraft landing aids but servicing points to the parked areas (e.g. fuel, electrics, air, water) and access to/refuge from the flight deck for flight deck personnel.

On the first point - airgroup size - Peter Fish is quoted in 2003 as saying "The CVF will carry 40 JSF aircraft and be able to operate the widest range of aircraft.  As we are multi-role and will work with all the services, we can adapt and also carry Chinook and Apache helicopters.  The Merlin and the new JSF are expected to be in service for 30 years, so the design will have had to have taken all these factors into account."

In April 2007 Rear Admiral Bob Love, CVF Integrated Project Team Leader, stated that "CVF will be expected to embark a wide range of aircraft, however only the Primary JFAG aircraft are considered cost and design drivers for the ship."  Any other aircraft will have to make do with what ever facilities are provided for the primary aircraft, namely:

  • JCA (fast jet strike aircraft),

  • MASC (Maritime Airborne Surveillance & Control), and

  • Merlin HM1 helicopter.

He also pointed out that a big problem is that of these primary aircraft only Merlin was (just) in service as the CVF (just) during the Assessment and Demonstration Phases, with the other two in varying stages of design

Thales have built up specialist aviation teams, drawing on US, UK and French experience, to optimise the interface between the carrier and its air group.  Sortie generation is the all-important metric: as firm and achievable figures became available the URD was changed by late 2002 from the original 1998 Staff Target (Sea) 7068 objective of 150 sorties per day with 50 aircraft, to a peak of 130 sorties per day with 48 aircraft (including up to 110 by JCA).  Specifically, an early 2003 issue of the URD stated that the requirements for aircraft operations were:

  • Generate up to 510 JCA sorties over 5 days^

  • Generate up to 110 JCA sorties in a 24 hour period^

  • Launch 24 aircraft* in 15 minutes

  • Recover 24 aircraft* in 24 minutes

  • Simultaneous launch and recovery (4 launches/4 recoveries)

  • Be able to de-conflict fixed wing and rotary wing aircraft

  • Able to reconfigure designated spaces

  • Be able to conduct night time operations

^ It is unclear how many JSF F-35B's (selected for JCA) this number is associated with, although 40 or 42 F-35B's were being mentioned in other sources at the time.  The UK requires that its F-35B's are able to sustain 2 sorties per day, and surge to 3.
* Standard airgroup aircraft only, i.e.  JCA, EH-101 Merlin and MASC.

The 60,000+ tonnes full load design selected in January 2003 was expected to meet all these requirements in full, the slightly smaller design that is now likely to be built may not be able to meet all of them in full, for example it will not be possible to maintain simultaneous fixed wing launch and recovery off the smaller deck.  However MOD officials have rejected potential savings such as dropping the "adaptability" feature and opting to accommodate either conventional or vertical take-off and landing planes but not both, and reduce the number of possible 'sorties' per hour that the ships are capable of deploying. 

During the second half of 2003 the aggregate sorties requirement was revised downwards to a new goal of 420 sorties over 5 days, with a threshold of 360 sorties - reflecting the reduction in CVF operating capacity to 36 (or less) JCA's that was being considered at the time.  In January 2004, Admiral Sir Alan West, First Sea Lord and Chief of Naval Staff publicly emphasised that he considered it to be essential that each carrier was able to carry 36 of the new joint strike fighters, and for each of those fighters to be capable of completing three sorties every day [surge] - which equates to 108 sorties per 24 hours assuming that all aircraft are serviceable.  And in April 2004 Admiral Sir Alan West again stated that "The plan is ... 36 JCAs and ... four MASCs, ... that is the basic airwing that we are basing it [CVF] around".  It thus appears that the RN has insisted on a return to the original requirements for JCA operations of 110 sorties per 24 hours, 510 in 5 days.  However the overall maximum CVF airgroup size was reduced to 40 (including 36 JSF's) rather than the 50 (including 40 JSF's) of the original Staff Target. 

In January 2005, Captain Chris Palmer, Deputy Assistant Chief of Staff Aviation, said that CVF would have an an air group including up to 36 JCA's, and other aircraft to be deployed on CVF included 4 MASC and 6 Merlin HM1 helicopters, i.e. an implied 46 aircraft capacity.  He also said that planned [JCA] utilisation rates are expected to allow each aircraft to fly twice a day, giving each CVF a maximum sorties generation of up to 360 flights over a 5-day period, with a surge [3 sorties/plane for one day] taking this as high as 396. 

In March 2005, the latest figures for JCA sortie generation from CVF were set at 108 launches in the first 24 hours, reducing to 72 per day for ten days and 36 for a further 20 days.  A standard strike tailored air group was defined as including 30 JCAs (with up to 36 for short periods), with up to six anti-submarine Merlins and four maritime air surveillance and control (ASaC) aircraft.

Central to the prime objective of achieving maximum sustained sortie levels is the issue of aircraft handling and movement.  The complex process of aircraft handling, movement, preparation, launch and recovery has been the subject of extensive analysis and modelling, bearing in mind that CVF should be able to simultaneously launch and recover aircraft, concurrent with fixed- and rotary-wing operations.  In turn, these analyses of aircraft cycling have influenced flight deck operating and parking areas, island footprint, hangar layout, aircraft and weapon lifts, and site of support services.  BAE Systems and Thales have both developed sortie-generation models respectively known as SURGE and SAILOR. Additionally the DPA has its own model known as CAPSTAN, later CAPSTAN2.


(Above) An indication of just how complex the CVF modelling is.

A Flight Deck Management System (FDMS) will optimally and efficiently assign flight deck park spots, assign work assignments, add required aircraft movement to the movement order task list, etc. 


(Above) This diagram shows the hanger layout of the final BAE Systems CTOL CVF design, dating to late 2002.  From the left, the hanger is accommodating 6 Merlin  helicopters, 16 F-35C fighters, and 4 Hawkeye E-2C's.  It has no resemblance to the current design, but is shown for interest.

Both fixed and rotary wing aircraft will have to be maintained, fuelled and armed then moved into optimum position before launching. A "pit-stop'' approach to servicing is now considered to be the most efficient way to minor maintenance, refuelling and re-arming - with stations known as Arming and Refuelling Points (ARP) on the flight deck itself in a bid to reduce aircraft turnaround time.  Thales' aviation systems team leader Gene Tucker, a former USN carrier aviator, explains: "What we envisage is one-stop servicing stations on the edge of the flight deck to minimise aircraft turnaround time and cut the number of personnel on deck. These service stations will prove for refuelling, re-arming, quick maintenance, and an interface into the ship's IT infrastructure."   In an early concept CVF's concepts, weapons handling, which is normally one of the most manpower intensive activities on board an aircraft aircraft, was almost completely automated.  By early 2003 the MOD was describing a vision for CVF in which weapon requirements were passed by the Aircraft Support Chain Management Information System (ASCMIS) to the magazine where the automated handling system selected the stores, initiated the weapons' built in test routines, and placed the items on the weapon lift.  The automation was facilitated by the use of standard weapon packaging and weapon handling is further simplified by the introduction of Insensitive Munitions (IM) and All Up Rounds, which allow the stowage of ready-use ammunition close to the point of delivery.  This vision of a fully automated handling system was dropped from the design in summer 2003 as part of a cost cutting exercise.  A less sophisticated but much cheaper to develop highly automated (i.e. semi-autonomous, partially manual) weapons handling systems, elevators and magazine equipment will now be used instead.

In December 2005 it was announced that ALSTEC had been identified as the preferred partner for this Highly Mechanised Weapon Handling System (HMWHS) for CVF.  The company has now begun high level system design work that will allow for operational flows in accordance with both Sortie Generation Profile and Replenishment Requirements, with detailed simulation of pallet/weapon movements around the weapons handling system in order to verify processes and design.  Other work includes the weapons handling system design, weapon lifts design and the operational integration of all systems using an integrated control system that interfaces with the ship’s Platform Management System.   Marinise’d commercially off-the-shelf equipment will be used where possible and appropriate.

The design of the flight deck and hangar takes many factors into account - allowing for parking areas, support services, lifts (for both aircraft and stores) as well as acoustic, heat and noise footprints.

Considerations for aircraft and helicopter basing suitability, and shipboard compatibility in particular, include of a wide range of complex integration issues such as: Approach flying qualities; Deck handling; Deck spotting; elevator compatibility; flight deck servicing; hangar deck maintenance; jet blast effects; landing systems; ship motion; shipboard environment; STOVL flying qualities; weapons loading.  The adaptable nature of CVF also means that factors such as steam ingestion; catapult location; catapult hookup; arresting gear capabilities and pull out distances; etc., must also be considered for possible future RN CTOL operations, and to meet more immediate possible French requirements.

In order to maximise flight deck area, Thales and BMT opted for a radical innovative design using two separate islands, this minimises the island footprint on the deck while providing enhanced operational survivability by physical separation of key ship and flight control functions, and furthermore according to Peter Robertson, "positioning the flying control centre on the aft island improves operational control and flight-deck safety." He adds that wind-tunnel testing and CFD analyses of the twin-island configuration has dispelled concerns over airflow anomalies.  The second island allows the ship to have a flight-control centre that principally looks aft, rather than forward, as the most critical 'evolution' is when the aircraft are landing. The two smaller islands also give much more 'parking space' for aircraft on deck. A further innovation will be the use of deck-edge lifts. Most carriers have lifts within the deck itself, sometimes in the runway, which can cause problems if the lifts get stuck.


This 2002 graphic shows the STOVL variant of the unselected BAE Systems CVF design concept from an interesting perspective.

The Thales design features two huge (approx 20 x 30 metres) starboard deck edge lifts of 70-tonnes (154,000 lbs) capacity, each is able to accommodate two JCA-size aircraft or heavy lift helicopters.  By comparison, the lifts on the Invincible-class carriers are just 16.75m x 9.75m (55ft x 32 ft), with a mere 18.1 tonnes (40,000 lbs) maximum capacity.

Unlike the Invincible class, CVF will be fitted with a Jet Blast Deflectors (JBD).  This is necessary because of the very high and potentially dangerous and destructive thrust that the F-135 engine in the JSF generates when running at maximum thrust for launch.  It is hoped that with modern materials it will be possible to avoid the cost and complexity of having to use sea water to cool these - the expected use or otherwise of afterburners during launch will be a big factor in this decision.

The Thales/BMT CVF STOVL design selected in January 2003 had two side-by-side JBD positions with "hold-back" restraints about 150 metres back from the ski-jump style bow.  This allowed pairs of aircraft to be launched in quick succession.  The take-off run was considered sufficient for F-35B's to be launched at maximum take-off weight (MTOW) given reasonable (30kts) actual wind over deck (WOD), while the configuration also allows for very rapid launch events.  But in addition the extended centre-line flight deck configuration allowed for occasional very long (over 200m) take-off runs from an unrestrained starting point right aft (like Harrier's on the current Invincible's) for heavily loaded aircraft in low WOD conditions. Some changes in this configuration may occur with the reduction in platform size.


This graphic shows the Alpha CVF flightdeck layout, dating to about January 2003 it's now superseded.

Work was also carried out to map the heat and acoustic footprints on deck.  Noise is a major issue for the CVF design as health and safety considerations restrict the allowable tolerance to high levels of acoustic energy.  The Jan 2003 design featured two vertical landing pad for F-35B's. 

Fish says that CVF and JSF offer the chance to improve STOVL operation significantly over today's Sea Harrier FA.2/Harrier GR.7A.  Options for the vertical landing element include approaching over the ships stern rather than coming alongside and manoeuvring over the landing spot.  This offers an improved landing rate and addresses environmental issues - such as the jet exhaust down blast associated with landing on.  The F-35's improved STOVL handling and control will be a factor in allowing this, while the aircrafts electro-optical sensors offer opportunities to present the pilot with improved cueing.

During cost reduction efforts in the second half of 2003, the flight deck arrangements for CVF were considerable simplified, this was partially imposed by the reduced size of the ship.  In the Bravo and later Delta designs, the side-by-side launch positions with convergent runs to a large bow ski jump were dropped, and only a single JBD is now fitted on the axial runway, beside the aft island.  The bow area was now split, with the ski jump ski jump limited to the port side, this has the significant benefit of allowing additional [although rather exposed] deck parking to starboard.  The special landing pads for F-35B VL's also seem to have been dropped.  The flight deck has been narrowed aft, making the provision for an angle landing lane very obvious.  The Delta flight deck area is about 4 acres (nearly three times that of an Invincible-class).

Reports emerged in Q1 2005 indicated that the design team was considering the feasibility of adopting the shipborne rolling vertical landing (SRVL) technique.  This offered some advantages, particularly in hot weather conditions, but issues such as bolters and fuel reserves also had to be addressed and the final decision was apparently negative.

Two overlapping photos of the flight deck of a model of Delta CVF at Euronaval in October 2004.  The single take-off run and new deck park area to starboard of the ski-jump are obvious.

The November 2002 'adaptable' Alpha CVF design was fitted with a very large hanger deck - the hanger length was about 180m and width 36m, giving a useable area of about 6480 sq metres - roughly three times that of the current Invincible Class carriers and apparently enough to accommodate up to 24 F-35B's plus 6 EH-101 Merlin size helicopters, or any equivalent mix.  It was stated before the January 2003 down-select that the clear height of the hanger would be 7-10m, the higher figure being assumed to apply only to a small maintenance bay area, but Thales later claimed that the entire hanger deck of their design was high enough (10m?) to ensure that any aircraft embarked could be maintained anywhere, eliminating the need to move airframes around during maintenance.  10m would have given the CVF's the highest hangers ever fitted to any aircraft carrier.

The optimised (Q3 2003) Beta CVF design had a smaller hanger, sized for up to 20 aircraft and helicopters, and also the clearance height was reduced by several metres over much of the length.  

In the latest Delta designs (end-2003 onwards), the hangar is 163 metres long and 29 metres wide - the total hanger area is 4,700 sq m.  Hanger height is stated as being 7.1 metres, increasing in the 'hard hat' area to over 9 metres, with a crane hook clearance of 7.5 metres.

The design allows for accommodating at least 20 JSF's (the F-35B is the worst case due to its non-folding wings), or up to 45 Sea King size helicopters, in three “bays” separated by fire curtains. There are large aviation support spaces fore and aft of the hangar, and along its port side.  Two rows of compartments will surround the hangar, for ease of access and as extra protection, and modular (containerised) storage space will have the capacity of 24 London buses.

The philosophy for determining the height of the hangar was that the hangar would be high enough to park and maintain JCA over its entire area. The hangar should also be high enough to stow all other JFAG aircraft, though limiting those operations that require considerable overhead height to “high hat” areas where there is a 9.5m clearance.  Secondary role aircraft (such as Apache AH) were not allowed to unduly drive hangar design.  This gives a hangar 6.5m high from deck to deck head with a minimum clear height of 6.1m (note that seems to be some contradiction in numbers) allowing for structure and fittings such as lighting, and is high enough to accommodate all JFAG modularised stowage boxes.   The hangar extends over two decks with a gallery deck between the hangar and flight deck in both variants.  The high hat areas extend into the gallery deck.

Flight deck area is about 15,700 sq m (nearly 4 acres),  flight deck length overall is 277 metres, STOVL flight deck breadth is 69 metres (excluding catwalks, minor sponsons, but including lifts), 6 operating spots, maximum available STO runway length is 274m.

In July 2007, DE&S stated "The flight deck area is nearly 13,000 square metres " - much less than previously thought if accurate (probably not).

(Below) This diagram shows the current flight deck and hanger layout of the CVF Delta design.  A maximum effort 'alpha strike' is arranged on deck - the parking arrangement required intense modelling to avoid problems due to jet efflux.

The middle diagram shows the CVF hanger layout.  The blue outline is the superimposed  cramped hanger layout of the CVS Invincible-Class (the shaded areas are the two lifts), the red outline of the CVF hanger (which excludes the deck edge lifts) has about 2.5 times as much useable deck space.   

 
 

(Above) The same basic carrier design, but re-configured for CTOL operations with catapults and arresting gear, the French CVF variant will presumably closely resemble this.  The slightly widen flight deck extreme (helicopter location) is obvious.  See also next page.   (Source: Aircraft Carrier Alliance)
 

(Above) A slightly superficial - but nevertheless impress illustration of the sheer size of the CVF fight deck - two CVSs and nine tennis courts are superimposed placed on it at the same scale.   (Source: DE&S)

Deck approach projector siteOther aviation related items that will be fitted to CVF include: suitable communication systems; the Joint Tactical Information and Distribution System (JTIDS) supporting NATO Link 16; other data links (NATO 10, 11 & 14); a precision carrier  approach radar; a tactical air navigation system (TACAN); all-weather approach system landing aids (CTL), possibly a new semi-automatic carrier controlled landing system; electro-luminescent panels for deck orientation; a deck lighting system compatible with night vision goggles; an operating limits instrumentation system (OLIS); a deck approach projector site (DAPS), a stabilised glide slope indicator (SGSI); and a Horizon Approach Path Indicator (HAPI) system.  

The CVF design will also introduce a mass of new or improved systems to the Royal Navy, including the Aircraft Support Chain Management Information System (ASCMIS), an aircraft Prognostics & Health Management (PHM) system, a new Low Observability (LO) Diagnostic System, an improved Flight Deck Management System (FDMS), new type undercarriage restraining devices and electromagnetic deck locks, and possibly even robot handlers that can be tasked by the FDMS to move aircraft on the flight deck.  These systems and equipment cumulatively all represent a very substantial investment in both money and crew personnel.

(Above) An interesting graphic showing superimposed STOVL and CTOL flight deck arrangements.   (Source: MOD)

In the event that the STOVL F-35B variant of the JSF is cancelled by the Americans, a contingency plan has been developed to complete HMS Queen Elizabeth in 2014 in a STOVL configuration to operate Harrier's.  HMS Prince of Wales would then be completed two years later in a CTOL configuration with catapults and arresting gear, probably to operated the F035C variant.   HMS Queen Elizabeth would also be converted to a CTOL configuration at the end of the decade, after the Harrier had left service.

In July 2007 it was officially stated that the flight deck area for the UK CVF variant was "nearly 13,000 sq m" (slightly less than previous statements had indicated), and the hanger volume was 29,000 cubic meters.

 

Rolling Landings

The Lockheed Martin F-35B JSF has a lower payload "bring back" capability when using a vertical landing than the 2300kg that the RN had hoped for - it may therefore be necessary to jettison some unused weapons before landing and with modern weapons being extremely costly this is a significant issue.

In the summer of 2004 the MOD asked BAE Systems to investigate the possibility of ship borne rolling vertical landings (SRVL) - an SRVL approach would exploit the ability of the short take-off and vertical landing F-35B to use vectored thrust to slow the speed of the aircraft while still gaining the benefit of wing-borne lift.  This offers the possibility of significantly increasing "bring-back" payload compared with a vertical recovery, while also reducing stress on the single-engined aircraft's propulsion system. Factors to be taken into consideration is the cost, feasibility and underpinning safety case of conducting shipborne rolling vertical landings aboard a CVF, adoption could also drive changes to the carrier design, pilot training regime and JCA flight control laws.

Following the initial UK studies, the American JSF programme office sponsored a more detailed analysis of the SRVL concept with Lockheed in 2004-5, culminating with a simulator trial at NASA's Ames Research Center in California in late 2005. 

It was revealed in April 2007 that Qinetiq's VAAC Harrier testbed will be used to demonstrate flight-control limits for a SRVL mode potentially applicable to the Lockheed Martin F-35B Joint Strike Fighter.  The VAAC testbed will perform a series of flight trials, potentially using a large-deck aircraft carrier such as the French navy's FNS Charles de Gaulle, and concluding with a final evaluation of a preferred SRVL approach and landing using a "dummy deck" at Boscombe Down around November 2007.  An MOD spokesman said "Consideration of the aerodynamic performance of JSF together with the available deck area of CVF design has shown that significant benefits could be realised by extending the principles of land-based RVL to shipborne operations ... the increasing maturity of this body of analysis and simulation indicates SRVL could be performed safely by JSF on CVF, although the effects of equipment failures and adverse conditions require further investigation".

Using SRVL F-35B aircraft would approach the carrier from astern at about 60 knots indicated air speed, 35 knots relative assuming 25 knots wind over deck (the maximum speed of a CVF will be 25 knots, so 25kts WOD is achievable even in dead calm) on a steep 5-6 degree glide path.  Touch down would be about 150 feet from the stern with a stopping distance of 300 to 400 feet depending on conditions (wet flight deck, pitching ships etc).  That would leave around 300 feet of flight deck for margin or even "bolters".

The SRVL technique has a significant impact on ship designs and aviation operations, Commander Tony Ray told a conference in February 2008 "We expect to trade some STOVL flexibility for increased bring-back and fuel.  We have to .. check for for relevant CV criteria that apply to slower SRVL operations.  For example flightpath control will be a far more important flight criteria for SRVL than it has been for STOVL.  It is a CV trait creeping in".

 

 

 

                                                                           Back to top                                       |<   <  Part 24  >   >|






 © 2004-8 Richard Beedall unless otherwise indicated.