The RAN’s new MH-60R combat helicopters will be able to operate with Mk54 torpedoes and AGM-114N Hellfire missiles from Hobart class air warfare destroyers (AWDs) from the time the ships are commissioned, although some alternative procedures will need to be used until the ships receive the “Romeo” modification after delivery.
Some confusion has been apparent over precisely when the MH-60Rs will be able to fly from AWDs while carrying their intended armament, given the need for the ships’ magazines to be modified to accept the Hellfires and the Mk54s in addition to the ship-launched Eurotorp MU90 torpedoes for which the magazines were originally designed.
The hangar and magazines of the RAN’s Anzac class frigates also need modifying to operate the MH-60R. This work will be carried out primarily in parallel with the Anzac antiship missile defence (ASMD) upgrade, although HMAS Perth, which has already benefited from the ASMD upgrade )see PXX for more), will the first ship to receive the Romeo modifications during her maintenance period in Henderson early this year.
The RAN’s first operational MH-60R flight will be embarked in an Anzac about March 2015. With the upgrades to the other seven ships scheduled to be completed by the end of 2016, it should not be necessary, therefore, to deploy an MH-60R aboard an unmodified Anzac.
The work on the Anzacs broadly reflects the changes also necessary on the AWDs, although planning for these is still in the conceptual stage.
“I haven’t got the final engineering proof design, we’re working on that with the AWD Alliance now but we think it will be a smaller package than originally envisioned,” Rear Admiral Tony Dalton, Head Helicopter Systems at the Defence Materiel Organisation (DMO) said to ADM.
To avoid any delays in AWD construction, these modifications are being held over until the first scheduled maintenance activity for each AWD, although implementation is still much earlier than originally anticipated.
“That’s a bit of a variable fix but at the moment it’s planned within 15 months of each ship being accepted. And because the quantity of work is coming down, we’re going to end up doing it faster than we thought – probably in less than six weeks,” RADM Dalton explained.
With the first AWD scheduled to be delivered to the RAN in March 2016, the second in September 2017 and the third in March 2019, full operational capability (FOC) on these platforms – and thus for the MH-60R in RAN service – should therefore be achievable by mid-2020, three years earlier than originally forecast.
“One of the reasons the MH-60R was the preferred solution (for Project Air 9000 Phase 8) was that the integration risk with both the Anzacs and the AWDs was significantly lower with the Romeo than with the NFH (Nato Frigate Helicopter),” RADM Dalton said. “The NFH is significantly larger than the MH-60R and that would have required more intrusive hangar modifications to both ships.
“The MH-60R is already compatible with RAST (Recovery Assist, Secure and Traverse) which is the deck securing and deck movement system on the Anzacs and ASIST (Aircraft Ship Integrated Secure and Traverse) which we will have on the AWDs, while the NFH was designed from the outset for the Harpoon decklock system that is more common in Europe.
“We’re taking a staged approach to the AWDs because we’ll be able to operate the aircraft from them without any mods and we didn’t want to introduce a whole bunch of risk into the construction program that we could reasonably work around in the first instance.”
Magazine storage
The Anzacs’ magazines were originally configured only for the Mk46 torpedo which is being replaced by the RAN in the antisubmarine role by the air-launched Mk54 and the ship-launched MU90. The Hellfire AGM-114N air to surface missile is also a new weapon for Navy, although the AGM-114M – the same missile but with a blast fragmentation rather than a metal augmented thermobaric warhead - already equips the Army’s Tiger armed reconnaissance helicopters.
The Mk54 is 107 inches long compared to the Mk46’s 102 inches, and at 608lb is about 100lb heavier, although both weapons fit standard 324 mm launch tubes. In comparison with the MU90 the Mk 54 is about one and a half inches shorter and some 50lb lighter.
The Anzacs’ magazines are therefore being reconfigured to allow the two longer, heavier new weapons to fit in. Chocks are being repositioned to ensure the weapons fit neatly into their cradles, while different tools are being used on the weapons handling gantry to cater for different centres of gravity. Dedicated Hellfire racks will allow the storage of a greater number of the missiles.
Adding complexity are the differing propulsion systems of the two new torpedoes. The MU90 is battery powered while the Mk54, as is its Mk46 predecessor and the Mk48 heavyweight torpedoes equipping Collins class submarines, is powered by liquid Otto Fuel II, a toxic combination of propylene glycol dinitrate, nitrodiphenylamine, and dibutyl sebacate.
“It’s a fuel we’re comfortable with handling, but the modifications on both ships will include an Otto fuel detector being fully integrated into the ships’ management systems and Otto fuel spill kits properly integrated into the magazine,” RADM Dalton said.
Space constraints within the magazines until modifications are complete involve some changes to the way the so-called flight-in-air material on the Mk54 is managed.
This material consists of the suspension bands that enable the weapon to be attached to the MH-60R (and which separate from the aircraft after launch), the drogue parachute that decelerates the weapon after launch and positions it at the right angle entering the water, and a frangible nose cap protecting the face of the sonar transducer that separates on water entry.
A number of safety pins are also tied to the aircraft and pull out to arm the warhead and motor when the weapon is fired, but not when it is jettisoned.
The flight-in-air material adds to the overall length of the Mk54 by about eight inches. Until the magazine is upgraded, readying the torpedo for launch will involve the bands and other flight-in-air material being fitted to the weapon in the hangar rather than in the magazine before it is presented to the aircraft on the flight deck.
Certification
The bottom line, according to RADM Dalton, is that from the time of their commissioning the AWDs will be able to deploy with the MH-60R, together with Mk54s and Hellfires albeit not with the full combat load, on the assumption that storage and workaround procedures receive formal certification.
“That certification process will have different elements to it if we’re preparing the weapons in different places; it may not be the final solution that we’re targeting for handling high explosives and fuels, but it will still be a certified process,” he commented.
Further work involves changing the external lighting systems, in particular the flight deck lights, of both the Anzacs and the AWDs to be more compatible with night vision devices.
“We use night vision goggles (NVGs) now, but what we don’t do typically is fly to and from the flight deck using NVGs,” said RADM Dalton. “We currently fly with the goggles up for take off, steer away from the ship and put the googles down, doing the reverse coming back for landing. After the mods we’ll be able to fly to and from the ship with the goggles down”.
Whether any lighting changes were required for NVG operation aboard the Canberra class Landing Helicopter Docks (LHDs) would be determined in first of class flight trials, probably conducted by either Army Blackhawks or MRH-90s
An additional capability being added to the Anzacs – but already included in the AWD design – is the provision to the hangar and flight deck of an upgraded 115 v 400Hz a/c external power source required for aircraft maintenance both by the MH-60Rs and the in-service classic S-70B Seahawks.
“What it means now is that if some maintenance is required on the S-70B that needs a high current draw on 115 v a/c external power it has to take place on the flight deck where we use the aircraft’s auxiliary power unit to provide a/c power. The ship can’t provide that to the hangar, it’s a very high voltage current, you do need to plumb it in properly, you can’t work around it,” RADM Dalton said.
“This means there are some restrictions on ship manoeuvring, and radiating while the aircraft remains ranged on deck. When you put an aircraft outside we get a little annoyed if there’s a port 30 turn and we get a big wave over the flight deck, so being able to work in the hangar will be much more pleasant and save some of the coordination issues that we currently have with the Seahawk classic.”
Defence says the RAN will continue to fly the S-70B Seahawks from the Adelaide class guided missile frigates until the FFGs are retired from service later this decade. A contingency plan is in place should the RAN need to deploy a MH-60R in an FFG, but this is understood to be a low priority.
