At the edge of Portsmouth naval base, on a grey, drizzly day, the building that serves as the headquarters of the Royal Navy’s 1710 Naval Air Squadron looks less than enticing. But once inside and out of the rain, it’s apparent that there’s a warren of corridors and doors, hiding more workshops and laboratories than you can keep count of, each containing a bewildering array of equipment.
Within this innocuous building, engineers and scientists are using the latest measurement and monitoring tools to improve the performance and maintenance of aircraft, from the F35 Lightning II to the Swordfish, the Lynx Wildcat, the Merlin and venerable Sea King. Engineers work late into the night to develop modifications that will transform the capabilities of aircraft, adding new avionic systems and defensive measures. There are teams of technicians ready to deploy to anywhere in the world at a moment’s notice to repair aircraft.
There are avionics and mechanical workshops, equipped with a range of equipment to make upgrades and fixes. There are large laboratories dedicated to materials analysis and corrosion chemistry. There is a workshop full of non-destructive testing equipment, from basic tapping hammers to CT scanners. Here in 1710 Naval Air Squadron (NAS) headquarters the old and the most modern machines sit side-by-side and are used every day. They range from spectroscopes, used to analyse specks of debris to ascertain which components in an aircraft are wearing the fastest, to 50-year-old tensile test machines that measure the strength of steel.
Fast response needed
The broad range of equipment and capability is needed because 1710 NAS is an amalgamation of different engineering units, dedicated to aircraft repairs and enhancements, support and maintenance, and research. The squadron’s mission statement is to “recover, sustain and enhance naval aviation force elements at readiness, as quickly and effectively as possible in any operating environment”.
The bulk of the squadron’s work focuses on the repair and modification of helicopters, but it also works with planes and ships. The squadron supports aviation across the Royal Navy, Royal Air Force and the army. There are five 1710 sites in the UK – at RAF Wyton in Cambridgeshire, RNAS Yeovilton in Somerset, RAF Benson in Oxfordshire, Wattisham in Suffolk, and the HQ in Portsmouth. There are 200 people in the squadron. Just over a third of them are civilians, but most are from the Royal Navy.
Commander Chris Ling, 1710’s commanding officer, says: “Our USP is in how all the different sections can work together. There really is nothing else like it.”
One of the largest spaces at the base is the hangar, which contains the frames of old helicopters and an assortment of aircraft components, on the floor and in racks at the sides. The space is dominated by an Apache helicopter, which was taken out of service to help engineers devise repair schemes and testing procedures. Alongside it, an old Puma helicopter is used for teaching structural forensic work.
In the corner is a small Gazelle helicopter that typifies the kind of modification work 1710’s engineers perform. The helicopter has a stretcher and dummy next to it. Engineers are developing a modification that will give the helicopter an emergency medical evacuation capability. This involves removing seats and installing life-support and medical equipment. “This is the biggest project we’ve done in a while,” says Paul T Smith, head of stress engineering at 1710 NAS. “But you name the aircraft and I can guarantee we’ve done a modification for it and, if we haven’t yet, then we will.”
The Gazelle project has followed a similar pattern to all the modifications the squadron handles. After initial meetings, where the requirements and what is possible are discussed, 1710’s engineers design the modification using 3D CAD software package Autodesk Inventor. Smith then ‘stress tests’ the effect the modifications will have on the aircraft using hand calculations with slide rule and finite element analysis via Ansys. The design is then validated, including a structural resonance test, proof testing with the drawings and safety assessments rigorously quality assured.
Recent modification projects have included fitting machine guns and moving maps to aircraft. A complex modification can take up to 18 months to complete. Simple brackets or fittings take just a few months, although all the stops are pulled out for urgent operational requirements. “We are Crown servants, so if we are told to stay until midnight we will. We deliver everything in-house, from design to certification and manufacturing,” says Smith. “For service modifications our aim is to enhance military operational capability. We are the only part of the MoD approved to design and manufacture fittings and electrical extensions for aircraft, as part of our Design Approved Organisation Scheme approval. But there is the proviso that the modifications must not affect structurally significant parts or flight-critical systems.”
The squadron’s engineers would not, for example, work on propulsion systems. But Smith adds: “If needs be, we can do the complete production run for a service modification. We are agile and effective. We design it, we trial it, we’ve proved it and the customer is happy.”
Worldwide travel
If one side of 1710 NAS is focused on upgrading aircraft, then the other concentrates on keeping them in the air. There are repair teams, all of whom are service personnel, out working somewhere in the world every day, in the US, Germany, Cyprus or Norway, for example, reflecting the operations of the different fleets.
Technicians are deployed in teams of three and can respond to an urgent task in 48 hours. Two work on the aircraft while the third works in the background, with support provided by the office in the UK. A five-tiered system is used to assess the damage and the fix, which ranges from the replacement of a component to entirely reverse engineering a solution. Around a quarter of repairs are unique and, if a failure repeats, it is put into the aircraft’s document set.
Smith says: “When it comes to structural repair we literally go around the world. There isn’t a place we haven’t been to. Our teams are deployed at a moment’s notice into operational fields of conflict.”
Recent operations have included supporting counter-piracy operations in Oman, and working in Afghanistan. The teams are deployed because it’s more cost-effective to repair an aircraft on site than to ship it back to the UK in a transport aircraft.
Work can concentrate on one particular aircraft, for example when a craft enters service or is nearing the end of its life. The repairs vary from battle damage to prangs that occur while the aircraft is being moved on the ground, or the replacement of windscreens. Most repairs are to cracks caused by fatigue.
Sharing expertise
Lieutenant Tom Lever, the deputy repair manager at 1710 NAS, says: “We are fully deployable and everyone is environmentally trained. The repair designer deploys to the aircraft to produce the solution in-situ. We also have a lot of interaction with the scientists when we are dealing with corrosion. We can tap into their expertise.”
A recent example of the interaction between technicians and scientists, says Smith, was a case where the heat from an exhaust nozzle was causing damage to an adjacent panel. Scientists assessed the material and worked with the repairers to produce the fix. “The repair was prepared and deployed in one week at next to no cost. If we had sent it out to industry, it would have taken at least six months to get a new panel made, and we’d have lost the aircraft for that time,” he says.
Engineers at 1710 NAS spend a substantial amount of time and effort researching materials and how to apply the latest inspection and monitoring technologies. Their forensic expertise is also called upon outside of the services. For example, the squadron’s non-destructive testing capability also fulfils an investigative role for accidents and failures, which often encompasses developing fixes. The squadron has seconded scientists to the Defence Accident Investigation Branch and they have investigated aircraft from the Chinook , to the recent incidents with the Red Arrows’ Hawk.
In addition, the squadron provides materials research support to the Royal Fleet Auxiliary. It looks at fuels and oils to identify contamination and for corrosion control, for both aircraft and ships. It has been involved in work on Type 45 destroyers’ weapons signature and survivability. The F35 Lightning II aircraft has high temperature from its jet efflux system, so in partnership with industry the squadron is developing heat-resistant deck coatings for the new Queen Elizabeth class aircraft carriers. “We are already engaging with the manufacturers on the F35 Lightning II Joint Strike Fighter,” says Smith.
The advancement of monitoring technology is a key aim within 1710 NAS. The squadron has made great strides with monitoring aircraft to provide early indications of faults and help plan maintenance. “Vibration within a helicopter is a massive thing to deal with,” says Smith. “We monitor as much as we are able to and look at wear debris analysis so we can determine which parts of the helicopter are wearing at appropriate rates and which are not.”
Aircraft are fitted with accelerometers and the transmission systems of helicopters are monitored to detect any bearing defects. Microphones are also used to record the noise in cockpits. The recordings are analysed – certain noises at certain frequencies are giveaways for problems.
Chief Petty Officer Aircraft Engineering Technician Paul Perry, vibration health usage and management system vibration specialist, says: “We are relying more and more on the data. The challenge we have is getting all the data back to the UK. We’ll set up the monitoring in the UK, but once an aircraft is fully deployed the data has to be transmitted securely from the ships.”
The goal is full condition-based monitoring for the entire fleet of aircraft, which Perry admits is some way off, but achievable. As with the other goals 1710 NAS has, the enthusiasm and expertise of its personnel will ensure they work towards full condition monitoring, supported by new technology such as laser scanning and 3D printing.
That such strong expertise is demonstrated in such a broad range of capability is testament to the varied requirements placed upon the squadron. It’s like an engineering multi-tool for the armed services.
Thanks to the pursuit of new technologies and the expertise at its core, the squadron will continue to evolve to meet the challenges of the future.