Return of the Vulcan

Avro Vulcan XH558 flying again in September 2009 © John Dibbs

A British aircraft that played a significant role during the Cold War has been restored to full working order. Dr Robert Pleming has been instrumental in developing the heritage project that saved the Vulcan bomber. He writes about the Vulcan’s historical importance and the benefits of maintaining an aeronautical icon.

Just after the end of the Second World War in Europe, Churchill, Stalin and Truman met at Potsdam to decide on Europe’s post-war structure. During the meeting, Truman was told of the successful test of the atomic bomb; Stalin’s spies ensured he knew too. By the end of August, the world had changed yet again. Truman had authorised the use of atomic bombs on Japan; Stalin had become fearful of America’s intentions; Churchill had lost the general election to Clement Atlee and on 28 August 1945, Atlee had presented a paper to his Cabinet proposing that, to retain control of its foreign policy, Britain should build its own atomic bomb. The Avro Vulcan, and its fellow four-engined V-bombers, the Vickers Valiant and the Handley Page Victor, were developed to carry that bomb to the Soviet bloc, in retaliation for a potential nuclear attack on the West. The concept of deterrence had been born.

Innovative design

The Vulcan was designed in 1946-7 by Roy Chadwick, Chief Designer of AV Roe & Co of Manchester (who had previously designed the Avro Lancaster) to meet the new requirement for a long-range bomber to carry the British atomic weapon. This innovative tailless delta design first flew in August 1952; the production versions embodied such innovations as first use of twin-spool axial turbojets, an AC power system, cabin pressurisation, electronic countermeasures, electro-hydraulic-powered flying control units and anti-lock brakes.

A total of 134 Vulcans were built. The flexibility of its design allowed upgrades from a free-fall bomber to carry the Blue Steel nuclear cruise missile, maritime radar reconnaissance, an air-to-air refuelling tanker and engine test variants. Vulcan XH558 is a B.Mk2 bomber, and first flew in RAF service in July 1960. XH558 is now the oldest Vulcan, as well as the last one able to fly.

From 1957, the Vulcan was the major delivery vehicle for the British strategic deterrent, until it was superseded by Polaris in 1969. Afterwards, in service in a tactical role, the swan song of the Vulcan was during the Falklands conflict in 1982, when a lone Vulcan, refuelled several times by a fleet of Victor tankers, put the Argentine-held Port Stanley airfield out of action. The last Vulcan squadrons were disbanded in 1984, but Avro Vulcan XH558 flew on in the RAF’s Vulcan Display Flight until 1992. Following MoD cost-cutting, the aircraft was sold, and in March 1993, flown to Bruntingthorpe Airfield in Leicestershire.

Feasibility study

Having followed the fortunes of XH558 during its final years in the RAF, I looked more deeply into the history of the Vulcan, and was amazed by the leap in aviation technology in the immediate post-war years that the aircraft represents. Conscious of the massive public support for XH558, and aware that the aircraft was retired before its time, in early 1997 I resolved to explore the feasibility of returning Vulcan XH558 to flight. The initial challenge was whether the civil aviation regulations would allow an ex-military aircraft as heavy, powerful and complex as the Vulcan to fly. The key to a positive response turned out to be to gain the support of BAE Systems, who had inherited design responsibility from AV Roe. With the aid of a project plan built by a small, expert team, and the enthusiasm of some senior BAE Systems personnel, this support was granted in May 1999. Theoretically, the Vulcan could fly again.

In September 1999, a three-day project definition workshop, with design representatives from BAE Systems and Engineering Authority, Marshall of Cambridge Aerospace, specified a detailed technical survey to determine whether there were any insurmountable technical issues with a return to flight. Not the least of these was finding a way of extending the airframe fatigue life – and determining the scope of the restoration work needed to return XH558 to airworthiness. The latter turned out to be a ‘Major Service’ – the most in-depth Vulcan servicing – with some additional inspections because of the craft’s age and time since last flight.

The restored pilot’s instrument panel – with modern instruments including GPS

By Spring 2000, the aircraft had undergone the technical survey, which verified that its airframe and systems could be restored to full airworthiness at reasonable cost. In addition, the availability of an almost complete library of original documentation and design data, and several hundred tons of spares – including, vitally, eight zero-time Rolls-Royce Olympus 202 turbojet engines – meant that the restoration to flight was now feasible.

Well over 100 original equipment manufacturers of all of the thousands of Vulcan systems and components were painstakingly sought out and contacted–many of these companies had been taken over. Each manufacturer agreed to assess and service their components as required. This major commitment meant that, with the appropriate Civil Aviation Authority (CAA) regulatory approvals and the technical support from BAE Systems, work could start on the return to flight.

It was already clear from project costings that funding of £3.5 million would be required. This was a mammoth task, one not easily undertaken by engineers, but we had gained the support of Felicity Irwin, a seasoned fundraiser. After two applications and considerable public support, in June 2004 the Heritage Lottery Fund confirmed that they would award £2,734,000 to the Vulcan to the Sky project, with the rest to be raised by ourselves. The scope of the grant included not only the restoration of XH558 to flight, but the provision of public access to the Vulcan on the ground, and the setup of educational activities to tell the story of the Cold War and to provide lessons for schoolchildren in technology, engineering and maths based on the aircraft and its operation. In August 2005, work started on the restoration with an 18-person technical team with various skillsets including airframe design and maintenance, propulsion, electrics and avionics.

Nose landing gear overhaul being undertaken at Kearsley Airways

Restoration commences

Initial planning estimated that the restoration project would last for 14 months and consume about 50,000 hours of work. Because of their experience in one-off aircraft projects and their CAA accreditations, engineering control was passed to Marshall of Cambridge Aerospace. The restoration project was to have four phases: a detailed inspection of the aircraft for faults, followed by rectification of those faults. During this period, hundreds of components were overhauled and returned for the recovery of the aircraft to the correct configuration for flight. Tests followed, first on the ground, and then, with ticks in all the boxes, the aircraft was released for its first test flight.

In preparation for the inspection, virtually everything that could be removed from the aircraft was removed, requiring a major logistical exercise to track each one of the components. Every aspect of the aircraft’s structure was inspected visually, and various non-destructive techniques were employed to discover any underlying problems, including X-ray (over 450 X-ray pictures were taken), ultrasound, eddy current and boroscope analyses. Numerous minor, repairable, faults were found, including skin and rib cracks, missing rivets and corrosion, but none significant enough to warrant concern.

The aircraft’s hydraulic, pneumatic and oxygen systems were removed for inspection and overhaul. All flexible pipes and seals were replaced, a significant and expensive logistical effort on its own. The Vulcan has many critical systems powered by electricity, including the flying controls, so the integrity of the aircraft’s wiring and electrical supplies is vital. Rewiring the aircraft was a major exercise in itself.

A year after work had started on the project, it was clear that the restoration was taking much longer than initially estimated, and labour costs were increasing rapidly. Not only were tasks taking longer, because of the learning curve associated with work on this unique aircraft, but some problems were more difficult than anticipated. For instance, significant corrosion was found on magnesium alloy skins and structure of the flying control surfaces, requiring rebuild of these units. A major campaign conducted in August 2006 raised the £1.2 million required to complete the project, including a significant donation of £500,000 from Sir Jack Hayward.

Recovery and testing

With aircraft structural rectification nearing completion in the spring of 2007, attention focused on refitting the aircraft’s systems. The following components taken off for overhaul were refitted: radome, ejection seats, canopy, landing gear, wheels and brakes, fuel tanks and pumps, elevons and rudder, powered flying control units and motors, artificial feel units, yaw and pitch dampers, undercarriage doors and hydraulic rams, air conditioning system, cockpit instruments, the fifth engine in the airborne auxiliary power pack and the engines, each with its the attached constant speed drive and 60kva alternator – the list went on and on.

With the exception of modern avionics, the restored XH558 is almost completely authentic, with only a few material substitutions being required because of the unavailability of the originals. The safety case for flying the aircraft is based on the in-service safety record of the Vulcan fleet; it is therefore vital that XH558’s specification is as near as possible to that of the original fleet, with each deviation requiring a separate risk assessment.

Ground testing started in early summer of 2007 with the application of electrical power – initially the 24v DC vital supply, followed by the 200v 400Hz three-phase AC and subsidiary supplies. One by one, the various systems were put through documented procedures to ensure correct setup and operation. Possibly the most time-consuming and messy was the fuel system, with its 14 fuel tanks (holding about 39,000 litres of fuel in total), 29 fuel pumps and associated pipe work. On the Vulcan, fuel is used to maintain the fore-and-aft centre-of-gravity in the correct position, so it is vital that this system works correctly.

With recovery complete in August, it was time to light the fires! One by one, the four new Rolls-Royce Olympus 202 engines were started and, on test, performed perfectly – over 25 years since they were last tested. It would be wrong to imply that there were no problems found – there were – but that is what testing is all about. A couple of the faults were spectacular, both of these arising from component failures in the 3000psi hydraulics. But all of them were fixed, and by October, XH558 was ready to move for the first time since the start of the project under its own power. Slow and fast taxi tests followed, including deployment of the brake parachute.

Finally, after 26 months, with over 100,000 hours of work on the project and £7 million spent, Vulcan XH558 was ready to fly again. Thursday 18 October 2007 was a perfect day for flying, and in front of the expectant crowd of those who had worked on the plane, XH558 roared down the runway and soared into the air. There were shouts, cheers and tears of joy – so much effort by so many people. I think we all felt awed and stunned, but remember thinking “I can’t relax until she’s safely back on the ground”. After a full 30-minute flight, our test flight crew returned to the airfield for a perfect landing – we had done it. Safely.

The return of the Vulcan to the air prompted national media coverage. It was a British aviation achievement the like of which had not been seen for many years.

Challenges

The major challenges in the restoration arose during the overhaul of various critical systems such as the powered flying control units and the chassis-mounted fuel systems for the engines. The companies responsible for these units had fortunately retained the original drawings and testing gear, but not necessarily the skills – several firms found themselves hiring back retirees just to work on XH558’s systems.

One major update was made, to replace the aircraft’s 1950s military flight systems with modern equipment, not only because the original equipment was deemed unreliable and unmaintainable at reasonable cost, but also to ensure compliance with current Air Navigation Order requirements. A new Horizontal Situation Indicator (also known as a compass!) and Artificial Horizon were provided for the pilots, with additional navigational equipment such as GPS, transponder and height-encoding altimeter– each requiring new aerials to be installed.

Finally, it is worth noting that the enthusiasm shown by the original manufacturers for the project in 2000 appears to have been overtaken by more risk-averse corporate governance of today. I conclude that the loss of system skills due to the inevitable consequences of old age, and a culture of risk-avoidance mean that were I looking to start restoring XH558 to flight today, the project would in all probability not get off the ground.

Aircraft operations

Following a series of further test flights required to iron out minor problems with the aircraft’s new avionics suite, XH558 was finally awarded its ‘Permit to Fly’ in July 2008. Two days later, it made its first display flight for an enthusiastic public at RAF Waddington. Since then, XH558 has flown more than 150 hours in front of seven million people at over 100 events around Europe, and has been seen by many more people in transit. The restored Vulcan has proved to be remarkably trouble-free.

To keep the aircraft in top condition, there is a rigorous servicing schedule: regular checks on the engines, landing gear and critical structure are driven by flying hour milestones. Every winter, the aircraft undergoes a thorough inspection and lubrication; critical components which have a calendar life, such as the ejection seats, fire extinguisher bottles and oxygen regulators are overhauled or replaced. This is not cheap; to keep XH558 going costs around £2 million a year, for 40-50 flying hours.

As I write this (in February 2012), XH558 is about halfway through winter service in a hangar at Robin Hood Airport near Doncaster, being prepared for a year which could be the pinnacle of its career. This year the UK celebrates Her Majesty The Queen’s Diamond Jubilee, but it is also the Diamond Jubilee of the first ever flight of a Vulcan; we plan for XH558 to be part of the celebrations!

Retirement

Unlike modern commercial airliners, which are built to a damage-tolerant design policy, the Vulcan was designed to a ‘safe life’ principle: XH558 has a limit to its fatigue life, beyond which it cannot fly. There is one further fatigue life extension modification which could be applied to the aircraft’s structure that would keep it flying for five or six more years, but the life left in the available Olympus engines means that XH558 may well be taking its final flight in the next couple of years. That flight will be to a museum, where the XH558 will remain as a functional but non-flying exhibit; probably in the best condition of any large British aircraft of its era. The success of this project was in my view due to three things: the determination and perseverance of the small team that made it happen; the enormous support coming from the public’s desire to see the Vulcan fly again; and the assistance from many firms in the British aviation industry. Sincere thanks must go to all these constituencies from everyone who has experienced the feeling of pride upon seeing this marvellous example of British engineering heritage in the sky.

The restoration and display of Vulcan XH558 to flight has demonstrably confirmed that engineering heritage, especially a working one, is able to communicate with the public on several levels: telling the historical story, exemplifying engineering innovation, inspiring the young and generating pride in successful endeavour.

For more information visit: www.vulcantothesky.org