Showing posts with label Rolls-Royce. Show all posts
Showing posts with label Rolls-Royce. Show all posts

21 February 2015

The Marine Corps Bet on the Harrier

Hawker P.1172 Kestrel in KES markings
For a large part of the postwar history of American military aviation, the procurement of non-American aircraft was an unusual exception. I had written back in 2011 about the efforts that led to the selection of the Dassault Falcon 20 jet as the basis of the US Coast Guard's HU-25 Guardian medium range search-and-rescue aircraft.  The two most significant prior examples of non-American aircraft procurement were the Martin B-57 Canberra selected by the USAF as its new interdiction bomber in 1951 and the selection of the Hawker AV-8A Harrier which entered service with the Marine Corps in 1971. The story of the Marine Corps' evaluation and procurement of the Harrier is one that readily demonstrates the Marines' political savvy in navigating the treacherous waters of Congressional funding as well as a single-minded commitment to efficient close air support to the Marines on the ground. The predecessor of the Harrier was the Hawker-funded P.1127 Kestrel demonstrator. Two prototypes and four development aircraft were built and then followed by nine more developed P.1127 airframes which in 1963 were to be part of what was called the Kestrel Evaluation Squadron (KES). The aircraft were designated Kestrel FGA Mk1 and the KES was staffed with test pilots from the Royal Air Force, the Royal Navy, the US Navy, US Army, US Air Force, and the German Luftwaffe. Because there were three nations in the Kestrel Evaluation Squadron, it was also referred to as the Tripartite Evaluation Squadron (TES). The unit was formed in 1965 for the purpose of exploring the possibilities of a V/STOL combat aircraft. 

At the time of the KES flight program, Lt. Col. Thomas Miller was assigned to the US Marine Corps' Air Weapons Systems Requirements Branch at the headquarters. It was the job of the staff of this department to review all the latest research and development to see what sort of equipment would be useful to the Marines. Miller and a fellow officer, Lt. Col. John Metzko, had gotten hold of film footage from the British Embassy in Washington DC of the Kestrels in action. By this point, the RAF had committed to getting the Kestrel operational with a more developed aircraft called the Harrier. They had monitored the P.1127 Kestrel program despite not having any Marine pilots in the evaluation squadron and when it became clear the RAF was going to go forward with the Harrier, they immediately briefed the USMC Deputy Chief of Aviation who was none other than General Keith McCutcheon. I had written about him recently as the "Father of Modern Close Air Support" and needless to say, given General McCutcheon's background as a passionate advocate for the Marines' own close air support, he was readily on board to find out more about the Harrier. The next step was the brief the Commandant of the Corps, General Leonard F. Chapman. With the enthusiastic support of the Commandant, the Marines then set about on getting flight time on the new Harrier. The British were adamant that anyone who would be evaluating the Harrier be a qualified test pilot and working through the defense liasons at the British Embassy and Hawker Siddeley, Miller and Marine test pilot Lt. Col. Bud Baker were chosen to head to the UK. Miller's test flying experience was getting the A-4 Skyhawk and F-4 Phantom into Marine service, so he was well versed in what an aircraft had to be able to do to support the Marines on the ground. At the request of the British, the two Marines would clandestinely make 10 flights each in the Harrier and would wear civilian clothing during their stay in Britain during their evaluation. Test pilot John Farley of the Royal Aircraft Establishment worked with Miller and Baker to prepare them for their Harrier flights. It was Farley who made the first flight of the P.1127 Kestrel prototypes in 1964 and he would come to amass 19 years of experience as a Harrier test pilot. 

Gen. McCutcheon, USMC Deputy Chief of Aviation
Miller and Baker realized very quickly during their flights that the Harrier was a new breed of combat aircraft that Marines had to have. To them, it could do everything the A-4 Skyhawk could do but not need a 6,000 foot runway to do it. All it needed was a 1,000 foot strip for rolling STOL takeoffs with an increased weapon load or the deck of an amphibious assault carrier. It was clearly close air support that could not only go where the Marines were, but be readily based close to where the Marines were in action. To get their hands on the Harrier, the Marines needed funding. Not only did the Marines have to deal with the US Navy since the Marine Corps is a department of the Navy, but they weren't sure how the US aircraft industry would react to the Corps wanting a British aircraft. After briefing Commandant Chapman, they met with the Presidential Scientific Advisory Board to get their support.

Fortunately the Navy was receptive and sent over their own team to fly the Harrier as well which allowed them to compare with their earlier Kestrel flights as part of the KES. Also fortuitous for the Marines was that a Marine was in charge of the Navy's A-4 Skyhawk program, Col. Edwin Harper, and he got to fly the Harrier as well, giving him the unique perspective of comparing the Skyhawk with the Harrier. With the ready support of the Navy in 1969, the Marines now had to lobby Congress for the funding. The FY1970 budget didn't have any money for Harrier procurement, but Harper, Miller, Baker and General McCutcheon briefed the Senate Armed Services Committee anyway. McCutcheon made his pitch to the chairman, Senator Barry Goldwater, that he didn't want just a handful of Harriers and do an evaluation. That'd been done already. "We want to buy a whole slug of them and get started and have a meaningful program!

Rep. Mendel Rivers (D-South Carolina) crucial to the Harrier program
Though the FY1970 Department of Defense budget was set at their time of their briefing to the Senate Armed Services Committee, the support of the Presidential Scientific Advisory Board insured that supplemental funding was secured as an amendment to the FY1970 budget bill. The supplemental funding was enough to procure 12 Harrier jets at a cost of $57.6 million. But there was a catch- the money was secured via the Marines canceling procurement of 17 McDonnell Douglas F-4 Phantom IIs. It would be necessary to win over McDonnell Douglas. As part of getting Congressional support, the House Armed Services Committee was also briefed on the Harrier plans and the chairman of the House committee, Representative Mendel Rivers of South Carolina, would support the procurement of the 12 Harriers as long as future Harrier buys were aircraft built in the United States. Realizing that the Marines was a significant ground breaking sale into the US defense market, Hawker Siddeley immediately sent representatives to the United States to canvas the aircraft industry and find an American partner for the AV-8A Harrier program. Hawker's team met with eight aircraft manufacturers and narrowed the list down to three- Ling-Temco-Vought, Grumman, and McDonnell Douglas. Hawker felt McDonnell Douglas was the best fit given their naval aircraft experience and at the time, the A-4 Skyhawk program was starting to wind down and the AV-8A Harrier would be good transition for McDD. On 29 September, Hawker Siddeley and McDonnell Douglas signed a 15-year agreement to cooperate on the AV-8A Harrier program. In tandem with this agreement came one from Rolls Royce to team up with Pratt and Whitney on the Pegasus engine. The teams developed a plan to transition production of the Marine's AV-8A Harrier flight as well as the Pegasus engine from UK production to US production over a span of five years. With a planned buy of 114 AV-8A Harriers, it was found by Representative Mendel Rivers' staff that it was cheaper to stick with UK manufacture instead of phasing in production in the United States. During the FY1971 budget debate, discussions centered on the pros and cons of moving production to the United States and eventually Congress agreed with Mendel Rivers' analysis that there was no need to phase in production of the AV-8A in the United States. Though the agreement never resulted in US production, it did lay down the foundations for the later AV-8B Harrier II program. 

AV-8A Harriers of VMA-513, the first USMC Harrier unit
With Mendel Rivers' support now behind them, McDonnell Douglas agreed to become the engineering group responsible for product support of the AV-8A Harrier which was more than adequate compensation for the 17 canceled Phantoms. The AV-8A Harrier first entered service in 1971 at the Navy's Flight Test Center at NAS Patuxent River, Maryland while the first Harrier squadrons prepared for the transition to the AV-8A. The first operational Marine Corps squadron was VMA-513 "Flying Nightmares" which had been flying the F-4 Phantom since 1963. VMA-513 become operational with the AV-8A Harrier in May 1971 at MCAS Beaufort in Representative Mendel Rivers' home state of South Carolina. 

Source: Harrier II: Validating V/STOL by Lon O. Nordeen. Naval Institute Press, 2006, pp 23-30. Photos: Wikipedia, USMC.

16 February 2015

The Sud-Ouest SO 6000 Triton: France's First Jet Aircraft


Sud-Ouest SO 6000 Triton prototype. Note the nose intake.
France's first jet aircraft has its roots during the German occupation during the Second World War. Sequestered away in a small Paris apartment a group of French engineers led by Lucien Servanty began work on what would become the Sud-Ouest SO 6000 Triton. Servanty was a graduate of the prestigious engineering school Ecole des Arts et Métiers and prior to the war started out working at Breguet before moving to SNCASO (Société nationale des constructions aéronautiques du sud-ouest) which was a conglomeration formed in 1936 out of several French aircraft companies including Blériot, Bloch, and Lioré et Olivier but was better known as Sud-Ouest. Sud-Ouest was one of the precursor entities to the post war Sud Aviation that would later become Aerospatiale. It was here at Sud-Ouest that Servanty worked on the last variants of the Bloch MB.150 fighter before the fall of France in 1940 to the Nazis. Some of the French aeronautical establishment fled to the Great Britain, some went south to work with the Vichy regime, some were imprisoned for refusing to collaborate (like Marcel Bloch, who later changed his name to Marcel Dassault), and others like Lucien Servanty went into hiding. This was the sort of environment that the Triton was developed, in secret places tucked away from the Nazi occupiers. Servanty's team even built small scale models and tested them in wind tunnels they constructed in secret. 

Lucien Servanty
Uniquely for pioneering jet aircraft of the time from other nations, the Triton was to be a side-by-side two seat aircraft with dual controls and a retracting tricycle undercarriage. A two seater was quite a departure from the first jets in the United States, Great Britain, Germany and the Soviet Union which were all single seaters. The cabin of the Triton wasn't really that much different from a two-seat cabin general aviation aircraft- this was Servanty's idea that the Triton might find use as more than a research aircraft but a training aircraft to introduce pilots to jet propulsion. As designed, the all-metal Triton was to use an indigenous French engine called the Rateau (named for Auguste Rateau who had done much work in the first half of the century on industrial turbines) which was also being developed clandestinely during the occupation. The intake for the Rateau engine was under the nose with the intake duct passing between the pilots to the centrally-mounted engine abreast the wings. Furthering the impression of the Triton as a general aviation aircraft was its crew access via car door-like hatches on each side of the cockpit. In fact, one writer even suggested the Triton may well be the first VLJ-class aircraft thanks to its design!

With the end of the war and the liberation of France, the new French government immediately placed an order for five Triton aircraft plus one static airframe as part of broader effort to rebuild the nation's aeronautical industry. Construction began in somewhat humble facilities outside Paris that were once the factories for Nieuport biplane fighters before moving to a more suitable facility that was once used by Farman. Like many pioneering jet aircraft of the day, the airframe work proceeded much more quickly than the engine development effort. Engineers working on the 3250 lb-thrust Rateau engine were running into difficulties and the Triton prototype was slightly modified to accept a German Jumo 004 engine as used on the Messerschmitt Me 262. This was something of a fortuitous coincidence for Lucien Servanty's team as the Jumo plants in Germany happened to be located in the French occupation sector. The first two Triton airframes would be powered by the Jumo 004. The first flight took place on 11 November 1946 with test pilot Daniel Rastel at the controls. Prior to his first Triton flights, he acquainted himself with jet propulsion by flying captured Me 262s. With this first flight, France become the fifth nation to join the Jet Age after Germany, Great Britain, the United States and the Soviet Union. The flight lasted only 10 minutes and never got about 1000 feet and it was quite clear the Jumo 004 wasn't enough engine for the Triton. 

The third Triton. Note the new lateral intakes and reprofiled cockpit.
The first Paris Air Show after the war took place only three days after the Triton's first flight and the third Triton airframe minus its engine was displayed. Not happy with the reliability of the Jumo 004 engine, Servanty's team switched to Rolls Royce Derwent engine, the same engine that powered the Gloster Meteor fighter. They then switched again to a more powerful Rolls Royce Nene engine which was the engine of the De Havilland Vampire fighter. The French company Hispano Suiza had just gotten a license to build the Nene for the French Air Force's order of Vampire fighters. Because of the increased mass air flow of the Nene engine, the third and fourth Triton featured lateral intakes and improvements to cockpit visibility. In addition, ejection seats designed by Heinkel were installed. The fourth Triton flew first on 19 March 1948 with the third Triton flying for the first time on 4 April 1950. In fact, the fifth Triton flew before the third Triton on 23 May 1949. The sixth airframe was the static test article. Of the last three flying Tritons, it was the fourth one that flew the most as the third and fifth airframes only made a few flights before getting grounded for mechanical issues. The airframe summary is as follows: 
  • Triton 01: Prototype, Jumo 004 powered. Eight test flights. Retired in November 1947.
  • Triton 02: Identical to prototype, but never flown as it was set aside for the French Rateau engine which never became available for use. 
  • Triton 03: Modified for the Nene turbojet. Only two test flights before getting grounded for mechanical issues. It can be seen today at the French aerospace museum at Le Bourget. 
  • Triton 04: Most successful one of the group. 189 test flights. Final flight in November 1950.
  • Triton 05: Damaged due to a forced landing after only eight test flights. 
  • Triton 06: Static test article not intended to fly. 

While modest in performance compared to the jet aircraft of the late 1940s, the Triton gave French industry its first jet experience and many of the prominent test pilots of the time got their first jet time on the Triton given it's trainer layout. Not a bad accomplishment for an aircraft that was designed in secret not out of security but out of fear of the Nazi regime. Lucien Servanty stayed on with Sud-Ouest which became Sud Aviation in 1957. He rose to engineering prominence at Sud Aviation and headed the French design team for the Concorde before his death in Toulouse in 1973. 

Source: X-Planes of Europe: Secret Research Aircraft from the Golden Age 1946-1974 by Tony Buttler and Jean-Louis Delezenne. Hikoki Publications, 2012, pp 22-26. Photos: Wikipedia, Walter Van Tilborg Collection. 


27 January 2015

The Early Days of Airbus Industrie and How the A300 Got Its Name


Roger Béteille, father of Airbus Industrie
The roots of the formation of Airbus Industrie are tied more to the abilities of one man more than any other individual in the early history of the Airbus consortium- Roger Béteille. A graduate of the prestigious École Polytechnique, he was the technical director of Sud-Aviation in the mid-1960s. Sud-Aviation produced the Caravelle and it was Béteille who was the director of the jet's flight test program. In postwar Europe prior to the formation of Airbus, the Caravelle was only one of two commercial aircraft programs to make money (the other being the BAC One-Eleven). He also worked closely with Hawker Siddeley on the Concorde program- this was an experience that unique among the French technocrats of the time, gave him a close working relationship and mutual respect of the British aerospace establishment. In the aerospace industry of France in those days, someone of Béteille's skills was unique given his flawless English, the respect afforded by the British engineering staff at Hawker, and his political skills in working with several European nations in the course of his career at Sud-Aviation. 

In the summer of 1966 there were three proposed commercial aviation projects that were commanding the attention of the European industry. The first one was the BAC Two-Eleven, a successor to the successful BAC One-Eleven. That summer BAC was riding high on the success of the One-Eleven which at the time was one of Britain's most successful and profitable aerospace programs. But it was already facing significant competition from the Douglas DC-9 and the Boeing 737 and BAC had been lobbying the British government for support to launch the Two-Eleven which would have been powered by a new engine Rolls-Royce was developing, the RB.211, that would also go to the Lockheed Tristar. The Two-Eleven was a larger development of the One-Eleven that for the most part, was intended to get British European Airways (BEA) to drop its interest in the Boeing 727-200. The problem with BAC was that it was heavily committed to the Concorde program and had little financial resources to devote to the further developing the Two-Eleven which is why they were keen on approximately $100 million in launch funding from the British government. 

Hawker-Breguet-Nord HBN 100
In the previous year (1965), the head of Breguet Aviation, Henri Ziegler (who later became Airbus's first president) had inked an agreement with fellow French firm Nord Aviation and Hawker Siddeley in the UK to jointly work on a widebody twin called the HBN 100 that was largely the product of Hawker's engineers at their Hatfield facility. The HBN 100 was to have two variants, one with a passenger capacity for 225 and a stretched one with a capacity for 260. The planned engines were to be either the Pratt & Whitney JT9D that was under development at the time for the Boeing 747 or the Rolls Royce RB.178 which was a three-shaft demonstrator engine called the "Super Conway" that eventually led to the RB.211. At the same time as the HBN 100, Sud-Aviation (Roger Béteille's firm) was working the Galion which was very similar in layout, appearance and size to the HBN 100. The Sud-Aviation Galion evolved from what had started out as an enlarged Caravelle. 

Sud Aviation Galion
In 1966 Béteille invited his friends from Hawker Siddeley to Sud Aviation's facility in Toulouse to see if the design work on the HBN 100 and the Galion might be aligned towards a common joint project. That invitation for Arthur Howes, who headed the Hawker team, to come to Toulouse is what gave birth to the Airbus. It soon become a joint program with engineers from all the involved companies shuttling down to Toulouse as needed as the designs of the Galion and the HBN 100 were more closely aligned. That December at a meeting in London, France, Great Britain, and West Germany- I'll soon get to how the Germans entered the picture- decided that a single consortium would build a widebody twin. At time time, Concorde had two production lines- one in France and one in the UK, and on top of the financial costs of the program, the duplication of effort was something Roger Béteille wished to avoid so that an attractively priced aircraft could be offered to the world's airlines. It was agreed that in exchange for Rolls Royce developing a new engine for their design, the Sud Aviation Galion would form the baseline design to work from with the HBN 100 being sidelined. 

It was obvious at the time that any joint effort would be spearheaded by Britain and France, the only Western European nations at the time that had the industrial capacity for large commercial aircraft design and production. But the West Germans were keeping an eye on the developments and the use of the name "Airbus" in reference to the nascent project actually came from them. Even though it was twenty years after the end of World War II, the German aircraft industry was still in shambles. Many legendary names like Messerschmitt and Dornier were still around, but even those entities were hollow shells of their former selves. What engineering staff hadn't left Germany after the war debated the future of their industry and decided the future lay in collaboration on a civil aircraft project. The year before Roger Béteille invited the British to meet in Toulouse, seven German aircraft companies (ATG Siebelwerke, Bolkow, Dornier, Flugzeug-union Sud, Hamburger Flugzeugbau, Messerschimitt and VFW) formed Studiengruppe Airbus (the Airbus Study Group) to determine what sort of aircraft the future airline market would need. It was this grouping of German companies that contributed the Airbus name to the young enterprise. It was at the following year's Farnborough Air Show that German participation was formalized. Up to that point, the Germans had been working on their own but it was decided that what the French and British had come up with baselined off the Sud Aviation Galion was a suitable candidate for their contribution to the effort. Officially becoming Airbus, each nation decided that one company from each nation would take the lead for that nation's contribution. Hawker Siddeley would lead the British contribution, Sud Aviation would lead the French contribution and the German Airbus Study Group was reorganized into a formal consortium of their own, Airbus AG, to lead the German contribution. 

But what to name this aircraft? Arthur Howes of Hawker Siddeley was partial to the name "Obelix" which was the giant in the Asterix series of comic books popular in those days. It was apparent, though, that the name had to be something that was essentially neutral to British, French and German interests. One evening at a dinner in Sud Aviation's Paris headquarters the upper level of management at Sud Aviation asked why a name for the aircraft hadn't been found yet. Different ideas were punted about before Howes himself spoke up as a joke and said "I propose we call it the HSA 300" and the room laughed as "HSA" was the initials of Hawker Siddeley Aviation. But Howes continued "H- Hawker Siddeley, S- Sud Aviation, A- Airbus, and 300 because it's a nice round number." As everyone enjoyed Howes' joke, it suddenly donned on him- why don't we call it the A300? 300 is still a nice round number closest to the proposed design's seating capacity and if "A" was used, the aircraft would always appear before Boeing in any alphabetical listing. Howes idea proved popular and the nascent enterprise's new design would be marketed as the Airbus A300.

Further reading on this blog on the early history of Airbus:

How American Airlines Shaped the A300
How Rolls Royce Scuttled British Participation in Airbus

Related reading:
American Airlines Picks the DC-10 (American's pick of the DC-10 is intertwined with the early history of Airbus)

Source: Close to the Sun: How Airbus Challenged America's Domination of the Skies by Stephen Aris. Aurum Press, 2002, pp 6-11. Images: Wikipedia, Air International

19 October 2010

How the Boeing 757 Almost Became a Joint US-UK Program


Following the withdrawal of the United Kingdom from the Airbus consortium and the A300 program, the 1970s were times of significant uncertainty for the British airframe manufacturers. Some in the British aircraft industry advocated for return to the Airbus consortium, some pushed for an indigenous airframe and yet others suggested joint ventures with other nations, even if that meant working with Europe or even the Americans. The indigenous solution was the least likely of the day in light of the UK government's unwillingness to invest in the promising BAC Three-Eleven program. In 1974 the French laid down the conditions for the return of the UK to Airbus- not only would the UK have to make a substantial contribution to the development and production costs of the A300, but British airlines would also have to purchase the A300 jetliner. It was the low point of relations between the French and British that once rode the wave of cooperation with the Concorde program. Accusations were even aired in the press of the day with each nation belittling the other's aerospace industry. 

Politics complicated the equation with the recession following the 1973 Yom Kippur War and the Arab oil embargo on the West. The West German government called for increase in financial commitment to Airbus as financial austerity in that nation called for a need to decrease the West German government's financial stake to 25% of what it was at the time. The suggested solution was to expand the Airbus consortium to include the UK and Italy to offset domestic decreases in the financial investment in Airbus by the Bonn government. In the UK, the bankruptcy of Rolls-Royce and the difficulties of the Lockheed Tristar program put the preservation of British aviation jobs as a top political priority. In 1976 further consolidation of the British aviation industry took place with the formation of British Aerospace with the merger of BAC and Hawker Siddeley. The new company's priority under the leadership of Lord Beswick was a new commercial airframe. 

At the time the French were holding discussions with McDonnell Douglas on a successor to the Dassault Mercure, the CFM56-powered Mercure 200. However, the leadership of McDonnell Douglas wasn't convinced the Mercure 200 was the aircraft to launch a trans-Atlantic venture. As a result of wanting to see what other European manufacturers had on the table, discussions were also held with British Aerospace. At the time there were several promising designs from Dassault, Aerospatiale, and BAC (which again was looking a new version of the One-Eleven provisionally designated the X-Eleven). Britain at the time was keen on the JET program (Joint European Transport)

In August 1976 a team of BAC/Hawker engineers (now in the employment of the new British Aerospace entity) visited Boeing in Seattle to review the progress on what would be come the Boeing 757. At the time work was taking place on what was provisionally designated the Trident Five which by coincidence shared a lot of features with the Boeing 757. Like the early 757 design that had a T-tail and 727 nose, the Trident Five had a Trident nose and T-tail combined with a stretched fuselage with a moderately swept wing mounting two RB.211 engines in underwing nacelles. Boeing's president at the time, the colorful Tex Boullioun, offered BAe design work on the wing, engines, RB.211 nacelles and landing gear on the 757. In fact, Boeing was willing to even have final assembly of the Boeing 757 in the UK with flight testing taking place there. "I can't understand why any would want final assembly- it's 7% of time spent on the aircraft with 97% of the problems" as Boullion put it to BAe's head, Lord Beswick.

The British investment to the Boeing 757 was less than what the French wanted for re-entry into Airbus and the potential value to British industry was well in excess of US$3 billion. Boeing went as far as to extend an invitation to British subcontractors to visit Seattle and discuss specific areas of involvement. British Airways was already discussing an order for the 757 and it wasn't a state secret that Lord Beswick disliked the French. But once again, politics sidelines the deal. Despite the new RB.211 engine variant for the 757 being key to Rolls-Royce's recovery, the political winds of the day called for cooperation with the Europeans and with Hawker Siddeley designing an all new supercritical wing for the upcoming A310, it was felt at the highest levels of the government to continue along with what Hawker Siddeley had started with Airbus. The UK had joined the European Economic Community in 1973 and a BAe deal with Boeing to design and build the 757 was unacceptable in light of the spirit of the EEC which pushed pan-European business and industrial cooperation.
 
Source: Flight of the Titans: Boeing, Airbus, and the Battle for the Future of Air Travel by Kenny Kemp. Virgin Books, 2006, p100-106.

08 October 2010

How Rolls-Royce Scuttled British Participation in Airbus


In the late 1960s as the nascent Airbus Industrie was formalizing the design of the A300, the original intent of the consortium was to use a new 47,500 lb-thrust turbofan in development by Rolls-Royce, the RB.207. Great Britain at the time was actively involved in the early days of Airbus as a full partner, riding on the heels of the Anglo-French Concorde program. The two main British companies involved with Airbus at the time were Rolls-Royce to provide the engines for the A300 and Hawker Siddeley to provide the wing design for the airliner. However, all was not well for the commercial airframe start up as development costs in Toulouse were rising and worse yet, RB.207 development was falling behind at Rolls-Royce. I had posted earlier on the A300 that the original design for the aircraft, the HBN100, was a much larger aircraft than what resulted, seating over 300 passengers compared to the 250 of A300 as built. As result of the HBN100 being a twin jet the size of the rival Lockheed L-1011 and McDonnell Douglas DC-10, it would need more powerful engines than the Rolls-Royce RB.211 used on the Tristar and the General Electric CF6 used on the DC-10 and this responsibility was assigned to Rolls-Royce to develop the RB.207. 

With the development of the RB.207 behind schedule, timing could not have been worse in 1968 when European financial houses made a run on the French gold reserves that depleted the reserves by 30% in a short period of time and caused not just the collapse of the French franc, but the collapse of President Charles De Gaulle's government amidst political unrest in the country. As economic malaise spread through Europe, airlines began to have doubts about the viability of the A300 and its original 300+ seating capacity. Airbus partners Sud-Aviation and Hawker Siddeley even began to prepare fall back designs based around a smaller aircraft. 

Matters worsened through the year for Airbus as the Rolls-Royce was also developing the RB.211 engine for the Tristar as well as the RB.207. Given that three engines were going into the Tristar versus only two engines for the original A300 design, Rolls-Royce began to divert engineering resources from the RB.207 program to the RB.211 program which was facing technical issues of its own as the world's first three-spool engine design. The RB.207 wasn't even Airbus' first choice for the A300. French engine manufacturer SNECMA had partnered with Pratt & Whitney to offer the JT9D engine which was initially favored by Airbus, but Rolls-Royce exercised its considerable political clout and had the UK government push for a "European" engine in the form of the proposed RB.207. Rolls-Royce even went as far as to suggest that it was wrong for an American engine be part of a European aircraft. Due to pressure from Rolls-Royce and the UK government, the RB.207 engine was selected for the original A300 design but in just a few years it was Rolls-Royce itself that was putting more emphasis on the RB.211 for the Tristar than the RB.207 it had pushed for just a few years earlier!

The writing on the wall came when Roger Beteille, the head of Airbus, found out the selling price of the RB.211 engine. He had found out that two RB.207 engines would cost more than three RB.211 engines which put the A300 at a considerable price disadvantage to the Tristar. There was no way the A300 would succeed if Airbus stuck it out with Rolls-Royce and the RB.207 engine. The only way Airbus could find a way out was to change the size of the A300 from a 300+ seat aircraft to a 250 seat maximum aircraft. It was a master stroke that saved the program as it now made existing engines in the form of the RB.211 and the CF6 now appropriate for the A300 and Pratt & Whitney/SNECMA could now offer the JT9D as well. 

In December 1968, the A300 was formally launched as a 250 seater with a wider range of engine options that left out the RB.207 engine. As a smaller aircraft, the airlines of Europe were more interested in the design and ironically, it was the head of Hawker Siddeley, Sir Harry Broadhurst, who announced that the RB.207 engine wasn't needed and that the JT9D was on the table as an option for the new A300 design. At this point things got very complicated for the UK government. Money had been provided for the development of the RB.207 engine for the original A300 design. Money had also been invested in the BAC Three-Eleven, which was now square in competition with new, smaller A300 design. The Three-Eleven would have been powered by two RB.211 engines, the engines that Rolls-Royce had given development priority over the RB.207. In the end, a need for address Great Britain's trade deficit meant that official support was given to the Three-Eleven program. This also increased the market for the RB.211 engine as continual problems at Rolls-Royce eventually resulted in the company going into receivership with the British government to keep it afloat. By the summer of 1970 Great Britain withdrew from the Airbus consortium as continued support for Rolls-Royce put it in conflict with the A300, but Sir Harry Broadhurst felt Hawker's investment was worth keeping and Hawker Siddeley remained with the Airbus consortium as a major subcontractor building the wings for the A300. 

07 September 2010

The Canceled British Aircraft that Cost the UK Industry

I bet you thought you were going to be reading about the BAC TSR.2 when you came across the title of today's post, but while there's no arguing the effects that the TSR.2 cancellation had on the British aerospace industry, there was a canceled aircraft that came before the TSR.2 that some have argued cost British industry far more than could ever have been imagined. In 1951 the government had issued a specification for a new long range strategic transport that would be able to move 120 troops long distances to replace the elderly piston-powered Handley Page Hastings. It was envisioned that this new transport could also move personnel and equipment rapidly around the world and deploy as necessary with the new V-force bombers that were soon to enter service with the Royal Air Force. The main condition of the specification was that it had be based on existing design. 

Five companies submitted proposals, with Bristol submitting a version of the Britannia turboprop transport, Saunders Roe submitting a variant of their Duchess flying boat, and Handley Page, Avro, Vickers, and Short submitting transports based on their bomber designs (Victor, Vulcan, Valiant, and Sperrin, respectively) and powered by the new Rolls-Royce Conway turbofan. De Havilland submitted a stretched version of its Comet 1 jetliner. Bristol's Britannia variant was eliminated early due to it being too slow, along with Saunders Roe's flying boat. The Sperrin was next eliminated as the transport version had a fuselage only 9 feet wide with accommodation for only 50 passengers or personnel. Handley Page and Avro's submissions were judged too risky for the RAF contract, leaving only Vickers and De Havilland as the remaining designs not eliminated.

It was realized early on after Vickers was named the winner of the RAF competition that what the RAF needed was not terribly dissimilar with BOAC's need for a long range jetliner that offered more capacity and range than the De Havilland Comet 1. The original specifications that Vickers won was then amended with the requirement that the jet transport also earn a certificate of airworthiness from the civil aviation authorities. With the new amended specifications in place, an order was placed with Vickers for the V1000 prototype aircraft, serial number XD662, in March 1953. 

The V1000 would be the RAF transport version and the anticipated civilian version was the VC7. With construction of the V1000 prototype underway in the summer of 1954, the RAF ordered six aircraft with an eventual requirement of twelve aircraft. BOAC was regularly consulted through this phase as they wanted to put the VC7 on the North Atlantic routes to Canada and the United States as well as on the longer Empire routes that couldn't be served by the Comet 1 jetliner. Besides BOAC, Trans Canada Airlines (Air Canada's predecessor) and Pan American showed significant interest in the VC7. Even BEA expressed an interest in the VC7 for its longer European services.

To meet BOAC's wishes, the V1000/VC7 was a bit larger than the RAF desired, mainly out of a need for the wing fuel capacity to meet BOAC's range requirements. Four Rolls-Royce Conway engines were mounted in the wing root similarly to the Vickers Valiant only the wing was larger and more swept with Kuchemann wingtips (similar to the 707-320BAdv and 707-320C's wingtips) and low mounted. The fuselage had six-abreast seating with a 12.5 foot diameter. This was significant at the time, as Boeing was wrestling with the cabin diameter on its anticipated Boeing 707 and Douglas at the time was still contemplating five-abreast seating for its coming DC-8. Unfortunately prototype construction at Vickers' Wisley facility showed that the V1000 prototype's weight would be about 18,000 lbs higher than planned.

It would have been a simple matter to have upgraded the Conway turbofans, but for whatever reason, BOAC's enthusiasm for the VC7 cooled as the planned weight with the intended engine would rule out London-New York nonstop services. Ironically, several years later when BOAC ordered the 707-430, it would have Conway turbofan engines that were upgraded that would have worked on the VC7! Government meetings in September 1955 formalized BOAC's disinterest in the VC7 and suggestions were made that De Havilland put forth a stretched version of the Comet as well as refinements to the Bristol Britannia as being suitable for BOAC's needs. In addition, BOAC looked further ahead to the mid-1960s for a possible supersonic transport. Despite BOAC's incomprehensible stance, Vickers anticipated the V1000 prototype's first flight in June 1956 with the first production aircraft flying in 1959 with inaugural airline services in late 1959/early 1960 (not too far off from when the Boeing 707 began its passenger services). In a bid to maintain the competitiveness of the VC7, Vickers explored other engine options and even looked at a version of the VC7 with each of the Conway turbofans in its own podded nacelle under the wing, not unlike that of the 707 and DC-8's layout.

By this point the RAF was entering a period of fiscal austerity and it's most expensive item to date was the V1000/VC7 project. Without mentioning the V1000/VC7, the British government cautioned the RAF to scale back its expenditures. Politics came into the picture with the prospect of the end of Comet production which would have affected one of the Comet's main subcontractors, Shorts in Belfast. A desire to keep Shorts busy shifted the support amongst some MPs in Parliament against the Vickers jetliner. In addition, the Britannia was having teething problems with its turboprop engines and was selling slow. Some ministers in the government felt that support should be given to the Britannia program instead of embarking on the all-new Vickers jetliner. 

Some historical accounts point the finger at BOAC for planning to procure US jets from the start and with the support of some in the government, did what it could to commit formally to the VC7. A spirited debate in Parliament dragged on for weeks with the supporters of the Vickers projects openly declaring that the VC7's cancellation would "give the large jet market to the Americans for the next 20 years". Rather obtusely, several government officials proclaimed that the planned performance of the Boeing 707 and DC-8 would make them cost-prohibitive for many of the world's airlines and the speed advantage over the Comet and Britannia would not matter to most passengers! With the V1000 prototype 75% complete, the project was ordered shut down by the British government on 11 November 1955, and this was despite intensive lobbying by Trans Canada Airlines. 

For many observers, it was the cancellation of the Vickers VC7 and not the TSR.2 where the British aerospace industry lost its way. Sir George Edwards, managing director of Vickers and the chief designer of the V1000/VC7, had lamented that BOAC and the government had simply handed over the lead in jetliner technology to the Americans for "generations to come."

Source: Stuck on the Drawing Board: Unbuilt British Commercial Aircraft Since 1945 by Richard Payne. Tempus Publishing, 2004, p38-42

17 July 2010

The First Russian Jet Bomber

Starting in January 1947 OKB Tupolev began design work on a twin jet tactical bomber powered by two Rolls-Royce Nene centrifugal-flow turbojets. With a few months of the start of the work, it became apparent that the Nene engines produced less thrust than anticipated which delayed development work. Although this jet bomber design carried the official designation Tu-14, it had the Tupolev in-house designation of "73", a continuation of the ANT number series that was discontinued as the official designation during the Second World War. The Politburo wanted the Tu-14 ready for the annual Aviation Day flypast at Moscow-Tushino. But the need to redesign the Tu-14 meant that the prototype would not be ready and Andrei Tupolev himself suggested re-engining a number of piston radial-powered Tu-2 bombers with Nene engines as a temporary measure.

The interim project was given the OKB designation "77" (ANT-77) but would have the official designation Tu-12. Work began in April 1947 even before an official decision was reached authorizing the Tu-12/"77" project. By May of that year the Soviet Air Force reviewed Tupolev's full-scale mockup. Even before the Air Force review of the mockup, Tupolev ordered work to begin in the OKB's workshops converting standard Tu-2S bombers to the Nene-powered configuration. At the end of the month the Air Force authorized conversion work to begin based on their mockup review.

For the sake of expediency, the changes to the Tu-2 bomber were kept to as few as possible. The main differences between the Tu-12 and the Tu-2 were as follows:
  • The Shvetsov ASh-82FN radial engines and nacelles were replaced by longer nacelles housing the Rolls-Royce Nene turbojets. 
  • The wing dihedral was reduced from 6 degress to 3 degrees.
  • The fuselage was stretched with a nose extension allowing the bombardier/navigator to sit ahead of the pilot and a rear fuselage stretch to balance the change in the cockpit.  The height of the midfuselage was increased with the top of the pilot's cockpit even with the top of the aft gunner's canopy. 
  • A tricycle undercarriage was fitted with the mainwheels rotating 90 degrees to lie flat at the bottom of the nacelles. 
  • Additional fuel tanks were added to compensate for the increased fuel consumption of the jet engines. 
  • Adjustments were made to the control system to compensate for higher speeds. 
  • The tail structure was reinforced as well to handle the increase in speeds. 
In July 1947 the prototype Tu-12/"77" was rolled out and on 27 July 1947 the first flight was made in the Soviet Union of a pure jet bomber with none other than Andrei Tupolev himself aboard for the maiden flight- to which he exclaimed "Well, now we've seen for ourselves that youc an fly without an airscrew!" After a handful of successful test flights, the Tu-12 participated in the Aviation Day flypast at Moscow-Tushino and then resumed its flight test program in September of that year. The aircraft was then handed over to the Soviet Air Force to begin state acceptance trials and even though the Tu-12 was only an interim type built from converted Tu-2 bombers, it gave both Tupolev and the Soviet Air Force valuable experience in operating jet bombers. Mock combat sessions were even conducted between the small batch of Tu-12s and the MiG-9 and Yak-23 jet fighters, allowing new tactics to be devised.

Six Tu-12s were made by converting Tu-2s. One aircraft was used as an engine testbed, another was used as part of jet drone development and the remaining four were used by the Soviet Air Force for crew training and familiarization for aircrews bound for the definitive Tu-14. The experience in developing the systems for the first Soviet jet bomber would serve Tupolev well during the development of the Tu-16 "Badger" and Tu-95 "Bear" bombers.

Source: OKB Tupolev: A History of the Design Bureau and its Aircraft by Yefim Gordon and Vladimir Rigmant. Midland/Ian Allan Publishing, 2006, p117-121.

19 June 2010

The Turboprop B-17 Flying Fortress

In the late-1950s, many of the surplus Boeing B-17 Flying Fortresses that were used by the Navy, Air Force, and Coast Guard in the air-sea rescue role found their way into the hands of several civilian fire bomber operations that for the first time along with surplus Consolidated PB4Y-2 Privateers, offered a quantum leap in performance with the ability to carry significant loads of fire retardant. In fact, prior to the arrival of the B-17s and PB4Y-2s, no other civilian fire bomber then in use even remotely approached the fire retardant capacity of the converted four-engined bombers. In 1960, the first of about two dozen B-17s were converted with bomb bay tanks for aerial delivery of fire retardants.

The bomb bays were fitted with tanks that could carry 2,000 lbs of retardant. The tank was then subdivided into four compartments, each compartment having its own quick-opening door to empty that tank on a forest fire target. The converted B-17s were based on the -F and -G variants primarily (the USAF's air-sea rescue SB-17G, for example). Stripped of all non-essential equipment, the B-17 offered a significant increase in power in the typical-high altitude areas that most forest fires were found. Most of the conversions flew on contracts with the US Forest Service.

However, by the late-1960s many of the fire bomber B-17s were retired from service as aircraft like the Douglas DC-6 and ex-military Douglas C-54s were converted for the role. In addition, the Wright R-1820 Cyclone radial engines of the B-17s were becoming increasingly difficult to support with spare parts. One enterprising outfit got around this issue by re-engining their B-17 fire bomber with four Rolls-Royce Dart turboprops that once belonged to Vickers Viscount. As the Dart engines were much lighter than the Wright Cyclone radials, the nacelles had to be extended far forward to maintain the center of gravity with the propeller spinners being nearly in line with the nose of the B-17. Only one B-17, N1304N, was converted in 1970. Some sources indicate that the aircraft had the nickname "Batmobile" and she was so overpowered, that with both outboard engines shut down and feathered, she was still faster than a stock B-17 and this was while carrying a full load of fire retardant. When the pilots made their drop, they had to shut down and feather the outboard engines to keep from overspeeding the airframe.

This unique and one-of-a-kind B-17 Flying Fortress was unfortunately lost in the same year it was converted. While fighting a forest fire near Dubois, Wyoming, the engines lost power due to excessive ingestion of heated air and smoke from the fire and the aircraft failed to pull out of a retardant drop.

Source: Boeing B-17 Flying Fortress (Warbird Tech No. 7) by Frederick A. Johnsen. Specialty Press, 2002, p97-99.

03 June 2010

Although progressively improved and more powerful versions of the Bristol Olympus jet engine powered the Avro Vulcan bomber, there were also other versions of the Olympus destined for other aircraft that made their initial flights on specially-converted Vulcan testbed aircraft. In addition, other similarly-equipped Vulcans served to flight test other engines during their development cycles as well.

The first engine to be flight tested on the Vulcan wasn't an Olympus variant, though. That honor goes to the Rolls-Royce Conway low-bypass turbofan. The first prototype Vulcan, tail number VX770, was retrofitted with four Conway engines in 1956 and delivered to Rolls-Royce for the start of the Conway flight test program in August 1957. Unfortunately, VX770 was lost during a Battle of Britain flying display at RAF Syterston in September 1958 when the maneuvers it was performing overstressed the airframe, resulting in the loss of the crew. A second Vulcan bomber, XA902, was then selected to undergo conversion with the Conway engines to replace VX770. The conversion work began at Avro's facilities in December 1958 and was completed in July 1959. The Conway engines used were the Conway 11 engines (RAF designation Conway Mk.102 and 103) which were destined for use on the Handley Page Victor B.2, an upgraded version of the original Victor B.1 model.

The Conway test program called for the engines to be run at cruise power at 40,000 feet- however, at that power setting, the Conway 11s were more powerful than the Olympus engines of the Vulcan and the testbed would have easily exceeded the Vulcan's maximum speed and overstressed the airframe! As a result, the Conway 11 engines had to be operated at lower thrust settings similar to what was used on BOAC's Boeing 707-430 jetliners. It was found that two Conways could be operated at cruise settings as long as the other two engines were run at lower settings. Given that the prototype Vulcan VX770 that was lost wasn't as structurally strong as XA902, it became possible to complete the Conway flight test program.

With the Conway test program complete in 1961, XA902 was then converted to take Rolls-Royce Spey engines on the inboard positions while retaining the Conway 11 engines on the outboard positions. It made its first flight in this configuration in October 1961 to support the Spey development for its use on De Havilland DH.121 Trident, the BAC One-Eleven, the Blackburn Buccaneer S.2 and the Hawker Siddley Nimrod. XA902 would be retired from service in 1963.

In 1962, another early-mark Vulcan B.1 was taken from service to test the Olympus 22R engine that was destined for the BAC TSR.2. Vulcan XA894 was modified with a large ventral nacelle with bifurcated intake on each side of the nose landing gear. Conversion work on XA894 began at Filton in 1960 and it made its first flight with the much more powerful Olympus 22R in February 1962 in support of the TSR.2 development program. In December of that year during a ground run test, an uncontained turbine blade failure resulted in a fire that destroyed XA894. No replacement was needed, though, as the Olympus 22R had completed enough of the needed test points for the TSR.2 program.

In 1964, another Vulcan was pulled from service to serve as an engine testbed, this time it was tail number XA903 which arrived at Filton in January of that year for conversion work to flight test the Olympus 593 in support of the development of the BAC/Aerospatiale Concorde. Using a similar ventral nacelle as had been used on XA894 in the Olympus 22R flight test program, this time instead of a bifurcated intake a straight-through intake was used that resembled a single-engine Concorde engine nacelle. A retractable spray bar was also fitted ahead of the intake and water from a bomb bay water tank was used to test water ingestion and icing conditions on the Olympus 593 engine. The first flight was made with the Concorde engine in September 1966 and the test program finally ended in 1971 with over 400 hours of flight time. With the Olympus 593 at full power, the Vulcan testbed could still fly and maneuver with its own four engines at idle!

Testbed work would continue for XA903, though. In August of 1971 XA903 was flown to Marshalls of Cambridge for conversion work to support the development of the Rolls-Royce/Turbo Union RB.199 engine for the Panavia Tornado program. The ventral nacelle used for the Olympus 593 program was modified by Marshalls to not only accommodate the RB.199 engine, but to replicate the starboard side of the Tornado's fuselage. The first flight with the RB.199 was made in April 1973 and one of the most unusual aspects of the RB.199 flight test program was that the ventral nacelle was even equipped with a Mauser 27mm cannon that would be used on the Tornado. The cannon's location in relation to the intake replicated its location on the Tornado so that gun gas ingestion trials could be carried out. The firing trials were carried out at Boscombe Down but weren't done while airborne- XA903 remained on the ground and firing butts were used while Rolls-Royce and Turbo Union engineers analyzed the engine's performance as gun gas was drawn into the intake. A total of 285 flight hours were accumulated with the RB.199 on XA903 when the Vulcan was finally retired in February 1979, the last early-mark Vulcan B.1 to have flown.

Source: Avro Vulcan- Britain's Famous Delta-Wing V-Bomber by Phil Butler and Tony Buttler. Midland Publishing/Aerofax, 2007, p70-73.

16 March 2010

British European Airways' Dart Dakota



While the Vickers Viscount and its Rolls-Royce Dart turboprop engines underwent an exhaustive test flying program befitting its groundbreaking status as the first turbine-powered production airliner to fly, the Dart engines themselves would also fly on a variety of testbed aircraft to allow not only Rolls-Royce's engineers to gain operating experience with the new engine, British European Airways (BEA) also gained operating experience as well with the Dart Dakota, a conversion of one of the airline's DC-3s with Dart turboprops. Two BEA DC-3s were converted to Dart engines- G-ALXN "Sir Henry Royce" and the other DC-3, G-AMDB "Claude Johnson", BEA's managers, pilots, and maintenance crews gained valuable experience in turbine operations before the arrival of the Vickers Viscount.

One of the unique aspects that made testing the Dart engine challenging was that it was a purely postwar civilian engine program that lacked a large body of military operating experience that in the past made applying civilian versions of military powerplants relatively smooth. Both BEA and Rolls-Royce lacked data on the ideal flight patterns, control methods, and maintenance pitfalls for the Dart engine and the use of the two Dart Dakotas would remedy this situation- rather than flying a test program, BEA's Dart Dakotas would be integrated into BEA's routine operations to see how the engines fared in routine use.

Early model Dart engines (designated Mk. 505s) replaced the Dakota's radial engines and the nacelle installation would approximate that of the Viscount as closely as possible. As the DC-3 was an unpressurized aircraft, it was impractical to operate the Dart Dakota at lower altitudes (which would have been inefficient for the engines) or at higher altitudes (as the passengers would have needed a bulky oxygen supplementation system). As a result, BEA would employ the two Dart Dakotas for freight only services as only the flight deck crew would need oxygen to operate at the at the efficient higher altitudes.

The first scheduled "operational" service was flown on 15 August 1951 when G-ALXN carried 1.5 tons of cargo from BEA's original base at Northolt to Hannover, Germany. Following succesful introductions to service, BEA then deployed the two Dart Dakotas on all-cargo scheduled services out of Northolt to Copenhagen and Milan in addition to Hannover until the end of the trial period in 1952.

Compared to a stock DC-3, the Dart Dakotas had the following performance figures: 202 mph/325 km/h for the Dart Dakota vs. 167 mph/270 km/h with a gross weight of 28000 lbs at an altitude of 25000 feet vs. only 7000 feet for a standard DC-3. Ultimately the trial period was uneconomic, as the Dart Dakotas weren't able to fly as many hours as planned thanks to a shortage of qualified flight crews and trained engineers and maintenance crews. Technical difficulties as well resulted in numerous canceled flights and delays- but these were the very sort of problems BEA, Rolls-Royce, and Vickers wanted to see before the Viscount entered scheduled passenger services.

At the end of the trial period, G-ALXN flew for a total 538 hours in Dart configuration and her sistership G-AMDB flew for 668 total hours. Both aircraft were then reconverted back to standard DC-3 configuration, flying services with BEA until early 1962 when they were passed on to the British independent operators of the day.

Source: A Celebration of the DC-3 by Arthur Pearcy. Airlife Publishing, 1985, p99-100.

08 March 2010

The Checkered Development of the Westland Wyvern

The original piston-engined Wyvern
The development of the only turboprop fighter to go into production in service was quite checkered, to say the least. The Westland Wyvern underwent three different changes of engine before ending up with the definitive Armstrong-Siddeley 3,667-horsepower Python engine- the first versions used the 24-cylinder Rolls-Royce Eagle engine, then a change to the Rolls-Royce Clyde turboprop before ending up with the Python in the S.4 version of the Wyvern. One of the reasons for the Wyvern's protracted development was that the first prototypes had three new components that test pilots were less than eager to test- a new airframe, a new engine, and a new contra-rotating propeller mechanism.

The original piston engine, the Rolls-Royce Eagle, was the largest and most powerful piston engine ever developed in Great Britain with a power output as high as 3,500 horsepower, the Eagle had an H-configuration (12 cylinders on the top, 12 cylinders on the bottom) and resembled a scaled up Napier Sabre engine. The power output of the Eagle required a contra-rotating propeller and it used two three-bladed props and early contraprops were quite literally engineering and maintenance nightmares. To simplify the mechanism of the Wyvern's contraprop, the ability to feather the props in the event of an engine failure was left out. Should the Wyvern's engine fail, those non-feathered props acted like a giant airbrake and the proscribed engine failure procedure was to enter a steep dive to maintain flying speed and hope that the pullout was judged correctly for a safe landing.

Handing issues and technical failures during the first months of flight testing culminated in the first of many test pilots killed in the flight test of the Wyvern. Squadron Leader Peter Garner suffered an engine failure, dove his Wyvern to avoid stalling and pulled out too late in the dive and the resulting belly-landing knocked him unconscious as his aircraft burned. The result of this was that Westland could not find volunteers to fly the Wyvern prototypes as many in the company and outside the company didn't feel the increased pay was worth the risk of flying a plane that already had a dangerous reputation.

Eventually Westland hired on one of Rolls-Royce's engine test pilots who helped develop the Eagle engine for flight test duties. But despite this, several more test pilots would lose their lives in Wyvern accidents, even as the engines were changed from the piston Eagle to the turbine Clyde engine and finally the definitive Python turboprop.

Squadron Leader Cliff Roger would have two close calls flying the piston-powered Wyvern, One of the Rolls-Royce engine test pilots who flew for RAF Bomber Command in the Second World War, Roger was flying a full-throttle test in the Wyvern when the engine overheated and quit. Before he put his aircraft into the prescribed steep dive, he recognized Lincoln Cathedral and remembered a disused airfield from his Bomber Command days just to the west of the city. Missing several obstacles on the way, he safely touched down in the field only to notice his control column moving by itself. Outside was an old man who was jerking the aileron and beating the aircraft with a stick- apparently he was an old farmer who bought the land that used to be the airfield and thought that his land was being taken back to be an airfield again. After Roger explained his situation, the farmer took him back to his farm house for a sumptous meal and for years afterward he allowed Garner to hunt on his land!

On another test flight, Rogers' Wyvern Eagle engine exploded and he again recognized a local landmark, the Lichfield Cathedral and knew of another old RAF airfield near his location. With his engine stopped and this time on fire, he entered a steep dive but this time missed the old runway, instead landing on a soccer field with a game going on as players and referees scrambled out of the way. Rogers considered retiring from test flying after another safe landing, but he stuck it out and ended up the Chief Test Pilot for Rolls-Royce.

Source: Tests of Character- Epic Flights by Legendary Test Pilots by Donald Middleton. Airlife Books, 1995, p95-100.