The Fokker F27 In Australian Service

The Australian scenario was fairly typical. A large number of DC-3s were in service and constituted the lion’s share of passenger carrying capacity in the late 1940s and early 1950s. However, despite the undoubted strengths of the DC-3 there were of course drawbacks. They were rather noisy, slow and had limited accommodation. Their comparatively low block speed of 140mph coupled with turbulence encountered often at their modest cruising altitude did not endear them greatly to the public. Even the larger DC-4 was not that much better in the comfort department and not until the introduction of the Convair 240, Douglas DC-6 and more importantly the Vickers Viscount, were notable improvements discerned by the passengers.

These aircraft decreased the dependence on the DC-3s to maintain services but even by the mid-1950s, the DC-3 still operated widely on routes not able to economically sustain more modern equipment. Thin traffic on secondary routes coupled with airstrip limitations were the primary reasons for the retention of so many DC-3s. By the end of 1956 there were still 79 DC-3s in Australian service and using TAA as an example, their 22 DC-3s were responsible for 33% of that airline’s passenger miles. Obviously, there was an urgent need for a replacement aircraft to more effectively operate this core of services maintained by the DC-3s, as increasing maintenance costs and passenger disquiet were causes for the airlines’ concern.

There was indeed a substantial market in prospect for the manufacturers which could supply the replacement aircraft for the remaining 1200 DC-3s in worldwide commercial service in 1956. As is now well known, Fokker came up with the best formula for a DC-3 replacement in the F. 27 Friendship, an aircraft sold in greater numbers in Australia than any other postwar airliner.

The long established Fokker company has produced many successful aircraft designs over many decades and ranks amongst the oldest aircraft manufacturers in the world. Anthony Fokker was born on 6 April 1890 in Java. His early years were spent on his father’s coffee plantation and the family returned to Holland in 1894 and settled in Haarlem. Fokker learnt to fly in 1911 and was involved in various aviation projects commencing with the registration of Fokker Aviation Limited in Berlin on 22 February 1912. A stream of aircraft were produced over the years first from the Fokker factory in Germany and later from US and Dutch factories. The American Fokker Corporation by the end of the 1920s was in fact the largest aircraft manufacturer in the world. One interesting design being worked on during 1938 was the Fokker F. 24, a high wing all metal aircraft powered by two Wright Cyclones with a cruising speed of 300mph and passenger capacity for 36. Although some components had been made, construction of the prototype did not eventuate due to the outbreak of war the following year. In general configuration the 1938 model F. 24 was an interesting pointer to the future.

In the postwar years Fokker, like so many other manufacturers, was keenly investigating the market to find a place for itself in the huge re-equipment period the airlines were facing. Companies like Boeing, Douglas and Vickers specialised in the medium to larger passenger carrying aircraft. Others like Convair and Martin were looking at smaller twin engine airliners. Fokker made the prudent decision not to directly compete with existing aircraft, but to set out and produce a DC-3 replacement. This sensible decision, coupled with the soundness of their eventual design, was to prove a turning point in the Fokker Company’s fortunes. Initial drawings prepared in 1951 already closely resembled the F. 27 we know so well today.

Questionnaires were sent to all DC-3 operators seeking their opinion for guidelines for a replacement aircraft. The answers were evaluated and fed into the design. Interestingly enough, the first questionnaire to be returned was from TAA.

An important marketing decision was forged during August 1952 when Fairchild took an option on a licence to build the F. 27 in the USA and they then undertook their own market research to determine the likelihood of sales in the USA. This arrangement between Fokker and Fairchild was to add significantly to future sales in an area which had been previously dominated by local manufacturers. A similar arrangement had been discussed with Australian Industry at the time but regrettably, no government funding was available to underwrite the project.

Meanwhile the F. 27 project was well under way during the early 1950s and Fokker showed themselves to be quite innovative in their approach to the design. On the subject of powerplants, Fokker came to the conclusion that the future lay with the Rolls Royce Dart which was plainly showing promise aboard the Vickers Viscount. Fokker had initially considered the Wright Cyclone piston engine as the powerplant, but felt the proper course would be to adopt turbine power. Surprisingly, Fairchild had reservations about the turboprop and wanted to influence Fokker to change back to the Wright Cyclone but Fokker stood firm.

For Fokker the final choice was between the Armstrong Siddeley Mamba and the Rolls Royce Dart. Despite the attraction of the lighter Mamba, the greater sales volume of the Dart being created by the Viscount seemed to indicate that the brighter future was with the latter engine. This decision ultimately determined the overall size of the F. 27, within the original design considerations of a twin-engine layout. The only remaining powerplant problem seemed to be the existing gear ratio of the Dart which was not suitable for a twin-engine aircraft in providing either sufficient takeoff thrust or the reserve of power in an engine-out situation. Rolls Royce were approached and assisted by lowering the gear ratio.

The selection of a high wing position was unusual but wind tunnel research showed that the maximum lift coefficient was superior to that of a low wing aircraft. Although it was necessary to reinforce the bottom of the fuselage to provide additional strength in the event of a belly landing, the lower seat-mile costs flowing from the wing design outweighed this. Other advantages of the high wing position were a lower floor level to ease loading and the superior view offered to passengers.

The use of a pneumatic undercarriage system was also a departure from the norm. Previously used on the de Havilland Dove, this was the first time it had been installed on a larger aircraft. The use of air over oil had several benefits such as: air is cheap, provides a fast retraction (within five seconds on the Friendship), is non-corrosive and also fireproof. Dunlop assisted in the system’s development and apart from early problems with sealing it proved a winner.

On the construction side, the F. 27 was the first aircraft to employ bonding in the primary structure. De Havilland had pioneered the process by successfully gluing metal to wood in the Hornet and Sea Mosquito and had progressed in the Dove to bonding panels of stressed skin to top hat stringers but Fokker intended using it to a far greater degree than ever before attempted. At first the bonding proved a big headache to Fokker because of a 50% rejection rate. Bonding in series production had to be carefully controlled, needed great precision with jigs and tools and great cleanliness was called for. These annoyances were surmounted and 400 major assemblies comprising 54% of the F. 27s total area were bonded ranging in size from 3. 6″ x 13. 6″, to tapered spar caps 408″ long and panels up to 52″ x 192″. The advantages of bonding were long fatigue life, lightweight structure and good aerodynamics.

During 1953 the name Friendship was adopted for the F. 27 and in September the construction of three prototypes was authorised and was later increased to four prototype aircraft which were designated F1, F2, F3, and F4. F1 and F3 were the first and second prototypes while F2 and F4 were used as static and fatigue airframes respectively. Construction of all four aircraft was underway by the end of 1954.

A major change to the F. 27 configuration was decided prior to the first flight of the first prototype. To improve stability the fuselage was extended by three feet from 73′ to 76′ and an advantage of this change was the addition of another row of seats. This stretch was accomplished by lengthening the constant section of the fuselage immediately in front of the wing. Because the construct!on of F1 was too far advanced, it did not incorporate this alteration and was completed with a 73′ long fuselage on 30 October 1955. This aircraft also differed by having a Dart 507 not used in production aircraft, smaller 1 O’ diameter propellers and was unpressurised with no de-icing. Flown by Captain H. B. Burgerhout, Fokker’s Chief Test Pilot, and accompanied by Mr C. Dik as Flight Engineer, the first prototype PH-NIV had a 34 minute maiden flight on 24 November 1955.

As a result of testing various changes were introduced. It was found that the double slotted flaps were unnecessary because during testing, the use of the first flap segment produced the desired landing performance. Extension of the second flap segment created higher than expected lift and the aircraft was difficult to fly in this configuration. The two flap components were vetted together and this new arrangement was entirely adequate to provide the necessary landing performance. Flight testing continued and by February 1956 despite bad weather PH-NIV had notched up 50 hours. Another control change was the substitution of a new aileron with a set back hinge instead of the previously fitted slotted type which had shown erratic control force behaviour and marginal capacity. Testing was accelerated during January 1957 when aircraft F3 PH-NVF joined the test programme. CAB certification was obtained on 19 October 1957 after the two prototypes had completed 800 flying hours including 300 hours of single-engine flying.

In parallel with the testing, the Fokker sales team were hard at work. The first order for Friendships was received from TAA on 9 March 1956 for six aircraft, the first of a total of 14 F. 27s to be sold that year. Things looked quite promising during 1957 when a further 15 were ordered but the situation started to look very bleak during 1958 when after a reasonable start, no sales were recorded between June 1958 and July 1959 until a sale of 12 Troopships for the Netherlands Air Force was secured. This was a very difficult time for Fokker but backed by a consortium of banks and further aided by Dutch Government guarantees, they were able to keep the production line going in expectation of further eventual orders. Gradually the tide turned and the orders started flowing in with 21 in 1959, 28 in 1960 and 30 in 1961. Twenty years after the first sale, Fokker had achieved a creditable 460 sales by the end of 1976.

The other part of the Friendship story is Fairchild’s contribution. Following the option taken out four years earlier, a licence agreement between Fokker and Fairchild was signed in New York on 26 April 1956. Fokker arranged for data and drawings to be sent to Fairchild at Hagerstown so that production could be started as soon as possible. A CAA certificate was obtained on 29 October 1957 and the initial flight of Fairchild’s first F. 27 registered N1027 took place on 14 April 1958 at Hagerstown. As 14 April was a Saturday a large crowd of several thousand had waited up to six hours “waiting for America’s first twin engine propjet to take to the air” according to the local press.

This aircraft had a briefer-than-expected career when less than a month later on 9 May, the undercarriage was accidentally retracted while parked in a hangar. It was written off and the wings, tail and other equipment was used in the second Fairchild prototype N2027. Bad luck continued and after the second prototype was converted to an F. 27A in 1959 and was sold to Aerovas Ecuatorianas, it was lost on 7 November 1960 when it hit a mountain 15 miles from Quito.

The first deliveries of Fokker Friendships took place late in 1958. On 19 November El-AKA ‘Fionntain’ (St. Fintan) and EI-AKB ‘Feargal’ (St. Fergal) were both handed over to Aer Lingus at Schipol-Oost. However, Fairchild had already made its initial delivery earlier when the first Fairchild F. 27 N2701 was handed over to West Coast Airlines on 24 July 1958.

Production proceeded steadily at first but not at the rate Fokker would have liked due to the slowdown in orders experienced in 1958/59. As the order outlook improved, production lifted and by the end of 1962 the need to subcontract assemblies arose. This was prompted by Fokker’s need to devote a major part of production capacity to Lockheed F-104 Starfighter manufacture coupled with the expanding Friendship order book. Although assembly continued at Shipol-Oost, other components were made by Fokker at Drechsteden, Dassault-Breguet in France and further into production by SABCA (part Fokker-owned) in Belgium and VFW-Fokker in Germany. Many other major items originated in the United Kingdom, notably the Rolls Royce engines and the Dowty Rotol propellers and undercarriage.

During the long production run many changes were introduced, brought about by the constant upgrading of the Darts and also as a result of customer requests. Through a variety of Marks gross weight grew from 35,700Ib to a 45,900Ib limit in civil use and up to 50,000lb in military versions. The initial Mk 100 version was powered by the Rolls Royce R. Da-6 Mk511 of 1650shp, could accommodate 36 passengers and had a gross weight of 35,700Ib. The Mk 200 which first flew in 1959 was powered by the improved R. Da7 Mk532-7, featured improved performance and offered a radar nose as an option.

The F. 27 Mk 300 Combiplane which first flew in May 1960 powered by the R. Da-6 Mk511 offered increased versatility. A strengthened floor coupled with a large forward cargo door enabled variations of passengers and/or freight to be uplifted. The military Troopship Mk 300M was a version with large freight doors on either side of the fuselage. Engine improvements became available which enabled the R. Da-6 Mk511 to be upgraded to Mk514-7E standard. The Mk 400 introduced in October 1961 had more powerful R. Da-7 Mk532-7 engines and coupled the improved Mk 200 performance with the Mk 300 cargo door and a reinforced floor.

A major improvement was made on the F. 27 Mk 500 with a 1. 5 metre fuselage stretch accomplished by an extra 90cm section forward and 60cm section aft of the wing. Apart from the extra passenger capacity the cargo door was also included. Powered by the 2030shp R. Da-7 Mk532-7, accommodation varied from 52-60 passengers and eleven windows were installed on each side of the fuselage. Emergency window type exits on each fuselage side were increased from one to two, a feature already requested by Australian operators in short fuselage Friendship versions.

An interesting variation of the Mk 500 was requested by Ansett which was also ordered by East-West and Air New Zealand. This variation involved the deletion of the large forward cargo door and the substitution of a twelfth cabin window in its place. The Mk 600 introduced during November 1968 was a variation of the Mk 200 fitted with a large forward cargo door but without the strengthened floor as available on the Mk 400. However the Mk 600 could be fitted with a quick change interior enabling roller tracks to be fitted, so that cargo pallets or palletised seats could be speedily exchanged. Other versions were the sole F. 27 Mk 700 produced for TAA, a Mk 100 (VH-TFH) with a large cargo door and the F. 27 Mk 800 for rough field use with a modified undercarriage. An important military derivative was the F. 27 Maritime patrol aircraft (which is available now in Fokker 50 form). Apart from these distinct model changes, constant improvements in decor and flight deck instrumentation have also been introduced.

In parallel with all these Fokker produced versions, Fairchild also initiated various changes based on their experience in the US marketplace. The basic Fairchild F. 27 was stretched by a 1. 98m forward fuselage plug to become the F-2711, later known as the FH-227 from September 1964 when Fairchild became the Fairchild-Hiller Corporation. Fairchild-produced aircraft embodied numerous structural and equipment changes to meet local demands. When the Fokker-Fairchild agreement was terminated in July 1973 a total of 206 had been produced by the Fairchild Company comprising 128 Fairchild F. 27s and 78 FH-227s.

By the end of Friendship production in June 1986, a total of 798 had been built by Fokker and Fairchild and by early 1987, 438 were still in service. The final Friendship was No592 built by Fokker and delivered to Air Wisconsin.

The Friendship’s role in bringing more comfortable air travel to remote areas has been enormous. Although total Friendship production is only a fraction of DC-3 output, it’s contribution has been substantial in providing economic and reliable transport for over 150 operators in excess of 60 countries. It is the aircraft which took over from the DC-3 in a variety of roles and will undoubtedly be in service for many years ahead. The contribution of the Friendship to civil aviation in Australia has been very significant. From the earliest days Australia, through TAA’s involvement, has exerted influence on Friendship’s fortunes and Fokker in return has received substantial orders from this region. To date 77 Friendships have operated in Australia representing about 13% of Fokker-built F. 27s. It has sold in greater numbers than any other postwar airliner in Australia, eclipsing other big sellers such as the Boeing 727 and Douglas DC-9. D

Next Issue: We examine the effect the Friendship had upon Australian regional air services and its history up to the present. Includes full specification chart and an exclusive listing of every Australian registered F. 27 since 1959. Don’t miss it