Flying in the bush of the Ivory Coast is work for specialists. It is demanding on both pilots and aircraft. Only a few of the numerous destinations in the hinterland have airfields with hardened runways.

Quite often the Fokker F27 Friendships of Air Ivoire have to perform a steep approach, make a very solid landing and brake hard to avoid the large trees surrounding the undulating runway.

Friendship crews have to be alert for trucks coming out of the bush and crossing the runway at the very moment the wheels of the aircraft are about to touch down. Sometimes a couple of low passes are required to clear the landing strip of a herd of grazing cattle or other animals. And even that is not always successful, with an unplanned barbecue resulting.

This is typical of areas still without railways or decent roads, with the result that aircraft are the sole means of transportation.

Outside air temperatures typically reach as high as 40°C. To call these strips 'airports' would be an exaggeration to say the least.

The foregoing type of operation was not unusual for the famous DC-3 (C-47) Dakota. And so when Fokker started designing the Friendship in the early '50s, it was a Dakota replacement that was in mind.

A role for Fokker among builders of large intercontinental transport aircraft such as Douglas and Lockheed, was out of the question - but building a Dakota replacement was reckoned to be within the Dutch company's capabilities. At that time, several thousands of Dakotas were still in service, in fact the type accounted for around 75% of all 20-to-30-seat transports.

But the Dakota was no longer a new design and many airlines were thinking about a replacement. Fokker had in fact already designed a Dakota replacement, the F24, shortly before the Second World War.

This was a high-wing twin aimed at succeeding the DC-2 and DC-3 on KLM's European network.

However, because of the War, it never progressed further than the drawing board. After the War, it became quite clear that aircraft manufacture in Holland could not be restarted without government help.

Naturally Fokker was not the only manufacturer thinking about building a Dakota replacement. For a while it looked as if one or two of the large North American airframe builders would enter the fray. Boeing and Canadair were known to be doing research along the same lines as Fokker.

As the Dutch company hoped to sell its new aircraft in America, talks were held with both of these companies and also with Douglas and Lockheed. The latter two however preferred to concentrate on larger, longerrange aircraft. In September 1951, Fokker reached agreement with Boeing that, using the results of the U.S. company's technical research, Fokker would design and build an aircraft which Boeing would have the responsibility for selling.

This agreement was discontinued in 1952 however because of Boeing's many military commitments - among them the Model 707 aircraft. Talks with Canadair produced no success either. Fokker's design department had meanwhile studied a number of possible layouts.

In the F27, various new technologies were employed that had not previously been used extensively by the aircraft industry. The most important of these was metal-to-metal bonding in place of riveting.

Test showed this technique had several advantages, the most important being a reduction in airframe weight. Aircraft construction is a continuous search for 'stronger and lighter', and bonding provided an answer to that and more.

In bonded structures, loads are transmitted not just via rivets but over the entire bonded area, resulting in less fatigue. The absence of rivet heads produces a smoother external surface, thus reducing air friction. The scaling of fuel tanks and pressure cabins also becomes easier. In addition, a bonded structure is less expensive to produce than a riveted one.

The Redux bonding process was developed from 1939 onwards by Aero Research Ltd in Duxford, England.

The name Redux is derived from a combination of REsearch and DUXford. The man behind the Redux process was Professor Dr. Norman de Bruyne, of British nationality but of Dutch ancestry. After a considerable number of tests by Ir. Rob Schliekelmann, Fokker decided to use this bonding process on the F27.

Metal-to-metal bonding was not the only novelty in the 'fifties. There was also the use of glass fiber-reinforced plastics. These are easy to produce, and are light and strong. For the F27, their application was confined to secondary structures that did not carry heavy loads.

Examples were the radome, nose wheel doors, fuselage-to-wing fairings, luggage racks and ducts for the air conditioning and deicing systems. Slightly more than 5% of the weight of an F27 comes from this type of material.

Selecting an engine for the F27 can best be described as a process of elimination. Jet engines were found unsuitable because of their high fuel consumption. The higher altitudes where such engines operate more efficiently, would not be reached on the relatively short routes for which the F27 was intended.

The good old piston engine was no candidate either.

In all, four prototypes were built, two flight aircraft known by their production line numbers as the Fl and F3 - and two non-flying aircraft, the F2 and F4. The latter two were for static tests. On the F2, wing load tests were performed, and the F4 was used for fatigue tests. At the end of the test program, the F4 had completed a total of 125,000 simulated flight hours.

The first flying prototype was rather different from the later production aircraft. Its fuselage was some 3 ft shorter and a number of components such as the crew door and ailerons were made of wood. The R-R Darts drove four-bladed propellers of 9 ft diameter. The cabin was not pressurized and no deicing system was installed.

Fokker's chief test pilot Gerben Sonderman was to have made the maiden flight. Unfortunately however, he was killed on 20 October 1955 - just one month before the first flight of the F27 - while demonstrating the Fokker S.14 jet Trainer to the U.S.

Air Force in Hagerstown, Maryland. Hugo Burgerhout, second in command of Fokker flight testing, took over and piloted the F27 on its maiden flight.

First operator to become interested in the F27 was KLM although some politics are suspected to have been involved in this. However, by 29 May 1957 when the Dutch airline signed its contract, Trans Australia Airlines had already ordered six F27s on 9 March the previous year. Braathens SAFE was next on 26 June 1956 with an order for three, followed the next day by Aer Lingus which ordered five.
At the end of that year the Australian Department of Civil Aviation also ordered two Friendships for testing and calibration of navaids in Australia. The sequence of ordering the F27 was not the same as for delivery. in fact, the contracts included a paragraph on delivery dates and so Aer Lingus was to be the first to have the F27 in operational service. Included in sales during 1957, were some VIP F27 Friendship de Luxe aircraft.

One of these was for the Dutch government for transport of senior officials and members of the Dutch royal family. At the end of that year the orderbook showed a total of 32 sales. The first series production aircraft was airborne on 23 March 1958, piloted by the new chief test pilot A. P. 'Jas' Moll. With appropriate ceremony, this and the next aircraft were handed over to Aer Lingus on 19 November 1958.

On that occasion, Aer Lingus' president Peter Lynch said that in 1939 he had bought his first DC-3 from Fokker who had the sales rights in Europe

The F27 was built in a number of versions. The basic model was the F27 Mk. 100 with accommodation for 40 passengers. In 1959, Fokker launched the Mk. 200 which had the more powerful Dart 7 engine. To absorb the additional power, a new propeller was introduced having square-cut tips rather than rounded tips of the propeller on the Mk 100.

Seating capacity of the Mk. 200 was 44. Initial customer for this new version was Ansett in Australia with first delivery taking place on 20 September 1959. When some customers requested a large freight door, the Mk. 300 was developed having a 5 ft 10 in x 7 ft 8 in door in the left-hand forward fuselage. This version was called the 'Combiplane' or 'Freightship'.

First flight was in May 1960. The military version of the Mk. 300 was designated Mk. 300M and named 'Troopship'.

In addition to the forward cargo door, it also had two sliding doors on either side of the aft fuselage to facilitate dropping paratroopers and supplies.

Seats were arranged with their backs against the side walls and provision was included for conversion to a medical evacuation role.

In addition to the Mk. 100 through Mk. 700 versions, there was also a number of sub-versions. The VIP variant, the Friendship de Luxe, has been mentioned already, and also the version used for navaid calibration which was used in Italy, Australia and New Zealand. Special versions were also built for mapping and aerial photography. The Friendship delivered to the French Postal Services had special mail sorting equipment onboard.

An important military derivative was the F27 Maritime, a patrol aircraft for submarine hunting, marine search-and-rescue, pollution control, fishing inspection and other offshore duties. A general increase in territorial waters protection operations appeared to create further sales opportunities but these did not materialize. A total of 15 Maritimes was sold which was somewhat less than Fokker had hoped. A version of the Maritime having underwing attachment points for bombs and rockets was called the Maritime Enforcer.

Not all designs of F27 variants were actually built, one of them being project P 301, a four-engined STOL version for very short runways. A model was shown at the 1971 Paris Air Show. It looked very much like the later de Havilland Canada Dash 7, for which demand proved to be limited. The P 301 was never built - neither was the F27 MS, a troopship version with rear-loading doors not unlike on the Andover variant of the Avro (now British Aerospace) 748. Vehicles could easily be driven in and out through these doors. An F27 flying boat and a jet-powered F27 were two more variants that were never built.

Two sub-versions that progressed little further than the drawing board were the Sentinel and the Kingbird.

The F27 was built not only in Holland but also in the U.S.A. by Fairchild. Manufacture of the F27 was first discussed in 1952 when Fokker was negotiating with Fairchild about licensed production of the Fokker S.11, S.12, S-13 and S.14 trainers.

Fokker considered it very important to have a production line and sales agency in America in order to have a foothold in that part of the world. On 29 August 1952, Fairchild opted for licensed production of the F27 and on 26 April 1956, five months after the maiden flight of the F27, the license agreement was signed.
It was agreed that Fairchild-produced F27s would be sold in North and South America only, except in Brazil where Fokker in those days had a factory of its own. American-produced aircraft did not use the name Friendship and were designated F27, not F27.

A major setback at least for some time was the imposition by the CAA in 1957 of operational restrictions on hot-and-high take-offs by turboprop aircraft. The somewhat odd result of these restrictions was that the DC-3 was permitted to takeoff from hot-and-high airfields, while the F27 was not.

This was despite the fact that the DC-3 was unable to maintain height after losing an engine whereas the F27 could continue climbing on one engine. Meanwhile Fairchild had won quite a few orders from among others, West Coast Airlines, Mackay, Bonanza, Frontier, Piedmont plus customers in Latin America. When the afore-mentioned restrictions were imposed however, some airlines that had ordered F27s decided to wait until the more powerful Dart 7-powered F27 became available.

This delay cost a lot of money and for some time gave Fairchild a nasty financial headache.

Although superficially similar to the F27, the American-built aircraft was in fact quite different from Dutch-built aircraft. In fact only the propellers, engines and undercarriage were identical. One particular Fairchild change that was later adopted by Fokker was a longer radome. Like Fokker, Fairchild developed a number of versions of its aircraft.
The original standard F27 had the same characteristics as the F27 Mk 100. The F27A had the more powerful Dart 7, and the F27B was the American counter part to the Mk. 300 with a cargo door. The VIP version of the F27A was the F27F. It had provision for installation of extra fuel tanks for extended range. The F27G was the successor to the F27B and had a cargo door and reinforced cabin floor.

The F27E was to be the counterpart of the Dutch-built F27 Mk. 500 with a longer fuselage, but was not built. The F27G was an F27F variant with more powerful engines. Using the F27G as a basis, the F27H was developed for hot-and-high airfields. It had larger-diameter propellers than hitherto. The F27S (S for STOL: short take-off and landing), was designed but not built. In answer to a market requirement, Fairchild developed a stretched F27.

Originally this was called the F27 II, but when Fairchild merged with Hiller to form the Fairchild Hiller Corporation, this was changed to FH-227.

Through the years the F27 has proved to be a jack of all trades, easy to operate and maintain and very reliable. As Jas Moll, Fokker's chief test pilot, said: "The F27 is an airplane that can do almost anything. It is very forgiving.

A mistake by the pilot or maintenance man will not usually be fatal. That is a very important characteristic of the F27".

What an F27 can do was proven in an evacuation flight in Australia.

On Christmas Day 1974, the town of Darwin in Australia was hit by hurricane 'Tracy'. A TAA Friendship flew from Alice Springs to the largely-demolished airport of Darwin, where the Royal Australian Air Force had cleared a landing strip just long enough for the F27 to land on.

As quickly as possible the aircraft flew out of Darwin to Brisbane, carrying a record 80 passengers!

Over the years, Fokker continuously improved the F27 to meet the constantly-changing requirements of air transport. A grand total of 786 F27s was built, including the American-built aircraft. No other Fokker airliner has ever been built in such large numbers.

The F27 is one of the most widely-used turboprop airliners in the world. Of its nearest competitor, less than half as many were produced. And production of the next runner-up, the Handley Page Dart Herald, was stopped after only a few tens had been built. In its class, the F27 is beaten in numbers-produced only by its Russian counterpart, the Antonov An-24.

Only in the early eighties did competition for the F27 become really serious. Although the Fokker aircraft is no longer in production, it will still be a while before the F27 makes its last landing.