Although Fokker offered and delivered F27 Friendships in various different versions, some operators wished to have modifications made for specific purposes, which Fokker did not supply. One of these modifications was fitting with an underwing spray-boom installation for aerial spraying. Two operators have used their F27s for aerial spray work.

Aramco

Aramco, now officially Saudi Arabian Oil Group, originates from California-Arabian Standard Oil, a subsidiary of Standard Oil of California that was established in 1933 for exploring oil in Saudi Arabia. The company found the first exploitable oil well near Dharan in 1938 and has grown ever since. The name Arabian American Oil Co. (Aramco) was adopted in 1944. Since 1980 the government of Saudi Arabia is the single shareholder of Aramco. Nowadays Aramco is the world’s largest oil company with respect to annual production, revenue and proven oil reserves.

Aramco built up their own aviation department, initially for transatlantic staff transport using Douglas DC-4 and DC-6 aircraft. Local and regional transport was performed with a large fleet of smaller aircraft, amongst which the venerable DC-3. In 1965 Aramco ordered two F27 Friendships from Fokker as replacements for the DC-3. At Aramco’s insistence Fokker developed the RF (rough field) version for operations at unpaved airports and desert landing strips. Over the years the Aramco F27 fleet grew to seven units, four of them were the 500RF version. The Fokkers were normally used for passengers and cargo services to remote drilling sites in the desert with a private runway.

Oil pollution at sea can be caused by damaged pipelines, offshore drilling rig and shipping accidents or by ships illegally flushing their oil tanks at sea. The biggest threat were oil spills causing damage to the water purifying plants along the Saudi coastline. For economic and environmental reasons the Saudi government wished to clean up oil spillage as soon as possible and Aramco decided to have the F27 converted for emergency oil dispersal tasks at sea.

The conversion was carried out in Canada by Conair Aviation Ltd. of Abbotsford, a company with large expertise in aerial spraying and aerial fire control. In collaboration with the National Aeronautical Establishment of Canada Conair equipped Aramco F27s with a low-drag spray-boom that was certified by the US FAA. The installation comprised a tailor-made spray-boom, tanks, pumps and controls. The boom span was overall 22 m, and had 44 spray nozzles on each side of the fuselage. It was mounted under the wing using special brackets fitted to the underwing and engine nacelles. The oil-dispersant fluid was carried in two tanks installed on the cabin floor; each had a capacity of 3,785 liters. The fluid was pumped into the boom through a pipe through a fuselage aperture; for this purpose a normal aircraft window was replaced by a special metal panel. The two pumps, located between the tanks, were electrically driven by the aircraft generator. The spraying control panel was mounted on the central pedestal. The entire spraying system could be installed within four hours.

Three Aramco F27s have been modified for spraying boom operations (see table). We have no information as to how often oil dispersion missions were flown during their career. When the Aramco F27s were phased out, the company acquired, in 1997, a number of Air Tractor AT-802 aircraft, which were modified from their usual agricultural crop duster role to combat oil spills at sea. With their aircraft and other equipment Aramco is unique in having a full-time oil spill clean-up group dedicated to pollution control in and around their production sites and export terminals. As a member of the Regional Clean Sea Organization Aramco may assist other member companies inside and outside Saudi Arabia in the event of a major oil spill.

As a result of the contacts between the Conair Aviation group and Fokker, Conair later decided to convert F27 airplanes to aerial firefighters in order to replace older piston-powered aircraft like the DC-6. The French Civil Security Organization has used three units; maybe a future article will deal with this particular Friendship modification.

Airwork

The Airwork Group was born as a small company established in 1936 by the Brazier brothers, who assembled Tiger Moths for De Havilland. Nowadays it is one of New Zealand's oldest and definitely the largest general aviation company. It focuses on fixed wing maintenance and leasing, as well as aviation operations for private and public parties. One of the Airwork customers is the New Zealand Post (NZ Post). Mail transport by air is more than one century old in New Zealand and was done with smaller aircraft. In 1990 NZ Post and Airwork founded a joint venture named AirPost for operating night postal services and Airwork bought two F27 Friendships for the joint venture and had them converted into freighter configuration. Later two additional F27s were acquired.

In May 1999 a population of the painted apple moth was found in the West Auckland area. This moth is a native of south-eastern Australia, but an invasive exotic species in New Zealand. It poses a risk to forestry and horticulture industries and the environment, because its caterpillars eat the leaves of its host, causing serious damage. The painted apple moth was detected on nearly 100 different species of plants, many of which are culturally and economically important to New Zealand. This and two other moths caused severe damage and financial losses to forestry. Therefore, the Ministry of Agriculture and Fisheries started an eradication campaign, initially by ground spraying and the removal of host plant material. Spots with dense vegetation where the moths were difficult to reach were sprayed from the air by helicopters and later two specially adapted F27 Friendships.

In 2009 two Airwork F27s were equipped with spray systems underneath the wings, similar to the Aramco aircraft described above. Apart from their job for NZ Post, they also operated for the Ministry of Agriculture and Fisheries. Both Friendships lost their NZ Post livery and were painted with dayglo nose and wingtips. The aerial eradication program was short and intense; for example West Auckland saw 48 discrete spray missions over 70 days during early 2003. The program was considered successful and the Ministry declared the painted apple moth pest eradicated in 2006.

Although the spray used (Foray 48B) is of biologic origin and was believed to not harm animals or people, a significant number of residents required medical attention or removal from the sprayed areas. An independent toxicologic investigation concluded that the ingredients in the spray were not injurious to health. Afterwards, the Ministry declared it had learned a lot from the spraying program and would take these lessons on board for any future operations. After the 2003 campaign, the spraying installation was removed from both Friendships and not used again.

Spraying Friendships

Spraying Friendship pictures

Aramco F27 N710A (10294) after installation of the spray boom during test flights, where a colored fluid was used for better visualization of the spraying result (Emile Lancée; Abbotsford, March 1982). Note the dash in the registration, which is rather unusual for American-registered aircraft.

Airwork Friendship ZK-NAO (10364) showing the spraying boom under the left wing (unknown photographer; Auckland, 2003)

Airwork Friendship ZK-NAO (10364) during a spraying mission over a residential area (Kenny Rodgers on NZHerald; West-Auckland, 2003)

Credits

• • Wikipedia: https://en.wikipedia.org/wiki/Saudi_Aramco (accessed 07-11-2023)
  • Wikipedia: https://en.wikipedia.org/wiki/Airwork (accessed 08-11-2023)
  • F. Homma and H.K. Groen. The Fokker F27 Friendship story. CD-ROM, April 2011.