De Havilland Australia DHA-3 Drover

de Havilland Australia

Industry	Aerospace, Aircraft manufacturing
Founded	1946
Headquarters	Bankstown , Australia
Products	DHA-3 Drover aircraft

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The de Havilland Australia DHA-3 Drover is a compact transport aircraft constructed by de Havilland Australia during the late 1940s and early 1950s. While it shared some design elements with the British two-engine de Havilland Dove, it featured a distinctive three-engine layout.

Design and development

Development of the DHA-3 commenced in 1946 when de Havilland Australia recognized the necessity to replace the widely used de Havilland Dragon biplane in Australian service. Although the British parent company was manufacturing the Dove concurrently, DHA determined that the Dove did not fully meet Australian operational requirements. Building upon the Dove’s framework, DHA engineered an aircraft powered by three four-cylinder Gipsy Major engines rather than the Dove’s two six-cylinder Gipsy Queen engines, and incorporated a fixed tailwheel undercarriage instead of the Dove’s retractable tricycle undercarriage. Similar to the Dove, the DHA-3 was designed to accommodate eight to nine passengers along with a single pilot.

The resulting design retained the Dove’s wingspan but featured a slightly reduced fuselage length. The designation 'Drover' was chosen by Sir Geoffrey de Havilland following a naming contest among DHA staff, with Thomas King from the Drawing Office submitting the winning suggestion. The inaugural DHA-3 Mk. 1 Drover made its maiden flight at Bankstown Airport on 23 January 1948, piloted by Brian (Black Jack) Walker, who served as DHA’s chief test pilot. Walker then conducted a trial flight to Melbourne for evaluation by the Australian Department of Civil Aviation, covering 460 miles at an average speed of 140 mph and consuming roughly 22 gallons of fuel per hour. During these tests, the aircraft demonstrated a climb rate of 240 feet per minute at sea level while operating with one engine disabled.

The second unit did not take flight until December 1949, although the first was delivered in October of that year.

By 1952, operational experience revealed several deficiencies in the aircraft’s performance. Notably, it suffered from inadequate power output, especially under high-temperature conditions, and experienced recurrent failures of its propellers during flight, which led to two crashes. To address these issues, the original de Havilland variable-pitch propellers were replaced with fixed-pitch models manufactured by Fairey-Reed, resulting in a revised variant designated as the DHA-3 Mk. 1F. Except for three units lost in accidents, all remaining aircraft were upgraded accordingly. However, this propeller modification did not enhance overall performance. To improve takeoff and landing capabilities, all Mk. 1F models were subsequently fitted with slotted flaps replacing the earlier plain flaps and reclassified as DHA-3 Mk. 2.

File:Historical Aircraft Restoration Society (VH-DHM) de Havilland Australia Drover.jpg

A Mark 2 Drover equipped with Gipsy engines and fixed-pitch propellers

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The Powerhouse Museum’s DHA-3 Mk. 3a Drover located at Bankstown Airport

File:DHA.3 Drover 3B VH-EOO Bankstown 04.10.70-1-.jpg

Drover 3B powered by Lycoming O-360 engines at Bankstown Airport in 1970

By late 1952, sixteen units had been delivered; however, persistent issues hindered further sales for several years. The final four of twenty produced were built in 1953 but remained unsold until between 1955 and 1956. In an effort to enhance performance further, seven Mk. 2 aircraft were re-engined with horizontally opposed Lycoming O-360 engines coupled with Hartzell feathering constant-speed propellers. Adjustments were also made to both flap control mechanisms and tailwheel assemblies. The first modified example, now designated as a DHA-3 Mk. 3, was returned to its operator, the Royal Flying Doctor Service of Australia (RFDS), on 4 June 1960. Subsequently, three Mk. 3 aircraft underwent additional alterations: two operated by RFDS New South Wales Section were converted into Mk. 3a variants featuring an increased tailplane dihedral angle of seven degrees (or fourteen degrees according to some sources) along with a wingspan extension of two feet (61 cm). The third received modifications as a Mk. 3b model with an increased maximum takeoff weight raised by 300 lb (137 kg) to reach 6,800 lb (3,087 kg).

Introduction of new aircraft

The aircraft model was first introduced into service with the Australian Department of Civil Aviation (DCA, currently known as the Civil Aviation Safety Authority) in 1949, with the DCA acquiring the initial two units. In 1950, both Qantas and the Royal Flying Doctor Service (RFDS) received their inaugural deliveries, ultimately obtaining five and six aircraft respectively. Qantas deployed the Drover on routes within the then Territory of Papua and New Guinea. Similar to numerous other aircraft before and after, the Drover proved insufficient for the challenging environmental conditions of the island. Of the four remaining aircraft (see below), three were withdrawn from Qantas operations by 1954 and 1955, with the final unit retired in 1960. The remaining DCA-owned aircraft (see below) was also phased out and listed for sale in the late 1950s, eventually being sold at the close of 1959.

Trans Australia Airlines (TAA) conducted a brief evaluation of the prototype lasting one month in late 1950 before receiving two of its eventual three new Drovers in 1952; the third arrived in 1956. TAA utilized these aircraft for scheduled flights within Queensland as well as for air ambulance missions, with one unit among six later operated by the RFDS. One Drover was lost in a crash in January 1952 just five weeks after delivery, while the remaining two were transferred to RFDS in 1963 and 1964. The Australian Department of Health became among the last primary operators of new Drovers, employing two for remote aeromedical services—one of which crashed in 1957. Additionally, Fiji Airways took delivery of two aircraft originally built for Qantas but rejected due to emerging operational issues. The final Drover constructed was a Mk. 2 model delivered to a private owner in July 1956.

Issues with propellers

On 16 July 1951, the third Drover produced (registration VH-EBQ, operated by Qantas) crashed near New Guinea's coast, specifically in the Huon Gulf close to the Markham River estuary, following failure of the center engine’s propeller. This accident claimed the lives of the pilot and all six passengers aboard. It marked the first of three fatal incidents involving Qantas within a four-month span during 1951. Notably, at the time of this crash, the aircraft had been in service for only ten months.

The prototype Drover VH-DHA, managed by the Australian Department of Civil Aviation, was forced to perform an emergency water landing (ditching) on 16 April 1952 in the Bismarck Sea, situated between Wewak and Manus Island. A port-side propeller failure caused a blade to penetrate the fuselage, rendering the pilot unconscious; consequently, a passenger executed the ditching maneuver. Fortunately, all three individuals on board survived and were subsequently rescued.

In September of that same year, another Qantas-owned Drover (VH-EBS) experienced a propeller failure while still on the ground.

Later service history

During the early 1960s, the RFDS upgraded its Drovers to the Mk. 3 specification and continued operating them until the late 1960s, when they began introducing more advanced models like the Beechcraft Queen Air. The seventh Mk. 3 was originally acquired from the Department of Health as a Mk. 2 and subsequently converted by the RFDS. These Mk. 3 variants were arranged to accommodate a pilot, two medical personnel, and two stretcher-bound patients, serving primarily in the Northern Territory as well as remote areas of New South Wales and Queensland.

Beyond their initial deployment in Australia, New Guinea, and Fiji, previously noted second-hand Drovers found registration across various Western Pacific locations, including the Solomon Islands, where they were operated by New Hebrides Airways and Air Melanesiae in the New Hebrides. Additional aircraft were registered in New Zealand and the United Kingdom, with further examples also delivered to Fiji.

By the close of the 1950s, only nine Drovers remained active in commercial airline operations worldwide. The last Drover used for scheduled airline routes in New Zealand belonged to Great Barrier Airlines; it was retired in 1985 and succeeded by a BN2A Islander.

The final Drover produced underwent modification during the late 1960s for agricultural purposes, operating for several years out of Toowoomba, Queensland, equipped with a substantial gravity-fed hopper installed within the cabin. This Mk. 2 model was restored between 1984 and 1986 by apprentices and staff at Hawker de Havilland and remained airworthy as of 2008. It was flown as VH-DHM from Illawarra Regional Airport by the Historical Aircraft Restoration Society on behalf of Hawker de Havilland Aerospace, now part of Boeing.

Although only a limited number were manufactured, a healthy number of Drovers have been preserved; besides VH-DHM, three others were listed on the Australian civil aircraft register as of November 2008—comprising one Mk. 3 and two Mk. 2 variants. A composite Mk. 2, assembled from parts of the tenth and seventeenth aircraft built, is exhibited at the RFDS base in Mount Isa, Queensland. Additionally, a Mk. 3a owned by the Powerhouse Museum is displayed at the Australian Aviation Museum located at Bankstown Airport. The Central Australian Aviation Museum in Alice Springs also houses a Mk. 3 example. Another Mk. 2 was formerly exhibited at a museum in Lasham, England before its closure; it is currently stored at Parkhouse Engineering in Booker. The Queensland Air Museum at Caloundra Airport maintains two Mk. 3 aircraft within its collection.

Variants

• Drover Mk. 1: Equipped with variable-pitch propellers.
• Drover Mk. 1F: Altered to incorporate fixed-pitch propellers.
• Drover Mk. 2: Enhanced by the addition of double-slotted flaps.
• Drover Mk. 3: Refitted with three Lycoming O-360-A1A horizontally-opposed engines.
  • Mk. 3a: Featured a redesigned tailplane with greater span and dihedral angle.
  • Mk. 3b: Maximum takeoff weight increased to 6,800 lb (3,087 kg).

Operators

File:AU-Qld-Caboolture-Airport with RFDS-2021.jpg

Historic Royal Flying Doctor Service VH-FDU 'George Simpson' at Caboolture Airfield, Queensland (2021)

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• Department of Civil Aviation
• Royal Australian Air Force Aircraft Research and Development Unit
• Department of Health
• Qantas
• Royal Flying Doctor Service
• Trans Australia Airlines (TAA)

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• Fiji Airways

/ New Hebrides (Template:Country data VanuatuTemplate:Namespace detect showallVanuatu)

• New Hebrides Airways
• Air Melanesiae

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• Great Barrier Airlines

Additional reading

• Airliners in Australian Service, Volume 1 by Eric Allen. Published by Aerospace Publications Pty. Ltd. ISBN 1-875671-14-5
• The Historic Civil Aircraft Register of Australia covering VH-AAA to VH-AZZ, VH-CAA to VH-CZZ, and VH-DAA to VH-FZZ. A trilogy authored by Tony Arbon and David Sparrow, privately issued by David Sparrow and AustAirData, without ISBNs

External links

• Image of the Prototype
• Drover photographs on Airliners.net
• Civil Aviation Historical Society's Drover information page