De Havilland DH.114 Heron
|De Havilland DH.114 Heron|
May 10, 1950
|Number of pieces:||
Immediately after the Second World War , de Havilland began developing the twin-engine De Havilland DH.104 Dove passenger aircraft , which was intended to replace the outdated Dragon Rapide . The new model proved to be successful from the start. De Havilland decided to bring an enlarged version onto the market. The fuselage was lengthened to accommodate additional passengers or cargo. The increased span made the installation of two additional engines possible.
The Heron was an all-metal aircraft of conventional design. It was designed as a low-wing aircraft without a pressurized cabin and had a fixed, from version Mk. 2 a retractable nose wheel landing gear . Four Gipsy Queen 30 engines served as drive . The extensive use of components from the Dove simplified the maintenance and repair of both types of aircraft.
The Heron was a simple, robust aircraft with low operating costs that should be used on short and medium-haul routes. With it, regions could be opened up in which there was no modern airport. It offered space for seventeen passengers in single seats on either side of the aisle and had large windows. The Heron had a luggage compartment in the stern and additional storage space in the bow.
The first flight took place on May 10, 1950. After test flights totaling a hundred hours, the aircraft was presented to the public on September 8, 1950 at the Farnborough Air Show. After approval was granted in November 1950, the flights to Khartoum and Nairobi were extended to test the suitability for use in the tropics .
Production ended in 1963 after 149 copies were shipped and sold in thirty countries. The first machine went to New Zealand . The largest customer was the French Union Aéromaritime de Transport (UAT). Some Heron were later converted to more modern aircraft, such as the Riley Turbo Skyliner , the Saunders ST-27 and the ST-28 .
The first production version, Model 1A, still had a few shortcomings. With its heavy but weak drives, it was considered to be underpowered. In contrast to the Dove, the non-retractable landing gear without a steerable nose wheel reduced maintenance costs, but increased aerodynamic drag.
After 51 aircraft of types 1A to 1D, the production of the Model 2 began, the landing gear of which could now be retracted. It therefore achieved a higher speed with lower consumption at the same time. The model 2A corresponded roughly to the basic model 1A, while the variants 1A and 1B had a higher take-off weight. The Model 2C had propellers that could be brought into the sail position. The takeoff weight of the Heron Model 2D was increased again, and the Model 2E was designed as a VIP transporter.
Heron 1 : light four-engine transport aircraft with rigid chassis, 49 units built
- Heron 1B : Version with increased takeoff weight
Heron 2 : light four-engine transport aircraft with retractable undercarriage, 101 units built
- Heron 2A : single Heron for a private customer from the USA
- Heron 2B : Version with increased takeoff weight similar to the Heron 1B
- Heron 2C : Heron 2B, optionally with propellers set up for sail position
- Heron 2D : light four-engine transport aircraft with increased take-off weight
- Heron 2E : single VIP van
- Heron C.Mk 3 : two Royal Air Force VIP transporters for the British royal family
- Heron C.Mk 4 : individual Royal Air Force VIP transporter for the British royal family
- Sea Heron C.Mk 20 : Transport and liaison aircraft of the Royal Navy , created in 1961 by converting three Heron 2 and two Heron 2B
- Riley Turbo Skyliner : aircraft converted to Lycoming IO-540 engines with 216 kW, carried out by the American Riley Turbostream Corporation
Saunders ST-27 : twelve conversions by the Canadian Saunders Aircraft Corporation , with a 3.60 m longer fuselage for 23 passengers and two PT6A-34 turboprop engines with 560 kW
- ST-27A and ST-27B : Designations of Origin of the ST-28
- Saunders ST-28 : improved version of the ST-27, only the prototype was built
- Tawron : Version of the Japanese airline Toa Domestic Airlines with Continental IO 470 engines
The Heron was well received by the crews and passengers alike, thanks in part to the greater safety provided by the four engines. Remote regions could be easily reached by plane. Nevertheless, the machine had some weaknesses. When the passengers first went to the seats in the stern, the Heron occasionally tipped backwards. The crews therefore got used to installing a stern support in good time.
Many operators decided to convert the drive to more powerful Lycoming engines. The starting properties and the speed could be increased. After production ended in 1963, Riley Aircraft and other aircraft manufacturers offered conversion kits especially for the drive. This has extended the life of some machines into the 21st century.
The biggest changes showed the Saunders ST27 / 28 , which was equipped with two turboprop engines, lost the prominent hump over the cockpit and had straight instead of round wing tips in addition to differently shaped windows.
From the first flight in 1950 to July 2019, the De Havilland DH.114 Heron suffered 41 total losses. 164 people were killed in 19 of them. Extracts:
- On April 18, 1955, a Heron 1B of the French Union Aéromaritime de Transport (UAT) ( aircraft registration F-BGOI ) coming from Yaoundé-Ville Airport flew into Mount Kupe (Cameroon). All 12 inmates were killed; a first Nigerian newspaper report that there were two survivors and fourteen inmates has not been confirmed.
- On November 7, 1956, a De Havilland Heron 2B of the Norwegian Braathens SAFE (LN-SUR) crash-landed on Mount Hummelfjell in Tolga, Norway during heavy snowfall . The pilot and one passenger were killed, while the remaining pilot and passengers survived. The accident in Hummelfjell was Braathens SAFE's first fatal accident. The cause of the accident was unusually heavy icing and a strong air flow downwards.
- On 26 October 1957, the pilot of a landed from Madrid-Barajas upcoming De Havilland Heron 2D of the Spanish Aviaco (EC-AOA) on the San Sebastian Airport . Due to a leak in the brake system, it was not possible to stop the machine before the runway end. It rolled over into the morass in the estuary of the Bidasoa River. All 22 occupants, 17 passengers and the 5 crew members survived this accident. The plane was destroyed.
- On November 15, 1957, the pilots of a Heron 2D of the Aviaco (EC-ANZ) coming from Barcelona flew on the approach to the airport Palma de Mallorca-Son San Juan 15 km from the airport into a 400 meter high mountain. All 4 occupants, two passengers and the pilots, were killed as a result of this navigation error.
- On April 14, 1958, the pilots of a Heron 2D from Aviaco (EC-ANJ) were forced to perform a violent evasive maneuver on the approach to Barcelona-El Prat Airport in order to avoid a collision with another Heron. The machine got out of control and crashed into the sea. All 16 occupants were killed as a result of this air traffic controller error.
- On January 26, 1960, a Heron 2D of the Portuguese Transportes Aéreos de Timor ( aircraft registration CR-TAI ) crashed on the flight from Darwin to Baucau 37 minutes after take-off northwest of Bathurst Island in the Timor Sea . All 9 occupants, 2 crew members and 7 passengers were killed. It is believed that the pilot had difficulties with poor visibility, for which he had not been trained.
- On October 14, 1960, a Heron 2 of the Italian Itavia (I-AOMU) flew into the mountainside of Capanne on Elba in bad weather. All eleven people on board were killed.
- On October 23, 1975, a Riley Heron 2 of the Australian Connair (VH-CLS) took off on approach to Cairns Airport , Queensland ( Australia ) near a thunderstorm and crashed in the process. All 11 people on board died.
Technical data (Heron 2D)
|Wing area||46.40 m²|
|Empty mass||3700 kg|
|Takeoff mass||6100 kg|
|Top speed||295 km / h|
|Service ceiling||5600 m|
|Engines||4 × 6-cylinder in-line engine de Havilland Gipsy Queen 30 Mk.2 with 186 kW each|
- Gordon Bain: De Havilland: A Pictorial Tribute. AirLife, London 1992, ISBN 1-85648-243-X .
- Accident statistics de Havilland DH-114 Heron , Aviation Safety Network (English), accessed on August 14, 2019.
- Air-Britain Archive: Casualty compendium (English), September 1996, pp. 96/88.
- Accident report Heron 1B F-BGOI , Aviation Safety Network (English), accessed on August 18, 2017.
- Accident report Heron 2B LN-SUR , Aviation Safety Network (English), accessed on June 6, 2020.
- Accident report Heron 2D EC-AOA , Aviation Safety Network (English), accessed on December 9, 2017.
- Accident report Heron 2D EC-ANZ , Aviation Safety Network (English), accessed on December 9, 2017.
- Accident report Heron 2D EC-ANJ , Aviation Safety Network (English), accessed on December 9, 2017.
- CNAPG ( Memento of the original from January 8, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (English)
- Accident report Heron 2D CR-TAI , Aviation Safety Network (English), accessed on June 22, 2020.
- Accident report Heron 2 I-AOMU , Aviation Safety Network (English), accessed on January 19, 2016.
- Accident report Heron 2E / Riley VH-CLS , Aviation Safety Network (English), accessed on November 19, 2019.