G-AGRH Zephyr was an Avro Super Trader IV cargo aircraft, which crashed on Mount Süphan

Mount Süphan

Mount Süphan , is a stratovolcano located in eastern Turkey, immediately north of Lake Van. It is the second highest volcano in Turkey, after the mount Ararat.-External links:*...

 in eastern Turkey

Turkey

Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...

 on 23 April 1959. The Super Trader IV was a modified Avro Tudor IV, which had been fitted with an aft cargo door and was flown unpressurized.

Loss

G-AGRH, owned by Air Charter Limited

Air Charter Limited

Air Charter was an early post-World War II private, British independentindependent from government-owned corporations airline formed in 1947. The airline conducted regular trooping flights to Cyprus as well as worldwide passenger and freight charter flights from its bases at Southend Airport and...

 departed Ankara

Ankara

Ankara is the capital of Turkey and the country's second largest city after Istanbul. The city has a mean elevation of , and as of 2010 the metropolitan area in the entire Ankara Province had a population of 4.4 million....

 for a flight to Bahrain

Bahrain

' , officially the Kingdom of Bahrain , is a small island state near the western shores of the Persian Gulf. It is ruled by the Al Khalifa royal family. The population in 2010 stood at 1,214,705, including 235,108 non-nationals. Formerly an emirate, Bahrain was declared a kingdom in 2002.Bahrain is...

, a leg of a cargo flight from the United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 to Woomera Airfield

Woomera Airfield

RAAF Woomera Airfield is an operational Royal Australian Air Force airfield located 4 km north of the Woomera Defence Village, in South Australia...

 in Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. The aircraft was carrying twelve men and top-secret equipment for Woomera rocket range. Between Ankara and Teheran, it was using an air corridor, which would take it over the middle of Lake Van

Lake Van

Lake Van is the largest lake in Turkey, located in the far east of the country in Van district. It is a saline and soda lake, receiving water from numerous small streams that descend from the surrounding mountains. Lake Van is one of the world's largest endorheic lakes . The original outlet from...

, Turkey's largest lake almost surrounded by mountains and situated close to the Soviet-Armenian border.

At 08:14, the aircraft passed Gemerek

Gemerek

Gemerek is a town and a district of Sivas Province of Turkey. The mayor is İrfan Sağırkaya ....

 at FL

Flight level

A Flight Level is a standard nominal altitude of an aircraft, in hundreds of feet. This altitude is calculated from the International standard pressure datum of 1013.25 hPa , the average sea-level pressure, and therefore is not necessarily the same as the aircraft's true altitude either...

115 and Elazığ

Elazig

Elâzığ is a city in Eastern Anatolia, Turkey and the seat of Elâzığ Province. It has a population of331,479 according to the 2010 census, and the plain on which the city extends has an altitude of 1067 metres....

 at 08:59 (at FL135). The last position report was received at 09:26 over Muş

Mus

-Computing:* Mus, a file extension used by Finale * MUS, the internal music format used in Doom -Three-letter acronyms:* Mitsubishi UFJ Securities * MUS, the NATO country code for Mauritius...

. The aircraft had crashed, and was found after six days on Mount Süphan, a little north of Lake Van.

A special RAF

Royal Air Force

The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...

 mountain rescue team of six men from Nicosia

Nicosia

Nicosia from , known locally as Lefkosia , is the capital and largest city in Cyprus, as well as its main business center. Nicosia is the only divided capital in the world, with the southern and the northern portions divided by a Green Line...

, Cyprus

Cyprus

Cyprus , officially the Republic of Cyprus , is a Eurasian island country, member of the European Union, in the Eastern Mediterranean, east of Greece, south of Turkey, west of Syria and north of Egypt. It is the third largest island in the Mediterranean Sea.The earliest known human activity on the...

 reached the crash site at the top of the mountain some days later, collected documents from the wreckage and carried out demolishing work with explosives brought with.

Causes

It was concluded that the aircraft, which had been flying on instruments, drifted north of its normal track because of strong winds and crashed into the mountain. Contributing factors were that winds were stronger than forecast; an accurate bearing could not be obtained at Muş, and Van

Van, Turkey

Van is a city in southeastern Turkey and the seat of the Kurdish-majority Van Province, and is located on the eastern shore of Lake Van. The city's official population in 2010 was 367,419, but many estimates put this as much higher with a 1996 estimate stating 500,000 and former Mayor Burhan...

 had not been checked; sub-normal temperatures would result in a high indicated altimeter

Altimeter

An altimeter is an instrument used to measure the altitude of an object above a fixed level. The measurement of altitude is called altimetry, which is related to the term bathymetry, the measurement of depth underwater.-Pressure altimeter:...

reading; calculations on the flight and contacts with beacons were not coordinated and controlled.