De Havilland DH.106 Comet

The four engine aircraft was completing a flight from Geneva to Nice, carrying eight crew members and ten members of the Saudi Royal Family. While cruising by night above the Alps and along the border between France and Italy, the crew was in communication with ATC based in Aix-en-Provence and was instructed to descent to 10,000 feet when the airplane struck the slope of Mt Matto located 28 km southwest of Cuneo. The wreckage was found a day later and all 18 occupants have been killed.

Flight UA869 departed from Hong Kong for Bangkok, an intermediate stop, on a scheduled service to Cairo. Takeoff time was 13:30 UTC. The flight climbed to 31000 ft, the selected cruising altitude. At 15:14 UA869 advised Bangkok ATC that the flight had crossed the Bangkok FIR boundary at 15:08 and passed over Ubol NDB at 15:13 and requested to fly direct from Ubol NDB to Bangkok VOR. This request was granted by Bangkok ATC. At this time UA869 advised Bangkok ATC that the ETA for Bangkok VOR would be 15:47. At 15:27 the flight advised Bangkok ATC that it would be over the 100 mile perimeter at 15:30. After reporting that it was 90 miles out the crew requested descent clearance to a lower altitude. Bangkok control cleared the flight to descend to 4000 ft on the Bangkok VOR radial of 073 degrees and to report when commencing descent from 31000 ft. The flight was instructed to contact Bangkok approach control at 15:39. At 15:35 the flight was cleared to 3000 ft and informed that the altimeter setting was 1007.8 mb. At 15:40 the flight transferred to the Bangkok approach control. Immediately after this UA869 reported to approach control that it was descending from 13000 ft and estimating Bangkok VOR at 15:44. Approach control advised the flight to adjust the altimeter setting to 1007.8 mb and then cleared the flight to cross Bangkok VOR for final approach on runway 21R and report immediately on descending from 3000 ft. This was the last contact with the flight. The Comet flew into the side of Khao Yai Mountain, 52 nm NE of Bangkok.

The aircraft was on a scheduled flight from London to Rome, Athens, Istanbul, Ankara, Nicosia and Tel Aviv. From Istanbul the flight was operated by British European Airways on behalf of Cyprus Airways. The operating crew, employed by BEA, consisted of a captain and two first officers. Also aboard were four cabin staff employed by Cyprus Airways and 27 passengers. The trip to Ankara was normal. The time between landing and starting engines at Ankara was 46 minutes during which light snow was falling. (At take-off the aircraft had a light covering of snow on the upper surface of its wings, however, this deposit had no bearing on the accident). The radio-telephony tape recording showed that the aircraft taxied out along the short taxiway, then back-tracked up the runway to its take-off position on runway 21 at the intersection with the longer taxiway. The runway length available from this position was 9,027 feet. Take-off weight was 53 465 kg, i.e. 18 185 kg below maximum permissible weight or 1 085 kg below the regulated take-off weight. The takeoff run as to distance and time was quite normal, as also were rotation and unstick. The first abnormality occurred a second or two after unstick when the aircraft rapidly assumed an excessively steep climbing angle. One witness put the angle achieved as about twice the normal, another as 45° to 50°. There was also evidence from witnesses of a wing drop and of variations in the engine noise during this climb. The aircraft stalled with the left wing down at a height of about 450 ft then sank to the ground in a relatively flat attitude. The accident site was 1 600 m and on a bearing of 214° from Esenboğa Tower. The accident occurred at 2343LT. The aircraft was almost completely destroyed by impact and fire. All 7 crew and 20 passengers were killed. Six passengers were seriously injured.

Less than two minutes after takeoff from Campinas-Viracopos Airport, at an altitude of 100 meters, the airplane struck trees, stalled and crashed in eucalyptus forest. The airplane was totally destroyed by impact forces and a post crash fire and all 52 occupants were killed.

The crew was completing a local training flight at Buenos Aires-Ezeiza-Ministro Pistarini. Following several maneuvers in the area, the crew started a new approach. The aircraft landed hard, causing the undercarriage to puncture the wings and the fuel tanks. The aircraft bounced then swung on runway before coming to rest in flames. While all six crew members were slightly injured, the aircraft was destroyed.

On final approach to Asunción-Silvio Pettirossi Airport, the crew encountered marginal weather conditions with limited visibility. The four engine aircraft was too low, hit trees and struck the ground. On impact, the undercarriage were sheared off and the airplane slid for several yards before coming to rest in a wooded area. A crew member and a passenger were killed while all 48 other occupants were evacuated, some of them wounded. The aircraft was written off.

Owned by BOAC, the aircraft was operated by South African Airways with a SAA crew under flight SA201. It left Rome-Ciampino Airport at 1932LT (25 minutes delay due to a technical problem) with an ETA at Cairo Airport at 2220LT. While cruising at an estimated altitude of 35,000 feet off the Italian coast, the aircraft disappeared from radar screens at 2004LT and crashed into the Tyrrhenian Sea, about 17 km off San Lucido. SAR operations were quickly dispatched but eventually suspended few days later as no trace of the aircraft nor the 21 occupants was found.

About twenty minutes after its takeoff from Rome-Ciampino Airport, while cruising at an altitude of 27,000 feet between the islands of Elbe and Montecristo, the airplane suffered a brutal decompression, disappeared from radar screens and crashed into the Tyrrhenian Sea. Some debris were found floating about 16 km south of Elbe Island and the main wreckage sank by a depth of 600 meters. All 35 occupants were killed. About 70% of the debris were recovered and the airplane was rebuilt in UK for investigations. As there were suspicions of technical issues, BOAC, Air France and SAA decided to suspend all Comet flights. After fifty modifications and improvements, the airplane started to fly again two months later. It was eventually discovered that the airplane suffered a structural failure and exploded in flight.

Because taxi lights were too dim to use at night, the crew had to use the landing lights while taxiing. Both lights had to be alternated left and right to avoid a meltdown by using a switch behind the captains seat. In a left hand turn the captain took his left hand off the steering wheel to select another landing light. The steering centered, and then the aircraft right wheel bogies ran off the paved surface. Engine power was applied on the two right engines, causing the bogie struts to be forced up and into the wing structure causing much damage.
Source:
https://aviation-safety.net/database/record.php?id=19530725-0

Following an uneventful flight and approach, the pilot-in-command landed properly and started the braking procedure when one of the main landing gear struck a hole in the runway surface. The gear's leg broke off and the airplane came on its belly, slid for dozen yards and overran before coming to rest about 40 meters past the runway end. There were no casualties but the aircraft was considered as damaged beyond repair. Brand new, it was delivered few weeks ago.