de Havilland DH-106 Comet 1

Incident Overview

Date: Thursday 8 April 1954

Aircraft Type: de Havilland DH-106 Comet 1

Owner/operator: South African Airways – SAA, lsf BOAC

Registration Number: G-ALYY

Location: ca 17 km W off San Lucido – ÿ Italy

Phase of Flight: En route

Status: Destroyed, written off

Casualties: Fatalities: 21 / Occupants: 21

Component Affected: Centre tank gaugeCentre tank gauge

Investigating Agency: MinTrans UKMinTrans UK

Category: Accident

On February 15, 1954, a commercial flight involving the Comet G-ALYP, leased to South African Airways from BOAC, experienced a significant problem during its flight between Johannesburg and London. The aircraft was grounded due to structural damage from a previous incident, requiring extensive repairs. The flight was subsequently resumed, and passengers were permitted to travel. During the flight, a critical issue emerged when the centre tank gauge revealed no reading, despite the tank being full. Investigation revealed a faulty co-axial cable, necessitating a replacement from England, leading to a delay of approximately 24 hours. The aircraft eventually departed Rome at 18:32, climbing through three cloud layers and reporting position to Rome Air Control, confirming its course and altitude. The aircraft’s subsequent communication ceased, suggesting a potential issue with the aircraft’s systems. Based on the investigation into G-ALYP, a structural failure within the pressure cabin was considered a probable cause.On February 15, 1954, a commercial flight involving the Comet G-ALYP, leased to South African Airways from BOAC, experienced a significant problem during its flight between Johannesburg and London. The aircraft was grounded due to structural damage from a previous incident, requiring extensive repairs. The flight was subsequently resumed, and passengers were permitted to travel. During the flight, a critical issue emerged when the centre tank gauge revealed no reading, despite the tank being full. Investigation revealed a faulty co-axial cable, necessitating a replacement from England, leading to a delay of approximately 24 hours. The aircraft eventually departed Rome at 18:32, climbing through three cloud layers and reporting position to Rome Air Control, confirming its course and altitude. The aircraft’s subsequent communication ceased, suggesting a potential issue with the aircraft’s systems. Based on the investigation into G-ALYP, a structural failure within the pressure cabin was considered a probable cause.

Description

DH-106 Comet G-ALYY was leased to South African Airways by BOAC. It was flown by SAA crew members between Johannesburg and London with several intermediate stops. The aircraft was grounded in January 1954 following the in-flight structural breakup of sistership G-ALYP. Special checks were carried out and a number of modifications were made affecting the airframe, the controls and the fire detection and protection at the engines. On the 15th February, 1954, the fuselage was subjected to a proving test to 11 lb/sq. in. The aircraft was returned available for service on the 24th February, 1954. Passengers services with Comet aircraft were permitted to resume on the 23rd March, 1954. G-ALYY arrived at Rome-Ciampino (CIA) on the 7th April from London and was due to depart the same evening. However, on completion of refuelling it was discovered that the centre tank contents gauge showed no reading although the tank was full. The fault was eventually traced to a co-axial cable for which a replacement had to be flown from England and the departure of the aircraft was consequently delayed for about 24 hours. SAA Flight 201 finally departed Rome at 18:32. G-ALYY climbed through three moderately thick layers of cloud. After taking off the aircraft from time to time gave its position by radio telephone to Rome Air Control at Ciampino and on the last such occasion at about 18:57 reported that it was abeam Naples and climbing to 35,000 ft. This position and those given earlier indicated that the flight was proceeding according to the B.O.A.C. flight plan. At 19:05 Cairo received a signal from the aircraft reporting its departure from Rome and giving its estimated time of arrival at Cairo. Thereafter no message was received from G-ALYY. Based on the findings of the accident to G-ALYP, it was concluded that G-ALYY must also have suffered structural failure of the pressure cabin, due to fatigue. PROBABLE CAUSE: “Owing to the absence of wreckage, we are unable to form a definite opinion on the cause of the accident near Naples, but we draw attention to the fact that the explanation offered for the accident at Elba appears to be applicable to that at Naples.”