Accidents at Portsmouth Airport...
Two high-profile accidents involving civilain aircraft on the same day were, combined with other factors, the beginning of the end of viable commercial operations at the airport. The accidents occured just over 90 minutes apart, involved the same type of aircraft (Hawker Siddley HS-748-222 Series 2), the same air operator (Channel Airways Limited) and a very similar set of circumstances.
Following a prolonged dry period - which had caused the grass strip runways to become hard and dry - weather conditions broke two days before the accidents. The 15th of August was overcast with approximately 0.5 inches of rain falling between 0800 and 1500 hours. The accidents occured at 1148 hours (G-ATEK) and 1334 hours (G-ATEH) on 15 August 1967.
The 1971 Accidents Investigation Branch (AIB) report into the accidents cited that "both accidents were caused by inadequate braking which had resulted from the extremely low coefficient of friction provided by the very wet grass surface over the hard, dry and almost impermeable sub-soil". Interestingly the AIB report also cited that "this condition of the grass surface was both unsusual and unexpected". This seems a slightly odd conclusion for the investigators to draw given the precursory prolonged dry weather conditions, the impermeable nature of the underlying sub-soil, and the prevailing wet weather conditions. In any case, the weather conditions and the resulting slippery conditions of the grass runways were indisputably contributory factors in both accidents.
As part of the investigation, it also became apparent that HS-748 operations at the airport were unsafe at the permitted maximum landing weight whenever the grass surface was wet. Bascially, in such occasions the available landing distances were inadequate. This was also cited as a contributory cause to both accidents.
The following provides a synopsis of the accidents, based on the official AIB Civil Aircraft Accident Report No. 1/71 published in 1971.
Summary
| Aircraft type (Category) | Hawker Siddley HS-748-222 Series 2 (Commercial Air Transport, Fixed Wing) |
| Aircraft registrations | G-ATEK (pictured above left) and G-ATEH (pictured above right) |
| Engines | Each aircraft fitted with two Rolls Royce Dart Type-531 engines |
| Owner and operator | Channel Airways Limited, Southend Airport, Essex, United Kingdom |
| Crew (G-ATEK) | Captain DP Dogherty (Commander, aged 34); First Officer KF Fenton (Co-Pilot, aged 32); Miss JW Goody and Miss J Hoare (Air Stewardesses) - all uninjured |
| Crew (G-ATEH) | Captain FP Mann (Commander, aged 41); First Officer C Petrides (Co-Pilot, aged 30); Miss GM Smith and Miss P Crane (Air Stewardesses) - all uninjured |
| Passengers (G-ATEK) | 19 - all uninjured |
| Passengers (G-ATEH) | 62 - all uninjured |
| Other persons | Nil |
| Place of accident | Portsmouth Airport, Portsmouth, Hampshire, United Kingdom |
| Date and times of accidents (GMT) | 15 August 1967 at 1148 hours (G-ATEK) and 1334 (G-ATEH) |
History of the flights and the aircraft
The first aircraft, G-ATEK, was operating a scheduled Channel Airways service from Southend to Paris via Portsmouth. The second aircraft, G-ATEH, was operating a scheduled Channel Airways service from Jersey via Guernsey to Portsmouth.
G-ATEK and G-ATEH had entered service in 1966 and 1965 respectively. Channel Airways had owned both aircraft since new and both aircraft had valid Certificates of Airworthiness and Certificates of Maintenance. At the time of the accidents G-ATEK had flown a total of 2,651 hours and G-ATEH a total of 3,037 hours 50 minutes.
At the time of the accidents the landing weights of the aircraft were 15,602 kg (33,520 lb) for G-ATEK and 17,047 kg (37,580 lb) for G-ATEH, both within the maximum permitted landing weight at the airport of 17,800 kg (39,240 lb) in 1967*.
*Note, this maximum had been increased from the 1966 permitted value of 16,300 kg (35,935 lb).
G-ATEK
After descending below the cloud base with the assistance of RAF Thorney Island precision approach radar, the pilot proceeded on a visual approach to Portsmouth. At 1142 hours the pilot was informed of the presence of slight rain at the airport and that runway 36 was in use (surface wind 010 degrees 6 knots veering 040 degrees 6 knots). After an overhead pass in a westerly direction the aircraft joined a left-hand circuit approach to runway 36. No information was relayed to the pilot concering the conditions of the runway surface.
At 1148 hours the aircraft touched down 500 feet (152 metres) after passing the displaced runway 36 landing threshold and 300 feet (100 metres) to the left of the centreline. Its direction and speed on touchdown were 010 degress at 84 knots. After the pilot had applied ground-fine-propeller pitch and continuous wheel braking the aircraft initially decelerated. However, in the later stages of the groundroll it became apparent that the aircraft was not going to come to a stop in the available distance. Power was subsequently applied to the starboard (right-hand) engine to induce a left-hand ground-loop. But, after a partial swing to the left the aircraft slid sideways, eventually coming to rest on the top of an embankment. The passengers (19) evacuated the aircraft in an orderly manner through the rear door.
G-ATEH
After descending to the south of Portsmouth using the Portsmouth very-high frequency direction-finding station (VDF) and while flying in low cloud and slight drizzle. the aircraft made a partial right-hand circuit south of the city to land on runway 07. The pilot misjudged his first approach (too fast and slightly misaligned) and after bouncing a number of times on the grass runway he elected to abort the landing and make a go-around. After a further right-hand circuit the pilot made a second approach to runway 07. During this approach the wind veered from 110 degrees to 180 degrees at 10 knots, and then backed again to 150 degrees.
At 1334 hours the aircraft touched down 336 feet (102 metres) after passing the threshold of runway 07 and exactly on the centreline at a speed of 88 knots. After a firm landing the pilot immediately applied ground-fine-propeller pitch and full wheelbraking. the aircraft duly decelerated for approximately 2/3rds of the landing roll but beyond this point deceleration was negligible. The pilot attempted a ground-loop to the right but abandoned this when when he realised that this might lead to a collision wth cars parked near the airport buildings. The aircraft slid until it came to a rest on the main road (Eastern Road). Shortly before impact the pilots shutdown the engines and took fire prevention actions. The passengers (62) evacuated through the main (front) doors whoch were at ground level since the nosewheel and mainwheels had been sheared off as the aircraft hit a raised banking at the side of the roadway.
The pilot of G-ATEH was aware of the poor braking conditions at the airport from his experience during a landing made some three hours previously. The tower controller also warned him to expect poor braking. However, the pilot was completely unaware of the accident involving G-ATEK. Subsequently, the pilot of G-ATEH stated that had he been informed of the G-ATEK accident then he would not have attempted to land at Portsmouth.
Injuries to persons
There were no fatal or non-fatal injuries to any of the crew and passengers on both aircraft.
Damage to aircraft and other damage
G-ATEK (below left after salvage) came to rest on top of an embankment that formed part of the northern boundary of the airport. No other damage was caused during the accident.
G-ATEH (below centre and below right after salvage) sheared off its nosewheel and mainwheels against a raised banking on the eastern boundary of the airport. While this was only slight damage to G-ATEH, extensive damage was caused to the rear of the fuselage due to attempts by unqualified personnel to remove it from Eastern Road before the arrival of qualified RAF salvage teams with the proper haulage equipment. This accident caused damage to part of the steel mesh and contrete posts of the perimeter fencing as well as the uprooting of an electricity supply lamp post. Fuel spillage was hosed off by the local fire service.
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Weather conditions
The weather forecast for Portsmouth airport for the period 1000 hours to 1900 hours on 15 August 1967 was:
| Surface wind: | 250 degrees, 15 knots |
| Visibility: | Generally 10 km but intermittently 4 km throughout period |
| Weather: | Rain |
| Cloud: | Generally 6/8th stratus at 1,200 feet and 8/8th stratocumulus at 2,000 feet but intermittently 6/8th stratus at 500 feet and 8/8th stratocumulus at 800 feet throughout period |
The weather at Portsmouth airport the time of the G-ATEK accident (1148 hours) was:
| Surface wind: | 030 degrees, 6 knots |
| Visibility: | 2.4 km |
| Weather: | Rain |
| Cloud: | 2/8th stratus at 450 ft, 6/8 stratus at 800 ft and 8/8th stratocumulus as 1,500 ft |
The weather at Portsmouth airport the time of the G-ATEH accident (1334 hours) was:
| Surface wind: | 150 degrees, 10 knots |
| Visibility: | 7 km |
| Weather: | Light rain |
| Cloud: | Trace stratus at 500 ft, 4/8th stratus at 600 ft and 8/8th stratocumulus at 2,500 ft |
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