No. 102 (BOMBER) SQUADRON (ACCIDENT). (Hansard, 25 March 1937)

§ Sir P. Sassoon

The Air Council have considered the report of the court of inquiry on the accidents to certain aircraft of No. 102 (Bomber) Squadron and the comments thereon of the Air Officer Commanding No. 3 (Bomber) Group and the Air Officer Commanding-in-Chief, Bomber Command.

Circumstances prior to the flight.—The squadron was due to return from Alder-grove to Finningley on the 10th December last. It was delayed by adverse weather conditions. On the morning of the 12th December the conditions at Aldergrove were fine and the squadron leader in command of the squadron received two weather reports from Finningley giving the weather conditions there, the second report being received immediately before he took off at about 10.50. He also received from the Meteorological Office, London, the following weather forecast of the route:

Forecast Aldergrove, Portpatrick, Finningley.—Surface wind light, westerly to variable, 310° backing to 160°, 10–15 m.p.h. 2,000 feet. A belt of rain and sleet with snow on hills across Northern England.

Cloud 3/10–7/10 at 1,500 feet into South Scotland, then 10/10 500–800 feet above sea level and on surface hills.

Visibility 5–8 miles into Scotland, falling to 500–1,500 yards in cloud and rain belt.

3096W

Before taking off the officer navigating the squadron discussed the weather conditions with the Meteorological Officer at Aldergrove, who informed him that the belt of low cloud over the Pennines was moving east and would probably reach the Huddersfield district about 1200 or 1230 hours.

In the opinion of the Air Council, the Officer Commanding was justified in undertaking the flight on the information supplied to him.

Circumstances in which accident occurred.—The flight from Aldergrove to Barrow-in-Furness was uneventful. When over Barrow-in-Furness, flying at 3,000 feet, white haze was encountered. A few minutes later the squadron ran into thick cloud and the aircraft became separated.

The accident was due to the squadron Commander meeting bad weather conditions before he had judged that this would be the case, and to the conditions causing ice accretion which he had not anticipated. In consequence, he did not turn south to skirt round the bad weather area until ice accretion had caused him to lose touch with his squadron and interfered with the wireless communications of the squadron.

Comments of the Air Council.—The Air Council have reviewed not only the particular circumstances of this accident, but also more general matters which are of importance to safe flying in conditions similar to those obtaining on this occasion.

It should be said at once that it is the duty of the Royal Air Force, always readily accepted, to fly in bad weather unless that weather is such as to prohibit flying, but it is necessary that stations and squadrons should be efficiently served both in direction-finding facilities and weather reports.

Direction Finding.—As regards direction-finding facilities, a network of Service direction-finding stations has been established and will be further extended. The stations already completed give an effective service over almost the whole of the United Kingdom south of Galashiels and extending to the eastern part of Ireland, and also over a wide area east and south of the English coast. In addition to this, aircraft can communicate with a number of civil stations.

Careful consideration has been given to the question as to whether the above 3097W facilities were in fact sufficiently available on the 12th December to enable the squadron to navigate its course to Finningley in the event of aircraft of that squadron requiring direction information. It has been ascertained that the following stations were in fact in operation and in a position to respond to any request by a wireless from the squadron for such information:

Service Direction-finding Stations:

Leuchars.
Bircham Newton.
Andover.

Civil Direction-finding Stations:

Newtownards.
Hull.
Renfrew.
Manchester (on request to Hull or Newtownards).
Doncaster (on request to Hull or Newtownards).

But it must be understood that once the wireless apparatus on an aircraft has been rendered inoperative by icing, as in fact it was in this case, effective communication becomes impossible.

In connection with the flight, arrangements were made for a listening watch to be kept by all the four wireless operators carried in the aircraft, and for the Royal Air Force stations at Aldergrove, Sealand and Driffield to maintain aircraft watch throughout the flight. Intimation of any major change in weather conditions which might have occurred after the flight had started would in consequence have been relayed to the aircraft in the air.

The wireless station at Finningley was not in action at the time of the accident, but this in no way affected the direction-finding facilities available since Finningley is not a direction-finding station.

Weather reports.—The weather forecast supplied to the squadron had been prepared in the Meteorological Office, London, and was transmited to Aldergrove by the Air Ministry. This forecast gave sufficient information as to the existence and extent of the area of bad weather, but it did not refer specifically to ice accretion. The Council have carefully investigated this omission. The forecasting of ice accretion is one of the most difficult of meteorological problems. Some degree of ice accretion is always present in clouds when the temperature is in the neighbourhood of the freezing 3098W point, but the amount of accretion varies greatly. At certain times there is very heavy accretion and at others, under apparently the same conditions, no significant accretion takes place. Up to the present it has been found impossible to draw up definite rules for forecasting ice accretion and each forecaster has to decide for himself whether to issue a warning of ice accretion or not.

On the morning of the accident conditions favourable to ice accretion existed and certain of the forecasters of the Meteorological Office issued warnings to pilots. The forecaster at Aldergrove, after considering the possibility of ice accretion, did not feel justified in issuing a definite warning on the information before him, but drew attention to the presence of rain, sleet and snow in the area of bad weather over the Pennines. The Air Council consider that it would have been wiser if the forecast transmitted to Aldergrove from the Air Ministry had contained a reference to the possibility of ice accretion. The fact, however, that ice accretion was not specifically mentioned was not a contributory cause of the accident since the warning given by the forecaster at Aldergrove made it clear that the weather over part of the route was such as must be avoided, and the Commanding Officer did in fact intend to avoid it.

De-icing equipment.—De-icing equipment is in an experimental stage, and, so far as is known, is not in every day use in any Air Force abroad, while its use by a few civil air lines is at present confined to devices dealing only partially with the problem. It is uncertain whether it will be possible in the near future to adapt any appliance as an effective standard equipment, but research and experiment are proceeding.