FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1945
1945 - 1061.PDF
MAY 3 IST, 1945 FLIGHT World Weather Transport Command's Vast Meteorological Service TRANSPORT COMMAND of the Royal Air Forceoperates routes that literally span the world, to meetthe air transport requirements in all theatres of war. Aircraft are delivered from North America and the United Kingdom to Europe, the Middle East and Burma. Great trunk routes cross the Atlantics, the Pacific, and often circumnavigate the world. But, in addition to the great distances that Transport pilots need to fly on their missions, there are the shorter, but intricate missions such as airborne operations involving the transportations of paratroops, glider-borne troops and freight in close support of army operations. And, by no means least, Transport Command operations include the transportation of impor- tant passengers and freight in non-scheduled flights to all parts of the world. For all these operations, detailed and accurate weather information is essential. For many of them it is impera- tive that a close forecast must be made of weather stretch- ing over many thousands of miles of the earth's surface. Great sea areas have to be crossed, such as the North and South Atlantics, or land areas of a swiftly changing nature. Therefore a vast and detailed meteorological organisation has been developed to meet the varied requirements. The weather forecast given to a Transport Command pilot operating on a long flight is prepared to cover his requirements as fully as possible. It is corrected at each halt, and weather indications are also sent by wireless to the aircraft as it progresses along the route. First, the pilot is given a small weather map which shows the actual positions of bad-weather areas and of pressure systems, i.e., depressions, anticyclones, etc., based on the latest available information. Cross-section Map In addition, so that the pilot may see at a glance the cloud layers, dangerous icing areas, etc., he receives a dia- gram which gives a cross-sectional view of the weather on the route. On this cross-section, the freezing level is marked with a red line, and all cloud below this line is coloured green, to show that dangerous icing is not likely to be experienced in such cloud. The —18 deg. C. level is also shown. This is an important temperature, since at temperature below this the risk of serious icing rapidly decreases. The clouds between the freezing level and —18 deg. C. line are coloured in red, to serve as a warning to the pilot that icing conditions are to be expected in such clouds. In addition to the two diagrams already described (a weather map and the cross-section), the pilot is given a written or typed forecast giving detailed information regarding all aspects of the weather on his route. This includes winds at heights ranging from the surface to 15,000 or 20,000 feet, or even higher if necessary, temperatures at these heights, visibility, amount and type of clouds, the height of the base of the clouds, heights at which icing will be experienced, the intensity and type of ice that will form, and the mean sea-level atmospheric pressure. This latter is given in order to ensure that serious errors in heights recorded in the altimeter, due to changes of mean sea level pressure, may be avoided. The whole route is divided into a number of zones, and the detailed information for each zone is given on a separate form. Forecasts of the weather for landing at the destina- tion airfield and possible diversion airfields are also given. This information is fastened into a folder, and the whole constitutes the " flight forecast." It is handed to the pilot at the briefing which takes place before every flight. At the briefing, a meteorological officer describes the weather to the pilot and the navigator, and explains the forecast in detail. So the pilot is given advice on every aspect of the weather to be expected on his flight, and on the basis of this advice the final details of the flight are worked out. The pilot decides the heights at which certain parts of the route are to be flown—he may fly high over bad weather in some zones, or low to avoid a dangerous freez- ing level in others. He may also adjust his heights to obtain the most advantageous wind, or he may even change his track for some reason. Using the winds given in the fore- cast, the point of no-return is calculated : that is the point which, when passed, leaves the aircraft with insufficient fuel to return to the airfield from which he has taken off, and it must then go on. The pilot works out the estimated ground speed, having regard to the forecast winds, and hence the estimated duration ol the flight This in turn gives the estimated time of arrival, or E.T.A. as it is usually called. The pilot also needs to be informed of the future con ditions at the airfield of departure, in case he should need to return for any reason, though this is rarely necessary A point to be remembered here is that conditions quite suitable for take-off may not always be suitable for landing. To furnish this detailed information, the Met. Officer must study very carefully all the meteorological informa tion at his disposal, and, in wartime, this information— particularly trom sea areas—is by no means too plentiful. Transport Command routes are world-wide, and extend through climatic conditions of every type. Transport Com- mand pilots may therefore, for example, need to be as familiar with the weather of the south-west monsoon in India as they are with the moving depressions that affect our own country. In a matter of a very few days, the Transport Command pilot may fly from cold arctic con- ditions to hot desert conditions. The training of such pilots, therefore, includes lectures on the weather experi- enced in all parts of the world where Transport Command aircraft operate. Scattered all along these routes are meteorological offices to issue forecasts and other meteorological advice to pilots passing through. Transport operations in support of Army operations need to be considered most carefully in regard to weather, and the meteorological advice required is of a very different character from that required for airline and aircraft delivery operations. For paratroop and glider operations the surface wind and gustiness are of paramount importance, and an accurate forecast of these is essential to the success of the operation. An incorrect forecast of surface wind might cause a large part of a paratroop and glider-borne unit to become casualties on landing, and thus have serious reper- cussions on the particular operation. It might also, for example, be necessary to use cloud cover as a protective screen, for paratroop operations, or possibly the complete absence of cloud might be required if the exact spot, called the "dropping zone," on which troops and equip- ment are to be dropped is to be found at night. Surface visibility is another factor of obvious importance. One of the most interesting aspects of the work of Transport Command is the organisation of special flights of very important persons, or V.I.P.s. In this connection, the Senior Met. Officer of Trans- port Command says: — "Late in January of this year a small R.A.F. unit was formed to proceed to an overseas destination. Neither the purpose nor place of the mission was disclosed, but the function of the unit was to make the ground arrangements for the safe and timely arrival and departure of a large number of aircraft, and I was in charge of the Meteoro- logical Section of this unit. These aircraft, as it was sub-
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
