Amongst the many pre-requisites to the growth of aviation, both military and civil, in a country, may be included such "essentials" as : vast distances and favourable weather conditions during the larger part of year; air-mindedness and sense of adventure on the part of the population; existence of technical institutions for training of ground and air personnel; aircraft industries; and above all, a network of airfields with modern navigational and air-traffic control aids with experts to man them.

Purely from the geographical aspects - fair weather and long distances - which influence the growth of aviation, our country may be said to have few equals. That our people, particularly during the last seven years, have grown "Air-conscious", there is little doubt. We have, in fact, sufficient number of suitable youth coming forward to become Service pilots and thus keep the Indian Air Force free of at least its personnel problems. On the civil aviation side, the growth is continuous and so far the available number of trained and professional aircrew have exceeded the demand. We, in this country may, however, have to wait for sometime more, before large scale aircraft industries are established to meet our military and civil aircraft requirements; our resources, both financial and in technical knowledge, have yet to catch up with those of other advanced countries. Indeed, a lot has been done in establishing new airfields and in modernising them by the installations of modern navigational aids. Yet there still remains a great deal more to be done. For instance none of our airfields, whether controlled by the I.A.F., by the D.G.C.A., or jointly, has so far been provided, with modern radar landing equipment.

Developed as an operational necessity during the last war, the ground control approach, known by its abbreviation G.C.A., has now been in existence for the last nine years. It is a highly developed, almost perfected radar landing aid, in use now by practically all western countries at their civil and military airfields. The G.C.A. is perhaps the only device known to control heavy air traffic on an airfield during adverse flying conditions, when cloud base may hang as low as fifty feet or even less, over the landing ground and at a time when the aircraft may have no visual contact with the ground or with its surroundings. The pilot of such a stranded aircraft, completely lost in the thick sea of clouds, may have a rough idea of his location, but dare not descend to land due to the airfield being red. Yet immediate landing may be a necessity due to shortage of fuel or other causes. An airfield under the grip of foul weather, but equipped with G.C.A., can guide a "lost" pilot to land with perfect safety. In fact the landing device is so effective that the pilot, "blinded" by clouds or heavy mist, is talked down to the airfield and he realises his position only after the 'divine voice' has guided him down and he sees his aircraft rolling on the hard ground with the entire stretch of the airfield in front of him.

G.C.A which is normally housed in a trailor for easy transportation wherever required, is a radar appliance in which several major engineering advances have been incorporated. With a number of rotating aerials connected with radar screens it can search and precisely locate the "lost aircraft". Against a fluorescent screen, a silhouette of the aircraft appears, after the C.G.A. operator has contracted the machine. Automatic devices determine the exact location of the aircraft; its height from the ground, the direction it is flying, its distance from the airfield and the surrounding topography above or around which the aircraft is flying. The search by G.C.A. can be made when the aircraft is forty miles from the airfield. The operator manipulates the second screen when the aircraft has been guided within two miles of the airfield, his voice over the radio telephonic communication helping him to avoid obstructions, which the operator can constantly and clearly see on the radar screen. The operator thus brings the pilot above the airfield, tells the pilot to circle, descend and approach the landing ground, until the aircraft touches the ground and makes a perfect landing.

Of course, used as he is to seeing the landing ground and the suburbs under normal conditions, the pilot when visually cut off from the ground would instinctively feel shaky in placing his faith completely in the ability of a man whom he has never met, who is invisible and only audible.