IV. The inner defenses of the canal 1. The inner patrol. An inner patrol is now being con- ducted by medium range bombers and flying boats on a radius of 400 nautical miles out from Panama. The main purpose of this patrol is to supplement the recognized gaps in our present outer patrol and to try to catch a carrier which has evaded that outer patrol. Its range, however, would afford no certainty of catching a carrier before she had released her bombers. On the Atlantic side a similar but less thorough short range patrol is also being conducted. 2. The airplane warning service. A number of both fixed and mobile detectors (called by the Navy RADAR) are now in operation at various points on the coast including Salinas. Their principal mission is to detect the approach of a hostile plane. At present this mission, is being carried out ineffectively, partly on account of great geographical difficulties (causing confusing echoes) and partly because these American detectors are not effective in catching the approach of a low flying plane. A few weeks ago I sent a British expert, Mr. Watson Watt together with some Canadian assistants to Panama to examine this service and also to locate the proper places for some Canadian CHL detectors which I had the promise of from the Canadian government. These CHL detectors are effective on low flying as well as high flying planes. These CHL's are now on the way to Panama and sites have already been selected and they will all probably be in operation before the end of April. These foreign experts have also given us useful assistance in relocating and improving our original American instruments. Note: One of the mistakes of our original location was in placing the detector on too high a base, it having been discovered that such a height produced confusing echoes which prevented proper detection, when still higher mountains lay behind the site. By these various steps the air warning service can be expected to be very considerably improved in detecting the approach of low flying hostile planes. Our force of interceptor planes must be enlarged. |