Viewing page 58 of 307
This transcription has been completed. Contact us with corrections.
T-20 MAY '44 There are several models. Some of them are improvements over old models, like a new automobile which is better than last year's. Some are simply designed for different kinds of bombers; for example, the model which goes on the B-26 is not quite the same as the one in the B-24. But if you can operate one Martin, you can operate them all. [[line]] FACTS AND FIGURES POWER The martin turret operates on power supplied from the bomber's central electrical system. SIGHT Its sight is usually the N-8 or N-6A optical, fully described in the Sights and Sighting section of this manual. (It may also be equipped with the Sperry K-9 automatic computing sight, described in the same section.) [[image - illustration of sight]] MOTION The turret can move 360 degrees—a full circle—in azimuth. In elevation, the turret guns can be lowered and raised from a little below horizontal(—6½ degrees) to almost straight up (85 degrees). [[image - illustration of turret motion]] SPEED The turret has two speeds—normal tracking speed and high speed. ARMOR Armor plate is ½ inch thick. It protects the gunner in front, no matter where he aims his guns. STOWING POSITION The stowing position for turret and guns is 0 degrees elevation and 180 degrees azimuth—guns pointing straight back toward the tail. [[image - illustration of stowing position]] ^[[20]] RESTRICTED [[end page]] [[start page]] technique Frangible Bullets In a new gunnery training program, plastic frangible bullets are fired at specially armored and equipped P-63s so that gunners in bombing planes may improve their marksmanship by shooting at "live" targets. With gunners blazing away at them - just as they would against attacking enemy fighters - pilots of these King-cobras make daring passes from every angle. When bullets hit the planes armor-plated skin, the plastic pellets splatter harmlessly and a large light in the nose blinks on for two seconds and then off again, like a pinball machine, telling the gunner that his aim has been accurate. Approximately 110 microphone pick-ups located under the dural deflector plates on the fighter transmit electrical impulses for the signal, while an additional automatic recorder in the P-63 cockpit tabulates all hits so each gunner can be radioed his score. The shatterable bullet which makes this superior type of gunnery training possible, represents two years of tests and study by AAFTC, National Defense Research Committee and ATSC engineers, as well as ballistic experts and laboraticians at Michigan, Duke and Princeton universities. The perfected result is a lead-plastic composition bullet molded and baked like a clay marble which is tough enough to withstand the rugged treatment of a machine gun, yet so brittle that it pulverizes upon impact. It can be inserted in a .30 caliber shell casing with a minimum powder charge, and despite a muzzle velocity of 1,360 feet per second, will not puncture piece of thick glass beyond 200 yards. The first air-to-air firing with these frangible bullets was against an armored A-20 called the "Alclad Nag" in the late spring of 1944 at Fort Myers, Fla. After the test, the pilot reported, "The bullets sounded like rain-drops and did no more damage than water." As a target plane, however, the A-20 was too slow and could not execute high-speed fighter tactics. Use of the P-63 for this purpose seemed indicated, since its thin, bullet-shaped nose had minimum frontal exposure and its engine and cooling ducts afforded built-in protection. Armor plate modifications increased its normal weight to 10,000 pounds gross, cut about 50 mph off its top speed and reduced its maneuverability. But at 25,000 feet - the selected firing altitude - the Kingcobra still presented a fast, difficult target. During a recent practice session against new P-63s, hit recorders showed that gunners in a B-17 using standard training sight equipment and flexible .30 caliber guns firing frangible bullets, scored approximately 100 hits during 10 to 12 attacks by the Kingcobras. Our New Aerial Armament More guns, faster shooting, greater sighting accuracy, precision gunlaying and remote turret control are only a few of the elements of greater firepower now packed into the armament of AAF bombing planes and fighters. 75 mm cannon have been converted from hand loading to automatic, some gunnery stations mount four instead of two .50 caliber machine guns, and fighters can carry four extra guns in droppable containers. In addition, rocket-firing devices have been improved, armor protection has been increased, bomb racks, releases and bomb control systems have been redesigned and bombsights have been perfected to drop the right number of bombs at the right instant with the right bombing angle on the right target. New electronic devices which permit bombing by precision instrument through overcast have also been developed. And more destructive weapons are on the way. High on the list of armament im- ^[[I shot at this plane from a B-29 waist position. Bill Jones]] [[image: circular photo of bullet with special tip]] [[image: airplane on tarmac]] [[caption: Target plane used for frangible bullet gunnery training. Nose bulb goes on when hits are recorded. At left is slug showing pulverization of composition tip. AIRFORCE ^[[21]] [/preprinted]]
