Monday 10 December 2018

American Guided Missiles - A.A.F. Missiles (Part 2)





American Projectiles and Explosives



Missiles




A.A.F. Missiles




2,500-pound GB-4 Air-to-Surface Missile



Overall length: 12 feet 2 inches
Wing span: 12 feet
Overall height: 6 feet 2 inches
Body diameter: 24 inches
Total weight: 2,536 pounds
Warhead: 2,000-lb G.P. Bomb AN-M66


General: GB-4 is a glide bomb which is launched from an aircraft and guided by remote radio control to its surface target by employing television intelligence picked up by a television camera on the missile and radioed to a receiver in the launching plane.  It has a special plywood airframe built around a 2,000-pound bomb, with rudders and elevators but no ailerons.  The airframe is fastened to a magnesium casting threaded to the tail of the bomb.

The missile is effective against well defined point targets, easily distinguishable from the surroundings on a television screen, and has an average circular error of 200 feet.  At present, the weapon can be used only under good visual bombing conditions, but it has been proposed to incorporate radar tracking of the missile by the parent aircraft to alleviate the handicap.

It is launched outside the normal anti-aircraft range from either a B-17 or B-25 at 175 mph at a preferred distance of 17 miles from the target at an altitude below 15,000 feet.  With a glide ratio of 6 to 1, the time of flight, at average rates of 250 to 300 mph, is four minutes.


Control: The television camera mounted under the bomb is set to point along the bomb's flight path, the standard setting being 3 degrees below the axis of the bomb.  The field of view is 14 degrees wide and 18 degrees high.  The camera scans the area and modulates a transmitter with the picture which is broadcast to the parent aircraft.  The radio control signals are transmitted by a "liaison" transmitter in the parent aircraft and are received by a standard or command set receiver installed in the glide bomb.  A modulator installed int he airplane will put out any one of the five audio tones to modulate the transmitter.  The relays in the control unit switch current to the elevator servo motor and the rudder capstan motor to move the control surfaces in the desired directions.  In addition, two more relays are actuated to shift temporarily the gyro pick-offs either to the right or to the left when those signals are given.  The missile is stabilized by a directional gyro to give roll and azimuth control.


Suspension: The missile is carried outside the plane on a Shackle D7.  Electrical cables, connected to it, pull out on release.


Destructor: The Destructor T9 is placed in the control box and is actuated, on impact, by the Fuze T62.







2,500-pound GB-8 Air-to-Surface Missile



Overall length: 11 feet 7 inches
Wing span: 12 feet
Tail: 4 feet 8 inches
Total weight: 2,555 pounds
Warhead: 2,000-lb G.P. Bomb AN-M66


General: This is a radio-controlled glide bomb, with flare observation, designed for use on large installations.  The wing is covered with plywood and is bolted to the boom assembly.  The two spar booms are of solid poplar and have hinged bands attached to their front ends which secure the bomb to the frame.  The elevator is covered with metal to prevent damage by the flares.

The GB-8 should be launched with the parent plane on a bomb run when the target is at bombardier's angle of 75 degrees - which is still outside normal A.A. range at altitudes from 10,000 to 15,000 feet.  It will glide at speeds varying about 6 to 1 depending on the elevator setting.


Control: The guiding system consists of a radio control link from the plane to the missile, servo connections to the control surfaces, gyro stabilization, and a flare panel of five Flares T3 and T4 (white and red) for observation.

Control surfaces are the ailerons on the wings, the elevator surface, and a single rudder on the left vertical stabilizer.


Suspension: The missile is carried outside the plane on a Shackle D7.  A warm-up electrical cable pulls out on release.


Destructor: The Destructor M8 mounted under and tot he starboard of the control compartment is actuated, on impact, by the Fuze M121.









Similar Project





JB-2 (A.A.F.) or "Loon" (BuAer) - A Modification of the German V-1


Overall length: 21 feet 1.1 inches
Span: 17 feet 8.1 inches
Total weight: 5,025 pounds

Warhead (T9):
Weight: 2,100 pounds
Filling: 1,875 pound of Tritonal


General: The JB-2 and "Loon" are copies of the German V-1, with modifications.  As far as the ordnance components are concerned, the Army and Navy modifications are the same.


Warhead: The warhead is an aluminum-encased charge of Tritonal.  The case is 3/8-inch thick and is bolted to the fuselage abaft the nose piece by four lugs.




Destructor (T15): At the appropriate distance from the target, as determined by the Veeder Root Counter, an electrical contact is closed, which sets off the electric blasting caps int he Destructor T15, igniting the small charge and blasting apart the two junctions in the wing spar.  The spar breaks; the wings come off; and the missile is forced into the dive toward its target.

Previously, the missile was put into its dive by the action of the Spoiler Actuators T1.  These were small steel bullet-like cups filled with black powder and an electric squib.  When activated by the Veeder Root Counter, they were fired down two vertical tubes in the tail section, releasing a spring-loaded knife arm which cut the rubber hoses from the servo motors to the controls; and, at the same time, the spring pulled the elevators down, putting the bomb into its dive.


Remarks: This missile uses liquid oxygen as fuel, this oxygen being highly explosive.



Next Time: ???

Monday 3 December 2018

American Guided Missiles - A.A.F. Missiles (Part 1)





American Projectiles and Explosives



Missiles





A.A.F. Missiles




1,000-pound VB-1 "Azon" Air-to-Surface Missile



Body diameter: 18.8 inches
Warhead: 1,000-pound G.P. Bomb AN-M44, M65, or M65A1


Construction: The VB-1 is a guided bomb employing a 1,000-pound G.P. body to which a special tail unit has been attached, replacing the standard tail assembly.  The VB stands for "Vertical Bomb" and indicates that the bomb is normally released from high altitude by use of a conventional bombsight and that the guided action for the bomb is relatively small, so that direction of the trajectory at the time of impact is essentially vertical.


Tail unit: More popularly known as the "Azon" bomb, since it can be controlled only in azimuth 2,000 to 3,000 feet to either side of the normal point of impact, the VB-1 has its controls in a radio receiver housed in the tail unit.  A radio transmitter, operated by the bombardier in the parent aircraft, sends signals to the receiver, which, in turn, activates a servo motor controlling the movement of the rudders in the tail fins.  Also incorporated in the tail is a gyro and solenoid system which prevents the bomb from spinning by changing the pitch of the small ailerons in the fins.

Guide flares attached to the after end of the tail unit assist the bombardier in following the flight of the VB-1.  Three flares, the T6E1 (white), T7E1 (red), and T8E1 (green) with an intensity of 1,000,000 candlepower each, are electrically armed and ignited three to four seconds after release, and burn from one to two minutes.  Three mechanically armed and ignited flares, T21, T22, and T23 are under development.


Suspension: Suspension lugs are welded to the case in a manner similar to the G.P. bombs.







1,000-pound VB-3 "Razon" Air-to-Surface Missile



Body diameter: 18.8 inches
Warhead: 1,000-pound G.P. Bomb AN-M44, M65, or M65A1


Construction: The VB-3 is a guided bomb similar to the VB-1, with the major difference that its flight may be controlled in range as well as in azimuth, and is known generally as the "Razon" bomb.  Like the VB-1, it has a special tail unit fitted to a 1,000-pound G.P. body, and is normally released from high altitude by use of a conventional bombsight, the guided action being relatively small, so that the trajectory at the time of impact is essentially vertical.


Tail unit: The controls for the VB-3 are contained in the cylindrical section of the tail unit and consist of a radio receiver, a gyro, and a servo motor.  Surrounding this unit are two shrouds; the forward shroud merely stabilizes the bomb in flight, while the after contains the stabilizing ailerons and range/azimuth control ailerons.

On each of the four struts supporting the after shroud is an aileron controlled by the gyro.  These four ailerons steady the bomb and prevent it from rotating while in flight.  They are set 90 degrees apart and operate in pairs; ie, those ailerons placed opposite to each other move together in unison.

Four move ailerons are located on the outer surface of the after shroud.  These are ailerons which control the trajectory of the bomb and adjust its flight in azimuth and range.  They also work in pairs, and are operated by connecting rods which pass through the control unit and are activated by the servo motor.  At present, two bombardiers are required with the VB-3 bomb; one controls range and the other azimuth.  They work independently of each other and, by use of a special bombsight, they are always able to see the bomb in flight, superimposed on the target.  As the bombardiers manipulate their control switches, radio waves are sent to the receiving unit in the tail.  This unit activates the servo motor, which, in turn, moves the ailerons on the shroud, altering the flight of the bomb.

As in the VB-1, flares are employed to assist the bombardier in the visual control of the flight of the bomb.  Currently used flares are the T6E1 (white), T7E1 (red), and T8E1 (green).  They are of 1,000,000 candlepower each, electrically ignited three to four seconds after release, and with one to two minutes of burning time.  Three mechanically activated flares, T21, T22, and T23 are under development.


Suspension: Suspension lugs are welded to the case in a manner similar to the G.P. bombs.









1,200-pound VB-6 "Felix" Air-to-Surface Missile



Overall length: 91.2 inches
Overall diameter: 18.6 inches
Total weight: 1,202 pounds
Warhead: 1,000-lb G.P. Bomb AN-M65


General: The VB-6 is a heat-homing, high-angle bomb for attack against targets which give higher heat radiation than the surrounding areas.  An added nose (84 pounds) and special tail assembly (143 pounds) carried on a standard 1,000-pound G.P. Bomb AN-M65 contain the heat-seeking equipment and the mechanism which operates the airfoil controls.  Requisites for proper performance are clear weather and a target which has necessary heat-radiation quality.  The bomb is sighted and released by standard Norden procedure.


Control: The tail assembly, which resembles that of VB-3, has range and azimuth control surfaces on an octagonal shroud, and gyro-stabilizes ailerons to keep the missile from spinning.  When a target passes into view, the increased heat radiations stimulate the nose unit to apply the necessary corrections to the shroud surfaces.


Suspension: Standard lugs.


Remarks: The Nose Fuze T85 has a special plate attached to it, on which the nose assembly is bolted.









12,000-pound  VB-13 "Tarzon" Air-to-Surface Missile

No picture available

Overall length: 21 feet
Warhead: 12,000-pound G.P. Bomb T10


General: This missile consists of a modified Bomb T10 with a circular, 54-inch shroud about its body for lift, an octagonal tail surface for control, and the radio control mechanisms for guidance in range and azimuth.  It is well suited for use against targets requiring direct hits, deep penetration, and heavy explosive loads.  Good visual bombing conditions are necessary, and, when several bombs are to be used on the same target, all must be dropped together, since the first explosion will visually obscure the target area.  Another tactical requirement is for the dropping aircraft to remain on its bomb run until the missile strikes.


Control: The control mechanism and procedure are fundamentally similar to those of the VB-3.


Suspension: Depending on the aircraft employed; generally similar to that of the Bomb T10.





Next Time: A.A.F Missiles (Part 2) and the "Loon"