- Title: TRACER METHOD OF AIR SIGHTING [Main Title]
- Film Number: AMY 204
- Other titles:
- Summary: A technical training film for air-gunners, describing the operation of air to air combat with a movable gun aimed by a gunner in the aircraft. The alternative is fixed shooting where the pilot alone must position the aircraft for shooting. The film comprises an almost continuous series of animated diagrams (with a great deal of numerical data), photography of the resultant tracer tracks (filmed at night for clarity) and a supporting narrative. The nature of the film is such that to understand the diagrams and photography of the tracer, the narrative is also clearly understood, and vice-versa. The summary of the film, given here is thus limited to basic principles.
- Description: Reel one: Film opens with enemy aircraft attacking a bomber, as seen through the circular target locator for the guns in the rear turret, the gunner moving his sight as the enemy weaves about. An analogy is made with a stream of water from a fire hose, the movement of the nozzle sideways causes the jet of water to curve towards one side. Exactly the same pattern is observed for a stream of bullets from a moving gun. Film cuts to view of the tracer seen from behind the gun, the degree of curvature dependant on how quickly the gun is being moved. Deflection is defined as the distance between the enemy aircraft and the line of sight (of the gunner). The smaller the deflection the greater the accuracy likely to be obtained. “Misuse of tracer”: Rather than moving the gun up, down or sideways continuously, thus wasting bullets, the tracer path should be viewed through the circular sight, moving only to maintain view of the enemy aircraft. To hit the enemy aircraft, the target must be put on the same range as the enemy aircraft. A sequence of animated diagrams plus a narrative explain in detail how the range may be estimated from the tracer path. “Use of tracer as an aid to sighting”: The G3 reflector sight is used throughout the film. Close up photographs of the sight. More complex instructions aided by animated diagrams and tracer paths explain how the deflection is calculated. Reel two: “Range estimation”: The range of an enemy aircraft is determined by its apparent size within the sight ring. As the apparent size depends upon the actual size as well as the range, it is first necessary to recognise the enemy aircraft. Film shows the wings of an approaching Me 109 (of known wing span) seen through the circular ring sight. When the ring completely encloses the wing tips, the value of the range may be determined. Other aircraft of differing wing span would present an incorrect range unless the G3 sight was adjusted to suit. Film shows a larger aircraft Me 1110, extending far outside the ring that was adjusted for the Me 109. Animated diagrams for the He 111 bomber and the He 112 fighter are shown. Accurate range estimations can only be obtained by constant practise with scale models on the ground. “Sequence of operations to be taken by an air gunner”: Having recognised the aircraft, the range is determined and put on the corresponding point of the bullet trace for any deflective shot. Example for the Me109 is shown in a sequence of diagrams. A point blank tracer burst is fired, and the target placed where the trace ended, the target followed until the aircraft wings fill the circular sight, then fire point blank. The film concludes with several more examples of other enemy aircraft, and ends with a warning: the strong tendency to believe one can tell intuitively which part of the trace is the same distance as the target. Such estimates are nearly always wrong, and must be resisted.
- Access Conditions:
- Featured Period:
- Production Date: 1941
- Production Country: GB
- Production Details: ROYAL AIR FORCE (Production sponsor) British Thompson Houston Research Laboratories (Production company)
- Personalities, Units and Organisations:
- Physical Characteristics: Colour format: B&W Sound format: Sound
- Technical Details: Format: 35mm Number of items/reels/tapes: 2 Length: 1876ft
- Link to IWM Collections page:
Related IWM Collections Objects:
AMY 138 (FIXED GUN AIR FIRING - PARTS 1 2 AND 3 [Main Title])