Jet Gunnery Runs: Fixed Ranging

e [Music] a [Music] [Music] [Applause] you have been trained in the use of the standard practice Gunnery pattern this practice pattern was designed specifically for training and safety reasons under actual combat conditions however the only part of the practice pattern which becomes important is the pursuit curve or that part from Reversal point to Breakaway how you get your aircraft to the reversal Turn Point is a matter of tactics and will vary according to existing conditions the pursuit curve covers the entire Gunnery problem and is the only part of the practice pattern which will concern Us in this film while we concentrate on the problems involved in flying fixed Range Pursuit curves two pieces of equipment with which you must be thoroughly familiar are the Target and the Fire Control System the target used in jet Gunnery training is a standard tow Banner 30 ft long by 6 ft high with a 2T diameter buye the Fire Control System is designed to establish lead angles during tracking the computed lead angle at any given instant is presented to the pilot in the following way the Gun Site has two Optical images one is a fixed retical image called the fixed cross which represents the axis of the guns and the plane the other is the gyro retical image or pipper which represents the axis of the gyro the pil uses the pipper as his point of aim on the Target in straight and level flight the two images are superimposed as shown here when the aircraft turns however the fixed cross and pipper are displaced since the gyro represented by the pipper will tend to maintain its orientation in space thus lagging behind the movement of the plane as represented by the fixed cross the direction of displacement represents the direction of turn and the amount of displacement represents the rate of turn it also represents the lead angle in Mills necessary to obtain hits at any preset range which is usually 1,000 ft for fixed ranging therefore in order to establish and maintain the correct lead angle the pilot must turn his plane at such a rate that the displacement between the fixed cross and the pipper remains constant he keeps the pipper on the target since that is his point of aim at the same time the fixed cross representing the nose of his plane will be ahead of or leading the target for demonstrational purposes we will assume a starting point that is a reversal turn point of 6,000 ft range from the Target and an angle off of 90° during the initial part of the run or from approximately 6,000 to 4,000 ft range the tracking plane must be established there are two methods of doing this in method one as you come out of the reversal turn you will fly the fixed cross to a point slightly behind the banner and on a line with the banner and toe line then uncage the gyro so that the pipper is free to l behind the fixed cross in a direction opposite to your turn fly the fixed cross up to the banner through it and up to the junction of the banner straps and tow line hold the fixed cross on this point until the pipper moves up to a position just after of the banner now disregard the fixed cross and fly the pipper into a position on top of the banner directly over the B the displacement between the fixed cross and pipper now represents the correct lead angle only for the 1,000 ft range which you have preset range to the Target should now be about 4,000 ft with the tracking plane established the second method of doing this is as follows begin the run as in method one by flying the fixed cross up behind the banner through it to the scrap toll line Junction but this time do not uncage the gyro until the fixed cross is steadied on the tow line then when you uncage the pipper will drift back to the banner in the direction opposite to the direction of your turn keep the fixed cross in one spot until the pipper stops its drifting movement then fly the pipper to the top of the banner this method of establishing the tracking plane is a little slower than the first method but is somewhat easier to use after establishing the tracking plane you will be concerned from there on in with controlling it several adjustments will have to be made as range closes the rate of turn to track will be continually increasing this means that the angle of bank will also have to be increased resulting in a small loss of lift with the assuming a slight downward attitude the pipper will therefore have a tendency to drift up since the Turning plane is changing to hold the pipper down you must increase G's since the angle of bank will be continually increasing this adjustment must also be continuous from 4,000 ft to the Breakaway point during final tracking or from approximately 1,500 to 800 ft F feet you will have another adjustment to make again due to the sharply increasing rate of turn during the last part of the run the pipper will also have a tendency to drift back there are two methods of handling this in the first method you simply glue the pipper to the top of the banner and hold it there adjusting your flight path to overcome the pipper movement Tendencies this is easier said than done but if you can Master this method you'll get more hits using the second method you start with the pipper at the top of the banner bar and allow it to drift back as far as the bull then hold it there during the firing run this method is easier but since false lead angle information will be generated during the pipper drift your percentage of hits will not be as high you've probably noticed that the pipper not only drifts back during final tracking but also moves down from its starting position the downward movement represents a compensation for Gravity drop that you will have to make from whichever position that you have glued the pepper you will have to bring it down during the last part of the run as the range decreases to compensate for the fact that the bullets are going to drop less at closer ranges as you recall the pipper represents your point of aim at the Breakaway range of 600 ft the bottom of the pipper should be tangent to the top of the bull and will appear to be much smaller than the bull the firing run covers the range from 1100 to 800 ft remember however that the lead angle solution in fixed ranging will only be correct for one range in this case the figure that you have preset is 1,000 ft fet any rounds fired before 1100 ft will fall short of the target any rounds fired between 1100 and 1,000 ft will be under leading the bull but will still hit the banner those rounds fired between 1,000 and 800 ft will over lead the Bull but will hit the forward part of the banner after you have passed 800 ft you will miss the banner completely and result in a waste of ammunition cease firing at 800 ft but continue to hold the pipper on target for a brief instant while the last rounds leave the guns the Breakaway must then be made by the time you reach a closing range of 600 ft or an angle off of 15° whichever occurs first your best indication of range and angle off is the apparent size of the banner and its relation to pipper size at the beginning of the run with a 6,000 ft range to the Target and a 90° angle off the banner will look like this a 2 m pipper will appear to be twice the height of the banner and the Banner's length will be five times its height at 3,000 ft and approximately 60° angle off the banner and pipper will appear to be of equal height while the apparent length of the banner will now be only about four times the height due to the foreshortening effect at a 1,000 ft range with an angle off of about 25° the pipper and Bullseye will be of equal size and the bannner length to height ratio will be about 2: 1 when the size of the pipper is only 1/2 the size of the bowl and the Banner's length to height ratio is only 6 to 5 you are at the Breakaway Point since range will be 600 ft and angle off 15° this is as far as you can go without danger of banner Collision if you ever permit your plane to get this close so that the banner appears to be square you are a very likely candidate for a face full of cloth never get yourself in this position you will be much more likely to get hit than hits now in order to tie together what you've learned so far let's look at it as you will actually see it during a run now reverse you don't see the fixed cross during these runs since the camera can only pick up one image at a time bring it up commence firing let's try it again you're on your own [Music] oh [Music]