This plane is manned by the luckiest crew of the luckiest squadron of the
Air Force. Their waist gunner is Triggered Joe with him at his post they can fly
anywhere with complete confidence. For a gun sight he uses a crystal ball.
He fires by instinct.
[gun shots]
Now stay there lucky lucky to be alive. Never mind that
crystal ball trigger he didn't have one. He didn't need one. There's science in
that kind of shooting. Take a look at it. A fighter has fixed guns all facing
forward to aim his guns he must aim his plane. He's like a flying
gun. In any type of attack the fighter must aim at the spot where you will be
by the time his bullets get there. In order to continue to fire at you he must
try a pursuit curve. This is the time he is really dangerous to you. This is the
time he is easiest to hit. There are five parts to a fighter's attack: over taking,
turn in, roll through, guns bearing,
and break away.
This is the pursuit curve. Now he is your target. To you he will
always appear head-on-- not this.
not this
but this, and this, and this. He's in his
curve. Head-on -- in range -- shoot! - Shoot?
[gunshots]
You know why you missed? You didn't allow for the
forward motion of the farmer being imparted to the fullest.
-Oh, yes. Uh, what was that?
-Remember when you were a paperboy? If you toss the paper directly towards the
porch you went sailing by and went next door? The same thing happens when you shoot
from a moving plane. If you fire point-blank at 90 degrees the bullet
continues to move in a direction you're going and will go up here. Before you
fire the bullet is moving with you on your line of flight. When you fire the
explosion sends it in a new direction. Upon leaving the muzzle the bullet
immediately turns and follows a direct path between them.
The paperboy never understood why but he soon learned he had to aim at this side
of the house for his paper to land on the porch. To hit this plane on the ground
then we must do the same thing. Make allowance for the effect our bombers
motion will have on the bullet.
We must make this allowance no matter where we shoot from.
Here,
here,
or here.
This deflection is always between the target
and the tail of our bomber.
At only one point are we a target for him.
At that time our point of aim is here. If we shoot accurately we get this.
Now if he is moving toward us our point of aim must be such that our bullets will
intercept him.
But what happens if we put him in the air, where he is free to
change his course and keep firing at us? As we move forward he must change the
angle of his approach. This is his pursuit curve
We apply the same principle of deflection we had for the moving plane
on the runway. As long as he stays in his curve we know where he will be and can
intercept him.
-Eh, paperboy deflection over here on a bicycle, yeah...
-Just remember the deflection is always between the target and the tail of your
bomber, but you have to make-- -I've got it, I've got it! Now watch this
[man] Between the Joker and my own tail. Let's see about here.
[gunshots]
-[Man] Hey! What the hell Doc?
-You're starting to get it -Starting? Brother, I got it!
-Your direction was right but you had no correction of your deflection as the
approach angle change. -Eh...for instance?
-We've seen that this amount of deflection is
right for a plane straight out at 90 degrees to your fore and aft axis and
when he's dead on your tail you can shoot straight at him
so at any other angle the deflection must be somewhere between these two.
-Eh, Doc... nothing personal but that don't look like nothing I ever seen in the air.
-Of course not you're not conscious at the forward movement of either your bomber
or the fighter. All you see is his movement in relation to your position in
the air.
He appears to slide toward your tail. - I ain't seen nothing like that either.
-How about this?
-That, I've seen. -All right.
This is just a bird's-eye view of that attack.
Here's the way you see it.
-Oh...yeah...
-Here's the amount of deflection for 90 degrees
Here's the 90 degree position as you see it. Now here's how you aim. Using the 35 mil
radius of your gun sight as a measuring stick the proper deflection is three
rads or three times the radius of the guns sight. One, two, three. There-- that's
where you aim for 90 degrees. -Eh, how do you figure that?
-Oh, you want it established mathematically
Very well. 1000 times the quantity 1 over V sub 0 minus V sub T sin 90 degrees
over to 2V sub 0 squared times B sub G sine 90 degrees minus 1000 times P sub T
sine of 4 over V sub 0 times the quantity 1 plus a rolled v sub
Row V sub 0 equals 100 mils equals 3 rads
-So it's 3 rads at 90 degrees. What next? -90 degrees was straight out from your
bead. Half way back from there to your tail at 45 degrees the deflection is two rads.
One, two. Any questions? -No.
-Half the remaining distance at 22 and 1/2 degrees it is one rad and half again at eleven
and a quarter degrees it is only one half rad.
Out here it's three. Half way back it's two
Half again is one. And half
again one half. If you're flying a straight course and traveling at a true
airspeed of 225 that's all you have to remember. Approach angle, amount of
deflection for that angle. Now when you're in the air ninety
degrees can be up, down, side, all the way around. It becomes
a wheel. No matter where he is on that wheel always allow a three rad
deflection towards the tail of your plane. If he is coming in at 45 degrees
above, below front or back the wheel becomes a cone with your fore and aft
axis running through the middle.
-Eh, Doc...that don't -[Both speak] look like nothing I ever seen in the air.
-[Narrator] I know, I know.
In the air all you would see is straight out
for 90 degrees. Then half way back about here for you, the two rad position. It's
easy to find. Just remember it's a complete circle all around your plane.
Halfway again at the one rad position the cone becomes small and continues to
diminish with the angle of the approach. Frontal attacks are exactly the same.
Even though they may not at first appear to be sliding towards your tail, but if
you aim here-- see what your forward motion does to your bullet? Change your
aim in a direct line toward your tail and there's one less fighter to worry about.
If it's a direct hit on attack your forward motion does not affect the
direction of the bullet so you fire point-blank as you do from the tail.
When the angle is 11 and 1/4 degrees give it the same 1/2 rad deflection toward your
tail at 22 and 1/2 degrees one rad.
At 45 degrees 2 rad.
and at 90 degrees 3 rad.
-Okay, I got it. Give me a plane. Give me a plane.
Here's a high side attack. 90 degrees straight out. This is the position of your bomber.
Where would you aim? -Hmm...90 degrees 3 rads towards my tail. One, two,
three. There ya are. -Well, 3 rads is right but you'd have to have
a weird looking tail for that direction to be in line. Take a line from the target to the tail that
was built on the plane and put your sight on it. There.
[gunshots]
Hey! Wait a minute!
No fighter is going to sit still like that for you. It is constantly sliding towards
your tail so you have to keep changing your amount of deflection to have the
right aim at the key positions.
From the nose to the beam it is increasing.
And from the beam to the tail it decreases
Here's one last tip. As soon as he gets in range fire a two-second first.
[gunshots]
Check your angle and fire another two seconds
[gunshots]
Remember these three points: shoot only when he is attacking you and in range;
aim between the target and the tail of your bomber;
estimate the approach angle
and apply the correct deflection.
That's the story. Think you can do it?
-Certainly. Give me a plane. -Ready? Here he comes.
Well? -Eh, goes kind of fast don't it? -Only a few seconds for the whole attack.
-How's for a chance to practice on a few, uh, slower ones?
-Okay. If you're sure you've got it straight.
-Oh I got it! I can talk it good. -Let's hear you. Here's a plane.
-Well... first I figure is he an enemy plane? In this case he is. Next, is
attackin'? Not yet but he looks suspicious! Yep... now he's turning in. I line
them up and just wait for him to get in range. There he is!
Headin' right for me. Hold it! Hold it! Hold it! Eh, I've got a lot of figuring to do with
this spot. Now I'm going this way he's coming this way. It's about 90
degrees it's three these red things on a line come at a tail and he's in range. I
guess I can shoot. Okay let him come! Hold It! Hold It!
That's two seconds.
Now here's looks like about a rad and a half maybe a little more yeah start him again.
How'd I do? -Didn't miss a thing.
How about taking one full speed? -Okay...
Why not? First I got to identify him. He's enemy all right. Looks like the same guy.
Eh, maybe I'll get him this time. Now he's coming in, gotta line him up, check the
range estimate, approach angle, towards my tail, 90 degrees, did equation country ranch
down here [shooting sound and quick talking]
-Look trigger! Look at the plane!
-Hey it works! Well I'll be a sad sack of --
..rads.
[music]