It was very very difficult to destroy a tank in an air strike with a fighter bomber like a P-47 Thunderbolt or a Hawker Typhoon. In fact the allied made a study after the Fallaise gap, where Typhoons and Thunderbolts were having a field day pounding German armour and infantry all day long with bombs and rockets. In this study they investigated what had knocked out every panzer left there. Anything that did not have a clear cause was given to the fighter bombers. They amounted to … drumroll… 6%. Including all the freebies from unexplained damage.
The problem is both with bombs and rockets. With bombs in a low level attack from 50–75 feet the accuracy of the bomb drop is 150 meters length wise and 10- 15 meters side wise. Because at the release point you cannot see the target. Your line of sight is blocked by that huge radial engine in front, so the release point is anyone’s guess.
Firing rockets was nearly as hard as hitting with a bomb. You would not be coming in slow in the attack run, because these bastards are shooting back and they had a lot of 20 mm AKAK. 20 mm cannon shell will rip your fighter to pieces regardless if you flew a Typhoon or a Thunderbolt. You did not want to be hit. Bailing out at that altitude was not an option. So you would blast in at 350–400 km/h in a single attack run guns blasting walking them on target and then release the rockets.
No one with half a brain would attempt a second strafing run, because at the time you had gone round for the second run the bastards have gotten their shit together and would release a hailstorm of FLAK at you. Pilots who tried rarely survived to tell the tale.
Now the rockets. They have a drop off in relation to where your cannon shells land of about 70 yards. So if you see your shells exploding on the tank at 1000 yards and fire your rocket, they fall 70 yards short. So you have to guesstimate your range combine that with the correct length of overshoot of the cannon shells and then release the rockets at the absolutely perfect time, while you are going nearly 400 km/h, all the while you see streams of tracers arcing up towards you from four difference directions, and you know if they hit, you’re toast. Your active attack is less than 3 seconds at that speed.
Now let us see it from the tanks Point off view. You are driving your Tiger 1 over an open field towards the enemy holdout. And you see a Typhoon lining up for an attack run. You do not want to take a hit of one of his rockets. They carry the whallop of a 125 mm high explosive shell. If he strikes you topside. It will blast through the thin armour there. And regardless where he hits you, it will at least be a mission kill.
So you turn into him but drive at an angle say 30 degrees offset. That would force the pilot to have to calculate his attack run in 3 dimensions making it a magnitude harder to get right.
so hitting a moving target with bombs or rockets was neigh impossible.
But hitting a column locked length wise on a road was effective, because you only had to work in one dimension. Rockets were also great at surprise attacks upon stationary tanks but moving tanks, nope.
If you wanted to hit tanks from the air, dive bombers like the JU-87 was better at it because at 90 degrees angle you reduce the targeting calculation to two dimensions. The Kanonen Vogel was even better, because you had two 37 mm high velocity cannons, and you could walk the aim on to the target by shooting the machine guns until you hit and then fire the cannons.
The Brit had pretty good experience with 40 mm cannons on the Hawker Hurricane in North Africa, but German 20 mm FLAK was always nasty.