When you link a bomber to a target, that's mission builder speak to dive bomb. For level bombers, just set a ground attack waypoint, and put it over where you want the bombs dropped. At least that's what I thought and the guide says.
I had no idea about the vanes. And since the U2 is such a speed demon, is there a workaround? Would coming in at a higher altitude work?


Update:
Did some really quick testing in the QMB and 6xFAB50s with instant fuse. It appears the cutoff altitude for instant fuse bombs is around 400 meters. All bombs dropped when the altimeter was above this exploded. Bombs dropped below the 400 meter mark were all duds and failed to explode. If I was to press tab key, the listed value for minimum drop is 89 meters.

Not quite: IL-2 can be linked and attack in strafing rocket/bomb runs. Diving while linked applies to stuka and val,ju88 and Pe-2 for the most part. The U2 AI is kind of quirky, even when set to unlinked its quite usual for the wingman to dive away at a start point, circle around etc. Almost acts as if its related to the swordfish for its behavior?

The U2 AI behavior is that of a level bomber, so the SET TARGET on the GATTack waypoint won't work.

Exactly my point, Ai cant execute the task of attacking a moving target. Good as level bomber over intersection, town etc.

Black Sea map bug
 

In map square BJ-25 on the Black sea map there is an unusual town called Ueunlar, it has 3 chimneys, no bldgs to be next to the chimney but blank spaces and a road running through where the bldgs should be.

I've noticed this still appears to be a major issue for the U-2 in 4.13.4, though hopefully it may have already been addressed by now in the 4.14 Beta.

If you want a perfect example just take a look at what happens to the two U-2VS wings in the stock TB-3 mission. It seems only the lead aircraft of each wing are able to fly for very long without crashing. The other four aircraft usually, if not always, just peel off and do descending spirals like they're trying to reach a point under the ground until the terrain avoidance fails and they crash.

Aircraft not being credited as destroyed
 

I’ve noticed that the CANT Z.506 will often not be credited as destroyed even when it clearly has been. Even when it has broken up in mid air in plain view of attacking fighters and is left with just the fuselage bobbing in the water it is still not credited as destroyed. This can be very frustrating. In my own mission design “Wildcat Ace over the Norwegian Sea” mission success is dependent on the destruction of the CANT and yet far too often the CANT is simply not credited as destroyed, resulting in the “Target Failed” message appearing when it clearly should be “Target Complete”.

I think this does happen with other aircraft also but I’ve mainly noticed it with the CANT.