BF42.de's Battlefield Vietnam Q&A talks with Armand 'Aj' Marini from DICE about the upcoming Vietnam War follow-up. They discuss the BF1942 mods with related features like EoD and Desert Combat, including this on how the helicopters in BF Vietnam will differ from those in DC:

The Battlefield vehicle system was never intended to be used with helicopters. We had looked at trying something similar with vertical take off (VTOL) vehicles in Secret Weapons, but the system did not allow for an acceptable level of control. The Desert Combat helicopters are the best attempt I've seen at trying to adapt the BF: 1942 system to be used in that capacity, but the issues of control and accessibility still exist.

We wanted a helicopter that was useful in a true helicopter sense. It had to hover with pinpoint accuracy, fly backwards, fly sideways, and airlift. It had to be immensely versatile and as easy to control as a tank. The BF: 1942 system didn't allow for any of those requirements. A new physics system was created for the helicopters and we are extremely pleased with the level of playability we've achieved. You can place it exactly where you want it to be.