Step 1: Have cobra pilots

Step 2: Make sure they're good ones

Step 3: Have them keep both dhsks dead so hueys don't get lit up as bad

Step 4: Have them keep the treeline and beach clear so that hueys can land even more safely

Step 5: Have good huey pilots that can land on the beach

Step 6: profit

Edit: If it's early/late war and you only have hueys, you either get all 4 hueys to land at the same time on the beach or you land on the flanks to allow the soldiers to push up. It's not a good idea to land on the beach with just one huey because unless the enemy is sleeping, everyone is going to die even if you do a hook landing to land as fast as possible.