Just thought I would help here... I was having an issue with the spawned transport heli's not having both gunners in it. Here is what I found as to being the issue. After I changed it, all is working fine now and both gunners are onboard and doing their thing
original code in the "callTrans_spwn.sqf" file under the THel folder.
Code:
_grp2 = createGroup side player;
_crew = [];
_cfg=configFile >> "CfgVehicles" >> typeof _helo >> "turrets";
for [{_n=1},{_n<=(count _cfg)},{_n=_n+1}] do {
_gunner = _grp2 createUnit [RUM_THEL_Pilot, getpos _spwn, [], 0, "FORM"];
_gunner moveinTurret [_helo,[_n]];
_helo lockTurret [[_n], true];
if!(_gunner in crew _helo)then{deleteVehicle _gunner};
};
Changed to this to make it work...
Code:
_grp2 = createGroup side player;
_crew = [];
_cfg=configFile >> "CfgVehicles" >> typeof _helo >> "turrets";
for [{_n=0},{_n<=(count _cfg)},{_n=_n+1}] do {
_gunner = _grp2 createUnit [RUM_THEL_Pilot, getpos _spwn, [], 0, "FORM"];
_gunner moveinTurret [_helo,[_n]];
_helo lockTurret [[_n], true];
if!(_gunner in crew _helo)then{deleteVehicle _gunner};
};
Hope this helps out a bit as well as for anyone else that might noticed and had the issue where only one gunner was in the transport helo. 
Cheers
VRCRaptor