[RedJohn]

pawn Код:

CMD:jetpack(playerid, params[])
{
    if(!IsPlayerAdmin(playerid)) return SendClientMessage(playerid,COLOR_RED, "ERROR: Only administrators can use this command.");
    new targetid;    
    if(sscanf(params,"u", targetid)) return SendClientMessage(playerid,COLOR_RED, "USAGE: /jetpack [ID/PartOfName]");
    SetPlayerSpecialAction(targetid, SPECIAL_ACTION_USEJETPACK);
    return 1;
}

Jet pack is not a weapon. It's special action.