[Kaliber]

You make a timer:

PHP код:

new checkFalling[MAX_PLAYERS char];
new Float:x,Float:y,Float:z;
GetPlayerPos(playerid,x,y,z);
SetTimerEx("@checkFalling",999,0,"if",playerid,z); //The playerid you wanna check
@checkFalling(i,Float:oZ);@checkFalling(i,Float:oZ) {
    if(!IsPlayerInAnyVehicle(i)) return checkFalling{i}=0;
    new Float:x,Float:y,Float:z;
    GetPlayerPos(i,x,y,z);
    if(z >= oZ) return checkFalling{i}=0;
    if(++checkFalling{i} == 3)
    {
        //Here he is falling with an Vehicle for over 3sec
        return checkFalling{i}=0;
    }
    return SetTimerEx("@checkFalling",999,0,"if",i,z);
} 


Greekz