[blewert]

This should work (compiled with no errors for me):

pawn Код:

//20 Score Aircraft
    if( (GetPlayerScore(playerid) < 20) && IsPlayerInVehicle(playerid, 519) )
    {
        SendClientMessage(playerid, COLOR_RED, "You need 20 flying minutes (20 Score) to use the Shamal!");
        RemovePlayerFromVehicle(playerid);
    }
    else if( (GetPlayerScore(playerid) < 20) && IsPlayerInVehicle(playerid, 563) )
    {
        SendClientMessage(playerid, COLOR_RED, "You need 20 flying minutes (20 Score) to use the Raindance!");
        RemovePlayerFromVehicle(playerid);
    }
    else if( (GetPlayerScore(playerid) < 20) && IsPlayerInVehicle(playerid, 548) )
    {
        SendClientMessage(playerid, COLOR_RED, "You need 20 flying minutes (20 Score) to use the Cargobob!");
        RemovePlayerFromVehicle(playerid);
    }
    //40 Score Aircraft
    else if( (GetPlayerScore(playerid) < 40) && IsPlayerInVehicle(playerid, 577) )
    {
        SendClientMessage(playerid, COLOR_RED, "You need 40 flying minutes (40 Score) to use the AT-400!");
        RemovePlayerFromVehicle(playerid);
    }
    else if( (GetPlayerScore(playerid) < 40) && IsPlayerInVehicle(playerid, 592) )
    {
        SendClientMessage(playerid, COLOR_RED, "You need 40 flying minutes (40 Score) to use the Andromada!");
        RemovePlayerFromVehicle(playerid);
    }
    else if( (GetPlayerScore(playerid) < 40) && IsPlayerInVehicle(playerid, 417) )
    {
        SendClientMessage(playerid, COLOR_RED, "You need 40 flying minutes (40 Score) to use the Leviathan!");
        RemovePlayerFromVehicle(playerid);
    }
    //60 Score Aircraft
    else if( (GetPlayerScore(playerid) < 60) && IsPlayerInVehicle(playerid, 520) )
    {
        SendClientMessage(playerid, COLOR_RED, "You need 60 flying minutes (60 Score) to use the Hydra!");
        RemovePlayerFromVehicle(playerid);
    }
    else if( (GetPlayerScore(playerid) < 60) && IsPlayerInVehicle(playerid, 592) )
    {
        SendClientMessage(playerid, COLOR_RED, "You need 60 flying minutes (60 Score) to use the Rustler!");
        RemovePlayerFromVehicle(playerid);
    }
    else if( (GetPlayerScore(playerid) < 60) && IsPlayerInVehicle(playerid, 425) )
    {
        SendClientMessage(playerid, COLOR_RED, "You need 60 flying minutes (60 Score) to use the Hunter!");
        RemovePlayerFromVehicle(playerid);
    }

As for the method you're using, I think it could be improved. You're using OnPlayerEnterVehicle which is called when the player starts to enter a vehicle. You're checking whether they're inside the vehicle when they start to enter it. The best way to check whether a player has just entered a vehicle is by checking their state, using OnPlayerStateChange:

pawn Код:

public OnPlayerStateChange(playerid,newstate,oldstate)
{
    if( oldstate == PLAYER_STATE_ONFOOT && newstate == PLAYER_STATE_DRIVER )
    {
        //The players state has changed from on foot to in a vehicle.
        
        //Check whether it's the vehicle here.
    }
    return 1;
}

Personally, I'd do the same thing using arrays to make it neater:

pawn Код:

enum cPlaneData_ENUM
{
    //enum of variables for plane data, so we can access them easier
    nScore,
    nVeh,
    szVehName[ 64 ],
};

new cPlaneData[ ][ cPlaneData_ENUM ] =
{
    //nScore, nVeh, nVehName
    //0 ,     1,    2

    { 20, 519, "Shamal"    },
    { 20, 563, "Raindance" },
    { 20, 548, "Cargobob"  },
    { 40, 577, "AT-400"    },
    { 40, 592, "Andromada" },
    { 40, 417, "Leviathan" },
    { 60, 520, "Hydra"     },
    { 60, 592, "Rustler"   },
    { 60, 425, "Hunter"    }
};

public OnPlayerStateChange(playerid,newstate,oldstate)
{
    //The players state changed
    if( oldstate == PLAYER_STATE_ONFOOT && newstate == PLAYER_STATE_DRIVER )
    {
        //They're now a driver.

        for( new i=0; i < sizeof cPlaneData; i++ )
        {
            //Loop through array for plane data

            if( IsPlayerInVehicle(playerid, cPlaneData[ i ][ nVeh ]) )
            {
                //They're in the vehicle from the array

                if( GetPlayerScore(playerid) < cPlaneData[ i ][ nScore ] )
                {
                    //If the players score is less than the defined score for this vehicle

                    new szStr[ 128 ];

                    format( szStr, sizeof szStr, "You need %d flying minutes (%d Score) to use the %s!", cPlaneData[ i ][ nScore ], cPlaneData[ i ][ nScore ], cPlaneData[ i ][ szVehName ] );

                    //Send message and remove them.
                    SendClientMessage( playerid, COLOR_RED, szStr );
                    RemovePlayerFromVehicle( playerid );
                }

            }

        }
    }
    return 1;
}