Исправлено с учетом парашютировавшихся
Код:
using System;
using maddox.game;
using maddox.game.world;
using System.Collections.Generic;


public class Mission : AMission
{

    const int TotalArrestTime = 30;  // Time in seconds

    public class prisonCell
    {
        public Player Prisoner { get; set; }
        public DateTime JailTime { get; set; }
        public bool Removable { get; set; }
    }

    public List<prisonCell> PrisonCamp = new List<prisonCell>();


    public override void OnPlaceEnter(Player player, AiActor actor, int placeIndex)
    {
        base.OnPlaceEnter(player, actor, placeIndex);

        if (actor == null) // if player bailed out the actor is null so remove him from prison
        {
            if (PrisonCamp.Count != 0)
            {
                foreach (prisonCell pri in PrisonCamp)
                {
                    if (pri.Prisoner == player)
                    {
                            pri.Removable = true;
                    }
                }
                PrisonCamp.RemoveAll(item => item.Removable == true);
            }
        }

        if (PrisonCamp.Count != 0)
        {
            foreach (prisonCell pri in PrisonCamp)
            {
                if (pri.Prisoner == player)
                {
                    TimeSpan ArrestTime = DateTime.Now.Subtract(pri.JailTime);

                    if (ArrestTime.TotalSeconds < TotalArrestTime)
                    {
                        GamePlay.gpLogServer(null, "Player: {0} get a {1} sec. penalty for leaving Airplane in flight\n", new object[] { player.Name(), TotalArrestTime });
                        GamePlay.gpHUDLogCenter(new Player[] { player }, "{0} you are under Arrest!", new object[] { player.Name() });
                        (actor as AiAircraft).hitNamed(part.NamedDamageTypes.FuelPumpFailure);
                    
                    }
                    else
                    {
                        pri.Removable = true;
                    }
                    
                }
            }

            PrisonCamp.RemoveAll(item => item.Removable == true);
        }
    }

    public override void OnPlaceLeave(Player player, AiActor actor, int placeIndex)
    {
        base.OnPlaceLeave(player, actor, placeIndex);

        if ((actor as AiAircraft).IsAirborne())
        {

            prisonCell NewPrisoner = new prisonCell();
            NewPrisoner.Prisoner = player;
            NewPrisoner.JailTime = DateTime.Now;

            PrisonCamp.Add(NewPrisoner);
        }
    }
}