airplane collision detection problem

Questions & Answers
1

hi their , i am doing a simple top-down view airplane game where u pilot a small airplane then u can land it on the airport , this is where i have the problem bcz the airplane is rigid body here is the scene settings:

1-a flat ground with a box collider(if over this it must crash)

2-a flat rectangle plane (Airport) with a box collider ,if over this it must not crash ever.

3-airplane that is controlled via physics that have box collider that prevents it from falling.

the problem :
when landing hard (i want to damage it only) it crashes as if it is over the flat ground , because the colliders intersect with each other and pass each other for a split second.

note:the airport is over the flat ground.

Script:

#pragma strict
var hits : RaycastHit[];
var airport : Collider;
var ground : Collider;
var height : float;

var boomObject : GameObject;
var airplaneObject : GameObject;
var planeWreck : GameObject;

var isLanded : boolean;


function OnGUI(){
	if(isLanded == true){
		GUI.Box(Rect(Screen.width / 2 - 50 , 10 , 100 , 25),"Landed!");
	}
}

function FixedUpdate () {
    hits = Physics.RaycastAll (transform.position, -transform.up, 0.5);
    for( var hit : RaycastHit in hits ) {
		if(hit.collider == airport){
			height = transform.position.y - hit.point.y;  
			if( height <= 0.5){
				isLanded = true;
				return;
			}
		}
		if(hit.collider == ground){
			height = transform.position.y - hit.point.y;
			if( height <= 0.5){
				Instantiate(boomObject, transform.position, transform.rotation);
				Instantiate(planeWreck, transform.position, airplaneObject.transform.rotation);
				Destroy(airplaneObject);
				Destroy(GetComponent(PlaneControl));
				return;
			}
		}
    }
}

please advice and thanks for any help i can get.

2

ok i have fixed it somehow (work around) , by adding a small timer to the crash script:

#pragma strict
var hits : RaycastHit[];
var airport : Collider;
var ground : Collider;
var height : float;

var boomObject : GameObject;
var airplaneObject : GameObject;
var planeWreck : GameObject;

var isLanded : boolean;

var timeToCrash : float;
var startTimeToCrash : float;

function Start(){
	timeToCrash = startTimeToCrash;
}

function OnGUI(){
	if(isLanded == true){
		GUI.Box(Rect(Screen.width / 2 - 50 , 10 , 100 , 25),"Landed!");
	}
}

function FixedUpdate () {
    hits = Physics.RaycastAll (transform.position, -transform.up, 0.5);
    for( var hit : RaycastHit in hits ) {
		if(hit.collider == airport){
			height = transform.position.y - hit.point.y;  
			if( height <= 0.5){
				isLanded = true;
				return;
			}
		}
		if(hit.collider == ground){
			height = transform.position.y - hit.point.y;
			if( height <= 0.5){
				isLanded = false;
				TimetoCrash();
				
				//return;
			}
		}
    }
}

function TimetoCrash(){
	timeToCrash = timeToCrash - 0.01;
	
	if(isLanded == true){
		timeToCrash = startTimeToCrash;
	}
	
	if(timeToCrash <= 0){
		Instantiate(boomObject, transform.position, transform.rotation);
		Instantiate(planeWreck, transform.position, airplaneObject.transform.rotation);
		Destroy(airplaneObject);
		Destroy(GetComponent(PlaneControl));
		timeToCrash = startTimeToCrash;
	}
}

i have set the (startTimeToCrash) to 0.1;

i know its kind of hackish way to do it but it did it for me.

if there is any better solution for it i wish somebody post it plz, thx.