No Erros in Creating Custom Objects With Methods

Hi,

i have created an object called plane with the bellow methods. I have not defined them anyway on my script file but i am curious to find out why flash does not respond by giving me any errors telling me that the methods i.e pitch to say that they have not been defined? This is something that i would have expected flash to tell me. This results in a successful build and as a result i am able to still run the file. Why does it not notify me of any erross even though clearly they have not been declared anywhere i my script.?

var plane:Object = new Object();

plane.pitch = 0;
plane.roll = 5;
plane.yaw = 5;

I am also using FlashDevelop

Cheers