Wow, it seems that my advice have been given a big thumbs down!
I do acknowledge the fact that the meters built in today's cameras are more sophisicated than those of some 15-20 years ago when I first got started. And unlike a Canon F-1 or Nikon F3, with this generation of cameras and their 'matrix' meters, you can indeed shoot in tricky situations, i.e. a white bodied aircraft or a very dark bodied aircraft (USAirways ect..) and pull some useable images......but they are not fool proof!
It all comes down to the built in meters. You must remember while the meters are more sophiscated nowadays, they are still basically reflective meters that are calibrated to read 18% gray also known as 'average reflectance'. Meaning that they are designed to read the light being reflected off of you subject. An it is assumed by the meter that anything you point your camera at is 18% gray. Well in the real world of photography not is 18%. If your frame is filled with an overly light or dark subject that are beyond the camera's meter to read then it will assume that the subject is of average illumination ...18%. If you shoot what your meter says or worse yet your camera is in program mode and you have no control over the F stop, shutter, well then, chances are good that your excessively lit subject matter may be underexposed or an overexposed image will result from a very dark subject.
What many pros, myself included still do is carry a hand held incident meter. This meter unlike the one built into your camera reads light 'falling' onto your subject, thus giving you an accurate meter reading. Many magazinge shooters still use these meters because they are shooting chromes and do not completly trust the camera's meter. These are expensive devices costing $350.00 on up, but there are ways to get an accurate reading without having to purchase this type of device. One of the best was is to take a reading off of the palm of you hand or point you camera to something that is netural in tone, like grass, a medieum tone sign..well you get the point. One thing that one must remember though is to make certain that your subject is in the same quality of light from where you metered.
But I digress, if you are shooting an aircraft from a distace (as most of us do), then you guys are right, I would not worry too much, since you frame will possibly be filled other objects, i.e. tarmac, vehicles, grass, sky ect.. thus balancing out your subject to an avarage reading. But as I stated before, if your frame is almost completely composed of the white body of an HA DC-9, then I would be apprehensive about using a 'programmed' mode.
I know this is a little wordy, but I hope you understand what I am trying say.
"Show me the Braniffs"