I'm far from an expert in aerial photography, but I just wanted to add one small comment to the previous post: having one aerial photograph in your portfolio can be a real plus for you, and I recommend it. For many years I've had just one single aerial photo in mine*, but people almost always linger over it and ask about it.
In general, photographers want their portfolios to say "I'll do anything," and that's usually a mistake. (Have I written a post yet about why you should never have one wedding photograph in your portfolio? If I haven't, I've been meaning to.) Your portfolio should target a specific clientele and work to convince that clientele that you're the absolute best person for the job at hand—it shouldn't be a hodgepodge of jobber work of various kinds. However, having a token aerial shot might well be the exception to that rule. It really does say to clients "I can do anything" in a meaningful way. Generally, amateur photographers who do casual pro work once in a while aren't trusted with the budget for a plane or a helicopter. An aerial implies that you were trusted with just such a important job—even if you weren't!
Adding one aerial shot to your portfolio isn't as hard as it sounds. You might have a friend who flies. Small planes and helicopters can be rented for not that much money. And there are even things like biplane rides at air shows and tethered hot air balloon rides that can get you way up in the air for very little inconvenience or expense. Best of all, while it's just as hard to get a great aerial shot as it is to get any other kind of great picture, getting a good one is fairly easy...lots of things look more interesting from high above, as most of us know from peering out the window of a descending airliner when the air is clear and the light is nice.
Anyway, I highly recommend adding an aerial shot to your general portfolio. It's unlikely to get you any work shooting them, but it says good things about you all the same.
*I'd show it to you if my darned scanner worked, but oh well.
Featured Comment by Dave: "As a former flight instructor I can tell you that if show up at your local airport, a flight instructor will be happy to help you take aerial photos. Most flight instructors will do just about anything to log additional flight time. A photo flight is considered a cherry assignment for a starving flight instructor. It beats teaching someone how to land.
"Some tips to get the most out of your photo flight:
1) Plan ahead—an hour of flight time will cost from $60–$120. You'll not want to waste a minute. Spend at least an hour with your pilot planning the photo mission. The pilot will need to have a plan for navigating to the photo site and dealing with local air traffic control.
2) Schedule to fly during good lighting conditions. Early morning or late afternoon.
3) Get some latitude and longitude info from google maps. Most aircraft are now equipped with GPS. If you come prepared with lat and long data you'll save the pilot a lot of work and possible wasted flight time.
4) Ask if you can fly the plane. A flight instructor won't mind handing the controls over for awhile and teaching you some turns or something more exciting if you're brave."
Featured Comment by Steve Renwick: "As a Cessna driver, I'd like to add a few comments.
"Make sure that you and the pilot are on the same page at all times, i.e., you both know how low the plane will fly, you ask before opening the window, etc. Never surprise the pilot.
"If you are not accustomed to small planes, it would be a really good idea to take a ride without your camera at first, just so you know what to expect.
"As somebody else said, looking through the viewfinder whilst going in circles is a very good way to upset your stomach. Don't try to tough it out, as that won't work. Look up at the horizon and ask the pilot to fly straight and level for a while. A little delay is better than the alternative."
Featured Comment by Stan Semuskie: "I agree with your comment about the aerial photo in your portfolio. A couple years ago I received a call from Forbes.com to shoot a photo of the home of one of the richest guys in the U.S. I was kind of taken aback by the request, and asked if the person would set up the shoot. She said just rent a plane or helicopter, find the house and take a picture. I still wasn't convinced that I could do it so I called the local airport, in Hillsboro, Oregon, and much to my surprise I could rent a helicopter with a pilot for $125/hr, and they would only charge me for what I used in 6-minute increments. I did the job, used up the whole hour and shot much more than the house—I also shot my company, my house, and all my friends' houses from the air. It was one of the best experiences I have had.
"By the way, the person whose house I shot was Phil Knight (founder of Nike). He just happened to live in my town of Hillsboro, and I was lucky enough to get the job from Forbes. I would recommend anyone to call around and see what it costs for an hour of air time. I think many will be very much surprised at how inexpensive it can be."