I take my canon 70D with a canon L 24-105mm with me pretty often. Any wider than 24mm on a crop sensor will get reflections from the cockpit and alot of flare. 105mm is sufficient if the other traffic is within 2nm and 1000ft vertically if you want a nice air-to-air shot. You also have wifi allowing for some fun editing in the air.
For street photography and filming it's a great combo as well. Since the 24-105mm is a kit lens that comes as standard together with the 5D you can find them for a good price second hand. The 70D has a superb autofocusing system. Most point and shoot cameras will have a big problem catching up with air-to-air shots unless you are flying parallel to the subject.
The solution for your problem is to get a bigger flight bag
