I'll be back later when I'm not at work, and can access some of my shots.
However, in the mean time, couple of thoughts on lenses, per your comment about not having the right length for RC.
First, don't sell yourself short. A couple of those are really fantastic shots. Specifically, #1 top row, and #2 second row especially.
There's no rule ANYWHERE that says you have to reach out and pull in an airplane in flight with some magical long lens. Heck...there pretty much aren't ANY rules, to be honest.
Considering the two photos i mentioned...let's remember, this hobby is NOT just about airplanes. heck, for a lot of us, the airplanes are really just the EXCUSE for getting together and playing a spirited game of "First fibber don't stand a chance".
This hobby is, for a lot of us, as much or more about the PEOPLE as it is the airplane. Pictures like those two capture an element that is missing in SOOOOO many RC photos.
Without meaning to be critical of your SKILLS, consider the composition of the fourth picture, top row...the one of the ultimate.
Bluntly...whee. It's a biplane...in the air. Yay. Again...I'm not criticizing your skill and shooting the picture in any way...but for ME (and ALL of this is simply a matter of personal preference), that's a non-starter of a picture. it's just an airplane in the air. I can't tell how high or low it is...I can't tell how big it is...I can't tell if there's anything unique about it or f it's "just another ARF"...or anything. beyond the fact that it's flying...and anything that flies is cool...the picture leave me completely "meh".
So...consider this. For at least ONE person here...the lens you've got is FINE...for a particular type of shot. I LOVE the two photos I mention above precisely BECAUSE there's some sort of context to them...context you simply could NOT get with a longer lens. What some may have seen as a "limitation"...the shorter lens...in those cases was a STRENGTH...it allowed you to get that close, and still retain the depth of field necessary to create the whole moment.
Is my opinion right or wrong? Absolutely not..it's just an opinion. Photography...and indeed our love of this hobby...is SO subjective. Just like you might love or hate my airplanes, and i yours...others may love or hate various pictures that show up on this thread. So be it. Ultimately, the photos ARE just like our airplanes...if we have fun creating and sharing them...then who CARES whether others like them?
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Having said all that, as an avid canon fan and owner myself, let me rcommend a couple of lenses if you ARE looking for longer stuff.
Canon makes a darn fine [link=http://www.amazon.com/Canon-55-250mm-4-0-5-6-Telephoto-Digital/dp/B0011NVMO8/ref=pd_cp_p_2/181-3201245-8934764]55mm-250mm lens[/link] that you can usually find for < $300. It's not "pro grade" optics by any chance, but it is a TERRIFIC lens for shooting RC imo. It'll reach out and grab airplanes from a gooddistance away, with considerable detail. a little experimentation with camera settings will let you do some really nice work, stopping airplanes but maintaining prop arcs, etc. It also happens to be a pretty decent lens for hobby-level sports photography, even for indoor events like NHL hockey.
If you have the budget, canon also makes a darn fine [link=http://www.amazon.com/Canon-70-300mm-4-5-6-Lens-Cameras/dp/B0007Y794O]70mm-300mm with IS[/link]. This, imo, is probably THE most "bang for the buck" lens on the market for sports/aviation photography, and happens to be my long lens of choice. For consumer level canon-compatible lenses, imo, it can't be beat.
Finally, there is my all time favorite sports/action lens, [link=http://www.amazon.com/Canon-100-400mm-f4-5-5-6L-Telephoto-Cameras/dp/B00007GQLS]Canon's 100-400mm[/link]. It ain't cheap at $1600, but holy cow. I've been blessed with the opportunity, over the last 4-5 years, to shoot almost every telephoto/zoom lens the Canon Rebel body will take, including some with price tags of 5 digits...and, honestly...even when compared with the best pro lenses out there...I'd take this 100-400 over ANY of them every day, ESPECIALLY for aviation photography. To give you a brief idea of what it's capable of:
Paul Bonhomme at > 200 kts, on a cloudy overcast day, at a range of about 200 yards.
It is a PHENOMENAL lens.
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Finally, certainly some pricetags can scare you...ESPECIALLY if you don't know whether you and the lens are going to get along. So...allow me to HIGHLY recommend [link=http://www.lensrentals.com/]lensrentals.com[/link]. INCREDIBLE service, top notch equipment, and VERY reasonable prices. As an example, you can rent the 400mm gem above for a whole WEEK for < $100, shipping included. I've done business with them multiple times (in fact, the pic above was shot with one of their lenses) and can NOT say enough good things about them. They offer a FANTASTIC way to try a lens before you buy, or, if you want a certain lens for a special RC event, but don't want to spring to buy it.
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Anywho, as i say...when I get back home, and can access a few shots, i'll be back to share. In the mean time, GREAT thread, can't wait to participate!