Shares of Motley Fool Rule Breakers recommendation AeroVironment (NASDAQ:AVAV) rushed out of the gate as markets opened yesterday, blasting 11% higher in response to an "earnings beat" the evening before. The shares gave back much of their gains as the day progressed, true -- but from where I sit, that's good news for investors.

I'll bite. Why?
Simply put, AeroVironment (AV) produced stellar results Tuesday, yet the price today has not risen in proportion to the good-ness of the news. Result: Investors now have a chance to buy more shares at a price that doesn't fully reflect the company's prospects.

Look, up in the sky!
After maintaining a level flight path for two years straight, cash from operations surged 150% in 2009. Free cash flow did even better, soaring 250% to $26.5 million.

Speaking of cash, AV boasts a fortress balance sheet -- $138 million in cash, equivalents, and short-term investments versus zero long-term debt. Net that cash out of the firm's $606 million market cap, we're looking here at a company selling for 17 times enterprise value, yet looking to grow its revenues at least 18% this year -- while maintaining its beefy 13% operating margin. (Eat your heart out, Boeing (NYSE:BA).)

Look farther
Time and again, AV has promised to grow sales at a long-term rate of about 20% or better. It didn’t quite hit that target in fiscal 2009, but I've every confidence it will succeed going forward.

You see, investors sometimes become overexcited when AV's growth rate spurts ahead of its long-term goal -- only to be disappointed when growth throttles back. Seeing AV achieve only 15% sales growth has investors feeling down on the stock again this week.

But consider: AV ended the year with funded backlog up 40% year over year. (This despite AV’s place in a crowded space with larger competitors such as Textron (NYSE:TXT) and Northrop Grumman (NYSE:NOC), and going toe-to-toe with Lockheed Martin’s (NYSE:LMT) tiny Desert Hawk in the UAV race.) As AV's megabacklog gets drawn into the revenue stream, revenue growth should accelerate.

Down to earth
Nor are UAVs the only revenue driver in AV's bag o' tricks. The firm's expanding alliances in the alternative energy sphere -- where it's inking deals with Japanese automakers like Nissan (NASDAQ:NSANY) and Toyota (NYSE:TM) to employ AV's PosiCharge battery charging technology -- helped AV's alt-energy division (EES) grow twice as fast as the UAV business. This division, at least, is making 25% revenue growth a reality.

Foolish takeaway
Once the firm's flagship UAV unit catches up, this stock will catch fire. If you aim to own it before that happens, the time to buy is now.

Everything you ever wanted to know about investing in UAVs:

Fool contributor Rich Smith owns shares of AeroVironment and Boeing. AeroVironment is a Motley Fool Rule Breakers selection. Nissan Motor is a Motley Fool Global Gains selection. The Motley Fool's disclosure policy folds easily into the original UAV -- a paper airplane.