Yesterday could be called "Bottle Rocket Tuesday." Two of the nation's air couriers are flying high -- figuratively and literally.

When we introduced readers to Air T (NASDAQ:AIRT) six trading days ago, it had just jumped 43% from $5.27 and was still rising. And it's still rising. The air under the wings of this carrier has now carried it to $20 -- a whopping 279% gain in six trading days.

Was it the Motley Fool Income Investor-pleasing 2.6% dividend, the 31% increase in revenue, the low price-to-earnings ratio of 10, the working relationship with FedEx (NYSE:FDX), or the unique operating model that helps the company avoid the operating expenses that occasionally cripple airlines such as AMR's (NYSE:AMR) American and Delta (NYSE:DAL)? It all helped.

Now that this bottle rocket has soared to 25 times trailing earnings, the question is, "Now what?" Consider our opinion way back when -- like, a week ago Monday. "Air T does not enjoy the operating margins of giant United Parcel (NYSE:UPS). Then again, it doesn't trade at 27 times earnings, either." Well, it's now trading at close to UPS levels.

No analysts cover Air T. With only 2.7 million shares outstanding, the stock is a true Lilliputian that, at current price levels, is hardly in line for a Motley Fool Hidden Gems recommendation.

Also making a big percentage gain yesterday was World Airways (NASDAQ:WLDA). Up 28%, the stock has been buoyed by expectations that the company will be profitable for the third straight year.

Unlike Air T, World Airways is highly leveraged. Like Air T, it gets a high percentage of its revenue from one customer -- and there is the rub. World Airways relies on the U.S. Air Force for three quarters of total revenue.

World Airways' stock is up 85% over the last 52 weeks. Trading at an extremely modest five times trailing earnings and 11% of sales, the company has upside potential if it can maintain margins, continue to produce free cash flow, and reduce leverage.

Spend time talking to other investors about Air T or the Best Travel Spots/Tips on the Fool's discussion boards.

Fool contributor W.D. Crotty, a Florida resident, pines for the sound of ukulele music and Hawaiian waterfront resort creature comforts. Keep sweating while you're dreaming, W.D.! He does not own stock in any of the companies mentioned.