Investors in Brazilian regional jet specialist and Motley Fool Stock Advisor recommendation Embraer (NYSE:ERJ) may want to tighten their seatbelts today. Writing here in the pre-market hours, I have no idea how the stock will react to today's news, but a slight miss on both the top and bottom lines could make for a little patch of turbulence.

The quarter wasn't all that bad. Sales rose more than 13% (vs. an expectation of 15%), and the company delivered 41 jets in the quarter. Margins were a bit soft, though. Gross margin actually fell more than five percentage points from last year's level, partly because of the appreciation of Brazilian currency (the real) and manufacturing inefficiencies in the newer 175 and 190 lines. Remember, although the company's sales are denominated in dollars, its costs are predominantly in reais.

Embraer did earn some of the loss back through lower operating expenses, and the operating margin did improve more than two percentage points from last year. Nevertheless, higher finance costs and currency losses led to a 3% drop in net income and a similar drop in earnings per American Depositary Share, missing estimates that called for a slight increase.

Although this quarter wasn't so hot, I wouldn't overreact. In fact, if a lot of people do overreact, it could be an opportunity for Fools to join Embraer's flight path. I still believe that the commercial aerospace market is on the upswing, and it still appears that Embraer has ample opportunity to penetrate the regional jet market -- a market where offerings from the likes of Boeing (NYSE:BA) and Airbus aren't always cost-effective.

Investors should note some risk factors, though. The company's sales are concentrated among relatively few customers, with U.S. Airways (NYSE:LCC), JetBlue (NASDAQ:JBLU), and ACE Aviation Holdings' Air Canada making up a little more than half of the order book. There's also the foreign currency risk, which came home to roost this quarter.

Fellow Fool Rich Smith has discussed comparative net margins in the aviation space, but I prefer to pay closer attention to return on invested capital. By that standard, Embraer is not only well above its industry averages, but also solidly in the double digits -- the level that I deem as "good." With an underlying industry upswing, solid returns on capital, and a good backlog of orders, there may be yet be room for Embraer to take off.

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Embraer and JetBlue are Motley Fool Stock Advisor recommendations. To find more stocks that are ready for takeoff, book a flight with co-pilots Tom and David Gardner. A free 30-day trial subscription is just a click away.

Fool contributor Stephen Simpson has no financial interest in any stocks mentioned (that means he's neither long nor short the shares).