Despite booking billions of dollars in new plane orders at the year's biggest air show this week, Boeing Co and other aerospace companies approach second-quarter earnings as victims of their own success.

Boeing's stock soared nearly 80 percent last year, outperforming the Dow Jones Industrial Average and the S&P 500 index. Many suppliers to the world's biggest plane maker also beat the market.

But as indexes pushed higher this year, investors sent Boeing down 5.7 percent amid concern that the aviation business cycle may have peaked and that Boeing's ability to produce positive surprises is limited. Suppliers also suffered.

For the stock to rise, Boeing needs to notch up profit margins on jetliners, run its factories smoothly, and win price cuts from suppliers. It also must keep booking orders.

Last month, Dubai-based airline Emirates canceled a $16 billion deal for Airbus Group NV's new A350. More cancellations could spook investors and ripple down to suppliers such as Spirit Aerosystems Holdings Inc, Precision Castparts Corp and Honeywell International Inc.

Boeing is considered on track to deliver a record 715 to 725 jetliners this year, having delivered 342 in the first half. But hiccups in 787 Dreamliner production this year suggest Boeing may struggle to keep its promise to make jets even faster.

"They need to continue to crank 787s out and get cash flow on them," said Jim Reed, co-manager of the Global Equity Fund at Scout Investments, in Kansas City, Missouri, which holds about $185,000 worth of Boeing stock.

"And they need to move from producing 10 787s a month to 12 a month, like they say they're going to do" by mid-2016.

GREEDY FOR ORDERS

At the Farnborough International Airshow, Boeing had booked 70 orders as of Tuesday, adding $11 billion to its record backlog. That is down from 260 deals worth $34 billion at the Paris Airshow last year. Boeing's orders are 12 percent lower this year through May than a year ago.

"Orders are one of those things you want to be greedy on," said Oliver Pursche, president of Gary Goldberg Financial Services, a money management firm in Suffern, New York, with about $1 million invested in Boeing.

As well, many Farnborough orders came from lessors, not airlines, underscoring concerns about a possible bubble in plane production and a recent spate of airline profit warnings.

Still, profits at plane makers and suppliers have soared 65 percent since 2007, said Eric Kronenberg, managing director at consulting firm AlixPartners.

He expects profits to keep climbing. Boeing is squeezing suppliers to cut costs and widen its margins. But suppliers will streamline their factories to avoid cutting their own profits, Kronenberg said.

Boeing's jetliner operating profit margin hit 11.8 percent in the first quarter, its highest level in a year. Investors want it to beat that number when it reports next Wednesday.

But even a good performance may not galvanize investors.

"A lot of the good news for Boeing is already out there," said Catherine Avery, chief executive officer of CAIM LLC, a money manager in New Canaan, Connecticut.

She sold Boeing in late 2013, capturing the 80 percent rise.

To buy again, she wants "some sort of indication that there's going to be a much stronger trend for order growth," she said. "And I'd like to see how things go with their production."