WASHINGTON • The turbulence began on Tuesday morning with one of President-elect Donald Trump's signature tweets of wrath: a public jab at Boeing alleging that the cost of building a new generation of Air Force One planes had spiralled out of control.
That came an hour after Boeing's CEO was quoted questioning Mr Trump's stance on trade.
In the afternoon, Mr Trump directed his attention elsewhere, taking credit, in a surprise announcement, for a Japanese conglomerate's months-old pledge to invest US$50 billion (S$71 billion) in the US.
This followed his assertion last week that he had saved 1,100 jobs in Indiana through a deal with air-conditioning company Carrier. The agreement includes US$7 million in state incentives for the company.
In the raucous hours in between, a top Trump aide announced offhandedly that, months before, Mr Trump had sold his entire stock portfolio, which some ethics advisers had worried could raise questions about conflicts of interest during his presidency.
It was a day of big pronouncements and few details, leaving many wondering whether this would be the unusual and unpredictable way that Mr Trump will govern the United States when he takes office next month.
That style, including his opaque personal financial dealings and his sudden shots at certain companies, has helped unnerve a corporate America that craves stability. Some business leaders and economists have worried whether executives can speak their minds about him or his policies without fear of provoking his rage.
"Twisting people's arms is inherently problematic" for a president, said Harvard economics professor N. Gregory Mankiw, who served as chairman of the Council of Economic Advisers under president George W. Bush.
"The president has so much power, you always wonder if there's some implicit threat to individuals, and that goes beyond what I think a limited government should do," Professor Mankiw said.
But some defended Mr Trump's highly visible way of doing business in his transition to the Oval Office.
Mr Lanhee Chen, policy director of Mr Mitt Romney's presidential campaign, who is now at Stanford University's Hoover Institution, said he was not terribly concerned by Mr Trump's interactions with individual corporations and chief executives.
"I just assume this is what generally happens," Mr Chen said. "I don't think it is that unusual for a president to make appeals to specific companies. What may be unusual is the public nature of the communications," he said.
Mr Trump has for months targeted companies that, like his own, have shipped jobs overseas. In a string of early-morning tweets on Sunday, he threatened "retribution or consequence" for companies that move operations out of the country, as well as a 35 per cent tariff on goods sold back to the US.
Mr Trump's Boeing slam, though, was something new. The contract for the two planes was to be about US$3 billion, but costs have been reported to be rising.
"Boeing is building a brand new 747 Air Force One for future presidents, but costs are out of control, more than US$4 billion. Cancel order!" Mr Trump tweeted.
In January, the US Air Force awarded Boeing a preliminary contract worth US$25.8 million, Reuters reported. In a statement on Tuesday, the Air Force said it had budgeted US$2.9 billion for research, development, testing and evaluation for the project in 2017, Fortune.com said.
Mr Trump's tweets came roughly an hour after the publication of a Chicago Tribune column citing Boeing chief executive Dennis Muilenburg's suggestion that Mr Trump and Congress "back off from the 2016 anti-trade rhetoric".
Trump spokesmen did not explain why he had targeted Boeing.