Boeing CEO Dennis Muilenberg reportedly put in a call with President Donald Trump on Tuesday to try to convince him not to ground his company’s embattled 737 Max 8 planes after two such models crashed in a matter of months. A number of countries have decided to keep the planes out of the air, but not the United States.

Maybe the US and the Federal Aviation Administration are right to see what investigators find out and take a prudent approach before taking action. But it would be a lot easier to believe that if Boeing weren’t so chummy with Trump.

The relationship between the Trump administration and Boeing has come under increased scrutiny in recent days amid concerns over the safety of one of the manufacturer’s planes. On Sunday, March 10, Ethiopian Airlines flight 302 from Addis Ababa, Ethiopia, to Nairobi, Kenya, faltered and crashed soon after taking off, killing all 157 people on board. Just five months before, in October, a Lion Air flight taking off from Jakarta, Indonesia, crashed, killing all 189 passengers. The flights were the same model of planes, the Boeing 737 Max 8.

Multiple countries have grounded the planes, and in the US, there is increased pressure on the FAA to follow suit, including from members of Congress from both sides of the aisle, such as Sens. Elizabeth Warren (D-MA), Richard Blumenthal (D-CT), Dianne Feinstein (D-CA), Mitt Romney (R-UT), and Ted Cruz (R-TX).

But thus far, the FAA isn’t budging. The agency says its team is working with the National Transportation Safety Board to investigate what happened with the Ethiopian Airlines flight and that if it identifies an issue that affects safety, it will take “immediate and appropriate action.”

The FAA may just be acting prudently and gathering all the facts. But given the cozy relationship between Boeing and Trump, there’s a shadow of a doubt that’s impossible to shake.

Trump and Boeing go back

Ken Vogel at the New York Times reported on Tuesday that Muilenburg, Boeing’s CEO, spoke with Trump on the phone in the morning to make the case that the Boeing 737 Max 8 planes are safe and do not need to be grounded in the US. According to a Boeing official, Muilenburg called after Trump tweeted that airplanes are “far too complex” and that the complexity “creates danger.”

Tuesday’s phone call isn’t the first time the pair have come into contact.

Boeing donated $1 million to Trump’s inauguration.

When he was elected, Trump complained that the price of the new Air Force One, which Boeing was set to make, was too expensive and threatened to cancel the order. As Reuters notes, Muilenburg and Trump personally negotiated the cost, and Muilenburg visited the president in Trump Tower. “He cares about business and he creates open communication lines, and we will have differences from time to time, we may not agree on every topic,” Muilenburg said in a recent radio interview of Trump.

Trump’s acting secretary of defense, Patrick Shanahan, worked at Boeing for 30 years. Trump’s former US ambassador to the United Nations, Nikki Haley, is about to join Boeing’s board. The president has held events at Boeing facilities in St. Louis and Charleston. When he got upset about the cost of Lockheed Martin’s F-35, he threatened to buy Boeing products instead.

Based on the tremendous cost and cost overruns of the Lockheed Martin F-35, I have asked Boeing to price-out a comparable F-18 Super Hornet! — Donald J. Trump (@realDonaldTrump) December 22, 2016

In the wake of the killing of dissident Saudi journalist Jamal Khashoggi, Trump publicly fretted that any action by the US could threaten defense deals for companies such as Boeing, Lockheed Martin, and Raytheon. (He cast his concern as one about jobs.) Per Reuters, Trump has pressured US allies to buy Boeing’s products.

Prior to landing at the White House, Trump bragged about making money off investing in Boeing’s stock.

"@carson_evans1: @realDonaldTrump You were right back in January when you said Boeing was the stock to buy..." Thank you! — Donald J. Trump (@realDonaldTrump) July 1, 2013

"@RealBboy360: @realDonaldTrump Boeing is at a record high, thanks for saying to buy a while back" You are welcome. — Donald J. Trump (@realDonaldTrump) September 18, 2013

It would actually be great to know that there’s nothing fishy going on here

Both the FAA and Boeing say they’re investigating what’s going on with the 737 Max 8 planes and are confident in the “continued airworthiness” of the model. Both have committed to making certain design enhancements to the jets by April, and they’ve set out to figure out what happened in both crashes in order to prioritize safety. Flying is and continues to be the safest mode of transportation in the world.

Still, the blurred lines between Trump and Boeing make this a bit harder to sit with for a flying public that is already anxious about what’s going on. To compound matters, the FAA doesn’t have a permanent administrator, only acting head Daniel Elwell. The top job at the agency has been empty for more than a year. In 2018, Trump reportedly floated the idea of appointing his personal pilot, John Dunkin, as head of the FAA.

The Trump-Boeing ties in this current context are telling of a couple of things. One, it’s unfortunate that we just can’t be quite sure the president isn’t being swayed by his personal leanings in keeping Boeing’s planes in the air. And two, that the chief executive of a major company has the ability to sway the president at all, frankly, sucks.

It’s an analogous scenario to the AT&T/Time Warner deal, which the Department of Justice sued to block (and lost). As Vox’s Matt Yglesias laid out, the Justice Department had valid reasons to oppose the deal. But because of Trump’s antagonism toward CNN, it was impossible to know whether it was only going after the merger on the merits or whether there was some sort of Trump personal vendetta element in play.

Or look at the Trump administration and Apple. CEO Tim Cook has spoken out against Trump at times, but in the interest of favorable tax and trade policies, he’s friendly with the president as well.

It would be reassuring to be absolutely confident that the FAA is doing the right thing here on Boeing and taking the correct approach. That may very well be the case. But given Boeing’s tight relationship with Trump — and its CEO’s ability to just get the president on the phone to try to convince him of something — we can’t be sure.

The news moves fast. Catch up at the end of the day: Subscribe to Today, Explained, Vox’s daily news podcast, or sign up for our evening email newsletter, Vox Sentences.