Delta Airlines used federal transparency laws to demonstrate how cozy the federal Export-Import Bank is with aircraft maker Boeing — and it appears officials at Ex-Im then tipped off Boeing about Delta's open-records request.

Delta is suing the Export-Import Bank, arguing that the agency is ignoring its mandate to consider how it harms U.S. companies. When Ex-Im subsidizes Air India's purchase of a Boeing jet, for instance, this helps Boeing, but it also helps Air India — thus harming Delta.

Congress requires Ex-Im to study the economic impact of its export subsidies. Delta charges that Ex-Im's economic impact policy doesn't meet Congress's mandate and doesn't actually take into account the harm to U.S. airlines of subsidizing foreign airlines.

Ex-Im, over email and in private meetings, gave Boeing a central role in crafting the economic impact procedure. This is a bit perverse when you think about it: to study how jumbo jet subsidies might hurt airlines, why do you ask the jetmakers instead of the airlines?

We know about Boeing's intimate role in the rulemaking process only because lawyers for Delta, at the firm Kellogg, Huber, Hansen, Todd, Evens & Figel, filed a Freedom of Information Act request in October 2012, asking for "all communications between" Boeing and Ex-Im "regarding the Bank's proposed Economic Impact Procedures …"

More than two years later, Ex-Im delivered these documents to Delta's lawyers, who have since petitioned the court to include the relevant emails in the case's administrative record — in effect, the evidence that a judge should consider.

Ex-Im is fighting in court to keep the email chains out of the administrative record, and the court has yet to decide.

But the FOIA trail in this case may reveal even more about the coziness of Ex-Im and Boeing. Here's the timeline:

Delta filed its FOIA in October 2012. Four months later, an attorney for Boeing Capital filed his own FOIA request, seeking "a copy of a FOIA request submitted to Ex-Im Bank by the law firm Kellogg, Huber et al. requesting copies of communications between The Boeing Company and Ex-Im Bank," according to Ex-Im's FOIA log published in April 2013.

Here's the question: How did Boeing know that Delta's lawyers had filed such a FOIA? When I first asked an Ex-Im spokeswoman, she suggested that Boeing learned about Delta's FOIA through the FOIA log. But the FOIA log hadn't been published at the time — it was published two months later.

So I asked Delta if they had publicized their FOIA request, "We did not inform other parties, like Boeing, of that," Delta spokesman Trebor Banstetter told me.

I asked Boeing how they learned. "I haven't found any record of how and when we became aware of the Kellogg Huber FOIA," spokeswoman Allison Bone told the Washington Examiner.

I asked Ex-Im again. Spokesman Matt Bevens pointed me to Ex-Im's FOIA guidelines about "confidential business information," telling me "[you] should find the answers to your questions there."

"Whenever Ex-Im Bank receives a FOIA request seeking disclosure of business information," the guidelines state, "Ex-Im Bank shall provide prompt written notice to" the company whose business information is being sought.

Sure enough, some materials produced by Ex-Im in the Delta FOIA contained such confidential business information, in Ex-Im's judgment. The agency, then, may have contacted Boeing at some point to ask permission to publish it.

But that doesn't explain how Boeing knew about the FOIA when it did. Ex-Im's FOIA log said that the agency had "Not Started" to process Delta's request by April 2013. Boeing, again, made its request in February 2013.

I attempted repeatedly to follow up on this point with Ex-Im, but received no answer.

The two most likely explanations: First, the FOIA log could have been either incorrect or misleading when it says Delta's FOIA was "not started" as of April 2013. More likely, Ex-Im officials tipped off Boeing officials about Delta's FOIA request before Ex-Im even began processing Delta's request.

This wouldn't appear to violate any federal rules, but it sure would illustrate the coziness of Ex-Im and Boeing.

Timothy P. Carney, The Washington Examiner's senior political columnist, can be contacted at [email protected]. His column appears Sunday and Wednesday on washingtonexaminer.com.