The City of Denver has asked the Federal Aviation Administration for additional time to gather information and prepare its response to the federal agency’s investigation of the city’s 2025 denial of a Denver International Airport ground lease expansion for Key Lime Air.

The FAA has agreed to extend the deadline, a spokesperson for Denver Mayor Mike Johnston’s office told The Denver Gazette, adding that asking for additional time is “standard procedure.”

In the formal Notice of Investigation, dated May 13, Michael Helvey, the director of the FAA’s Office of Airport Compliance and Analysis, asked the city to provide the agency with “specific reasons and arguments for the denial,” along with documentation, communications and records of meetings where Key Lime’s airport access may have been discussed.

The city originally had 30 days from the date of the notice to respond, but the deadline “was extended into July,” Johnston’s spokesperson said.

The Denver City Council voted, 11-1, in December to reject a contract that would have expanded Key Lime Air’s operations at DIA, citing disagreement with the company’s suspected involvement in federal deportation flights on behalf of U.S. Immigration and Customs Enforcement.

Specifically, the contract was for a 1,200-square-foot expansion of the company’s current ground lease so that personnel could store equipment in their own space rather than in a common storage area shared by other operators on the ramp.

“I have been following Key Lime Air for the greater part of this year, and I’m very, very concerned about the illegal deportations that this vendor is taking part in at the Centennial Airport,” District 11 Councilmember Stacie Gilmore said during the December council meeting, adding that there was no way she could “morally or ethically” vote affirmatively on the expansion of space.

Among the many documents requested, the FAA specifically has asked for communications regarding Key Lime Air’s safety record and complete transcribed minutes of any City Council meetings, committee meetings and executive leadership meetings where Key Lime airport access or lease matters may have been discussed.

Additionally, the FAA wants to see public and news release statements from the city regarding Key Lime Air operations at DIA, as well as documentation explaining the reasons for any other aeronautical users who have been denied access or leases to operate at DIA by the City Council since January 2025.

The investigation aims to determine whether the City of Denver, which owns and operates DIA, violated federal grant assurances by rejecting a proposed ground space lease for expanded access to the airport for reasons not defined by the FAA.

Because much of the airport’s planning and development has been financed, in part, with funds provided by the FAA under the Airport Improvement Program — more than $1.9 billion in federal airport assistance since 1988 — acceptance of those funds creates a legally binding contract guaranteeing that public funds are not misused and that the airport is operated safely, efficiently, and fairly.

Airports may legally deny an operator a lease if the decision “is reasonable, non-discriminatory, and aligns with FAA regulations,” according to the FAA.

Valid grounds for denial include a lack of available space, failure to meet local minimum standards, safety or efficiency compromises, and intentional use of airport facilities or land for purposes that do not support the flight of aircraft. 

The contract air carrier, which also operates under the name Denver Air Connect, has been under fire after protests erupted outside of its headquarters at Centennial Airport and at CU Boulder over the outfit’s suspected operation of federal deportation flights.

While several news agencies have reported that the contract airline is providing transportation on behalf of ICE, the company has not detailed its exact relationship with the federal agency.

“I think there’s a lot of ways that the airport will try to say that we can’t do this,” Gilmore said prior to the vote to reject the Key Lime lease. “Well, I think we need to test those waters, and this might impede on some FAA ground or FAA grant dollars that Denver International Airport might get.”