"The FAA's performance was poor and its compliance was pitiful," commission member Tim Roemer, the former Democratic congressman from Indiana, told United Press International. "I am glad that the commission has acted in such a bipartisan aggressive and thorough fashion to use the weapons in its arsenal" to ensure cooperation, he added.
He said the commission would not hesitate to issue more subpoenas if it was warranted.
In a statement, the bipartisan panel said that, despite having been told by the FAA that it had all relevant documents, "over the past two weeks ... the commission learned that various tapes, statements, interview reports, and agency self assessments highly material to our inquiry inexplicably had not been included in the FAA's production."
Although the agency had immediately turned over "dozens of boxes and materials that its representatives now claim satisfy our request," the 10-member commission said it was issuing the subpoena because "the delay had impeded the progress of our investigation and undermined our confidence in the completeness of the FAA's production."
The FAA said it was "surprised" by the decision, which it called "unnecessary."
"There was never any intention on our part to withhold anything they wanted," spokeswoman Laura J. Brown told UPI. "We just didn't fully understand the scope of their request. It was a communication problem."
She said that the agency had turned over 40 boxes of documents -- totaling 150,000 pages -- and 230 hours of recordings of conversations between air traffic controllers on Sept. 11.
"We're continuing to work with them to get them everything they want," she said.
Roemer said that, in addition to directly ensuring that the FAA produced everything they wanted, the subpoena also was intended as a message to other parts of the administration.
"The fact that we're still dealing with access questions 10 months in, when there's more sand in the bottom of the hourglass than there is in the top, is very frustrating," he said.
The commission said last week it is still negotiating with the White House over access to certain very sensitive national security documents.
Among the documents being requested by the commission, UPI learned earlier this year, are the highly classified presidential daily briefings, which summarize intelligence about the most important threats to national security, and the minutes of National Security Council meetings.
Media reports have suggested that one presidential daily briefing in August had warned that al-Qaida might try to use jetliners as weapons. One Republican congressional source, who said the contents of the document had been described to him, told UPI earlier this year that those reports were inaccurate, but the issue lingers.
"As a member of the Joint Congressional Inquiry (into Sept. 11), I believed that investigation should have had access to the PDBs (presidential daily briefings)," Roemer said. That inquiry was not allowed to see them. "As a member of the commission, I believe that we need access to the PDBs. I hope we get access to all the sensitive documents we need."