City officials were warned as early as January 2009 of the need to formally notify the Federal Aviation Administration that a planned commuter rail line could run too close to the Honolulu International Airport.

Construction of the $5.3 billion rail system was supposed to begin last December but is being delayed in part because the route may be too close to an airport runway and might endanger the operation of aircraft. The city cannot begin construction on the project until the airport issue is resolved.

On Wednesday, city, state and federal officials met to discuss moving either the train's route or the affected runway.

If the route has to be moved, it could push back the start of construction by up to six months.

On Jan. 29, 2009, state transportation director Brennon Morioka wrote his counterpart at the city, Wayne Yoshioka, saying the city should file what is known as a Form 7460 with the FAA to ensure that the elevated train complies with runway obstruction height limits.

On Feb. 2, 2009, Moses Akana, an FAA air traffic support specialist at the Honolulu airport, e-mailed the city comments on the train's environmental impact study. He said that an aeronautical study must be done before construction starts to ensure there's no impact on airport flight operations.

The airport issue must be resolved before the project's final environmental impact statement can be released. Gov. Linda Lingle then must approve the study before the city can start construction.

Lingle yesterday said the city will need to change plans to address the airport airspace issue.

"The FAA will not sign off on it because the rail impedes one of the runways," she said yesterday following a speech to the Pearlridge Rotary Club. The city has "known this all along," Lingle added. "They've been told this."

"They're going to have to alter their plan because they cannot impede the operations of the Honolulu airport."

Yesterday, the FAA said the city still has not filed the Form 7460.

CITY HASN'T FILED

The city yesterday said the FAA form doesn't need to be filed until a later date.

"The form does not need to be filed at this time, as it is not a requirement of the environmental process and has not been noted as such by the FAA in any discussions regarding the current evaluation of the rail guideway in the vicinity of the airport," the city said in a written response yesterday to an inquiry for this story. "Nonetheless, the city has completed an airspace analysis of the (environmental impact statement) alignment to ensure that FAA clearance requirements are complied with."

The statement added: "The city has also discussed the results informally with the FAA to help in identifying appropriate mitigations needed to clear the runway protection zone."

The city has said the current complications are a result of newly adopted federal aviation regulations. The city also said that the FAA did not raise its concerns until October.

However, the FAA this week said that there were no new regulations implemented that would affect Honolulu's rail project. The FAA would not comment on whether the city's failure to file a construction notice sooner could have helped address the current airspace issues.

The FAA said the filing of proposed construction forms is integral to the agency's review of potential airspace impacts.

"Anyone who wants to build a structure near an airport must file a 7460 form so that the FAA can do an airspace study of the project," FAA spokesman Ian Gregor said in an e-mail. "The study determines whether the project could pose hazards to air navigation and, if so, whether the hazards could be mitigated.

"Ideally, the airspace study for the project and the (environmental impact statement) would be done at the same time," he said.

The FAA said it was notified by a city consultant late Thursday that the required forms will be filed for all of the project alternatives.

DELAY POSSIBLE

The city council voted in January 2009 to divert the path of the train from Salt Lake to the airport. That change adds about $220 million to the cost of the 20-mile East Kapolei-to-Ala Moana project, but was expected to generate higher ridership and greater community acceptance.

Under current plans, the elevated train track and a station planned for the intersection near Aolele Street and Lagoon Drive would be at least four stories tall and less than 1,000 feet from airport runways. That encroaches on a runway airspace buffer imposed to keep buildings and other obstructions from affecting airplane operations.

How long it will take to address the airport concerns and when construction on the project can begin remains unclear.

Options the city could pursue to mitigate the train's airport impacts include moving the rail route closer to or on top of the Nimitz viaduct. The city also may be able to stick with the currently planned route, if the state is willing to make changes at the airport, such as extending the length of the opposite ends of affected runways.

If the city has to change the train's route, it could take another three to six months to complete the train's environmental impact study, City Council Chairman Todd Apo said earlier this week. An environmental impact study of airport changes, including moving one runway, would take longer, but would not necessarily delay the release of the train's final environmental impact study, Apo said.

Whether to allow the city to build in the runway protection zone is up to the state, according to the FAA.

However, airports that allow unmitigated construction in a protection zone could jeopardize the availability of future federal funds for airport improvements.

During the fiscal year ended Sept. 30, the Honolulu airport received more than $21 million in FAA airport improvement grants.

City Council member Ikaika Anderson yesterday said he was told by city administration officials that the council will be provided with an update on the airport issue.

"They're comfortable that the project will move forward, and upon more information being available, the mayor's office plans to brief the appropriate City Council committee ," Anderson said. "We're going to keep on top of this. We will get back in touch with them again next week and try to see if we can nail them down as to when they're going to brief the committee."