Pilots on Comair Flight 5191 were using an out-of-date diagram for Lexington's Blue Grass Airport on the day the plane crashed.
But a revised chart issued to pilots Friday -- nearly two weeks after the crash -- may be even more problematic.
The diagram of Blue Grass distributed to Comair pilots last week shows that the best way to get onto the airport's main 7,000-foot runway (Runway 22) is to use a taxiway connector that hasn't even been built yet. And the taxiway connector pilots should use to get to the runway isn't shown at all on the revised chart.
The Federal Aviation Administration and Blue Grass Airport yesterday said that the revised chart shows what the airport is supposed to look like after construction is completed in about three months.
To make pilots aware of the error, the airport is issuing a "Notices to Airmen," or NOTAM, that will be in place today, said John Coon, the airport's operations director.
The NOTAM will notify pilots that Taxiway A7 -- the one that doesn't exist -- is closed and will be under construction, Coon said. Pilots can receive NOTAMs in paperwork attached to their flight release forms or by tuning into a radio frequency to access pre-recorded messages from the air control tower.
It will also direct pilots to use Taxiway A -- the connector not shown on the revised chart -- to reach the runway, Coon said.
Extreme caution urged
The problems with the new diagram of Blue Grass became known on Friday when Comair received its first updated chart of the airport since Jan. 27.
Comair noticed inaccuracies in the diagram and warned its pilots to use extreme caution in Lexington because the published chart did not accurately reflect conditions on the ground.
The new diagram shows a completed Taxiway A7, which the airport is scheduled to begin construction on in two weeks, Coon said. Depending on the weather, it will take about eight weeks to construct Taxiway A7, he said.
The new taxiway connection is needed to line up the taxiway with the relocated end of Runway 22. The runway was repaved and shifted 325 feet to the southwest last month.
The charts Comair uses are provided by Jeppesen, a Colorado-based company. Jeppesen interprets and produces charts based on information from the FAA.
Yesterday, a Jeppesen spokesman said the company was working with the federal agency and Comair to determine if its chart printed Friday is inaccurate. Virtually all U.S. commercial airlines receive their airport charts from Jeppesen.
Laura Brown, an FAA spokeswoman, acknowledged the agency sent Jeppesen and other charting companies the diagrams for a completed Blue Grass Airport on June 23.
The FAA received its chart of Blue Grass from the airport, Coon said. It is the airport's responsibility to notify the FAA about physical changes to the airport's layout, he said.
The charting companies often need advance time before publishing the charts, so the FAA provides them information as it is received from the airports, Brown said.
It's up to the companies to decide when to publish the information, she said.
When a chart is published in advance of actual construction, as was the case at Blue Grass, NOTAMs are used to explain any discrepancy, she said.
"The charts are published on a regular basis but the airport environment during a construction project is a little more dynamic so they use the NOTAMS to say what's happening on any given day," Brown said.
Since Jeppesen receives its data from the FAA, it would not have known that it was distributing a diagram of what Blue Grass is supposed to look like in a few months, Coon said. He said he did not know why the FAA had released the diagram before the construction was completed.
"We just supply the information to them (the FAA) and they arrange to have the information published and charted," Coon said.
Correct taxiway was shown
Comair Flight 5191 mistakenly took off from Runway 26, the airport's general aviation runway, which was too short for the regional jet. The plane went off the end of the runway and crashed on a nearby farm.
On the day of the crash, which killed 49 of the 50 people on board, Pilot Jeffrey Clay and First Officer James Polehinke were using diagrams that did not reflect recent changes to Blue Grass Airport's runways and taxiways, said Comair spokeswoman Kate Marx.
However, the January diagram did show the correct taxiway connector that the pilots should have used to reach the runway. That connector is not on the revised map issued last week.
In August, a week before the crash, Blue Grass Airport repaved its runway and closed the taxiway connection that planes normally used to reach the main runway. Information regarding changes in signage, markings or construction work at the airport had been issued to pilots through NOTAMs, said Brian Ellestad, airport spokesman.
Whether the January diagram was accurate will be for the National Transportation Safety Board to review as it investigates the crash, Marx said. A spokesman for the NTSB did not return phone calls yesterday.