The crew of a cargo freighter didn't expect the controller's instructions: Taxi to runway 23R on the far side of the airport. Nor was the crew able to tell in the October night where taxiway "N" was to get to the runway.
The taxiway was new and not on the plane's cockpit map of Indianapolis International Airport. Lumbering past one taxiway sign and then another–the captain slammed on the brakes, realizing the runway he almost got on was the wrong one.
"I see the runway ahead … stopped short of runway 32/14!" the rattled pilot recalled in a report he filed with the federal Aviation Safety Reporting System six years ago.
Runway 32/14 was much shorter than the one the heavy jet was supposed to use. "Never," the unidentified captain added, in hindsight, "move/taxi the aircraft without being completely sure of the assigned taxi route. If in doubt, stop and ask!"
That advice might have saved the lives of 49 people aboard a Comair jet that crashed last month in Lexington, Ky. Apparently confused by recent changes made to the airfield, the crew rocketed the Bombardier jet down a short runway meant for general aviation planes. It hit an embankment at 160 miles per hour and burst into flames.
Accounts reported to the NASA database show how airfield mistakes that contributed to the Kentucky crash also occur here, although the number of "surface incidents" has declined in recent years, thanks largely to improvements to taxiways.
Mistakes wrought of confusion could have spelled disaster in Indianapolis in a number of instances had safety procedures–or, in some cases, sheer luck–not intervened.
"I always tell my first officer, 'Keep me out of trouble on the ground,'" said Matt Ellis, an ATA Airlines Inc. captain who flies Boeing 737-800s between Los Angeles and Honolulu.
Ellis said good crew communication, such as challenging one another as a backup, is critical no matter how experienced the flight crew is.
"That might be one of the biggest problems we face as aviation professionals–complacency," Ellis added.
On a foggy March morning seven years ago, a Boeing 737 was about to push back from Concourse C for a flight to Denver. "With the parking brake still set," the captain and his first officer concurred on their taxi instructions.
But taxiway markers weren't visible, they complained. So they reasoned that, since they were facing southeast, they needed to taxi forward and make a right turn.
"That was our first mistake," said the pilot, recalling that the crew normally took a different taxiway than the one designated for them that day. After wandering in the fog, they told the tower they were lost, and stopped on taxiway M.
Then the captain noticed a light ahead in the fog moving to his left. "I heard ground control clear another aircraft to turn off taxiway G onto taxiway M."
Good thing he was listening to the controller chatter. "As I watched this light appear to turn toward us, I broadcast on the ground control frequency for 'the aircraft on taxiway G to stop.' He complied immediately."
Later, the Denver-bound captain blamed the incident on his crew's failure to reconcile its position, a scarcity of taxiway markers and the early departure time for the West Coast crew whose sleep patterns were interrupted. It was, he concluded, "a potentially catastrophic accident."
Confessional for pilots
Making a report to the ASRS database is voluntary. It's also confidential–a confessional for procedural sins, if you will. But the confidential nature is credited for encouraging candid responses.
Back in 2001, the John A. Volpe National Transportation Systems Center reviewed 76 pilot reports to ASRS of "runway transgression incidents."
The biggest batch–37 of the reports–involved crews that failed to hold short at a taxiway or runway as requested by controllers.
Another 27 of the reports involved taxiing onto or crossing runways without authorization, such as accepting a clearance for another aircraft with a similar call sign.
"Even though it's a 2001 [report], I can tell you that the causes stay the same. The only change is that the number of incursions attributed to poor markings has decreased as our airport markings have improved," said Kim Cardosi, a national expert in aviation human factors at the Volpe center in Cambridge, Mass.
A runway incursion is when an aircraft or other object creates a collision hazard.
Indianapolis International hasn't had a report of a runway incursion in several years. But in the late-1990s, it was on the Federal Aviation Administration's infamous list of top 10 airports with the most surface incidents. A surface incident is one involving an unauthorized or unapproved movement that could affect safety.
Nearly all the incidents involved runway 14/32, the crosswind runway just southwest of the terminal that virtually all aircraft wanting to use the airport's two parallel runways must cross.
The problem was that, although controllers would tell pilots before taxiing to hold short of the runway and then await clearance, sometimes the cockpit crew was so busy with things like checklists that it forgot, said Michael Medvescek, general manager of airport operations.
Airport improves markings
Perhaps the biggest changes have been to taxiways where they meet runway 14/32. Better warning lighting was installed in recent years, including flashing red signs at the intersection of 14/32. Initially installed on the left side of the taxiway where the pilots see them, additional lights subsequently have been placed on the co-pilot's side, as well.
The changes have paid off, with the airport receiving the FAA's "no discrepancies" award for the airfield since 2000.
"Our record has improved considerably," Medvescek said.
Medvescek said Indianapolis International also has gotten a jump on the FAA's 2008 mandate for clearer taxiway center lines to improve visibility, already installing them around runway 14/32.
Operations may become easier for pilots in 2008 when the airport's midfield terminal is set to open. No longer will airliners be forced to taxi across runway 14/32, as they do now, going to and from the terminal.
One advantage of Indianapolis International is that most of its taxiways are perpendicular, at 90-degree angles, rather than a maze of multiple angles as at other large airports, said Dale B. Oderman, a former military pilot who now is associate professor of aviation technology at Purdue University.
Even the best-laid-out airport can be trouble, however.
"In most cases, [confusion] is a lack of familiarity with an airport," said David Zwegers, director of aviation safety at Embry-Riddle Aeronautical University in Daytona Beach, Fla.
In the case of the Comair flight, although the crew had flown out of Lexington many times before, the main taxiway was closed due to paving. They took an alternate taxiway. But instead of proceeding onto the larger taxiway, they turned onto the shorter one and attempted takeoff.
Zwegers noted there are other systems in place designed to prevent mistakes. One is the Notice to Airmen, or NOTAMs, which is an FAA database about construction projects and other changes at airports.
There also are tools in place to counteract poor weather conditions, such as cockpit devices that display the location of other aircraft–something used aboard Embry-Riddle's fleet of training planes.
Pilots also can ask the tower for instructions to steer them along a taxiway.
But crew fatigue can defeat the best of procedures, experts said.
Fatigue is usually greater after a pilot has landed, and it can build during the day. "You can be up at 4 in the morning and you can be awake at midnight," Zwegers said of crew routines. "You may have had eight or nine flights" that day.
Fatigue can also affect controllers.
On one afternoon in May 2005, Indianapolis' runway 23R was closed for an inspection. Despite a note at his console to remind him, a controller reported to ASRS that he cleared an air taxi for takeoff–with a vehicle apparently still on the runway.
"I don't know when or where the vehicle exited the runway … . I did a bad job," wrote the controller.