United 497 Emergency: Effort To Clear Runway Falls Short
While the crew of United 497 was struggling with smoke in the cockpit and loss of electrical power to the Airbus A-320's instrumentation, ground crews had their hands full, too. The aircraft had just departed New Orleans en route to San Francisco when fire or smoke detection equipment in the cockpit alarmed and smoke began filling the cockpit. The crew immediately requested a vector back to the airport and shortly thereafter declared an emergency. It also requested runway 10/28, New Orleans' longest runway, at 10,080 feet. But the runway was undergoing maintenance and cluttered with numerous vehicles and workers. Despite an urgent request from the tower to clear the runway, it remained obstructed and United 497 landed on the 7001-foot runway 19 instead. Because its steering and braking may have been compromised by the electrical failure, the Airbus departed the runway to one side and came to a stop with the nosewheel mired in mud. All 109 persons aboard evacuated without serious injury. The NTSB reported that one forward slide failed to deploy, but neither the airline nor the safety agency provided any information on the extent of fire damage in the cockpit.
From takeoff to emergency landing, the entire event transpired in 12 minutes. Flight 497 took off from runway 19 at 7:07 a.m. and reported smoke in the cockpit just as it climbed through 4000 feet, four minutes later. The aircraft then turned northeast and flew a wide loop over Lake Pontchartrain as it was vectored back to runway 19 at Louis Armstrong Airport.
According to recordings of approach, tower and ground operations provided courtesy of LiveATC.net -- download the MP3 here -- the crew requested the longest runway, 10/28, but the tower informed the flight that "there is a bunch of equipment on there. They're trying to get it off now." An unidentified voice on the tape, which may have been 497 or an interphone reply, said, "You need to clear it for us." At one point, the tower operator said to ground ops: "Can you verify the vehicles are exiting … 'cause I haven't seen any of the vehicles move and the aircraft is 10 to the northwest and they have to have runway 10." A ground operator told the tower, "We can start trying to pull them off, but I don't know if we're going to get them off in time." The runway was not cleared in time and Flight 497 landed on the same runway it departed from, 19.
At 7:15 a.m., Flight 497 was given a 140-degree vector to intercept the runway 10 localizer, but a minute later, at 7:16:10, it reported that all of its primary instruments had failed, although its comms continued to function normally. The crew said, "Ah … we've lost all of our instruments right now and we're gonna need … just a PAR." ATC responds by saying, "I can give you no-gyro, sir, if you need it." (New Orleans has publish ASR radar minimums, but not PAR capability.)
The radar controller then issued stop turn directives to line the aircraft up with the Pontchartrain shoreline and a straight-in visual approach for runway 19.
The weather at the time of the incident was reported as 2500 broken with visibility of 7 miles. The wind was 180 at 15 knots, with gusts to 22 knots.