Insider Green

Liz Walker
Walker pictured with her husband, Kenny.

On the morning of Aug. 6, 2015, the pilot of a Cessna Citation made a typical departure out of San Francisco International Airport (SFO) into low cloud cover. There were visual meteorological conditions to the east of the aircraft as well as instrument meteorological conditions to the west. After departure, the pilot requested to level off at 2,000 feet. Elizabeth Walker, working as a departure controller at Northern California TRACON (NCT) at the time, was overseeing departures out of Oakland (OAK) and SFO. There was a considerable amount of frequency congestion when she approved the aircraft to climb to 2,600 feet. Immediately, she could sense something was off.

"The pilot said he couldn’t climb and was indicating at 1,600 feet,” Walker said. “He wasn’t climbing to where he wanted to stay at 2,000 feet. The minimum vectoring altitude in this area is 2,600 feet so I continued to ask him to climb.”

Walker reiterated her instruction for the pilot to climb the aircraft to 2,600 feet, and then she issued a climb to 3,000 feet. In addition to the frequency congestion, several calls, from the pilot of another aircraft not displayed on Walker’s scope, began to block transmissions. This aircraft was on Walker’s frequency in error and it caused considerable confusion as the pilot began requesting a localizer frequency for “Runway 10.” As Walker and other controllers working in the area began to realize an aircraft was on the wrong frequency, the Citation pilot declared an emergency and requested to return to the airport because the door to the aircraft was open.

“I have never felt like my hands were tied, even working other emergencies, in the same way this event made me feel,” explained Walker. “It caught me off guard and in these situations, you just have to remain calm and maintain other traffic. The aircraft on the wrong frequency only added to the need to maintain a good handle on exactly what was occurring.”

The pilot indicated he was in the clouds, unable to climb, and could not maintain his terrain and obstruction clearance. After getting input from her supervisor on what course of action to take, Walker began using an emergency vector map as her supervisor requested a halt of SFO departures .That was a crucial decision that alleviated some frequency congestion. With the use of the emergency vector map, Walker provided vectors to pilot in the troubled aircraft, which was descending from 1,600 feet to 1,300 feet. The pilot was able to avoid a 1,600-foot obstruction to the north as well as a 900-foot obstruction to the south while also safely exiting the clouds with the airport in sight because of Walker’s guidance.

“I think it’s just part of the job,” said Walker, upon reflection of the event. “I’ve never been the kind to say “Hey! Look at what I did!” because it’s what all controllers do every day. I was really thankful for my supervisor, Carlos Henley, fellow controllers David Galuszka, David Brown, Steve Giddens, and Scott Nash who all helped to ensure that this had a positive outcome.”

Thanks to the great work by Walker and every controller in the area, the seven people on board the aircraft were able to land safely at the airport.

This event has been nominated for an Archie League Medal of Safety Award.