NTSB Advisory on sleep in tower incident at Reagan Airport




National Transportation Safety Board

Washington, DC 20594

March 24, 2011





The National Transportation Safety Board today opened an

investigation into an air traffic control service

interruption incident that occurred early Wednesday morning

at Washington Ronald Reagan National Airport (DCA) in

Arlington, Virginia.

On March 23, 2011, between approximately 12:04 am and 12:28

am EDT, an air traffic control service interruption occurred

when two air carrier aircraft and controllers at the Federal

Aviation Administration's Potomac Terminal Radar Approach

Control (TRACON) were unable to establish contact with the

supervisory controller working alone in the DCA control


The last radio transmission made by the tower controller

before the service interruption occurred at 11:55 pm EDT on

March 22.  At 12:04 am EDT on March 23, American Airlines

flight 1012, operating as a scheduled 14 Code of Federal

Regulations part 121 flight between Dallas-Fort Worth and

DCA, was instructed to contact Washington tower by approach

controllers at TRACON.

Following numerous attempts to contact the DCA tower, the

flight crew executed a missed approach. The crew reported to

TRACON their inability to make contact with the DCA tower;

TRACON then vectored the aircraft back to the airport for

another approach.

The approach controller and the TRACON supervisor on duty

made several attempts to contact the tower controller via

telephone, but were unable to establish contact. The TRACON

approach controller advised the crew of American flight 1012

that the tower was apparently unattended, and that the

flight would be handled as an arrival to an uncontrolled


The flight was again cleared for approach, and instructed to

switch to the tower frequency. At 12:12 am, the crew

returned to the tower frequency, still unable to make

contact with the tower, made position reports while inbound,

and landed on runway 1.

United Airlines flight 628T (UAL628T), operating as a

scheduled 14 CFR 121 passenger flight from Chicago-O'Hare

International Airport to DCA, was advised of the service

interruption by the TRACON approach controller and

subsequently transferred to the tower frequency at 12:22 am.

The United flight, unable to make contact with the tower,

made position reports on the tower frequency while inbound,

and landed at 12:26 am.

At 12:28 am, American flight 1012, on the ground at DCA,

established contact with the tower controller, and normal

services were resumed.

The controller in the tower at the time of the incident,

along with other FAA officials at DCA, were interviewed by

the NTSB today. The controller, who had 20 years'

experience, 17 of those at DCA, indicated that he had fallen

asleep for a period of time while on duty. He had been

working his fourth consecutive overnight shift (10 pm - 6

am). Human fatigue issues are one of the areas being


The NTSB will be interviewing officials at the TRACON

facility tomorrow.

NTSB Air Traffic Control specialist Scott Dunham is the

investigator-in-charge. He is being assisted by an NTSB

human performance specialist. Parties to the investigation

are the FAA and the National Air Traffic Controllers union.

Citing a fatal aircraft accident and two incidents that

occurred in a 23-month period between 2007 and 2009, on

Monday, March 21, the NTSB issued a safety recommendation

letter to the FAA asking the agency to improve the safety of

air traffic control operations by prohibiting air traffic

controllers from providing supervisory oversight while

performing operational air traffic duties. The entire letter

is available at http://go.usa.gov/2Ws.