You may be trying to access this site from a secured browser on the server. Please enable scripts and reload this page.
Turn on more accessible mode
Turn off more accessible mode
Skip Ribbon Commands
Skip to main content
Top Link Bar
NEWS & EVENTS
Speeches & Testimony
Most Wanted List
The Investigative Process
Data & Stats
General Aviation Safety
Administrative Law Judges
Strategic Plans & Reports
Safety Recommendation Details
The Investigative Process
Data & Stats
General Aviation Safety
ON AUGUST 24, 1984, WINGS WEST AIRLINES, INC., FLIGHT 628, A BEECH C99, N6399U, AND A ROCKWELL AERO COMMANDER 112TC, N112SM, COLLIDED IN MIDAIR NEAR SAN LUIS OBISPO, CALIFORNIA. THE TWO CREWMEMBERS AND 13 PASSENGERS ABOARD WINGS WEST FLIGHT 628, AND THE TWO PILOTS ABOARD THE AERO COMMANDER WERE KILLED IN THE CRASH. PRELIMINARY ANALYSIS OF THE NATIONAL TRANSPORTATION SAFETY BOARD'S ONGOING INVESTIGATION OF THIS ACCIDENT INDICATE THAT FLIGHT 628 WAS PROCEEDING OUTBOUND FROM THE SAN LUIS OBISPO COUNTY AIRPORT ON A "CREPE ONE" DEPARTURE, WHICH REQUIRES DEPARTING TRAFFIC TO CLIMB TO CREPE INTERSECTION ON THE SAN LUIS OBISPO LOCALIZER COURSE BEFORE TRANSITIONING TO THE EN ROUTE FLIGHT PLAN. THE SAFETY BOARD'S INVESTIGATION TO DATE ALSO INDICATES THAT THE AERO COMMANDER WITH A FLIGHT INSTRUCTOR GIVING AN AIRCRAFT CHECKOUT TO ANOTHER RATED PILOT WAS PROCEEDING INBOUND TO SAN LUIS OBISPO COUNTY AIRPORT ON THE LOCALIZER COURSE TO RUNWAY 11, AND MAY HAVE BEEN MAKING A PRACTICE LOCALIZER APPROACH. CONSEQUENTLY, THE FLIGHT PATHS OF THE TWO AIR PLANES WERE DIRECTLY OPPOSED.
THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: ISSUE AN AIR CARRIER OPERATIONS BULLETIN DIRECTING THE PRINCIPAL OPERATIONS INSPECTORS OF WINGS WEST AND IMPERIAL AIRLINES TO REQUIRE THAT THE AIRLINES AMEND THEIR OPERATING PROCEDURES SO THAT THEIR FLIGHTS CONTACT LOS ANGELES CENTER PRIOR TO DEPARTURE FROM SAN LUIS OBISPO COUNTY AIRPORT AND OBTAIN EITHER AN IFR CLEARANCE OR A DISCRETE TRANSPONDER CODE IF DEPARTING VFR. (URGENT)
Original recommendation transmittal letter:
Closed - Unacceptable Action
SAN LUIS OBISPO, CA, United States
Midair Collision of Wings West Airlines Beech C-99 (N6399U) and Aesthtec, Inc., Rockwell Commander 112TC N112SM
Addressee(s) and Addressee Status:
FAA (Closed - Unacceptable Action)
Safety Recommendation History
We do not agree with the FAA's rationale for not providing a discrete transponder code to a pilot requesting VFR traffic advisory service. If the provision of this service could be misleading because of workload, frequency congestion, radar limitation or traffic volume, then we see no reason why the pilot should not be informed accordingly at the time he makes his request. This recommendation stemmed from our strong belief that the ability of pilots to see and avoid other aircraft would be appreciably enhanced if they were alerted to the presence of other aircraft. We maintain the validity of this recommendation and consider the FAA's other actions, such as the internal memo of November 7, 1985, and the reference to ACOB No. 8-78-3, as not being responsive to this recommendation. In view of the FAA's repeated opposition to this recommendation, we are classifying it "Closed--Unacceptable Action."
"AS NOTED IN MY RESPONSE DATED MARCH 19, 1985, RELATIVE TO RECOMMENDATION A-84-125, I STILL BELIEVE THAT ASSIGNING DISCRETE TRANSPONDER CODES TO PILOTS ON VISUAL FLIGHT RULES (VFR) FLIGHTS COULD BE MISLEADING. I BELIEVE THIS PRACTICE COULD LEAD PILOTS TO BELIEVE THAT THEY ARE RECEIVING A SERVICE THAT THE CONTROLLER MAY NOT BE ABLE TO PROVIDE TO VFR TRAFFIC BECAUSE OF WORKLOAD, FREQUENCY CONGESTION, RADAR LIMITATIONS, AND TRAFFIC VOLUME.-"
Your response indicates that the FAA disagrees with this recommendation because "the assigning of discrete transponder codes in this situation could lead pilots into believing they are receiving a service that the controller may not be able to provide because the advisory services provided to VFR traffic are predicated on workload, frequency congestion, radar limitations, and traffic volume. Safety Advisories, while a higher priority action by the controller, also are influenced by the same factors. In addition, the assigning of discrete transponder codes from takeoff could encourage departing traffic to expedite changing to an air traffic control frequency and not monitoring the Common Traffic Advisory Frequency (CTAF) for airport advisories, which in our opinion is more important." Your response also stated that there is no plan to issue an Air Carrier Operations Bulletin directing the Principal Operations Inspectors of Wings West and Imperial Air Lines to require that the airlines amend their operational procedures in accordance with the Safety Board's recommendation. Further, your response stated that the FAA has directed its Principal Operations Inspectors to ensure that their carrier's training programs stress the importance of maintaining external vigilance. Finally, the FAA stated that "we share the Board's concern; however, the airspace system in which we are operating demands that the flightcrews must, at all times, comply with the basic principles of see and avoid. We believe that present procedures, when properly observed and executed are adequate." In view of the results of the analysis of this accident, the Safety Board still believes that additional operating procedures are necessary to improve the safety of air carrier operations at San Luis Obispo County Airport. The fact that the standard instrument approach procedures (SIAP) course also is used for the standard instrument departure (SID) procedure, and the potential inability of the pilots reasonably to "see-and-avoid" each other in this situation under VFR conditions, as well as the inability of the ATC controllers consistently to provide separation in this situation suggests strongly the need for positive steps to prevent future accidents of this type. As a result, the Safety Board has classified Safety Recommendation A-84-125 as "Open--Unacceptable Action" pending a reevaluation by the FAA. Additionally, the Safety Board believes that similar hazardous conditions may exist at other uncontrolled airports served by air carrier aircraft, i.e., whenever SIAPs and SIDs share the same localizer course so as to place airplanes on a head-on collision course in a see-and-avoid environment under conditions where the ability of pilots to actually see-and-avoid each other may be so marginal as to place air carrier passengers unnecessarily at risk. These hazards should be reduced by appropriate remedial measures similar to those recommended for San Luis Obispo.
FAA LTR: THE FAA'S INVESTIGATION INTO THE USE OF DISCRETE TRANSPONDER CODES DISCLOSED THAT THE ASSIGNING OF DISCRETE TRANSPONDER CODES IN THIS SITUATION COULD LEAD PILOTS INTO BELIEVING THEY ARE RECEIVING A SERVICE THAT THE CONTROLLER MAY NOT BE ABLE TO PROVIDE. IN ADDITION, THE ASSIGNING OF DISCRETE TRANSPONDER CODES FROM TAKEOFF COULD ENCOURAGE DEPARTING TRAFFIC TO EXPEDITE CHANGING TO AN AIR TRAFFIC CONTROL FREQUENCY AND NOT MONITORING THE COMMON TRAFFIC ADVISORY FREQUENCY (CTAF) FOR AIRPORT ADVISORIES, WHICH IN OUR OPINION IS MORE IMPORTANT. ENCLOSED FOR THE BOARD'S INFORMATION IS A COPY OF AN INTERNAL FAA MEMORANDUM, DATED NOVEMBER 7, 1984. THIS MEMORANDUM WAS SENT TO ALL REGIONAL FLIGHT STANDARDS DIVISION MANAGERS REQUESTING THAT THEIR PRINCIPAL OPERATIONS INSPECTORS REVIEW AIR CARRIER OPERATIONS BULLETIN NO. 8-78-3, TO ENSURE THAT THEIR CARRIERS' TRAINING PROGRAMS, OPERATIONS MANUALS, AND/OR BULLETINS STRESS THE IMPORTANCE OF MAINTAINING EXTERNAL VIGILANCE.
Strategic Plan, Performance & Accountability Reports & More
Directions to Conference Center
Web Policies & Notices
Annual Review of Aircraft