Matt Potter 3 p.m., Jan. 24
- Community Blog
Situation awareness, is the perception of environmental elements within a volume of time and space, the understanding of their meaning, and the projection of their status into the near future. Lacking or having inadequate situational awareness has been identified as one of the primary factors in accidents attributed to human error.
The evening of October 16, 1986 was dark, with overcast skies in the Los Angeles area. A 22-year old flight instructor was giving his student instrument flying instruction in a Cessna 172N, registration number N1048F. The flight instructor worked for American Flyers, a flight training school based at Santa Monica Airport. It was only his second day of work, having moved to Los Angeles from Florida. The instructor and his student took-off from Van Nuys airport, and were being given radar vectors by air traffic control to DARTS intersection, which is the initial approach fix for the instrument approach to Santa Monica Airport.
As the instructor and his student passed over the Van Nuys VOR (a radio navigation station), they were to be handed-off to the next air traffic controller down the line. Normal air traffic control procedures are to hand-off airplanes over the Van Nuys VOR. The controller would normally give the airplane an assigned heading and altitude, and then tell the pilot to contact the next controller on a specific frequency, a hand–off to the next controller. Cessna N1048F was given an assigned altitude of 3,000 feet and a heading of 080°. However, the air traffic controller failed to give the pilot a new radio frequency. No hand-off.
Van Nuys Airport is located about in the middle of the San Fernando Valley. The Valley runs almost due east and west. To the south are the Santa Monica mountains, and on the other side of those mountains is the Los Angeles basin and Santa Monica Airport. The assigned altitude of 3,000 feet is just high enough that N1048F could safely fly right over the Santa Monica mountains. To the north and east of the San Fernando Valley, the San Gabriel mountains rise rapidly to over 6,000 feet. The last assigned heading of 080° would head the Cessna directly into a 6,176 foot mountain.
According to the National Transportation Safety Board Report (NTSB), the first controller handed off N1048F at 7:29:12pm. The next controller acknowledged accepting the hand-off on his computer. Four minutes later, at 7:33pm, both the first and second controller’s shift was over and they were relieved. They gave the incoming controllers a beginning briefing. On the controller's radar screen, the data tag showed that N1048F was being controlled by another air traffic control facility. While the controller could see N1048F on his radar, he disregarded it, as it showed it was being controlled by others. Moments later, the Cessna hit the mountain at its last assigned altitude of 3,000 feet, killing the instructor and his student.
The NTSB assigned the blame for the accident on both the Air Traffic Control personnel and the instructor pilot. An experienced pilot, or even one who looked at the approach chart, would know he could not maintain a heading of 080° outbound from the Van Nuys VOR for very long without having a terrain clearance problem.
If you look at the approach chart below, there are two circles on it, a big one and a small one. The small one shows the Minimum Safe Altitude within a 25 nautical mile radius of the Santa Monica Airport. It shows that north of the airport, the Minimum Safe Altitude is 7,700 feet. The red arrow shows the last assigned course of the Cessna. The green arrows show the proper course into Santa Monica Airport.
On the night of the accident, I was flying my airplane to Santa Monica from Stockton, California. I was the airplane ahead of N1048F on the approach to Santa Monica Airport, and could hear the pilot of N1048F and controllers talking until I crossed the Van Nuys VOR and changed frequency for the approach to Santa Monica. It was a dark and overcast night, so there was little other air traffic coming into Santa Monica Airport.
As I was pushing my airplane back into its hangar, I wondered why the airplane behind me on the approach to Santa Monica never landed.