The Low-Tech Approach

The Safety Alert (www.ntsb.gov/safety/safety-alerts/Documents/SA_045.pdf) carries the title "See and Be Seen: Your Life Depends on It." It states, in part, "All pilots can be vulnerable to distractions in the cockpit, and the presence of technology has introduced challenges to the see-and-avoid concept. Aviation applications on portable electronic devices such as cell phones, tablets and handheld GPS units, while useful, can lead to more head-down time, limiting a pilot's ability to see other aircraft."

The Safety Alert includes a series of suggestions for what pilots can do to be sure adequate visual lookout is maintained. At the top of the list is a call for vigilance and using proper techniques to methodically scan for traffic throughout a flight, not just when operating in high-traffic areas. Next is to be sure to divide your attention between what you need to do inside the cockpit and looking out the windows. The Safety Alert suggests that you make your aircraft as visible as possible, whether in daylight or at night, by turning on all available lights. There's a suggestion that passengers be encouraged to help look for traffic and that, during instructional flights, one of the pilots is always responsible for scanning for traffic. Also, pilots are reminded to use on-board traffic advisory systems when available, but not as a substitute for an outside visual scan.

In the Safety Alert, the NTSB provides examples of mid-air collisions it has investigated.

Cessna 172 And 180
On March 23, 2012, at about 11:43 a.m., a Cessna 172S and a Cessna 180 collided during flight near Longmont, Colo. The Cessna 172 crashed on an embankment adjacent to a two-lane road, about five miles east of the Vance Brand Airport (LMO). The 180 hit power lines and a chain-link fence during a forced landing adjacent to LMO. The flight instructor and private pilot receiving instruction on board the 172 were killed. The pilot of the 180 received minor injuries. Visual meteorological conditions prevailed. The 172 had departed Rocky Mountain Metropolitan Airport (BJC) at about 11:30. The Cessna 180 had departed Erie Municipal Airport (EIK) about 11:36.

At 11:30, the Cessna 172 was cleared for takeoff by the tower controller at BJC. Radar data showed that at 11:32, a 1200 transponder code appeared in the vicinity of BJC. Based on the course flown, investigators identified the track as being the Cessna 172. The radar track data took a northwest course from BJC before turning to a north-northeast course. About 11 miles north of BJC, the airplane executed a left 360-degree turn and returned to a north-northeast course. The track data depicted the airplane converging with a second target about 0.5 miles south of the location at which the 172 crashed.

At 11:36, an aircraft squawking 1200 showed up on radar in the vicinity of EIK. Based on the subsequent course flown, this aircraft is presumed to be the Cessna 180. The radar data indicated that the airplane departed to the south and turned right 180 degrees to take up a northwest course. The airplane subsequently turned right to a north-northeast course.

The radar track data depicted the flight paths slowly converging to a point about 0.5 miles south of where the Cessna 172 crashed. The data indicated that the 172 was at 7,200 feet MSL, while the 180 was in a slow climb from 6,800 feet to 7,000 feet MSL. At 11:42:28, the airplanes were separated laterally by about 393 feet and vertically by about 200 feet. Two of the data points that would have been expected to be generated by the 180 didn't appear, indicating that the 180 was very close to the 172.

Additional radar data showed that the 180 descended to 7,000 feet and entered a right 270-degree turn to a west course. At 11:43:37, it had descended to 6,200 feet MSL. Track data associated with the 172 showed that the airplane continued on a north course in the direction of the accident site. At 11:42:37, the 172 was at 7,200 feet MSL. The airplane subsequently entered a descent, passing 6,800 feet MSL at 11:42:42. The final radar data point was recorded at 11:42:46, with an associated altitude of 6,300 feet MSL. The accident site was located 0.14 miles north-northeast of the final radar data point.

Investigators interviewed the pilot of the 180. She told them that she was northbound at approximately 7,000 feet when she heard a loud bang. The airplane immediately pitched up about 50 degrees and rolled into a 45-degree right bank. She adjusted engine power to control airplane pitch and was able to maintain flight. However, the airplane was descending at about 200 feet per minute. She said that although aileron control and engine operation were normal, there was limited elevator control. The pilot attempted to divert to LMO, but realized she wouldn't make it to the airport. She landed on a small open area adjacent to the airport in order to avoid trees short of the runway. She said she thought the loud bang was a failure of the elevator system, and didn't initially believe that she had been involved in a mid-air collision. She said she hadn't seen or heard another airplane, only the loud bang.

She was a commercial pilot and instructor, and an FAA designated pilot examiner. She had about 6,315 hours total flight time, with about 825 hours in Cessna 180s.

The commercial pilot/instructor in the Cessna 172 had about 796 hours total time, with about 565 hours giving instruction. The private pilot receiving instruction had logged about 312 hours.

Cessna provided investigators with infor­mation related to the field of view through the windows of 172 and 180 airplanes. For a 172, someone seated next to a side window has a view from approximately two degrees up and 53 degrees down. When looking across the cabin out of the opposite side window, the field of view is restricted to three degrees up and 22 degrees down. For a 180, a person seated next to a side window has a view from approximately three degrees up and 55 degrees down. When looking across the cabin out of the opposite side window, the field of view is restricted to two degrees up and 17 degrees down.

The Cessna 172 airplane was equipped with an integrated cockpit display system, which is capable of providing traffic advisories using the TIS-B system. This traffic information is derived from air traffic surveillance radars. According to the FAA, TIS-B is advisory only and isn't intended to be used as a collision avoidance system, and doesn't relieve the pilot's responsibility to "see and avoid" other aircraft.

The NTSB determined that the prob­able cause of this accident was the inadequate visual lookout by the pilots of both airplanes, which resulted in a mid-air collision.

Cessna U206G And 180B
On July 30, 2011, at about 2:15 p.m., a Cessna U206G and a Cessna 180B had a mid-air collision near Amber Lake, about 16 miles southwest of Talkeetna, Alaska. Both airplanes were equipped with floats. It was VFR at the time of the collision. The private pilot and three passengers on the 180 were killed. The pilot on the 206 escaped injury. He flew to Anchorage International Airport where he landed. The Cessna 180 crashed and burned in a wooded area next to a lake. Both aircraft had been en route to Amber Lake at the time of the collision.

The pilot of the 206 told investigators that a few seconds before impact, he saw the 180 coming at him from the right. He maneuvered his airplane up and to the left in an attempt to avoid being hit. He said his altitude was approximately 900 to 1,300 feet MSL, and he had the landing, taxi, strobe and beacon lights on. The radio was tuned to 122.8 MHz for traffic advisories, and he didn't hear the Cessna 180 pilot on that frequency. After the collision, he called on 122.8 MHz for help in the area and also called Talkeetna Radio, giving the accident location and asking for help. He said the airplane had a strong vibration, and it took a lot of right rudder to fly straight and a lot of elevator to hold the nose level. He needed to add power to hold altitude. He decided to go to Anchorage because rescue and fire-fighting crews were there.

At the time of the accident, the pilot of the Cessna 206 was employed by a commercial air carrier as a Boeing 737 captain. He had about 19,100 hours of flight experience. No logbooks were found for the private pilot of the Cessna 180.

The common traffic advisory frequency designated for the area in which the collision occurred is listed in the FAA's "Alaska Supplement" as 122.8 MHz. However, according to a pilot-rated member of the Cessna 180 pilot's family, another pilot heard the Cessna 180 pilot making position reports on 122.9 MHz at the time of the accident. The family member said the MULTICOM frequency of 122.9 MHz was commonly used by the Cessna 180 pilot and himself at all remote lakes.

As a result of this accident, representatives from the FAA, AOPA, Alaska Airmen's Association, Alaskan Aviation Safety Foundation and other organizations formed a working group to identify inconsistent and confusing guidance concerning radio frequencies, and make suggestions to the FAA to end the inconsistencies and confusion.

The NTSB determined that the probable cause of this accident was the inadequate visual lookout and failure to see and avoid by the pilots of both airplanes while maneuvering to land, which resulted in a mid-air collision. Contributing to the accident was the lack of standardized, unequivocal procedures concerning common traffic advisory frequencies used in the area.

Peter Katz is editor and publisher of NTSB Reporter, an independent monthly update on aircraft accident investigations and other news concerning the National Transportation Safety Board. To subscribe, visit www.ntsbreporter.us or write to: NTSB Reporter, Subscription Dept., P.O. Box 831, White Plains, N.Y .10602-0831.