Monday, April 26, 2004
Everybody needs TCAS
The acronym stands for traffic alerting and collision avoidance system, and TCAS technology is required for all passenger planes. It is not required for smaller general aviation (GA) aircraft. The dry wording of the National Transportation Safety Board (NTSB) preliminary account may not do full justice to how close the accident described below became one in which the pilots on both airplanes were killed. See the photographs while reading the NTSB's description. The NTSB account has been edited slightly:
He Ducked in a Reflex-Like Manner
"On Jan. 16, 2004, about 1415 Pacific Standard Time, a Cessna 180 and a Beech 95 collided about 6.5 nautical miles west of Tehachapi, Calif. The Cessna was destroyed and its airline transport certificate pilot was [killed]. The Beech was substantially damaged, and its private pilot received minor injuries. Visual conditions prevailed. At the time of the collision, neither airplane was on a flight plan. The Cessna's flight originated at an undetermined time and from an undetermined location. The Beech's flight originated from Tehachapi, the pilot's home base airport, approximately 1412. At the time of the collision, the Federal Aviation Administration (FAA) was not providing any [air traffic control] services to the pilots.
"Two witnesses reported to the NTSB investigator that they observed both airplanes seconds prior to the collision. [They] reported that the larger Beech airplane was flying in a westerly direction and appeared to be cruising in level flight. The smaller Cessna appeared to be cruising in an easterly direction and also appeared to be in level flight. Neither airplane appeared to change its course or alter its wing-level appearance prior to the collision. Following the collision, the Beech continued flying in a westerly direction. A portion of the Cessna, subsequently identified as its entire right wing, was found on a hillside near where the main wreckage was located.
"The Beech pilot reported to the NTSB investigator that, at the time of the collision, he was in cruise climb. Less than a second prior to the collision, he observed the right landing gear of an approaching airplane at his 1 o'clock position. He then ducked in a reflex-like manner and the collision occurred. He observed a dirt airstrip near his location and made a precautionary landing."
This was a case where neither aircraft was equipped with TCAS. Now consider the case below, submitted to the National Aeronautics and Space Administration (NASA) Aviation Safety Reporting System by recently-retired American Airlines captain, a B-777 international pilot, ex-Navy carrier pilot, and GA pilot with 28,000 hours of flight time (emphasis in original):
My First and Only Warning
"I am filing this 'near miss' report in hopes that there might be a modification of FAA air route traffic controllers training to hopefully avoid what happened to me (and the other three people in my plane - and the occupants of the other plane).
"This 'near miss' would absolutely and positively been a crash with the loss of our plane and people, and the other plane and people, had I not had the Honeywell [HON] Traffic Avoidance System (TAS) installed in our plane. We were not given any warning of other traffic by our FAA controller at any time.
"I was in the right seat. My wife (also an ATP rated pilot) was in the left seat ... Daylight with haze conditions. I did not write down the exact time or frequency. Since we departed SNA [Orange County, Calif.] at approximately 0733 local time, I am guessing the near miss occurred at approximately 0850 to 0930 local time.
"What happened ... On autopilot, our TAS gave us aural and visual (yellow threat symbols) warning. We looked at the multi-function display screen and the traffic was shown to be approximately 100 feet below us (climbing) and under us. That was my first and only warning (except for the continuous aural and visual warnings from the Honeywell system). No warning or traffic call by our controller at any time. We looked up to see another plane directly in front of us with its left wing to us, at our altitude and approximately 30 feet in distance. I could see the [other] pilot and the paint color in that split second. I put our airplane into a 45 to 60 degree right bank and my guess is we missed that plane by less than 30 feet.
"As we rolled into our bank, we received two sharp 'bumps' from the other airplane's wake. If we had not had the TAS on board, and not immediately rolled away from the other plane, both planes would certainly have crashed with all lives lost. I am absolutely sure of this. When we were back in control of the situation (emotionally and physically), I asked the controller why she did not call out the traffic and she said, "I did not think he would climb that fast." She said nothing else.
"I am assuming she gave the other plane a clearance through our altitude based on what she thought his climb capability was. Perhaps I am wrong in assuming that the other plane was under ATC control at all.
"The purpose of this NASA report is to perhaps convince the FAA controller management to really think twice before giving climb clearances through altitudes assigned to other aircraft if there is any question at all as to the climbing capability of the newly cleared plane. Perhaps the other plane had only one person aboard (I only saw the pilot in that split second) or had low fuel and thus was fairly empty, etc., and therefore climbed 'fast.' But to predicate our safety on another plane's climbing ability is pretty scary. Only once before - during my airline career - have I come that close to another plane in a near miss situation. That near-crash was resolved only by 'rolling' our 707 over that other 707 and resulted in massive changes in the New York departure control training and numerous newspaper articles on what happened.
"I had hoped that I would never ever be that close to a midair again. We were even closer last Friday."
This pilot's account almost reads like advertising copy for Honeywell's TAS.
Other avionics manufacturers offer comparable systems. These "black boxes" are building blocks for IHAS, the acronym for Integrated Hazard Avoidance System, including weather radar, TCAS, and enhanced ground proximity warning system (EGPWS) for the GA community. IHAS, also known in its application for larger jets as AESS (aircraft environment surveillance system), will be deployed in the new Airbus A380, sources say. In Boeing's [BA] new 7E7 airplane, the acronym is ISS, for integrated surveillance system. So many acronyms, but all generally for the same purpose: to improve situational awareness, to mitigate the risk of controlled flight into terrain (CFIT) accidents - by EGPWS - and to mitigate the risk of mid-air collisions - by TCAS.
For the big jets, terrain and midair collision avoidance technology is required. For GA aircraft, simpler but effective EGPWS and TCAS technology can be installed for around $30,000 - about the cost of some airplanes used by enthusiasts for weekend flying. The "affordable" aspect is, of course, very subjective. One industry observer said, "If the FAA mandated even rudimentary protection against terrain and other aircraft, there would be a hullabaloo the likes of which we haven't seen before. So it's see and be seen and pray that the other guy is flying somewhere else."