As a flight engineer, I fly regularly on commercial airliners. I have witnessed many near misses, and I admit that I have at times almost been the victim of one myself. (In retrospect, I can say with absolute certainty that I am much better at avoiding collisions than I have ever been at hitting one.) Even on the most uneventful flights, passengers in my section hear a strange noise or feel a sudden jolt. The captain comes on and explains that the computer system has detected a possible collision with another plane, and that the pilots are checking to see whether a collision actually occurred. The flight continues normally until we hear that the pilots have not seen a collision, but they have discovered something even more alarming; there is a serious malfunction in the plane’s navigation system. During the next two or three hours, the pilots fly the plane manually in order to regain control of the aircraft. Airlines seldom cancel flights because of a collision. If the collision is serious enough, the plane is diverted to the nearest airport. Although all passengers are accounted for, they are required to spend a night in a hotel and to reschedule their flights. The computerized onboard warning system is effective, but it is not foolproof

The author of this opinion piece argues that, because onboard warning systems receive signals from another plane’s transponder, pilots can anticipate and avoid collisions. If a collision actually occurs, the pilots will know that they have lost control of the aircraft. The pilots can navigate manually until they regain control of the plane. If the collision is minor, and the pilots still have control of the plane, they can land safely. However, it must be said that, while the on-board warning system is an effective means of detecting and responding to collisions, it does not detect all collisions. In July 1980, a Boeing 747 jetliner out of Singapore made an emergency landing at Madras Airport in India. The pilots had flown normally for 20 hours, until they encountered a typhoon. The pilots decided to land for fuel, but the pilots could not maintain control of the plane when it touched down. The pilots were able to restart the plane, but in the process, they crashed the plane. Both pilots were killed

One of the biggest risks to aircraft in flight is bird strikes. The most frequently reported strikes are against commercial jet liners. In June 2013, a United Airlines jetliner flying from Newark, New Jersey to Newark, New Jersey struck a flock of geese. One of the engines of the plane exploded, and the plane diverted to Philadelphia. The flight left Philadelphia for Newark 4 hours later. The airport is closed overnight, so the passengers spent the night in a hotel, and the flight was delayed for 6 hours. The jetliner’s engines were repaired, and flight resumed

The argument that computerized onboard warning systems will virtually solve the problems of midair collisions is flawed. The warning system is effective, but it cannot detect all collisions. There are many factors that could prevent the warning system from detecting a collision. A collision with a bird, for instance, might go unnoticed by the system. If the collision is serious enough, the pilots will still lose control of the plane. Also, the system cannot detect all collisions with other aircraft. Planes must be flying at the same altitude in order for their transponders to communicate. If the collision is with a military plane, the onboard warning system will not detect it. The on-board warning system is a valuable tool for the pilots. If a collision occurs, the pilots know within seconds whether the collision was serious enough that they should divert the plane to the nearest airport.