Convair F106 accident at Saxis, Virginia, 11 Oct 1974

Accident narrative

About 2023 e.d.t. on October 11, 1974, a New Jersey Air National Guard Convair F106 and a privately owned Piper PA-24-250, N6876P, collided in midair near Saxis, Virginia. The Piper crashed into a marshland and was destroyed, killing its four occupants. The F106 returned to the National Aviation Facilities Experimental Center (NAFEC) at Atlantic City, New Jersey, without further difficulty.

### The flights

The Piper was on a visual flight rules (VFR) flight plan from White Plains, New York, to Georgetown, South Carolina. The pilot had accumulated 1,606 flight-hours, including 421 in the PA-24-250. He had requested and was receiving radar following from the en route FAA Air Traffic Control Centers.

Two F106 aircraft, operating as Echo Lima 08 (EL08) and Echo Lima 10 (EL10) from the 177th Fighter Interceptor Group based at NAFEC, were conducting low-level intercepts under the control of the North American Air Defense Command (NORAD) facility at Fort Lee, Virginia. The pilot of EL08, the intercepting aircraft, had 1,422 military flight-hours, with 315 in the F106.

### The sequence of events

At 2010:29, the Piper contacted Washington Center over Salisbury, Maryland, stating it was at 8,500 feet on airway V-1.

Meanwhile, EL08 was being vectored for a stern attack on the target aircraft, EL10, which was at 3,000 feet on a heading of 190 degrees. EL08 planned to make the attack at 6,500 feet. At 2020:35, NORAD instructed EL08 to maintain five thousand feet. At 2020:49, EL08 transmitted that it had a "Judy" (a military term for target), and NORAD cleared EL08 on target.

At 2022:12, Washington Center advised the Piper of traffic at its six o'clock position, five to seven miles away and slowly overtaking. The Piper pilot replied, "we'll be looking over our shoulder here."

At 2022:48, NORAD advised the F106s of traffic paralleling them to the starboard side, bearing 250 degrees at four miles. EL10 replied "Tally ho" (visual contact), and EL08 acknowledged the transmission.

At 2023:07, Washington Center told the Piper the traffic was at its eight o'clock position at about five miles, looking like it would be off the left wing. There was no reply, and the Piper's radar squawk disappeared.

At 2023:25, EL08 requested to head to an emergency field, and at 2024:14 transmitted, "Zero eight just hit something."

### What the investigation found

A ground witness in Saxis saw the jet approach and strike the small aircraft from the rear. The Piper fell straight down, and the jet proceeded south-southeast while rolling and descending. Examination of the wreckage confirmed the Piper was struck from the rear. A section of the Piper's right wing was recovered from the intake of EL08, while other tail and wing components fell several hundred yards from the main impact point. Only the left side of the F106 was damaged.

The pilot of EL08 could not accurately recall the events preceding or following the collision, but remembered seeing a bright red light and tightening his right turn just before impact. The pilot of EL10 could not recall seeing any traffic in the area, despite his "tally ho" transmission.

The Washington Center controller had observed the Piper and EL10 on radar. The controller did not see a primary or secondary radar return from EL08, which the Board noted was probably because EL08's transponder was not set for Mode III, Code 1200. The traffic references given to the Piper were based on EL10's secondary radar return.

The investigation found that the F106s were training in the Hog Island low-level area, which is crossed by three airways. FAA manuals did not require the Air Defense Command to coordinate such VFR training flights with air traffic control, and Washington Center was unaware the intercepts were taking place.

The NORAD controller was aware of the conflicting traffic and advised the F106s three times, but neither the controller nor the pilots suspended the intercept. The controller cleared EL08 for an attack with the conflicting traffic in the area. The Board noted that the controller called the conflicting traffic at four miles from the F106s when they were actually two miles apart and EL08 was closing within one mile of the traffic.

The Board stated it was probable that EL08 either did not see the Piper, or saw it, returned to intracockpit duties, and inadvertently locked onto the civil aircraft instead of EL10 while maneuvering to salvage the run. This probability was substantiated by computer radar plots and the fact that EL08 climbed from its initial intercept altitude of 6,000 feet to the collision altitude of 8,500 feet, which was the Piper's cruising altitude.

### Probable cause

The National Transportation Safety Board determined that the probable cause of the accident was "the failure of the interceptor pilot to see and avoid a civil aircraft during a high-speed, low-altitude, intercept training flight conducted in an area which included major north-south airways. Also contributing to this accident was the system which permitted an incompatible mix of traffic in controlled airspace which resulted in the probability of an inadvertent radar lock-on to a civil aircraft."