EC-135N 61-0328

• On 6 May 1981, EC-135N, Serial Number 61-0328, call sign AGAR 23, departed Wright Patterson AFB, Ohio, at 1005 Eastern Daylight Savings Time (EDT) on a routine training mission. On board the aircraft were 17 crewmembers and four authorized passengers. The flight proceeded uneventfully as planned for approximately 45 minutes. Then in a few brief moments, a sequence of very rapid events resulted in a crash with the loss of all onboard.
• At 1049:48 EDT, The Federal Aviation Administration (FAA) lost radar contact with AGAR 23. The aircraft was cruising at Flight Level 290, at .78 Mach while performing a navigational training leg. The aircraft commander, Capt Emilio, occupied the right pilot seat and a passenger, Mrs. Emilio, occupied the left pilot seat. Also in the crew compartment were the 2 navigators, Lt Col Frederick and Capt Fonke, and 2 passengers, Mrs. Fonke and SSgt Brundige.
• For undetermined reasons, the aircraft pitch trim moved to the full nose-down position. The aircraft then a rapidly pitched over, most likely upon release of the auto-pilot, and induced sufficient negative "G" forces to cause the generators to trip off line, resulting in the loss of all AC electrical power. The pitch trim could not then be moved electrically. This condition, while unusual, can be controlled if prompt corrective action is taken; however, if corrective action is delayed approximately 8 seconds, the aircraft pitch angle will be greater than 30 degrees nose-down in the airspeed in excess of 350 knots indicated airspeed. Under these conditions, the aircraft cannot be controlled until the pitch trim is moved toward neutral. While it is evident that recovery was delayed, the reason for the delay is unknown. The aircraft became uncontrollable and entered a steep descent. During the rapid descent, an explosion occurred at approximately 1300 feet above ground level followed immediately by catastrophic failure, and complete break-up of the aircraft.

Source: Accident Report

• EC-135 aircraft, S/N 61-0328, had 4 passengers on board during the mission. Two passengers were wives of crewmembers participating in the HAVE PARTNER Program (TAB 4.1.). One passenger, SSgt Joseph T. Brundige, Jr., was an Administrative NCO assigned to the Wing. He was onboard as an official observer for an orientation and motivation flight. The fourth passenger, Michael W. Reilly, was a Contract Engineering Technical Services representative For Bell and Howell Company. He was onboard the aircraft to complete an engineering evaluation of the recorder system recently installed by his company. All passengers were manifested in accordance with proper directives.
• Pitch trim was full nose-down as determined from the aircraft wreckage. The cockpit pitch trim indicator recovered from the aircraft wreckage indicated full nose-down trim (3.5 units nose-down). This indicator is a strong mechanical structure that should continue to indicate accurately after the force of impact. Additionally, the horizontal stabilizer trim jackscrew was recovered from the wreckage and indicated full nose-down trim. Since the jackscrew can be changed only by rotation of the screw, there is no possibility that the position of this jackscrew could have been altered by impact forces. The pitch trim is driven by an AC motor. Once AC electrical power is lost, the pitch trim cannot be electrically changed, but may be manually driven by the pitch trim wheel. This is a slow, laborious process which would require approximately 35 revolutions to return the trim from full nose-down to zero. Additionally, the stabilizer trim cut-out switch was found with the safety cover raised in the switch in the "cut-out" position; presumably activated by the pilot in an effort to stop the trim from driving to a more extreme position.
• The aircraft AC electrical system is powered by 4 generators, 1 on each engine, driven by a constant speed drive from that engine. A characteristic of this system is that the generators will trip OFF under conditions of negative "G" forces. This may occur at "G" forces as high as .2 positive "G." Conditions of flight during an abrupt pitch-over maneuver, resulting in negative "G" sustained for more than 2 seconds, would result in loss of all AC electrical power.
• At 1049:48 EDT, FAA lost radar contact with the aircraft. The aircraft was cruising at flight level 290 at .78 Mach and was performing a navigational training leg. Navigational legs are normally flown on auto-pilot, and FAA altitude readouts showed the aircraft was within 100 feet of assigned altitude, characteristic of auto-pilot flight. The aircraft commander, Capt Joseph Emilio, occupied the right pilot seat and a passenger, Mrs. Peggy Emilio, occupied the left pilot seat. Also in the crew compartment were the 2 navigators, Lt Col Benjamin B. Frederick and Capt Donald V. Fonke, and 2 passengers, Mrs. Linda Fonke and SSgt Joseph T. Brundige. This phase of flight, the navigational leg, was the least demanding on the pilot and was the logical time for the passengers to come forward to view the cockpit area. There is no evidence that the presence of the passengers in the crew compartment contributed to, or caused, the accident.

Source: Accident Report

The cause of this explosion was undetermined; however, the aircraft was in an unrecoverable condition at the time of the explosion and a crash was already inevitable.

Source: Accident Report