1981 — May 6, USAF EC-135N Crash, near Walkersville and Frederick, MD — 21
— 21 Aviation Safety Network. Accident Description. USAF Boeing EC-135N, 06 May 1981.
— 21 Baugher, Joseph F. 1961 USAF Serial Numbers. 10-29-2011 revision.
— 21 FlyARIA. Apollo/Advanced Range Instrumentation Aircraft. “ARIA Aircraft 61-0328.”
— 21 Frederick Post (MD). “Air Force Surveillance Jet Explodes…21 Perish,” May 7, 1981.
— 21 Gero. Military Aviation Disasters: Significant Losses Since 1908. 1999, p. 136.
Narrative Information
Baugher: “Boeing C-135A-BN Stratolifter….0328 (c/n 18235) suffered abrupt pitch-down resulting in structural failure with ensuing midair explosion and crash near Walkersville, MD May 6, 1981. All 21 onboard killed. (ASN)” (Baugher, Joe F. 1961 USAF Serial Numbers. 10-29-2011 rev.)
FlyARIA: “The beginning…The National Aeronautics and Space Administration required a platform to provide tracking and telemetry to fulfill Apollo requirements in remote locations across the world. This platform would also be tasked to fulfill Department of Defense requirements. In 1966 the Apollo Range Instrumentation Aircraft program was born.
“The price…On May 6, 1981, the Advanced Range Instrumentation Aircraft 61-0328 departed from Wright-Patterson Air Force Base on a training mission; it was to be her last flight. The aircraft crashed at Walkersville, Maryland, 21 souls were lost.” (FlyARIA)
Gero: “…the modified jet transport [61-0328], which was on a navigational training flight out of Wright-Patterson Air Force Base, in Ohio, crashed approximately 2 miles (3km) north-northeast of the town of Walkersville, located some 40 miles (65km) north-west of Baltimore. All 21 persons aboard perished; except for two dependents and one other civilian, the victims were all American military personnel, including the 17 designated crew members. One of the dependents, the wife of the aircraft’s commander, had apparently been seated in the pilot’s position at the start of the accident sequence.
“The EC-135 had been cruising at an altitude of 29,000ft (9,000m) and an indicated air speed of around 550mph (885kph) when, for undetermined reasons, its pitch trim moved to the full nose-down position, which was evident from post-impact examination of the cockpit indicator and the horizontal stabilizer mechanism itself. As a result, 61-0328 rapidly pitched down, most likely upon the release of the autopilot, which should have been able to overcome its trim except when near the full nose-down position. This attitude would have induced sufficient negative gravitational forces to trip off-line the generators, causing a total loss of electrical power and, in turn, preventing the pitch trim from being removed electrically. While unusual, this condition can easily be controlled with prompt corrective action, within 8 seconds, according to simulator tests, but in this case recovery was delayed for reasons that could not be determined….Under the circumstances, the pitch angle and the air speed of the aircraft would increase until the pitch trim is moved to the neutral position. Without electrical power, this must be accomplished manually with the control wheel on the console between the pilots’ seats, which, in this situation, would have required about 35 revolutions to return the trim to zero.
“The four-engine jet was seen to emerge from a low overcast in a nose-down attitude of 20 to 30 degrees and at an air speed in excess of 460mph (740kph). It was around that time, and while at an approximate height of 1,500ft (500m) above the ground, that an explosion occurred in the pressurized compartment of the aircraft, resulting in the break-up of its fuselage and the separation of the wings. Around 90 seconds elapsed from the beginning of the descent until the final impact. Wreckage was strewn in an elliptical shape some 2,400ft (730m) long by about 1,800ft (550m) wide, with all debris being found within approximately 21/2 miles (4km) of the main crash site. The surface weather in the area at the time was characterized by light rain, a slight breeze from a south-south-westerly direction, and a visibility of around 21/2 miles (4km), but had been clear at the cruising altitude, with cloud tops at about 20,000ft (6,000m).
“The investigation found no evidence that the presence of passengers on the flight deck caused or contributed to the disaster, or of any explosion or structural failure prior to the uncontrolled descent. No previous problems had been reported with 61-0328, and although the cause of the pre-impact explosion could not be determined, the accident report concluded that by that time recovery from the dive would not have been possible and the crash was thus inevitable.” (Gero 1999, pp. 136-138)
Newspaper
May 7, Frederick Post, MD: “An Air Force surveillance plane, carrying 21 military officers on a training flight from Wright Patterson Air Force Base in Dayton. Ohio, exploded in the air over Walkersville Wednesday morning, littering farm fields with bodies, parts of the craft, and electronic components and manuals that were on board the EC-135 jetliner. There were no survivors. Eyewitnesses to the worst air disaster in Frederick County history said the aircraft — a modified Boeing 707 — “appeared to explode in midair,” sending a giant fireball through the cloudy skies. Late Wednesday afternoon, a special Disaster Assistance Team from Andrews Air Force Base near Washington arrived to begin the grim chore of identifying the bodies of the crew, and starting the tiresome task of trying to determine what caused the crash of the sophisticated $50 million plane…. The plane, one of about eight similar aircraft, was “used to track missiles and unmanned satellite craft.”…. The white aircraft, with a special nose cone, carried members of the Air Force’s 4950th Test Wing Aeronautics Systems Division, air force officials said…. Police ‘were being told it (the plane) was being used for passenger transport …’…. The C-135 tanker transport apparently exploded in midair, exploded a second time in midair, then hit the ground…” (Frederick Post (MD). “Air Force Surveillance Jet Explodes in Sky over Walkersville; 21 Perish,” May 7, 1981.)
Sources
Aviation Safety Network. Accident Description. United States Air Force, Boeing EC-135N, 06 May 1981. Accessed 3-9-2009 at: http://aviation-safety.net/database/record.php?id=19810506-0
Baugher, Joseph F. 1961 USAF Serial Numbers. 10-29-2011 revision. Accessed 2-23-2012 at: http://www.joebaugher.com/usaf_serials/1961.html
FlyARIA. Apollo/Advanced Range Instrumentation Aircraft. “ARIA Aircraft 61-0328.” Accessed 3-9-2009 at: http://www.flyaria.com/61-0328.html
Frederick Post, MD. “Air Force Surveillance Jet Explodes in Sky over Walkersville; 21 Perish,” May 7, 1981. Accessed at: http://www.newspaperarchive.com/freepdfviewer.aspx?img=10439857
Gero, David. Military Aviation Disasters: Significant Losses Since 1908. UK and Newbury Park, CA: Patrick Stephens Limited, an imprint of Hayes Publishing, 1999.