Allegheny Airlines Flight 853

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Allegheny Airlines Flight 853
Accident summary
Date September 9, 1969
Summary Mid-air collision
Site Moral Township, Shelby County, near Fairland, Indiana, United States
39°37′02″N 85°55′14″W / 39.61722°N 85.92056°W / 39.61722; -85.92056Coordinates: 39°37′02″N 85°55′14″W / 39.61722°N 85.92056°W / 39.61722; -85.92056
Total fatalities 83 (all)
Total survivors 0
First aircraft
Douglas DC-9-30 Allegheny N993VJ.png
An Allegheny Airlines DC-9-30, c.1970
Type McDonnell Douglas DC-9-31
Operator Allegheny Airlines
Registration N988VJ
Flight origin Boston Logan Airport
1st stopover Greater Cincinnati Airport
2nd stopover Indianapolis International Airport
Destination St. Louis International Airport
Passengers 78
Crew 4
Fatalities 82 (all)
Survivors 0
Second aircraft
N8814W (7529194862).jpg
A Piper PA-28 similar to the accident aircraft
Type Piper PA-28-140
Operator Private
Registration N7374J
Passengers 0
Crew 1
Fatalities 1 (all)
Survivors 0

On September 9, 1969, Allegheny Airlines Flight 853, a McDonnell Douglas DC-9 passenger jet, collided in mid-air with a Piper PA-28 light aircraft near Fairland, Indiana, United States. The DC-9 was carrying 78 passengers and 4 crew members. The Piper was leased to a student pilot on a solo cross-country flight. All 83 occupants of both aircraft were killed in the accident and both aircraft were destroyed by the collision and ground impact.[1][2]

Flight history[edit]

Allegheny Airlines Flight 853, a DC-9-31, registration N988VJ,[3] was a regularly scheduled flight departing Boston, Massachusetts, for St. Louis, Missouri, with stops in Baltimore, Cincinnati and Indianapolis. Captain James Elrod (47) and First Officer William Heckendorn (26) were at the controls. Elrod was a seasoned veteran, with more than 23,800 flight hours. The young co-pilot had accumulated close to 3,000 flight hours.[4] The flight departed Cincinnati at 3:15pm en route to Indianapolis. Allegheny 853, flying under Instrument Flight Rules (IFR) clearance to Indianapolis, was instructed by Indianapolis Approach Control to descend to 2500 feet after passing the Shelbyville VOR at 6000 feet. The flight was then vectored to a 280 degree heading.[citation needed]

Meanwhile, the private Piper PA-28, registration N7374J,[5] piloted by Robert Carey (34), was on a southeasterly heading. It was operating under a filed visual flight rules (VFR) flight plan which indicated a cruising altitude of 3500 feet. The PA-28 was not in communication with Air Traffic Control, and was not transponder equipped,[6] and there was no evidence it appeared as a primary radar target on the radarscope.[citation needed]

Witness reports[edit]

Eight witnesses saw the aircraft collide. They reported broken to scattered cloud cover in the area, but both aircraft were below the clouds and could be seen clearly at the time of the collision. According to the witnesses, neither aircraft attempted a collision avoidance maneuver. Wreckage analysis later concluded the PA-28's left forward side just forward of the left wing root clipped the DC-9's upper right vertical tail severing the horizontal stabilizer.

The PA-28 was struck by the DC-9 at a speed of roughly 350 mph (560 kph) and was sliced in half by the vertical stabilizer, which ripped straight through the cabin and killed the small plane's pilot instantly. Most of the PA-28 immediately plummeted to earth along with the airliner's vertical stabilizer, but the other third of it still had some momentum left and landed a few hundred feet further away. Meanwhile, the crippled DC-9 pitched over on its back and fell inverted into a soybean field at speeds exceeding 400 mph (640 kph). Some witnesses claimed it was spinning as it went, but the NTSB investigators disputed these assertions. Flight 853 was shattered to pieces, the wreckage scattered over half a mile. The passengers and crew were dismembered by the forces of impact, with no intact bodies found (although the PA-28 pilot's body was intact) Despite all this, there was no fire or explosion because impact speeds were so great that the DC-9's fuel load dispersed quickly and did not ignite.

Probable cause[edit]

The National Transportation Safety Board in a report adopted July 15, 1970, released the following Probable Cause:[1]

The Board determines the probable cause of this accident to be the deficiencies in the collision avoidance capability of the Air Traffic Control system of the Federal Aviation Administration in a terminal area wherein there was mixed instrument flight rules (IFR) and visual flight rules (VFR) traffic. The deficiencies included the inadequacy of the see-and-avoid concept under the circumstances of this case; the technical limitations of radar in detecting all aircraft; and the absence of Federal Aviation Regulations which would provide a system of adequate separation of mixed VFR and IFR traffic in terminal areas.

Legacy[edit]

After this and similar mid-air collisions and near misses, both the NTSB and FAA realized the inherent limitations of the "see and be seen" principle of air traffic separation in visual meteorological conditions, especially when aircraft of dissimilar speeds or cloud layers and other restrictions to visibility are involved.[1] The following mitigating steps have since been taken:

  • Transponders are now installed in most general aviation aircraft[7] and all commercial/air-carrier aircraft, dramatically increasing radar visibility of lower and slower-flying smaller aircraft, especially near atmospheric disturbances or other clutter (see Air Traffic Control Radar Beacon System and Secondary Surveillance Radar)
  • Most airports with scheduled airline service now have a surrounding controlled airspace (ICAO designation Class B or Class C) for improved IFR/VFR traffic separation - all aircraft must be transponder equipped and in communication with ATC to operate within this controlled airspace[8]
  • Most commercial/air-carrier aircraft (and some general aviation) now have an airborne collision avoidance or TCAS device on board, that can detect and warn about nearby transponder-equipped traffic[7]
  • ATC radar systems now have "conflict alert" - automated ground based collision avoidance software that sounds an alarm when aircraft come within less than a minimum safe separation distance[9]

See also[edit]

References[edit]

  1. ^ a b c NTSB Report (PDF). Retrieved March 25, 2016[permanent dead link]
  2. ^ McGlaun, Dan. "Allegheny 853 Crash Site Pictures". www.mcglaun.com. Retrieved 2008-01-27. 
  3. ^ "FAA Registry". Federal Aviation Administration. 
  4. ^ "Archived copy" (PDF). Archived (PDF) from the original on 2016-04-24. Retrieved 2013-05-30. 
  5. ^ "FAA Registry". Federal Aviation Administration. 
  6. ^ "Death in the Skies" - Time magazine article Archived May 5, 2005, at the Wayback Machine.
  7. ^ a b FAA Statistics, 2005 Archived March 3, 2016, at the Wayback Machine.
  8. ^ FAA Federal Aviation Regulations[permanent dead link]
  9. ^ NTSB Conflict Alert Safety Recommendation, 2003[permanent dead link]

External links[edit]