Allegheny Airlines Flight 853
|Date||September 9, 1969|
Moral Township, Shelby County, near Fairland, Indiana, U.S. |
|Total fatalities||83 (all)|
An Allegheny Airlines DC-9-31 sister ship of N988VJ, 1977
|Type||McDonnell Douglas DC-9-31|
|Flight origin||Boston Logan Airport|
|1st stopover||Greater Cincinnati Airport|
|2nd stopover||Indianapolis International Airport|
|Destination||St. Louis International Airport|
A Piper PA-28 similar to the accident aircraft
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.
Allegheny Airlines Flight 853, a DC-9-31, registration N988VJ, 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. 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.
Meanwhile, the private Piper PA-28, registration N7374J, 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, and there was no evidence it appeared as a primary radar target on the radarscope.
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.
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. The following corrective steps have since been taken:
- Transponders are now installed in most general aviation aircraft 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
- 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
- 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
- List of notable civilian mid-air collisions
- Aeromexico flight 498
- Piedmont Airlines Flight 22
- PSA Flight 182
- Aircraft Accident Report, Allegheny Airlines, Inc., DC-9, N988VJ, and a Forth Corporation, Piper PA-28, N7374J, Near Fairland, Indiana, September 9, 1969 (PDF). National Transportation Safety Board. July 15, 1970. NTSB-AAR-70-15. Retrieved March 25, 2016.
- "FAA Registry (N988VJ)". Federal Aviation Administration.
- "FAA Registry (N7374J)". Federal Aviation Administration.
- "Death in the Skies" - Time magazine article Archived May 5, 2005, at the Wayback Machine.
- FAA Statistics, 2005 Archived March 3, 2016, at the Wayback Machine.
- FAA Federal Aviation Regulations
- NTSB Conflict Alert Safety Recommendation, 2003