Narrative:Allegheny Airlines Flight 853 was a regularly scheduled flight from Boston, Massachusetts, to St. Louis, Missouri, with intermediate stops at Baltimore, Maryland, Cincinnati, Ohio, and Indianapolis, Indiana. The flight proceeded routinely to Cincinnati from where it departed at 15:15 hours local time.
An IFR clearance was received to Indianapolis via airway V-97 at an altitude of 10,000 feet.
At 15:22 the Indianapol1s Air Route Traffic Control Center (ARTCC) controller advised, "Allegheny e1ght fifty three is in radar contact, cross Shelbyville (VOR) at and maintain six thousand and your position now thirty-two miles (unintelligible) ... southeast of Shelbyville."
Approximately 3 minutes later, the flight reported leaving 10,000 feet, and during its descent, was instructed to contact Indianapolis Approach Control. At 15:27, the approach controller advised,
"Allegheny eight five three roger, squawk ident heading two eight zero radar vector visual approach three one left." Allegheny 853 acknowledged the vector and was, almost immediately instructed to descend to 2,500 feet. The flight acknowledged at 15:27:29, "Eight five three cleared down two thousand five hundred and report reaching." This was the last recorded transmission from the flight.
At the same time a Piper PA-28-140, N7374J, was operating in the area on a solo training flight from Brookside Airpark, Indiana, to Bakalar Air Force Base. The aircraft was on a VFR flight plan indicating a cruising altitude of 3,500 feet. The pilot advised the Indianapolis Flight Service Station at 15:21 that he had departed Brookside, requesting activation of his flight plan. This was the last known communication with N7374J.
The approach controller did not notice any conflicting traffic in the area of Allegheny 853. Yet both aircraft were on a converging course, with the DC-9 descending towards the altitude of the PA-28.
After the DC-9 broke through the clouds, both flights had a window of 14 seconds to see and avoid. The NTSB determined that the captain, from his position, was unable to see the Piper. The first officer was likely monitoring the altimeter in preparation for a 3500 feet altitude call. Two seconds after this call, both aircraft collided. The initial impact between the two aircraft occurred at the forward upper right side of the vertical fin just below the horizontal stabilizer, of the DC-9, and the left forward side of the PA-28, just forward of the left wing root.
The horizontal stabilizer of the DC-9 broke off and the aircraft impacted the ground inverted, almost wings-level, in a nose-down attitude. The Piper broke up and crashed about 4500 feet from the DC-9. All 82 occupants of the DC-9 and the pilot of the PA-28 were killed.
Probable Cause:
PROBABLE CAUSE: "The deficiencies in the collision avoidance capability of the Air Traffic Control (ATC) 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."
Accident investigation:
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Investigating agency: | NTSB  |
Status: | Investigation completed |
Duration: | 10 months | Accident number: | NTSB/AAR-70-15 | Download report: | Final report
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Classification:
Mid air collision
Loss of control
Sources:
» NTSB-AAR-70-15
Follow-up / safety actions
NTSB issued 1 Safety Recommendation
Issued: 23-JAN-1970 | To: | A-70-9 |
BOARD HAD RECOMMENDED THAT PARTS 21 AND 23 OF THE FAR BE MODIFIED TO REQUIRE ALL AIRCRAFT UNDER 12,500 LBS., MANUFACTURED AFTER SOME APPROPRIATE DATE, TO POSSESS A RADAR CROSS SECTION SUITABLE FOR PRIMARY TARGET DETECTION. THE BOARD WAS NOW OF THE VIEW THAT A MORE APPROPRIATE REGULATORY APPROACH WOULD BE TO AMEND PART 91 OF THE FAR\'S TO REQUIRE ALL AIRCRAFT OPERATING IN RADAR SERVICE ENVIRONMENTS TO HAVE A MINIMUM LEVEL OF RADAR CROSS SECTION. SUCH ACTION WOULD MAKE IT POSSIBLE FOR SOME OPERATORS, NEVER INTENDING TO OPERATE IN RADAR ENVIRONMENTS, TO AVOID THE NECESSITY OF REFLECTIVE AUGMENTATION. (Closed - Unacceptable Action) |
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Photos

accident date:
09-09-1969type: McDonnell Douglas DC-9-31
registration: N988VJ
Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does
not display the exact flight path.
Distance from Cincinnati/Northern Kentucky Airport, KY to Indianapolis-Weir Cook Municipal Airport, IN as the crow flies is 158 km (99 miles).
Accident location: Approximate; accuracy within a few kilometers.
This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.