ATL84IA160

NTSB incident investigation · Douglas DC-9-32 · Mount Vernon, IL · May 4, 1984

Incident · No injuriesIncident investigationFinal report
Date
May 4, 1984, 10:24 local (15:24 UTC)
Place
Mount Vernon, IL
Injuries
84 uninjured
Damage
No damage
Phase of flight
Enroute
Aircraft
N923LDouglas DC-9-32
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Case key
6351

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the incident.

On this page

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Near collision between aircraftCruise - normal
Crew/group coordination - improperAtc personnel(artcc)Cause
Crew/group coordination - improperPilot of other aircraftCause
Procedures/directives - not followedAtc personnel(artcc)Cause
Procedures/directives - not followedPilot of other aircraftCause
Flight advisories - not usedAtc personnel(artcc)Factor
Radar separation - not maintainedAtc personnel(artcc)Cause

Analysis

Kansas city ARTCC (zkc) had cleared ozark flt 709 (a DC-9, N923L) to cruise at FL270. While proceeding ese near the edgeof the zkc area, the DC-9 converged on zorro 11 (a flt of 3 F-4'S). The F-4'S had been cleared by indianaplolis ARTCC (zid) to proceed westbound at FL260 to rendesvous with a KC-135 tanker (shake 81) to refuel on aerial refueling route AR110W. The beginning of AR110W was in the zid area; from there it continued westbound into the zkc area. The tanker wasorbiting under control of zkc & was cleared to maintain block alt FL260 to FL290. Zid cleared the F-4'S to the tanker freq without handing them off to zkc & without obtaining approval from either zkc or the tanker. After establishing radio contact, the tanker crew incorrectly cleared the F-4'S to climb to FL270. When the zkc controller realized the F-4'S & DC-9 were converging, he told the DC-9 crew to immediately turn left. The DC-9 crew saw the F-4'S & took evasiveaction. Zid had not properly coordinated the F-4S' position & none of the plts were informed of conflicting traffic.

Aircraft

Registration
N923L
Reported as
Douglas DC-9-32
Category
Airplane
Serial number
47109
Airframe hours
43,480
Engine
P&W JT8D-9A, turbo fan
Damage
No damage
Flight
Part 121
Registered owner
Ozark Airlines, Inc.
Airworthiness certificate
Standard, Normal
Last inspection
Continuous airworthiness · July 23, 1983 · 2,098 hours before
Departed
STL · St. Louis, MO
Destination
SDF · Louisville, KY
Flight plan
IFR

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
40
Certificates
Airline transport, Commercial, Flight instructor
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Seat
Left
Flight hours
13,727 total · 8,061 in this make and model · 7,949 as pilot in command · 5 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Lowest ceiling
None