ATL98FA060 · Cessna 525
Cessna 525 and Cessna 172N · Accident: midair collision en route
Event
- NTSB case
- ATL98FA060
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 5 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Aircraft 1 · Cessna 525
- Aircraft type
- Cessna 525
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N111LR
- Operator
- Marion H. Allen · private individual
- Onboard fatalities
- Unknown
- Route
- From DeKalb Peachtree Airport (PDK), Chamblee, GATo Harrisburg International Airport (MDT), Harrisburg, PA
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · climb to cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Midair collision
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Aircraft 2 · Cessna 172N
- Aircraft type
- Cessna 172
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N737WD
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From 84A · Cumming, GATo not recorded
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Midair collision
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Tree(s)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Pilot in command › Procedures/directives, not followed
- Pilot in command › Visual lookout, inadequate
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
A Cessna 525 and a Cessna 172 collided in flight about 3,400 feet mean sea level on converging courses, with the 525 heading north and the 172 heading southwest. The converging speed was about 300 knots. The 525 departed under instrument flight rules, received vectors, and was initiating a climb on course. Training in the 525 emphasizes maximum use of the autopilot to afford greater outside scanning by the single pilot. The 525 was in radio contact with terminal approach control and the pilot's acknowledgement of the climb clearance was interrupted by the collision. The 172 had departed a local airfield, located just outside the 30 mile Mode C veil airspace of a terminal airport, and proceeded southwest. The collision occurred as the 172 was approaching Class D airspace of a military tower, and the pilot was initiating radio contact with the military tower. The terminal approach controller in contact with the 525 stated he did not observe the primary target of the 172, and conflict alert software was not installed. The 172 did not display a transponder signal and the transponder switch was subsequently found in the 'off' position. A cockpit visibility study indicated that from a fixed eye position the 172 was essentially hidden behind aircraft structure of the 525 for the 125 seconds before impact. The 172 could be seen by shifting the pilot's eye position. The 525 was viewable in the left lower section of the 172's windscreen. Both airplanes were operating in visual flight conditions.
Probable cause
The failure of both pilots to see and avoid conflicting traffic, and the failure of the 172 pilot to operate the transponder as required by current regulations. Factors were the controller's failure to observe the traffic conflict, the lack of radar conflict alert capability, and the training emphasis on maximum autopilot usage with the autopilot controller placed at the rear of the cockpit center mounted pedestal.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ATL98FA060
- Event ID
- 20001211X09798
- Case number
- ATL98FA060
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 7755d087de1ecaacf1334432fdc4563d2d38b901aaaa68dec20ace8ed210c4e8; retrieved 2026-09-20T22:38:19.610Z.