LAX99LA204 · Cessna 172P
Southwest Flight Center Cessna 172P and Hoac Austria HK 36R SUPER DIMONA HK 36R SUP · Accident: midair collision on approach
Event
- NTSB case
- LAX99LA204
- 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
- 0 · 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 172P
- 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
- N66018
- Operator
- Southwest Flight Center
- Onboard fatalities
- Unknown
- Route
- From Scottsdale Airport (SDL), Scottsdale, AZTo FFZ
- 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
- Approach · VFR pattern downwind
- 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
- Substantial
Aircraft 2 · Hoac Austria HK 36R SUPER DIMONA HK 36R SUP
- Aircraft type
- Hoac Austria HK-36
- 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
- N1066F
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From FFZTo 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
- Approach · VFR pattern downwind
- 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
- Minor
Cause areas
- Atc personnel(lcl/gnd/clnc) › Communications/information/atc, not issued
- Atc personnel(lcl/gnd/clnc) › Visual separation, not maintained
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The midair collision occurred on downwind leg while both aircraft were in the touch-and-go landing pattern at the tower-controlled airport. This high-wing aircraft, which had completed three touch-and-go patterns, climbed up under the low wing aircraft prior to the collision. Both aircraft landed safely. The investigation revealed that the pilot of this aircraft had not been issued a landing sequence or a traffic advisory by the air traffic controller, and, the pilot believed he was following another high wing aircraft well ahead of them on downwind. The local air traffic controller acknowledged that he had become confused with the sequence of landing aircraft and had not issued a landing sequence or traffic advisory to this aircraft. There were six aircraft in the landing pattern and five more awaiting departure. The accident occurred during daylight hours and there were high, scattered clouds and visibility of 40 statute miles.
Probable cause
The failure of the tower (local) air traffic controller to issue a landing sequence to the climbing, high wing Cessna 172 aircraft, and the controller's failure to maintain visual separation between the two aircraft on downwind leg.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record LAX99LA204
- Event ID
- 20001212X18830
- Case number
- LAX99LA204
- 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: b66e7b04342e049dc1bf54d0f33d126abc55f77f477a5d8acce52dbc9a0d6142; retrieved 2026-09-22T15:01:00.294Z.