Flight 528 · Boeing 737
Boeing 737 · Incident on approach
From Toronto Pearson International Airport (YYZ) to LaGuardia Airport (LGA)
Event
- NTSB case
- NYC99IA036
- 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
- Incident
- 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
- Airline
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Instrument Meteorological Cond
Boeing 737
- Aircraft type
- Boeing 737
- 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
- GCPX
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Toronto Pearson International Airport (YYZ), TorontoTo LaGuardia Airport (LGA), NY
- 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 129: Foreign
- 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
- 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
- Miscellaneous/other
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- None
Cause areas
- Pilot in command › Evasive maneuver, not required
- Pilot in command › Identification of aircraft visually, inaccurate
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The Boeing 737 was on downwind for La Guardia's runway 4, at 4,000 feet msl, when the crew caught a glimpse of three lights. The lights were red, white, green, and aligned vertically with the red light on the bottom. The first officer saw the other airplane, and had enough time to realize they were not going to collide, but not enough time to execute an evasive maneuver. In addition, the airplane's traffic alert collision avoidance system went from 'TRAFFIC' to 'MONITOR VERTICAL SPEED' to 'CLEAR OF CONFLICT' in approximately 2 seconds. The other airplane was a Cessna 172, IFR, at 5,000 feet msl. The pilot of that airplane saw the Boeing 737 at his 12 O'clock position, and perceived it to be at the same altitude. To avoid a perceived collision, the Cessna pilot executed a descent, and at 4,000 feet msl, the two airplanes passed 0 feet vertically and 500 feet horizontally from one another.
Probable cause
The Cessna pilot's incorrect visual identification of the Boeing 737's altitude, and decision to take evasive action that was not required, which resulted in the two airplanes coming within 500 feet horizontally, and 0 feet vertically of one another.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record NYC99IA036
- Event ID
- 20001211X11621
- Case number
- NYC99IA036
- 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, damage. 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: 9de490210ef3176711f077b08656615c70291b39ce60c44e53ba24e60683eb55; retrieved 2026-09-18T17:01:52.622Z.