Comair Flight 5751
Canadair CL-600-2B19 · Incident: airframe, component or system failure en route
From Cincinnati Northern Kentucky International Airport (KCVG) to Greenville-Spartanburg International Airport (KGSP)
Event
- NTSB case
- MIA01IA051
- 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
- Unknown
- 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
- Visual Meteorological Cond
Canadair CL-600-2B19
- Aircraft type
- Canadair CL-600
- 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
- N729CA
- Operator
- Comair
- Onboard fatalities
- Unknown
- Route
- From Cincinnati Northern Kentucky International Airport (KCVG), Hebron, KYTo Greenville-Spartanburg International Airport (KGSP), Greer, SC
- 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 121: Air Carrier
- 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
- Airframe, component or system failure
- 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
- Manufacturer › Acft/equip, inadequate design
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
While climbing through 20,000 feet in visual meteorological conditions, the captain's windshield "shattered." The captain did not declare an emergency; the flight returned to the departure airport and landed uneventfully. The damaged windshield (PPG part number NP 139321-5, S/N 99018H7134) was removed from the airplane and initial examination revealed that the center ply was failed. The window was further examined in the presence of representatives of the NTSB, FAA, Bombardier, and PPG, at one PPG's facilities. A report of the damaged windshield prepared by PPG indicates, "The fracture originated 0.20 inch from the bottom edge and 3.8 inches from the center of the forward corner. The origin of the fracture was a peel chip that developed on the outboard surface in the bottom forward corner area. The initiation point of the peel chip damage was located 0.115 inch from the inner edge of the Teflon tape and 0.325 inch from the glass edge." The report also indicates that examination of the peel chip using a microscope, "...did not reveal any surface damage at the peel chip initiation point, nor was there any indication of manufacturing defects." No discrepancies were noted with the anti-ice heating system and sensing elements. Optical distortion check of the damaged window was performed which revealed, "There was no slope-line distortion apparent in the critical vision area. However, facilities were not available to perform a quantitative distortion evaluation." Residual visibility examination could not be performed due to the absence of a standard and prescribed method of evaluation. Manufacturing of windshield S/N 99018H7134 was completed on January 18, 1999; the window was installed in the incident airplane by Comair maintenance personnel on March 27, 1999, to replace the previous window which "shattered while sitting at gate power off." The incident window had accumulated a reported 4,422.8 hours and 4,526 cycles at the time of failure.
Probable cause
The inadequate design of the flight compartment windshield by the windshield manufacturer resulting in cracking of the center ply.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record MIA01IA051
- Event ID
- 20010110X00108
- Case number
- MIA01IA051
- 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: c1abf09b6aa0de2c94c45245f4b2e94372166535e53379889ebd2ffd46d0db9b; retrieved 2026-09-18T16:18:44.894Z.