Swift Air Flight 3518
Boeing 737 8Q8 · Accident: part(s) separation from aircraft during initial climb
From Southern California Logistics Airport (VCV) to San Diego International Airport (SAN)
Event
- NTSB case
- DCA20LA107
- 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
- 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
Boeing 737 8Q8
- 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
- N820TJ
- Operator
- Swift Air
- Onboard fatalities
- Unknown
- Route
- From Southern California Logistics Airport (VCV), Victorville, CATo San Diego International Airport (SAN), San Diego, CA
- 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
- Initial climb
- Defining eventThe 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
- Part(s) separation from aircraft
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
After departure, the air carrier airplane was climbing through an altitude of about 8,000 ft, at which time the flight crew heard a loud bang. Because the flight instruments and gauges showed nothing abnormal, the flight crew elected to continue the flight to the destination airport. The airplane landed uneventfully. Postflight inspection of the airplane found that the dorsal fin and three panels on the lower left side of the vertical stabilizer were missing, and that the left horizontal stabilizer was substantially damaged. Most of the dorsal fin, the vertical stabilizer panels, and 7 of the 14 bolts attaching the dorsal fin to the fuselage were not recovered. Of the seven bolts that were recovered, four remined installed, and three were found loose. Three of the four installed bolts remained attached to pieces of the dorsal fin structure. Examination of the photographs showed that the bolts installed in three positions on the left side of the dorsal fin were the correct part number. The bolt installed in a position on the right side of the dorsal fin was not the correct part number, and the bolt was longer than required. The photographs also showed remnants of old sealant at each of the bolt locations but no evidence that sealant was applied during maintenance of the dorsal fin in February 2019 (less than 3 months before the accident). The seven missing bolts for the dorsal fin structure became loose, had fractured, or were not properly installed.
Probable cause
Improper installation of dorsal fin attach bolts which caused the dorsal fin to separate during flight, substantially damaging the left horizontal stabilizer.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DCA20LA107
- Event ID
- 20200521X63755
- Case number
- DCA20LA107
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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, cause areas. 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: 616352a02eee31280b3b41dcc2c3c9f692e30e0310b3216731ac9c266a44380a; retrieved 2026-09-16T11:40:33.264Z.