WPR15FAMS1 · Cessna 172S S
Cessna 172S S · Accident: missing aircraft
From Palo Alto Airport (PAO) to an unrecorded destination
Event
- NTSB case
- WPR15FAMS1
- 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
- 1 · 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
- 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
Cessna 172S S
- 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
- N191TG
- Operator
- William McAdams
- Onboard fatalities
- Unknown
- Route
- From Palo Alto Airport (PAO), Palo Alto, CATo not recorded
- Aircraft age
- About 4 years (built 2011)
- 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
- Unknown
- 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
- Missing aircraft
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Not recorded
Cause areas
- Not determined › Not determined
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The commercial pilot departed the airport in the middle of the night for an unknown destination. Later that day, a representative of the operator reported that the pilot and airplane were missing. The representative reported that the missing pilot was a contract flight instructor for the operator; however, the accident flight was not authorized, and local law enforcement officials later classified the airplane as stolen. Recorded radar data attributed to the airplane showed a radar track west to the Pacific Ocean, then south along the California coastline. The last transponder return was recorded over the water about 5 miles west of the shoreline at an altitude of 800 ft above sea level. Primary targets consistent with the airplane's flight were recorded heading southwest over the ocean until no longer visible on radar. A sea search for the missing airplane and ramp checks at several airports along the apparent route of flight were conducted; however, no wreckage was found. The airplane and pilot remain missing.
Probable cause
Undetermined because the airplane was not located.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR15FAMS1
- Event ID
- 20150527X15318
- Case number
- WPR15FAMS1
- 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. 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: 7c1fb7b1cfd0f03983df3379ec5b78651b2b0fe41da98af86595962dca8d7656; retrieved 2026-09-14T19:15:20.374Z.