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WPR22LA149 · Dietrich Ryan S-4 COYOTE 1

8 Apr 2022 · Chula Vista, CA, United States

Dietrich Ryan S-4 COYOTE 1 · Accident: system/component malfunction/failure (non-power) during takeoff

From John Nichols Field Airport (0CL3) to an unrecorded destination

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Event

NTSB case
WPR22LA149
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
Event fatalities
Unknown
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

Dietrich Ryan S-4 COYOTE 1

Aircraft type
Dietrich Ryan S-4
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
N3156D
Operator
Unknown
Onboard fatalities
Unknown
Route
From John Nichols Field Airport (0CL3), Chula Vista, CATo 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
Takeoff
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
System/component malfunction/failure (non-power)
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

  • Aircraft › Aircraft handling/service
  • Aircraft › Aircraft structures
  • Personnel issues › Task performance

Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.

NTSB narrative

The pilot of the accident airplane was attempting to depart after his airplane had recently been returned to service following a hard landing about 9 months before that had collapsed the right main landing gear and damaged the wing strut. During the takeoff attempt on the day of the accident, when the pilot started to rotate, the airplane immediately entered an uncommanded right roll. The pilot’s attempts to counteract the roll were unsuccessful and the airplane impacted the ground.

Postaccident examination of the airplane revealed that the right wing’s aft lift strut was not bolted to the right wing attachment clevis. As the left wing was intact and continued to produce lift, the unsecured right wing would have reduced the lift force acting on the right wing and, therefore, inhibited the pilot’s ability to maintain level flight. This condition is what likely resulted in an uncommanded right roll and impact with the ground.

The airplane had recently been repaired by the pilot (who was also the owner) with assistance from his mechanic. During the rebuild, the mechanic placed a bolt upside down and with a finger-tight nylon locknut in the right wing’s aft lift strut to secure it to the right wing attachment clevis while they transported the airplane to a new hangar. The pilot and the mechanic never removed the bolt and the strut was never properly secured to the wing as required by the build manual before the accident flight. Both the pilot and mechanic performed the rebuild together and were both aware of the temporary measure used to secure the right wing’s aft lift strut to the right wing. The mechanic should have correctly completed the installation before he returned the airplane to service and the accident pilot should have recognized the absence of the hardware before he departed on the accident flight. Further, the pilot also missed the absence of the improper installation, having incorrectly assumed that the mechanic had performed a preflight inspection for him while they developed a preflight checklist.

Probable cause

The pilot/owner and maintenance personnel’s improper installation of the right wing’s aft lift strut to the right wing, which resulted in a loss of lift during takeoff, an uncommanded right roll, and an impact with terrain.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record WPR22LA149
Event ID
20220411104926
Case number
WPR22LA149
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, coordinates, 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: 100efecdfde15700d2cd04919ef9b582d30b53d143967255b96a512840babc13; retrieved 2026-09-16T15:07:20.254Z.