Stout Garry V EUROPA-TRIGEAR N133AC

Summary

On 16 August 2021 at about 21:15 local time, a Stout Garry V EUROPA-TRIGEAR registered N133AC was involved in an accident near Hanksville, Utah, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

16 August 2021 at 21:15

Classification

Accident

Location

Hanksville, Utah, United States

Coordinates

38.0586, -110.9611

Aircraft

Stout Garry V EUROPA-TRIGEAR

Registration

N133AC

Category

Airplane

Year built

1999

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Halls Crossing → Manti

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR21LA325

Nobody was injured.

The pilot’s installation of a non-original equipment manufactured radiator cap, which resulted in the loss of coolant and the engine’s exceedance of the maximum admissible cylinder head temperature. Contributing to the accident was the lack of suitable terrain for the forced landing.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot replaced lost fluid in the airplane engine’s cooling system with water and after a successful ground run, the pilot departed. During a “stair-stepped” climbout, the engine’s cylinder head temperature (CHT) increased into the red arc of the CHT gauge (the maximum admissible cylinder head temperature of 180°C [356°F]). The pilot immediately reduced the throttle setting to ide and elected to conduct a forced landing. The airplane sustained substantial damage to the wings and fuselage after impacting rough terrain during the landing. Postaccident examination of the cooling system revealed that system components were secured and void of all fluid. Testing of the accident radiator cap revealed that it was a non-original equipment manufactured (OEM) part by a third-party vendor and that the pressure relief valve opened and released air pressure about 0.2 bar (3 psi), less than the manufacturer’s recommended coolant system maximum pressure value of 1.2 bar (18 psi). It is likely that the lack of pressure created by the non-OEM radiator cap reduced the coolant boiling point and system pressure. The pressure reduction and lowering of the boiling point would have allowed the coolant to evaporate, leading to a loss of coolant in the system and the engine’s exceedance of the maximum admissible cylinder head temperature of 180°C (356°F).

Quoted verbatim from the NTSB record.