CEN24LA317

NTSB accident investigation · Vans RV8 · Guthrie, OK · August 15, 2024

Accident · No injuriesClass 3 · LimitedFinal report
Date
August 14, 2024, 20:21 local (Aug 15, 2024, 01:21 UTC)
Place
Guthrie, OK
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N184DCVans RV8
Defining event
Initial climb: Loss of engine power (total)
Weather
Visual (VMC) · Night
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Central Region
Parties
FAA, Superior Air Parts
FAA report
20240814009959A
Case key
194935

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Probable cause

A loss of engine power due to the separation and ingestion of an air filter retaining bracket into the engine cylinder.

Findings · 3

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

AircraftAircraft › Aircraft structures · FailureChapman Gregory C RV-8A: 1 caseAll aircraft: 72 casesProbable cause
Maintenance: fabricationPersonnel issues › Task performance · Owner/builderChapman Gregory C RV-8A: 1 caseAll aircraft: 30 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The pilot reported that about 40 ft above ground level (agl) during the initial climb from the grass airstrip, engine cylinder Nos. 2 and 3 lost power. About 10 seconds later, engine cylinder Nos. 1 and 4 lost power. The pilot was unable to maintain altitude. He switched fuel tanks in an attempt to regain engine power but noted no change in the engine performance. The airplane impacted trees beyond the departure end of the runway and sustained substantial damage to both wings, fuselage, and empennage. Postaccident examination of the engine revealed an air filter retaining bracket that was fastened to a fiberglass air snorkel/box had separated and was ingested into the No. 2 cylinder. The separated bracket then jammed the intake valve into the open position, resulting in a loss of engine power. Elongation was noted on the fiberglass where the rivets secured the fabricated retaining bracket.

Factual narrative

On August 14, 2024, about 2021 central daylight time, a Vans RV-8A airplane, N184DC, sustained substantial damage when it was involved in an accident near Guthrie, Oklahoma. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, about 40 ft agl during the initial climb from the grass airstrip, engine cylinder Nos. 2 and 3 lost power. About 10 seconds later, engine cylinder Nos. 1 and 4 lost power. The pilot was unable to maintain altitude. He switched fuel tanks in an attempt to regain engine power but noted no change in the engine performance. The airplane impacted trees beyond the departure end of the runway. The airplane sustained substantial damage to both wings, fuselage, and empennage. Postaccident examination of the engine revealed no compression was noted on the No. 2 cylinder. The air filter was removed from the fiberglass air snorkel/box, and one of the four fabricated retaining brackets was separated and missing (see Figure 1). Elongation was noted on the fiberglass where the rivets secured the fabricated retaining bracket. Figure 1. Air filter retaining brackets; one bracket separated and missing. The No. 2 cylinder intake tube was removed, and a foreign metal piece, consistent with the separated retaining bracket, was observed within the cylinder. The bracket was jammed in the cylinder and under the intake valve seat. The intake valve and retaining bracket were removed from the cylinder and photo documented (see Figures 2 and 3). Figure 2. No 2. cylinder intake and separated retaining bracket. Figure 3. Separated air filter retaining bracket located in the No. 2 cylinder intake.

Aircraft

Registration
N184DC
Reported as
Vans RV8 (A)
Category
Airplane, amateur-built
Serial number
80744
Built
2018
Airframe hours
592.7
Engine
Superior XP-IO-360-B1AD3, 185 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Special, Experimental (Special)
Last inspection
Condition · November 15, 2023
Destination
2OK2 · Newalla, OK
Airport
0OK6 · Ellis/Harvey, runway 18, 2,400 × 90 ft, grass/turf
Equipment
Data recorder, Auto-pilot, Angle of attack indicator, ADS-B, Electronic primary flight display, Electronic multifunction display

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
69
Injuries
Minor
Certificate
Private
Airplane ratings
Single-engine land
Medical
BasicMed, Without waivers/limitations
Last flight review
June 19, 2024
Seat
Front
Restraint
4-point
Flight hours
1,666 total · 598 in this make and model · 1,666 as pilot in command · 25 in the last 90 days · 5 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Night
Wind
160° at 11 knots, gusting 17
Visibility
10 statute miles
Lowest ceiling
None
Temperature
91 °F, dew point 72 °F
Altimeter
29.87 inHg
Observed at
KGOK, 2 nm away
METAR
KGOK 150053Z AUTO 16011G17KT 10SM 33/22 A2987 RMK AO2 SLP101 T03330222 $

Docket · 5

The files NTSB released with the investigation on April 1, 2025, on NTSB’s docket system: statements, records, photos and specialists’ reports. 5.7 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.