Textron Aviation INC 172S accident near Erie, Colorado, November 9, 2023
On November 9, 2023 at about 4:30 pm local time, a 2018 Textron Aviation INC 172S, registered N1817E, was substantially damaged in an accident during maneuvering near Erie, Colorado. It was an instructional flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A partial loss of engine power while maneuvering at a low altitude due to a stuck exhaust valve.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- November 9, 2023 · about 4:30 pm local time
- Place
- Erie, Colorado · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Textron Aviation INC 172S, built 2018
- Registration
- N1817E · registry record · serial 172S12169
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The flight instructor started the engine for the instructional flight, and it began to shake. The flight instructor shut down the engine, inspected it, and the alternator belt. Everything appeared to be normal, so he decided to restart the engine. After engine start, all indications were “in the green” and the engine no longer shook. All systems during the run-up appeared normal, and the instructor and student pilot departed. After completing several maneuvers, the flight instructor gave the student pilot a simulated emergency. The student pilot addressed the simulation with the appropriate steps and the airplane descended to about 700 ft above ground level (agl). As the student pilot applied full power to recover from the simulated emergency, the engine started to shake again. The flight instructor took the flight controls and observed that the engine rpm started to drop. The flight instructor maneuvered the airplane to land in a field. During the landing, the airplane rolled nose-first into a culvert and sustained substantial damage to the right wing and engine firewall. During the engine examination, no compression was observed at the No. 4 cylinder. Further examination revealed that the No. 4 exhaust valve was stuck open, and the No. 4 push rod was bent. No other anomalies were noted with the engine or systems that would have resulted in a loss of engine power. A review of the maintenance records revealed that a service bulletin (SB) to examine the exhaust valve and guide condition was not completed, nor was it required to be. The SB suggested that an inspection should be performed at every 1,000 hours of operation for engines equipped with Hi-Chrome exhaust valve guides, as the accident engine was. The partial loss of engine power was likely due to the stuck exhaust valve. Compliance with the engine manufacturer’s SB, although not required, may have prevented the stuck valve.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Powerplant sys/comp malf/fail during maneuvering defining event
- Loss of engine power (partial) during maneuvering
- Off-field or emergency landing during emergency descent
- Collision with terrain or object (not controlled flight into terrain) during landing (landing roll)
The NTSB's findings
- Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Malfunction
- Personnel issues › Task performance › Maintenance › Scheduled/routine maintenance › Maintenance personnel
Flight instructor
- Certificate: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane
- Flight time: 493 hours in all; 389 in this make and model; 204 in the last 90 days; 34 in the last 30 days; 416 as pilot in command; 203 on instruments
- Last flight review: July 11, 2023
- Medical certificate: Class 1 (waiver time limited special)
- Seat: rgt
- Injury: no injuries
Dual student
- Certificate: student
- Flight time: 88 hours in all; 88 in this make and model; 75 in the last 90 days; 18 in the last 30 days; 10 as pilot in command
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 4,111 hours
- Last inspection: 100-hour inspection, October 21, 2023
- Maximum gross weight: 2,550 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming IO-360-L2A (piston); 16,426 hours total
- Operator: Atp Aircraft 6 LLC
The flight
- Departed from: BKBJ Broomfiled CO at 3:40 pm
- Flight plan: none
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 020° at 3 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 37°F (3°C), dew point 28°F (-2°C)
- Altimeter: 30.28 inHg
- Observation at 9:15 am from KEIK, 3 miles away
Weather report (METAR): KEIK 091615Z AUTO 02003KT 10SM CLR 03/M02 A3028 RMK AO2 T00321016
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 2 |
Photographs from the investigation 5 pictures from the NTSB's docket, as the NTSB released them
Photograph 1 – Right Wing
Photograph 2 – Rear View of the Airplane
Photograph 3 – Number 4 Intake and Exhaust Valves
Photograph 4 – View of Cylinder Number 4 Pushrod
Photograph 5 – “C” Stamp on Number 4 CylinderThe NTSB's photographs with the NTSB's captions, at screen size. Open a picture to see it full size or to report one that should not be shown.
Documents from the investigation the NTSB's docket: the evidence folder behind the report
6 documents, released by the NTSB on October 22, 2025. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Flight Instructor Statement to FAA | PDF, 1 page | View Download |
| 3 | Engine Examination | PDF, 1 page | View Download |
| 4 | Photo Array | PDF, 6 pages · our copy | View Download |
| 5 | Lycoming Mandatory Service Bulletin 388C | PDF, 13 pages | View Download |
| 6 | Lycoming Service Instruction - Exhaust Valve and Guide Identification Procedures | PDF, 2 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.