# NTSB ERA19LA019: Cessna 172, N924MM, Lynchburg, VA, October 18, 2018 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 18, 2018, 10:57 local (14:57 UTC) - Place: Lynchburg, VA - Coordinates: 37.330001, -79.199996 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=37.3300&lon=-79.2000&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report April 13, 2020 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: Liberty University, FAA/FSDO - NTSB case key (mKey): 98509 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA19LA019 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/98509/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=98509 - Page: https://openairdocs.org/ntsb/ERA19LA019 ## Probable cause The stuck No. 2 cylinder exhaust valve, which resulted in a partial loss of engine power and a subsequent forced landing and impact with a ditch. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Malfunction (probable cause); cases with it: [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340); cases with it: [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The flight instructor reported that, shortly after the student pilot conducted the takeoff for the instructional flight, they felt the engine vibrate and the airplane shudder. They then noticed that the rpm had decreased and that the engine's performance had degraded. The instructor took the controls and lowered the nose to prevent a stall. He attempted to land on the intersecting runway, and the airplane touched down with about 100 ft of runway remaining. Realizing that the airplane could not be stopped within the remaining runway, the instructor steered the airplane right to avoid a steep drop-off past the runway end. The airplane subsequently impacted a ditch and then came to rest in grass in a nose-down position. The left wing sustained substantial damage. Postaccident examination of the engine revealed that the No. 2 cylinder exhaust valve was stuck open. Given this evidence, it is likely that the stuck exhaust valve resulted in the partial loss of engine power. ## Factual narrative On October 18, 2018, about 1057 eastern daylight time, a Cessna 172S, N924MM, was substantially damaged following a partial loss of engine power and forced landing after takeoff from Lynchburg Regional Airport (LYH), Lynchburg, Virginia. The flight instructor and the student pilot were not injured. The airplane was operated by Liberty University under the provisions of Title14 Code of Federal Regulations part 91 as an instructional flight. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight that was originating at the time of the accident. The flight instructor, who was in the right cockpit seat, reported that ground operations were normal, including pretakeoff engine indications. The student performed the takeoff on runway 4. After flap retraction, about 200 feet above the ground, they observed an engine vibration and the airplane shuddered. They noted a decrease in engine RPM with degraded performance. The flight instructor took the controls and noted that the airspeed had dropped to just above stall speed and the stall warning horn sounded. He lowered the airplane's nose to prevent a stall and attempted to land on the intersecting runway 35. The airplane touched down with about 100 feet of runway remaining. Realizing that he could not stop the airplane within the remaining runway, the instructor steered the airplane to the right to avoid a steep drop-off under the extended centerline of the runway. The airplane departed the runway surface, collided with a drainage ditch, and came to a stop in the grass in a nose down position. The pilots egressed the airplane and were met by first responders. A Federal Aviation Administration inspector responded to the accident site and examined the wreckage. He reported that the outboard portion of the left wing sustained structural damage during the landing. The propeller struck the ground during the event.The inspector examined the engine after the recovery of the wreckage. A cylinder pressure/leak check (with 80 psi input pressure) was performed. The Nos. 1, 3, and 4 cylinder readings were 74, 74, and 78 psi, respectively. The No. 2 cylinder read 22 psi. The No. 2 cylinder spark plugs were oil soaked. The No. 2 exhaust valve was stuck open; air could be heard escaping past the valve. There were no cracks or leaks observed in the cylinder body. The engine had accumulated 2,106 hours since overhaul, and the manufacturer's overhaul interval on the engine was 2,200 hours. ## Aircraft - Registration: N924MM (not matched to a registry record) - Reported make and model: Cessna 172 (S) - Category: Airplane - Serial number: 172S11056 - Year built: 2010 - Airframe hours: 3592 - Engines: Lycoming IO-360-L2A 180 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Liberty University - Registered owner: Liberty University - Airworthiness certificate: Standard, Normal; Standard, Utility - Last inspection: 100 hour, August 17, 2018, 78 hours before - Departed: LYH, Lynchburg, VA - Destination: LYH, Lynchburg, VA - Airport: LYH, Lynchburg Regional, runway 04, 7,100 × 150 ft, asphalt - Equipment: Stall warning system, Onboard weather, Electronic primary flight display, ADS-B, Electronic multifunction display, Angle of attack indicator, Auto-pilot ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 22; injuries: none; commercial, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review May 21, 2018; seat: right; restraint: 3-point; flight hours: 328 total, 282 in this make and model, 278 as pilot in command, 81 in the last 90 days, 37 in the last 30 days, 2 in the last 24 hours - Student pilot; age 20; injuries: none; student; medical: class 1, without waivers/limitations; seat: left; restraint: 3-point; flight hours: 4 total, 4 in this make and model, 0 as pilot in command, 4 in the last 90 days, 4 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 360° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 54 °F, dew point 34 °F - Altimeter: 30.45 inHg - Observed at: LYH ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20181018023769A](https://openairdocs.org/incident/20181018023769A), Oct 18, 2018: Cessna 172S, Lynchburg, VA, Substantial damage. Instructional flight taking off from rwy 4 at Lynchburg Regional Airport(lyh) experienced loss of engine RPM and vibration at approx 300 ft AGL. Performed… ## Docket (7 files) The files NTSB released with the investigation on November 18, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=98509. 8.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 5.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478062&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Pilot-in-Command Written Statement (item 2, .PDF, 202 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478063&FileExtension=.PDF&FileName=Pilot-in-Command%20Written%20Statement-Master.PDF - FAA Inspector Statement (item 3, .PDF, 817 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478064&FileExtension=.PDF&FileName=FAA%20Inspector%20Statement-Master.PDF - Commonwealth of Virginia Report (item 4, .PDF, 255 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478065&FileExtension=.PDF&FileName=Commonwealth%20of%20Virginia%20Report-Master.PDF - Photo Array (item 5, .PDF, 5 photos, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478066&FileExtension=.PDF&FileName=Photo%20Array-Master.PDF - Flight Path (item 6, .PDF, 197 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478067&FileExtension=.PDF&FileName=Flight%20Path-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 7, .PDF, 525 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478068&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Master.PDF From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.