# NTSB CEN19LA292: Cessna 172, N53432, Denver, CO, August 29, 2019 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: August 28, 2019, 20:10 local (Aug 29, 2019, 02:10 UTC) - Place: Denver, CO - Coordinates: 39.750331, -104.99974 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.7503&lon=-104.9997&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Runway excursion](https://openairdocs.org/ntsb-events/300) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Hartzell, FAA - NTSB case key (mKey): 100165 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN19LA292 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100165/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100165 - Page: https://openairdocs.org/ntsb/CEN19LA292 ## Probable cause A total loss of electrical power for reasons that could not be determined, and the student pilot’s subsequent runway overrun during a no-flap landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Electrical power system](https://openairdocs.org/ntsb-findings/01022400): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Cessna 172P, 1 case](https://openairdocs.org/ntsb-findings/01022400/cases.md?model=2072436), [All aircraft, 48 cases](https://openairdocs.org/ntsb-findings/01022400/cases.md) - [Training: total instruct/training recvd](https://openairdocs.org/ntsb-findings/02031510): Personnel issues › Experience/knowledge · Student/instructed pilot; cases with it: [Cessna 172P, 1 case](https://openairdocs.org/ntsb-findings/02031510/cases.md?model=2072436), [All aircraft, 24 cases](https://openairdocs.org/ntsb-findings/02031510/cases.md) - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Student/instructed pilot (probable cause); cases with it: [Cessna 172P, 19 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=2072436), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Cessna 172P, 8 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=2072436), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330); cases with it: [Cessna 172P, 2 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=2072436), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Landing: Runway excursion](https://openairdocs.org/ntsb-events/300) (defining event); cases with it: [Cessna 172P, 29 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=2072436), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) ## Analysis The student pilot was completing a solo cross-country flight when he noticed the low voltage warning light illuminate; however, since the voltmeter continued to indicate about 28 volts (v), he continued the flight to the destination airport and completed a touch-and-go landing before proceeding back to the departure airport. The pilot later stated that he was “not confident that he completely understood how an electrical system failure may affect the aircraft.” As the pilot attempted to lower the flaps before landing, the airplane experienced a complete loss of electrical power, and the flaps did not extend. The student pilot conducted a no-flap landing to the 3,600-ft-long runway, during which the airplane bounced multiple times and continued off the end of the runway and over a retaining wall, resulting in substantial damage. The pilot reported that he had not received training in no-flap landings. Examination of the alternator revealed no anomalies that would have precluded normal operation. Some wiring associated with the alternator displayed areas of broken insulation and exposed wire; however, it could not be determined if this was due to preaccident chafing or the result of impact damage. Based on the available information, the reason for the loss of electrical power could not be determined. ## Factual narrative On August 28, 2019, about 2010 mountain daylight time, a Cessna 172, N53432, was substantially damaged when it was involved in an accident near Denver, Colorado. The student pilot received minor injuries. The airplane was operated as Title 14 Code of Federal Regulations Part 91 instructional flight. The student pilot was conducting a solo cross-country flight. During the first leg of the flight, he noticed that the low voltage warning light illuminated intermittently and turned a faint red. He explained that although the voltmeter dropped from 28.5 volts (v) to 28.4v or 28.3v, it appeared to remain about 28v all the way to his destination, so he did not perceive a problem that required immediate action. The student pilot conducted a touch-and-go landing at the destination airport and proceeded back to the departure airport. Shortly thereafter, the voltmeter “began to decline more.” The pilot requested visual flight rules flight following from air traffic control and climbed to about 10,000 ft. He reported that he was “not confident that he completely understood how an electrical system failure may affect the aircraft.” The voltmeter continued to indicate a loss of voltage as the pilot approached the departure airport. He reported the electrical issue to the tower controller, requested a straight-in approach, and was cleared to land on runway 03; at this time, the voltmeter indicated about 12v. About 10 miles from the airport, the student pilot moved the flap selector to 10°; however, the airplane lost all electrical power, and the flaps did not extend. The student pilot reported that he had not previously completed a no-flap landing. The airplane crossed the runway numbers at 100 knots and touched down about the 1,000 ft. markings. The airplane bounced multiple times. The pilot applied brakes once the airplane remained on the ground but could not stop the airplane before it continued off the end of the runway and over a retaining wall, impacting a guardrail. The airplane sustained substantial damage to the propeller, fuselage, and landing gear. The alternator was examined at the manufacturer’s facility with oversight from the Federal Aviation Administration. The alternator suffered impact damage to the pulley, cooling fins, and front housing. The damaged front housing was replaced with an exemplar unit and the alternator passed the acceptance test procedure for a new/rebuilt alternator. Some wiring was shipped with the alternator, including the aircraft-side connector and harness for the alternator control unit. The wiring from the alternator control unit displayed some insulation cracking and areas of exposed wires. It could not be determined whether this damage was the result of chafing or impact damage. The aircraft-side alternator control unit connector pin sockets were loose, with no apparent sealing or strain relief. Two wires displayed crimp splices, which remained intact when manipulated. ## Aircraft - Registration: [N53432](https://openairdocs.org/deregistered/N53432-2022-03-05), registration cancelled 2022-03-05, S/N 17274748, built 1981 (OpenAirDocs) - Reported make and model: Cessna 172 (P) - Registry model: [Cessna 172P](https://openairdocs.org/model/cessna-172p) (registry code 2072436) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17274748 - Year built: 1981 - Engines: Lycoming O-320 SERIES reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Rocky Mountain Flight School - Registered owner: G & M Aircraft Inc - Airworthiness certificate: Standard, Normal - Departed: COS, Colorado Springs, CO - Destination: Same as departure - Airport: BJC, Rocky Mountain Metro, runway 03/21, 3,600 × 75 ft, asphalt - Equipment: ADS-B, Electronic flight bag or handheld device, Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 23; injuries: minor; student; medical: class 3, without waivers/limitations; seat: left; restraint: 3-point; flight hours: 65 total, 65 in this make and model, 10 as pilot in command, 22 in the last 90 days, 8 in the last 30 days ## Weather - Conditions: Visual (VMC), Night - Wind: 50° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 84 °F, dew point 27 °F - Altimeter: 30.11 inHg - Observed at: KBJC, 10 nm away - METAR: KBJC 290145Z 05003KT 10SM SKC 29/M03 A3011 ## 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 20190828014739A](https://openairdocs.org/incident/20190828014739A), Aug 28, 2019: Cessna 172P, Broomfield, CO, Substantial damage. Upon touchdown aircraft bounced several times skidded off end of runway through safety area, continued off embankment impacting public road. ## Other investigations on N53432 (2) 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. - [NTSB DEN90LA035](https://openairdocs.org/ntsb/DEN90LA035), Dec 27, 1989: Cessna 172P (N53432), Billings, MT, substantial damage. Probable cause: THE FAILURE OF THE PILOT TO MAINTAIN DIRECTIONAL CONTROL DURING ADVERSE WIND CONDITIONS. - [NTSB SEA86LA001](https://openairdocs.org/ntsb/SEA86LA001), Oct 1, 1985: Cessna 172P (N53432), Winnemucca, NV, substantial damage ## Docket (4 files) The files NTSB released with the investigation on February 15, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100165. 9.6 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 14 pages, 6.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12341354&FileExtension=pdf&FileName=NTSB%20Form%206120%20W.%20Belk%20with%20narrative%20-corrected%20flight%20time_w%20blocks_for%20docket_Redacted-Rel.pdf - Alternator exam findings (item 2, PDF, 3 pages, 166 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12340652&FileExtension=pdf&FileName=CEN19LA292%20-%20N53432%20Alternator%20Exam%20findings_Redacted-Rel.pdf - Copy of student pilot certificate (item 3, PDF, 1 page, 665 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12341628&FileExtension=pdf&FileName=Copy%20of%20Student%20Pilot%20Certificate%20for%20Docket_Redacted-Rel.pdf - Photographs (item 4, PDF, 3 pages, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12341364&FileExtension=pdf&FileName=Photos%20for%20Docket-Rel.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.