# NTSB WPR23LA146: Cessna 172M, N1399U, Santa Ana, CA, April 1, 2023 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: April 1, 2023, 13:43 local (20:43 UTC) - Place: Santa Ana, CA · KSNA - Coordinates: 33.675662, -117.86823 - Nearby events: https://openairdocs.org/map.md?lat=33.6757&lon=-117.8682&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Aircraft wake turb encounter](https://openairdocs.org/ntsb-events/361) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 106999 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR23LA146 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/106999/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=106999 - Page: https://openairdocs.org/ntsb/WPR23LA146 ## Probable cause The flight instructor’s failure to maintain clearance from a commercial airliner which resulted in an encounter with wake turbulence and subsequent loss of control resulting in impact with terrain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Turbulence: wake turbulence](https://openairdocs.org/ntsb-findings/03032025): Environmental issues › Conditions/weather/phenomena · Ability to respond/compensate (probable cause); cases with it: [Cessna 172M, 2 cases](https://openairdocs.org/ntsb-findings/03032025/cases.md?model=2072418), [All aircraft, 47 cases](https://openairdocs.org/ntsb-findings/03032025/cases.md) - [Performance/control parameters: descent/approach/glide path](https://openairdocs.org/ntsb-findings/01062040): Aircraft › Aircraft oper/perf/capability · Not attained/maintained; cases with it: [Cessna 172M, 15 cases](https://openairdocs.org/ntsb-findings/01062040/cases.md?model=2072418), [All aircraft, 809 cases](https://openairdocs.org/ntsb-findings/01062040/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Student/instructed pilot; cases with it: [Cessna 172M, 123 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=2072418), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Aircraft wake turb encounter](https://openairdocs.org/ntsb-events/361) (defining event); cases with it: [Cessna 172M, 2 cases](https://openairdocs.org/ntsb-events/361/sequence.md?model=2072418), [All aircraft, 37 cases](https://openairdocs.org/ntsb-events/361/sequence.md) ## Analysis The flight instructor reported that while practicing crosswind landings with his student, the tower advised the pilot of wake turbulence from a commercial airliner on the parallel runway. They flew a steeper approach but noticed a moderate right quartering headwind on the windsock. At about 100 feet above ground level the airplane encountered wake turbulence and banked sharply to the right. Both pilots added full left aileron and applied backpressure to the yoke as the airplane contacted the terrain. The airplane sustained substantial damage to the right wing. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. ## Aircraft - Registration: [N1399U](https://openairdocs.org/aircraft/N1399U), registered now, S/N 17267070, built 1976 (OpenAirDocs) - Reported make and model: CESSNA 172M - Registry model: [Cessna 172M](https://openairdocs.org/model/cessna-172m) (registry code 2072418) (OpenAirDocs) - Registry engine: [Lycoming O-320-E2D](https://openairdocs.org/engine/lycoming-o-320-e2d) (registry code 42123, 4 cycle) (OpenAirDocs) - Category: Airplane - Serial number: 17267070 - Year built: 1976 - Airframe hours: 9779 - Engines: Lycoming O-320-E2D reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Oc 172 Group LLC - Registered owner: Oc 172 Group LLC - Airworthiness certificate: Standard, Normal; Standard, Utility - Last inspection: Annual, September 13, 2012 - Departed: KSNA, Santa Ana, CA - Destination: Same as departure - Airport: KSNA, John Wayne/Orange County Airport, runway 20L, 2,886 × 75 ft, asphalt - Equipment: Stall warning system, ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 21; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review December 8, 2021; seat: right; restraint: 3-point; flight hours: 891.5 total, 890.5 in this make and model, 862.3 as pilot in command, 175.2 in the last 90 days, 64.5 in the last 30 days, 7.5 in the last 24 hours - Pilot; age 26; injuries: none; student; medical: class 1, without waivers/limitations; seat: left; restraint: 3-point; flight hours: 0 total, 0 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 9 knots - Visibility: 10 statute miles - Temperature: 66 °F, dew point 45 °F - Altimeter: 30.12 inHg - Turbulence: Severe - Observed at: KSNA - METAR: KSNA 012053Z 22009KT 10SM FEW035 FEW200 19/07 A3012 RMK AO2 SLP199 T01890072 56007 ## 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 20230401008269A](https://openairdocs.org/incident/20230401008269A), Apr 1, 2023: Cessna 172M, Santa Ana, CA, Substantial damage. On April 01, 2023, just after 13:21 pacific standard time, U.S. Registered aircraft, located in Santa Ana California experienced severe turbulence while… ## Other investigations on N1399U (1) 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 LAX77DVA53](https://openairdocs.org/ntsb/LAX77DVA53), Aug 20, 1977: Cessna 172 (N1399U), Lost Hills, CA, substantial damage ## Docket (3 files) The files NTSB released with the investigation on July 7, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=106999. 8.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 7.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15329313&FileExtension=pdf&FileName=NTSB%206120%20Alex%20Asp_Redacted-Rel.pdf - Memorandum for record a�� telephone interview, pilot (item 2, PDF, 1 page, 83 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15322673&FileExtension=pdf&FileName=Memorandum%20of%20Record%20Alex%20Asp%2004102023%20Phone-Rel.pdf - Photos (item 3, PDF, 1 page, 415 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15458566&FileExtension=pdf&FileName=WPR23LA146%20pic%20N1399U-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.