# NTSB CEN21LA190: Gates Learjet 35A, N354EF, Colorado Springs, CO, April 15, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: April 15, 2021, 10:30 local (16:30 UTC) - Place: Colorado Springs, CO - Coordinates: 38.805813, -104.70077 - Nearby events: https://openairdocs.org/map.md?lat=38.8058&lon=-104.7008&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA - NTSB case key (mKey): 102925 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA190 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102925/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102925 - Page: https://openairdocs.org/ntsb/CEN21LA190 ## Probable cause The flight crew’s improper decision to continue the unstabilized approach, which resulted in an aerodynamic stall and impact with the runway during landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Action: lack of action](https://openairdocs.org/ntsb-findings/02041030): Personnel issues › Action/decision · Flight crew (probable cause); cases with it: [Gates Learjet 35A, 3 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md?model=5170602), [All aircraft, 792 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md) - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Capability exceeded; cases with it: [Gates Learjet 35A, 3 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=5170602), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach: Course deviation](https://openairdocs.org/ntsb-events/281); cases with it: [Gates Learjet 35A, 1 case](https://openairdocs.org/ntsb-events/281/sequence.md?model=5170602), [All aircraft, 52 cases](https://openairdocs.org/ntsb-events/281/sequence.md) - [Landing: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241) (defining event); cases with it: [Gates Learjet 35A, 3 cases](https://openairdocs.org/ntsb-events/241/sequence.md?model=5170602), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md) - [Landing: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Gates Learjet 35A, 1 case](https://openairdocs.org/ntsb-events/060/sequence.md?model=5170602), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Landing: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490); cases with it: [Gates Learjet 35A, 2 cases](https://openairdocs.org/ntsb-events/490/sequence.md?model=5170602), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The flight crew was conducting an instrument approach to the destination airport with the captain as the pilot monitoring and the copilot as the pilot flying. The airplane exited an overcast layer of clouds about 650 to 700 ft above ground level and about 1/2 mile right of the runway centerline. The captain requested the flight controls and returned the airplane to the runway extended centerline about 100 ft above ground level and reduced the throttles to “idle.” During landing, the stick shaker activated, and the captain applied engine power; however, the airplane stalled, and the right wingtip fuel tank impacted the runway, resulting in substantial damage. There was no mechanical malfunction/failure of the airplane that would have precluded normal operation. The operator’s operations manual specified that a stabilized approach should be established no later than 500 ft above airport elevation. ## Factual narrative On April 15, 2021, about 1030 central daylight time, a Gates Learjet Corp. 35A airplane, N354EF, was substantially damaged when it was involved in an accident near Colorado Springs, Colorado. The two pilots and two crew members onboard were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 positioning flight. According to the first officer, who was initially the pilot flying, they departed from Centennial Airport (APA), Denver, Colorado, for a short positioning flight to Colorado Springs (COS). After departure, air traffic control provided vectors to intercept the GPS approach for runway 17R at COS. The airplane exited the overcast cloud layer at an altitude of 650 to 700 ft above ground level and the first officer visually acquired the airport, realizing that the airplane was offset about ½ mile right of the runway centerline. The captain requested control of the airplane and then made the required course correction to line up with the runway centerline. This correction occurred about 1.5 to 2 miles from the runway threshold. About 100 ft above the ground, the captain reduced the throttles to "idle," was able to establish runway centerline, and continued the descent for landing. As the airplane descended through 10 to 20 ft above the runway, the captain reported that the "stick shaker" activated. The first officer was monitoring and announced "stall," and the captain advanced both throttles. Just before the airplane touched down, it experienced an un-commanded roll to the right and the nose dropped. The captain attempted to arrest the roll by applying left aileron, but the airplane did not respond in time and the right wing fuel tip tank impacted the runway surface just before the landing gear contacted the runway. The crew was able to maintain control throughout the landing roll and the crew taxied the airplane off the runway. The airplane sustained substantial damage to the right wing. The operator stated that there was no mechanical malfunction or failure of the airplane. The company operations manual stated: V.4 Stabilized Approach Concept (ref. AC 120-71) It is essential that a stabilized approach to the landing runway be flown. A stabilized approach must be established before descending below the following minimum stabilized approach altitudes: 500 feet above the airport elevation during visual flight rules (VFR) or visual approaches and during straight in instrument approaches in VFR weather conditions. Minimum descent altitude (MDA) or 500 feet above airport elevation, whichever is lower, if a circling maneuver is to be conducted after completing an instrument approach. 1000 feet above the airport or touchdown zone elevation during any straight- in instrument approach in instrument flight conditions. 1000 feet above the airport during contact approaches. It is essential that the airplane touchdown in the first one-third of the available landing distance (ALD), but in no case greater than 3000 feetdown the runway, whichever is less. If touchdown in the first one-third of the ALD, but in no case greater than 3000 feet down the runway is not assured, a rejected landing must be executed. The Flight Safety Foundation Approach and Landing Accident Reduction Briefing Note, 7.1 – Stabilized Approach, listed one of the deviations in unstabilized approaches as: Excessive flight parameter deviation when crossing the minimum stabilization height: - Excessive speed - Not aligned with the runway - Excessive bank angle - Excessive vertical speed, or - Flight path above glideslope The Briefing Note also stated that one behavior involved when unstabilized approaches are continued is excessive confidence in a quick recovery by postponing the go-around decision when flight parameters are exceeded. ## Aircraft - Registration: [N354EF](https://openairdocs.org/deregistered/N354EF-2024-05-01), registration cancelled 2024-05-01, S/N 35A-378, built 1981 (OpenAirDocs) - Reported make and model: GATES LEARJET CORP. 35A - Registry model: [Gates Learjet 35A](https://openairdocs.org/model/gates-learjet-35a) (registry code 5170602) (OpenAirDocs) - Registry engine: [AiResearch TFE731 series](https://openairdocs.org/engine/airesearch-tfe731-series) (registry code 01518, turbo-jet) (OpenAirDocs) - Category: Airplane - Serial number: 35A-378 - Year built: 1981 - Airframe hours: 16955 - Engines: Honeywell TFE731-2-2B 3500 lbs thrust turbo fan; Honeywell TFE731-2-2B 3500 lbs thrust turbo fan - Damage: Substantial damage - Flight: Positioning, Part 91 - Operator: Medway Air Ambulance LLC - Registered owner: Med Air LLC - Airworthiness certificate: Standard, Transport - Departed: KAPA, Englewood, CO - Destination: Same as departure - Flight plan: IFR - Airport: COS, City Of Colorado Springs Muni, runway 17R/35L, 11,022 × 150 ft, asphalt - Equipment: Stall warning system, Auto-pilot, Electronic flight bag or handheld device, Onboard weather ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 53; injuries: none; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review January 28, 2021; seat: left; restraint: 5-point; flight hours: 13,150 total, 5,500 in this make and model, 10,000 as pilot in command, 200 in the last 90 days, 60 in the last 30 days, 5 in the last 24 hours - Co-pilot; age 38; injuries: none; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review October 30, 2020; seat: right; restraint: 4-point; flight hours: 2,551 total, 450 in this make and model, 549 as pilot in command, 202 in the last 90 days, 33 in the last 30 days, 2 in the last 24 hours - Other flight crew; injuries: none; restraint: lap only - Other flight crew; injuries: none; restraint: lap only ## Weather - Conditions: Instrument (IMC), Day - Wind: 230° at 4 knots - Visibility: 3 statute miles - Lowest ceiling: 300 ft overcast - Temperature: 32 °F, dew point 32 °F - Altimeter: 29.98 inHg - Observed at: COS ## 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 20210415004689A](https://openairdocs.org/incident/20210415004689A), Apr 15, 2021: Gates Learjet Corp. 35A, Colorado Spring, CO, Substantial damage. On April 15, 2021 at approximately 1030 MST, N354EF, a Learjet model 35A aircraft was substantially damaged during a landing at the city of Colorado Springs… ## Docket (5 files) The files NTSB released with the investigation on July 27, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102925. 9.4 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 9.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13885060&FileExtension=pdf&FileName=NTSB%206120%20N354EF_Redacted-Rel.pdf - Statement - pilot in command (item 2, PDF, 1 page, 76 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13885750&FileExtension=pdf&FileName=Pilot%20Statement-Rel.pdf - Statement - second in command (item 3, PDF, 1 page, 115 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14046233&FileExtension=pdf&FileName=Salhadin%20Said%20Statement_Redacted-Rel.pdf - Company operations manual excerpt (item 4, PDF, 2 pages, 63 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13886392&FileExtension=pdf&FileName=Medway%20GOM%20Rev%2027%20-%20Stabilized%20approach-Rel.pdf - Photo log (item 5, PDF, 2 pages, 197 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13886114&FileExtension=pdf&FileName=Photo%20Log-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.