CEN21LA190

NTSB accident investigation · Gates Learjet 35A · Colorado Springs, CO · April 15, 2021

Accident · No injuriesClass 3 · LimitedFinal report
Date
April 15, 2021, 10:30 local (16:30 UTC)
Place
Colorado Springs, CO
Injuries
4 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N354EFGates Learjet 35A
Defining event
Landing: Aerodynamic stall/spin
Weather
Instrument (IMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Central Region
Parties
FAA
FAA report
20210415004689A
Case key
102925

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

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 · 2

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Action: lack of actionPersonnel issues › Action/decision · Flight crewGates Learjet 35A: 3 casesAll aircraft: 792 casesProbable cause
Performance/control parameters: angle of attackAircraft › Aircraft oper/perf/capability · Capability exceededGates Learjet 35A: 3 casesAll aircraft: 990 cases

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

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
Reported as
Gates Learjet 35A
Category
Airplane
Serial number
35A-378
Built
1981
Airframe hours
16,955
Engines
Honeywell TFE731-2-2B, 3,500 lbs thrust, turbo fanHoneywell TFE731-2-2B, 3,500 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

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew · 4

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
53
Injuries
None
Certificate
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
Role
Co-pilot
Age
38
Injuries
None
Certificates
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
Role
Other flight crew
Injuries
None
Restraint
Lap only
Role
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

Docket · 5

The files NTSB released with the investigation on July 27, 2022, on NTSB’s docket system: statements, records, photos and specialists’ reports. 9.4 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.