DEN07IA048

NTSB incident investigation · Raytheon B300 · Englewood, CO · January 8, 2007

Incident · No injuriesIncident investigationFinal report
Date
January 8, 2007, 09:33 local (16:33 UTC)
Place
Englewood, CO
Injuries
8 uninjured
Damage
Minor damage
Phase of flight
Landing
Aircraft
N945SHRaytheon B300
Weather
Visual (VMC) · Day
Status
Completed · report August 30, 2007
Report
Approved by Office Director
Parties
FAA Flight Standards District Office
FAA report
20070108000029I
Case key
65156

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

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Probable cause

This case was modified 10/30/2007

Failure of the nose landing gear upper torque knee due to overstress, and the pilot's inability to maintain aircraft control.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Airframe/component/system failure/malfunctionLanding - flare/touchdown
Landing gear,nose gear assembly - fracturedCause
Loss of control - on ground/waterLanding - roll
Rudder - attemptedPilot in command
Directional control - not possiblePilot in commandCause
On ground/water collision with objectLanding - roll
Airport facilities,runway/landing area condition - snowbankFactor

Analysis

The airplane landed, drifted left, and struck a snowbank. The wind was from 130 degrees at 6 knots and braking action was "good." A portion of the nose landing gear upper torque knee was found on the runway. The remainder of the upper torque knee and the entire lower torque knee remained attached to the nose landing gear. These items were sent to NTSB's Materials Laboratory for metallurgical examination. According to the metallurgist's factual report, the lower torque knee was fractured in overstress at two locations: on the forward and on the aft sides of the pivot fastener bore. The aft fracture was consistent with the lower knee being loaded in tension. The forward fracture was more extensively deformed, indicating it was secondary to the aft fracture. The smaller, separated piece of the lower knee showed significant elongation and deformation of the pivot bore, consistent with the forward end of the lower knee moving downward and forward relative to the upper knee. Deformation at the fracture through the grease-fitting hole at the forward fracture location was indicative of bending and twisting out of the plane of pivot. There was no evidence of preexisting cracking, corrosion, or damage.

Factual narrative

On January 8, 2007, at 0933 mountain standard time, a Raytheon B300, N945SH, piloted by an airline transport certificated pilot, sustained minor damage when it collided with a snow bank while landing at Centennial Airport (APA), Englewood, Colorado. Visual meteorological conditions prevailed at the time of the incident. The executive/corporate flight was being conducted under the provisions of Title 14 Code of Federal Regulations Part 91, and an instrument flight rules (IFR) flight plan had been filed. The captain, first officer, and six passengers were not injured. The cross-country flight originated at Columbia, Missouri, approximately 0730 central standard time, and was en route to APA.

According to the incident report and captain's statement, the flight was cleared to land on runway 17L. ATIS (automatic terminal information service) information Oscar reported the wind to be from 130 degrees at 6 knots, and braking action was "good." Estimated landing weight was 12,500 pounds, and the computed Vref speed was 101 knots. The captain said touchdown was on centerline with 8,000 feet of runway remaining. As the nose was lowered, the aircraft began to drift "quickly" to the left. Opposite rudder (but no brakes) was applied. The left main landing gear rolled onto packed snow and ice at 80 knots and the airplane decelerated rapidly as it entered the snow drift. The captain said the airplane "spun around to the left and came to rest approximately 60 degrees off runway heading, just prior to taxiway A8."

A portion of the nose landing gear upper torque knee was found on the runway. The remainder of the upper torque knee and the entire lower torque knee remained attached to the nose landing gear. These items were sent to NTSB's Materials Laboratory for metallurgical examination. According to the metallurgist's factual report, the lower torque knee was fractured in overstress at two locations: on the forward and on the aft sides of the pivot fastener bore. The aft fracture was consistent with the lower knee being loaded in tension. The forward fracture was more extensively deformed, indicating it was secondary to the aft fracture. The smaller, separated piece of the lower knee showed significant elongation and deformation of the pivot bore, consistent with the forward end of the lower knee moving downward and forward relative to the upper knee. Deformation at the fracture through the grease-fitting hole at the forward fracture location was indicative of bending and twisting out of the plane of pivot. There was no evidence of preexisting cracking, corrosion, or damage.

According to Raytheon, both the upper and lower torque knees of the early King Air models were aluminum. As the airplane grew in size and weight, it was felt that the upper torque knee needed to be "beefed up." Today, it is made of steel.

The cockpit voice recorder (CVR) was removed from the airplane and shipped to NTSB's Vehicle Recorder Division for readout and analysis. After consultation with the CVR specialist, it was agreed that convening a CVR group and preparing a transcript would be unnecessary, and that a summary report would suffice. According to the CVR Specialist's factual report, the crew planned on a landing speed of 108 knots. The airplane was configured for landing "with landing gear down and landing flaps." The first officer noted on final approach that the aircraft was at 200 feet, 130 knots, and descending at a rate of 800 feet per minute. From the time the main gear and nose gear touched down, 1.42 seconds had elapsed. The first sounds of impact occurred 2.4 seconds later. The airplane came to a halt 5 seconds after the first sounds of impact.

Weather reported at Centennial Airport (APA), Englewood, Colorado, at 0944 mountain standard time, was reported as wind from 150 degrees at 9 knots, visibility 10 statute miles, clear skies, temperature 35 degrees Fahrenheit, dew point 19 degrees Fahrenheit, and a barometric pressure setting of 30.16 inches of Mercury.

Aircraft

Registration
N945SH
Reported as
Raytheon B300
Category
Airplane
Serial number
FL-458
Airframe hours
176
Engines
Pratt & Whitney PT6A-60A, 1,050 horsepower, turbo propPratt & Whitney PT6A-60A, 1,050 horsepower, turbo prop
Damage
Minor damage
Flight
Executive/Corporate · Part 91
Operator
Central Missouri Aviation, Inc.
Registered owner
Shelter Enterprises LLC
Airworthiness certificate
Standard, Normal
Last inspection
Continuous airworthiness · November 1, 2006
Departed
COU · Columbia, MO
Destination
APA · Englewood, CO
Flight plan
IFR
Airport
APA · Centennial, runway 17L, 10,002 × 100 ft, asphalt

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 · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
50
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
November 1, 2006
Seat
Left
Flight hours
6,588 total · 162 in this make and model · 4,737 as pilot in command · 72 in the last 90 days · 29 in the last 30 days · 3 in the last 24 hours
Role
Co-pilot
Age
46
Injuries
None
Certificates
Airline transport, Commercial, Foreign, Flight instructor
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, With waivers/limitations
Last flight review
December 1, 2006
Seat
Right
Flight hours
3,080 total · 52 in this make and model · 1,287 as pilot in command · 12 in the last 90 days

Weather

Conditions
Visual (VMC) · Day
Wind
130° at 6 knots
Visibility
10 statute miles
Temperature
36 °F, dew point 19 °F
Altimeter
30.15 inHg
Observed at
APA

FAA reports on this event · 1

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