SEA01IA161

NTSB incident investigation · de Havilland DHC-8-102 · Portland, OR · August 28, 2001

Incident · No injuriesIncident investigationFinal report
Date
August 28, 2001, 16:00 local (23:00 UTC)
Place
Portland, OR
Injuries
3 uninjured
Damage
No damage
Phase of flight
Initial climb
Aircraft
N827PHde Havilland DHC-8-102
Weather
Visual (VMC) · Day
Status
Completed · report June 3, 2002
Report
Approved by Office Director
Parties
FAA
FAA report
20010828027239I
Case key
53138

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

The NTSB’s determination of the probable cause, and any contributing factors.

Improper tension of the right control yoke chain; a worn right aileron spring tab hinge bearing; improper tension of the left aileron spring tab aft spring and worn contact stud; improper tension of the right aileron spring tab and a worn contact stud; a worn left aileron hinge bearing.

Analysis

The operator reported that shortly after departure the first officer noted stiffness in the flight controls when attempting to roll the airplane to the left. After assessing the situation, the captain elected to continue the climb. Shortly after level off, the crew noted that the stiffness increased proportionally with airspeed. This was also noted during the descent phase of the flight, specifically, the first officer stated the resistance increased for left roll inputs as the aircraft accelerated. The captain reported that they attempted to relieve the pressure with aileron trim, however, when the trim indicator reached the first index on the indicator, the control wheel "snapped" approximately 25 degrees and the airplane banked to the right. The crew reported that as the airplane slowed, while on approach, the roll control stiffness decreased. After landing, the crew accomplished a full control check and noted no abnormal indications with the ailerons or spoilers. Post flight inspection disclosed a number of discrepancies that are believed to have contributed to the stiff flight controls. The items are as follows: the right control yoke chain tension was high; the right aileron spring tab hinge bearing did not rotate freely; the left aileron spring tab aft spring tension was low and the contact stud was worn; the right aileron spring tab tension was low and the contact stud was worn; the left aileron hinge bearing did not rotate freely.

Factual narrative

The factual narrative380 words

On August 28, 2001, about 1600 Pacific daylight time, a de Havilland DHC-8-102, N827PH, operated by Horizon Airlines as flight 2185, experienced roll control difficulties shortly after takeoff from Klamath Falls International Airport, Klamath Falls, Oregon. The two pilots, one flight attendant, and 37 passengers were not injured. The airplane was being operated as a scheduled, domestic, passenger flight under the provisions of Title 14 CFR part 121, when the incident occurred. Visual meteorological conditions prevailed and an instrument flight plan was in effect at the time of the incident. The airplane continued to its planned destination, Portland International Airport, Portland, Oregon, and landed without further incident.

The operator reported the airplane departed runway 32 at Klamath Falls. Shortly after departure, during the initial climb, the first officer noted stiffness in the flight controls when attempting to roll the airplane to the left. After assessing the situation, the captain elected to continue the climb. Shortly after level off, the crew noted that the stiffness increased proportionally with airspeed. This was also noted during the descent phase of the flight, specifically, the first officer stated the resistance increased for left roll inputs as the aircraft accelerated. The captain reported that they attempted to relieve the pressure with aileron trim, however, when the trim indicator reached the first index on the indicator, the control wheel "snapped" approximately 25 degrees and the airplane banked to the right. The crew reported that as the airplane slowed, while on approach, the roll control stiffness decreased. After landing, the crew accomplished a full control check and noted no abnormal indications with the ailerons or spoilers. The airplane sustained no damage during the incident.

Post-incident inspection of the airplane by personnel from Horizon Airlines and the Federal Aviation Administration, Portland Flight Standards District Office, disclosed a number of discrepancies that are believed to have contributed to the stiff flight controls. The items are as follows: the right control yoke chain tension was high; the right aileron spring tab hinge bearing did not rotate freely; the left aileron spring tab aft spring tension was low and the contact stud was worn; the right aileron spring tab tension was low and the contact stud was worn; the left aileron hinge bearing did not rotate freely. Additional inspection information attached.

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/malfunctionTakeoff - initial climb
Flt control syst,aileron control - wornCause

Aircraft

Registration
N827PH
Reported as
de Havilland DHC-8-102
Category
Airplane
Serial number
275
Airframe hours
25,997
Engines
P&W PW120A, 2,000 horsepower, turbo propP&W PW120A, 2,000 horsepower, turbo prop
Damage
No damage
Flight
Part 121
Operator
Horizon Air Inc
Registered owner
Wells Fargo Bank NW, NA
Airworthiness certificate
Standard, Transport
Last inspection
Continuous airworthiness · July 10, 2001 · 331 hours before
Departed
KLMT · Klamath Falls, OR
Destination
KPDX · Portland, OR
Flight plan
IFR
Airport
KPDX · Portland International Airport, runway 28R, 8,000 × 150 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
36
Injuries
None
Certificate
Airline transport
Airplane ratings
Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Last flight review
June 16, 2001
Seat
Left
Flight hours
3,600 total · 1,900 in this make and model · 1,300 as pilot in command · 150 in the last 90 days · 70 in the last 30 days · 5 in the last 24 hours
Role
Co-pilot
Age
37
Injuries
None
Certificates
Flight instructor, Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--w/ waivers/lim
Last flight review
August 1, 2001
Seat
Right
Flight hours
1,800 total · 900 in this make and model · 600 as pilot in command · 200 in the last 90 days · 80 in the last 30 days · 5 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
322° at 12 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
81 °F, dew point 59 °F
Altimeter
29.95 inHg
Observed at
PDX

FAA reports on this event · 1

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