FTW02LA052

NTSB accident investigation · Piper PA-23-250 · Duncan, OK · December 13, 2001

Accident · Serious injuriesLimited investigationFinal report
Date
December 12, 2001, 22:31 local (Dec 13, 2001, 04:31 UTC)
Place
Duncan, OK
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N127CAPiper PA-23-250
Weather
Instrument (IMC) · Night
Status
Completed · report September 30, 2003
Report
Approved by Office Director
Parties
The New Piper Aircraft, Inc., FAA FSDO, Textron Lycoming
FAA report
20011212036839A
Case key
53905

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

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Probable cause

The pilot's descent below the minimum descent altitude, and his failure to maintain obstacle clearance. Contributing factors were the below approach/landing minimum weather, the dark night conditions, and the inoperative REIL's.

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.

In flight collision with objectApproach - faf/outer marker to threshold (ifr)
Minimum descent altitude - belowPilot in commandCause
Clearance - not maintainedPilot in command
Object - wire,transmission
Weather condition - below approach/landing minimumsFactor
Facility,inadequate instrument lightingAirport personnelFactor
Light condition - dark nightFactor
In flight collision with terrain/waterDescent - uncontrolled
Terrain condition - ground

Analysis

The instrument rated commercial pilot received a weather briefing for a positioning flight. His weather briefing included an Airmet for IFR conditions, calm winds, visibility of 1/4 mile, fog, low ceilings, and matching temperature and dew points. The flight departed the airport and the pilot received radar vectors to the initial approach fix (IAF), was cleared for the localizer approach, and issued the altimeter setting. The IAF is 5.0 nautical miles from the runway threshold and the minimum decision altitude is 1,600 feet (503 feet agl), with a minimum approach visibility of 1 mile. Subsequently, the controller noted static on his radio frequency and a power fluctuation at the facility. The power company recorded a power fault. Radio contact could not be established with the pilot. The airplane struck power lines (38 feet 6 inches agl) and impacted the terrain short of the runway. Power line cables were found entangled about the fuselage and the horizontal stabilizer. Following the accident, the LOC approach was flight checked satisfactory by the FAA. The REIL's were inoperative. Flight control continuity was confirmed. The cockpit approach receivers, indicators, and communication equipment were checked and no anomalies were noted that would have affected the approach. No anomalies were found with the vacuum pumps, airframe, or engine that would have precluded operation prior to the accident.

Factual narrative

History of flight

On December 12, 2001, approximately 2231 central standard time, a Piper PA-23-250 twin-engine airplane, N127CA, operating as Swiftwing 200, struck power lines and terrain at the Duncan/Halliburton Field (DUC) near Duncan, Oklahoma, during a localizer (LOC) approach. The airplane was operated by Safewing Aviation Company, Inc., of Kansas City, Missouri, and was registered to Delta Sales Company of Davenport, Iowa. The positioning flight, which was operating under 14 Code of Federal Regulations (CFR) Part 91, departed Wiley Post Airport (PWA), Oklahoma City, Oklahoma, about 2130 with a destination of DUC. The instrument rated commercial pilot received serious injuries, and the airplane sustained substantial damage. Night instrument meteorological conditions prevailed for the flight, and an instrument flight rules (IFR) flight plan was filed with PWA as the alternate.

Prior to the flight, the pilot called the McAlester Automated Flight Service Station (AFSS) at 2126:24 and received his requested abbreviated weather briefing on the current conditions for southern Oklahoma including DUC and Lawton. The pilot was briefed on an Airmet for IFR conditions throughout the night with the current conditions at DUC showing wind calm, visibility 1 1/2 mile, fog, ceiling broken clouds at 100 feet, temperature and dew point equal at 6 degrees Celsius (43 degrees Fahrenheit). The DUC AWOS was showing wind calm, visibility 1/4 mile, fog, 100 scattered clouds, ceiling broken at 1,000 feet, temperature and dew point at 4 degrees Celsius ( 39 degrees Fahrenheit). The Chickasha Airport, located approximately 35 nautical miles north of DUC, reported a ceiling of 100-foot overcast, 1/4 mile visibility. The Fort Sill (Lawton) Airport, located approximately 24 nautical miles northwest of DUC, reported a 1,200-foot broken ceiling with 3/4 mile visibility and mist.

The pilot of Swiftwing 200 requested and received radar vectors from the Fort Sill approach controller. At 2227, the flight was 2-3 miles south of the initial approach fix (IAF)(GYROE) and was cleared for the localizer 35 approach. Approximately 2229, Swiftwing 200 was identified at GYROE, and cleared to change to the airport advisory frequency (122.8 Megahertz). Approximately 2231, the controller noted static on his radio frequency and a power fluctuation at the approach facility. Subsequently, radio contact could not be established with Swiftwing 200. The approach facility personnel contacted the fixed base operator (FBO) at the airport, who reported that the airplane had not landed at the airport. Search and rescue was initiated by Fort Sill and airport personnel.

A witness/company pilot, who was located at the approach end of runway 35 in his vehicle, with a handheld radio turned to the frequency of 122.8 Megahertz (MHz), reported that he heard the pilot of Swiftwing 200 report reaching GYROE, and transmit "Duncan traffic Swiftwing 200 GYROE inbound, are the lights full intensity." The witness replied "Roger Swiftwing 200." At 2232, according to the clock in his vehicle, the witness observed the airport power fluctuations with the airport lights. When Swiftwing 200 did not land, the witness initiated a search for Swiftwing 200.

The pilot reported that his weather briefing indicated fog at the destination airport. En route, the pilot noted patchy fog, and during the controller's vector of the airplane, he recalled seeing the entire airport. He recalled the following sequence: descent to 2,700 feet, base leg, localizer intercept, the approach clearance, approach checklist, seeing the runway and continuing the descent, respectively.

Personnel of the power company reported the height of the power lines was 38 feet 6 inches above the ground (AGL) at the point of impact. Physical evidence at the accident site was consistent with the aircraft striking the electrical static wires near mid-span between two H-frame structures, which were approximately 47 feet 6 inches agl. The power company recorded a power spike (fault) at 22:31:11 on the night of the accident.

Personnel information

A review of FAA records and company data revealed that the pilot was issued a first class medical certificate without limitations on June 28, 2001. The commercial pilot held airplane single-engine land, twin-engine land, and instrument ratings. He was a certificated flight instructor for the single-engine land and instrument ratings.

The pilot was employed by Safewing Aviation Company, Incorporated, in July 2001, and he completed their training program for the PA-23 airplane. He satisfactorily completed the CFR Part 135 airman competency/proficiency check in a PA-23-250 airplane on July 16, 2001.

According to the company records and the Pilot/Operator Aircraft Accident report (NTSB 6120.1), the accumulated flight time at the time of employment, was 1,211.9 hours, of which 199.3 hours were the pilot-in-command of multiengine land airplanes. At the time of the accident, the accumulated flight time was 1,660.5 hours of which 45.3 hours was actual instrument flight time. The accumulated flight time for the pilot under CFR Part 135 was 423.7 hours.

At the time of the accident, the company was authorized to conduct on demand operations under CFR Part 135. The company operated 3 multiengine airplanes for passenger and/or cargo flight, and 6 single-engine aircraft for cargo only flights. The airplane, N127CA was flown on two round trip cargo flights Monday through Friday of each week. Three pilots rotated the flights. The commercial pilot of Swiftwing 200 flew both round trip cargo flights on the day of the accident. The first route trip of the day consisted of four segments: DUC to LAW, LAW to OKC, OKC to TUL, and TUL to DUC. The second route trip of the day consisted of four segments: DUC to OKC, OKC to TUL, TUL to OKC, and OKC to DUC. During the second route trip, on the day of the accident, Swiftwing 200 diverted to PWA due to weather at OKC during the TUL to OKC route segment.

Aircraft information

The original registration number, N40365, was changed to N7FV in 1975, and to N127CA prior to the accident date. The Piper PA-23-250 airplane, serial number 27-7305125, was registered to the current owner on December 29, 1999. The aircraft was maintained under CFR Part 135 by Safeway Aviation Company, Inc. The last annual inspection was performed on August 1, 2001, at a total airframe time of 8,611 hours (Hobbs 2,695 hours). The accumulated time on the aircraft at the time of the accident was 8,664 hours (53 hours since the last annual inspection).

The left engine, a Lycoming IO-540-C4B5, serial number L-11296-48, was overhauled at T.W. Smith Engine Company., Inc., Cincinnati, Ohio, and re-installed in June 1996. At the last annual inspection, this engine had accumulated 730 hours since major overhaul (SMOH), the left propeller, a Hartzell HC-E2R-2RBSF, serial number BP3570, had accumulated 470 hours SMOH.

The right engine, a Lycoming IO-540-C4B5, serial number L-8996-48, was overhauled at T. W. Smith Engine Company., Inc., Cincinnati, Ohio, and re-installed in June 1996. At the last annual inspection, this engine had accumulated 730 hours SMOH, the right propeller, serial number 54, had accumulated 720 hours SMOH.

In May 1978, the navigation equipment was installed. In April 1983, an overhauled turn coordinator was installed. In March 1984, the right vacuum pump was replaced. In April 1986, the manifold pressure gage was replaced. In February 1987, the standby horizon was replaced with an overhauled unit. In September 1999, the HSI on the left instrument panel was installed following repair. In October 1999, the Apollo model GX-50-GPS unit was installed and interfaced with the HSI via MD41-724 annunciator panel. In August 2000, the ADF was removed and replaced with an overhauled unit. In November 2000, the directional gyro was r

Aircraft

Registration
N127CA
Reported as
Piper PA-23-250
Category
Airplane
Serial number
27-7305125
Engine
Lycoming IO-540-C4B5, 250 horsepower, reciprocating
Damage
Substantial damage
Flight
Positioning · Part 91
Operator
Safewing Aviation Company, Inc.
Registered owner
Delta Sales Company
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · September 28, 2001 · 53 hours before
Departed
PWA · Oklahoma City, OK
Destination
DUC · Duncan, OK
Flight plan
IFR
Airport
DUC · Duncan/Halliburton Field, runway 35, 6,650 × 100 ft, concrete

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

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
27
Injuries
Serious
Certificates
Commercial, Flight instructor
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Last flight review
July 16, 2001
Seat
Left
Flight hours
1,661 total · 417 in this make and model · 1,410 as pilot in command · 292 in the last 90 days · 70 in the last 30 days · 6 in the last 24 hours

Weather

Conditions
Instrument (IMC) · Night
Wind
Calm
Visibility
0.25 statute miles
Lowest ceiling
100 ft overcast
Temperature
41 °F, dew point 41 °F
Altimeter
29.98 inHg
Observed at
DUC

FAA reports on this event · 1

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