# NTSB WPR13LA154: Piper PA-23-250, N318CA, Hillsboro, OR, March 18, 2013 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 18, 2013, 15:15 local (22:15 UTC) - Place: Hillsboro, OR - Coordinates: 45.425556, -122.945274 - Nearby events: https://openairdocs.org/map.md?lat=45.4256&lon=-122.9453&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report June 2, 2014 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration FSDO - NTSB case key (mKey): 86451 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR13LA154 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/86451/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=86451 - Page: https://openairdocs.org/ntsb/WPR13LA154 ## Probable cause A runway overrun due to an insufficient stopping distance due to the downsloping runway during a rejected takeoff. Contributing to the accident was a cabin door that inadvertently opened during the takeoff roll. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Doors: passenger/crew doors](https://openairdocs.org/ntsb-findings/01035210): Aircraft › Aircraft structures · Unintentional use/operation (probable cause); cases with it: [Piper PA-23-250, 1 case](https://openairdocs.org/ntsb-findings/01035210/cases.md?model=7102308), [All aircraft, 86 cases](https://openairdocs.org/ntsb-findings/01035210/cases.md) - [Aircraft capability: landing distance](https://openairdocs.org/ntsb-findings/01061030): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Piper PA-23-250, 1 case](https://openairdocs.org/ntsb-findings/01061030/cases.md?model=7102308), [All aircraft, 68 cases](https://openairdocs.org/ntsb-findings/01061030/cases.md) - [Terrain: sloped/uneven terrain](https://openairdocs.org/ntsb-findings/03021017): Environmental issues › Physical environment · Effect on operation (probable cause); cases with it: [Piper PA-23-250, 1 case](https://openairdocs.org/ntsb-findings/03021017/cases.md?model=7102308), [All aircraft, 270 cases](https://openairdocs.org/ntsb-findings/03021017/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) (defining event); cases with it: [Piper PA-23-250, 3 cases](https://openairdocs.org/ntsb-events/900/sequence.md?model=7102308), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) - [Takeoff-rejected takeoff: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Piper PA-23-250, 4 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=7102308), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) - [Takeoff-rejected takeoff: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490); cases with it: [Piper PA-23-250, 2 cases](https://openairdocs.org/ntsb-events/490/sequence.md?model=7102308), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The flight was to be the private pilot's first multiengine lesson. Both he and the instructor performed an uneventful preflight check and run-up, which included a check of the brakes and the security of the cabin door. During the takeoff roll, the cabin door opened, and the flight instructor called for the pilot to abort the takeoff. The pilot reduced engine power to idle and applied pressure to the brake pedals. The airplane began to decelerate; however, as it approached the end of the runway, brake effectiveness began to dissipate, and the airplane travelled beyond the threshold, coming to rest in a ditch. The airplane was equipped with foot-operated brakes on the left side only, which was occupied by the pilot undergoing instruction. The remaining runway distance, had it been flat, should have provided for an adequate distance to stop; however, the runway sloped downhill, with its gradient rapidly increasing beyond the threshold. It is likely that this increased downsloping gradient resulted in an increased distance needed to stop the airplane. Postaccident examination of the braking system revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. ## Factual narrative The Federal Aviation Administration (FAA) Digital Airport/Facility Directory indicated that the airport elevation was 170 feet. Runway 20 was 2,465 feet long, with a 1.5% downward gradient. The FAA inspector who responded to the accident site stated that the runway sloped downwards for its entire length, further exhibiting a distinct downward gradient for the last 300 to 400 feet of its length, before dropping off rapidly beyond the threshold of runway 2. Examination of the runway utilizing a topological mapping program revealed that beyond the threshold, its paved surface continued 170 feet while descending 7 feet. On March 18, 2013, about 1515 Pacific daylight time, a Piper PA-23-250, N318CA, departed the end of the runway following a rejected takeoff from Stark's Twin Oaks Airpark, Hillsboro, Oregon. The airplane was registered to Twin Oaks Airpark, Inc., and operated by the private pilot as a local instructional flight under the provisions of 14 Code of Federal Regulations Part 91. The certified flight instructor and private pilot undergoing instruction were not injured. The airplane sustained substantial damage to both wing spars and the forward fuselage structure during the accident sequence. Visual meteorological conditions prevailed, and no flight plan had been filed. The flight was to be the private pilot's first multiengine lesson. Both he and the instructor reported performing an uneventful preflight check, brake check, and engine run-up. They confirmed that the door was closed and locked, and the flight instructor inflated the door seal, and checked that the parking brake was disengaged. The private pilot positioned the airplane at the end of the runway, and applied full engine power. Both he and the instructor stated that once the airplane approached a speed of 80 mph, and just prior to rotation, the right cabin door opened about 1 inch. They had travelled about 1/3 of the way down the runway at that time, and the flight instructor called for the pilot to abort the takeoff. He reduced engine power to idle, and applied pressure to the brake pedals. The flight instructor stated that the airplane began to decelerate, however, a few seconds later she became concerned that they would not be able to stop in time on the remaining runway. The private pilot felt the airplane decelerate, however, as they approached the end of the runway, brake effectiveness began to dissipate. The airplane subsequently overran the runway, coming to rest in a ditch. Two witnesses provided corroborating statements regarding the accident sequence, that during the takeoff roll both engines went to idle about 1/3 of the way down the runway. They observed the airplane begin to decelerate, assuming it would stop in time; however, it continued, ultimately departing the runway end at a walking pace. The airplane was not equipped with foot brakes on the right side, which was occupied by the flight instructor. The flight instructor held an airline transport pilotcertificate, and reported a total flight experience of 9,368 hours, 5,440 of which was in multiengine airplanes, and 5.1 in the accident make and model. She further reported 3,551 hours as a flight instructor, 74 of which was in multiengine airplanes. The pilot undergoing instruction held a private pilot's license, with ratings for single-engine land and instrument airplane. He reported a total flight experience of 191.4 hours, all in single-engine airplanes. According to the flight instructor, the airplane's gross weight at the time of the accident was 4,230 pounds. The applicable flight manual provided an accelerate-stop distance performance chart. Utilizing the weather conditions and airplane's weight after reaching an indicated speed of 80 mph, with zero flaps on a level dry paved runway, the distance required would have been about 1,800 feet. The manual did not provide factors for runway slope. The Emergency Procedures section of the flight manual provided the following procedure for closing the cabin door in flight: "In the event the cabin door is inadvertently unlocked in flight or the handle is not pushed forward and locked before take-off and becomes dislodged from its latching position, the following procedure has been determined to be practicable for closing the cabin door while in flight, assuming adequate altitude has been attained. a. Retard throttles. b. Reduce airspeed to 90 MPH or less. c. Open storm window (left of pilot). d. Close door. e. Recover power and airspeed." The manual further stated that should the door become unlocked during take-off, landing approach, and general low altitude flight, the required action will be at the discretion of the pilot. The FAA inspector performed an examination of the airplane's brake system following the accident, and reported no mechanical failures or anomalies which would have precluded normal operation. When asked about the decision to abort the takeoff, the flight instructor stated that she had heard anecdotal evidence from other flight instructors that the airplane type was hard to control if the door opened in flight, so she chose to abort the takeoff rather than risk having a flight control problem after departure. ## Aircraft - Registration: [N318CA](https://openairdocs.org/deregistered/N318CA-2014-09-05), registration cancelled 2014-09-05, S/N 27-2908, built 1965 (OpenAirDocs) - Reported make and model: PIPER PA-23-250 - Registry model: [Piper PA-23-250](https://openairdocs.org/model/piper-pa-23-250) (registry code 7102308) (OpenAirDocs) - Registry engine: [Lycoming TI0-540 series](https://openairdocs.org/engine/lycoming-ti0-540-series) (registry code 41533, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 27-2908 - Year built: 1965 - Airframe hours: 5009 - Engines: LYCOMING IO-540 250 horsepower reciprocating; LYCOMING IO-540 250 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 8, 2013, 5 hours before - Departed: 7S3, Hillsboro, OR - Destination: 7S3, Hillsboro, OR - Airport: 7S3, Hillsboro, runway 20, 2,465 × 48 ft, asphalt - Equipment: Stall warning system, Auto-pilot ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 42; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review August 29, 2011; seat: right; restraint: 3-point; flight hours: 9,368 total, 5 in this make and model, 4,936 as pilot in command, 66 in the last 90 days, 23 in the last 30 days - Pilot; age 26; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review February 4, 2013; seat: left; restraint: 3-point; flight hours: 191 total, 0 in this make and model, 117 as pilot in command, 16 in the last 90 days, 4 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 52 °F, dew point 34 °F - Altimeter: 30.23 inHg - Observed at: HIO, 7 nm away ## 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 20130318003459A](https://openairdocs.org/incident/20130318003459A), Mar 18, 2013: Piper PA-23-250, Hillsboro, OR, Substantial damage. On March 18, 2013, at approximately 14:30 (2130 z), a Piper aztec PA-23-250, N318CA, went off the end of runway 20 at Twin Oaks Airpark in Hillsboro, OR. This… ## Docket (5 files) The files NTSB released with the investigation on March 21, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=86451. 3.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407680&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Witness Statements (item 2, .PDF, 616 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407683&FileExtension=.PDF&FileName=Witness%20Statements-Redacted.PDF - Photo 1- Airplane at Accident Site (item 3, .PDF, 128 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407681&FileExtension=.PDF&FileName=Photo%201-%20Airplane%20at%20Accident%20Site-Master.PDF - Photo 2- Airplane at Accident Site (item 4, .PDF, 158 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407682&FileExtension=.PDF&FileName=Photo%202-%20Airplane%20at%20Accident%20Site-Master.PDF - PA23-250 Flight Manual Excerpts (item 5, .PDF, 193 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40407806&FileExtension=.PDF&FileName=PA23-250%20Flight%20Manual%20Excerpts-Master.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.