# NTSB CEN15IA385: Piper PA-23-250, N900AM, Joliet, IL, August 27, 2015 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: August 27, 2015, 11:10 local (16:10 UTC) - Place: Joliet, IL - Coordinates: 41.577777, -88.173057 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.5778&lon=-88.1731&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Birdstrike](https://openairdocs.org/ntsb-events/901) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report October 19, 2015 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA DuPage FSDO - NTSB case key (mKey): 91877 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN15IA385 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/91877/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=91877 - Page: https://openairdocs.org/ntsb/CEN15IA385 ## Probable cause A bird strike. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Empennage structure: horizontal stabilizer](https://openairdocs.org/ntsb-findings/01035510): Aircraft › Aircraft structures · Damaged/degraded; cases with it: [Piper PA-23-250, 1 case](https://openairdocs.org/ntsb-findings/01035510/cases.md?model=7102308), [All aircraft, 23 cases](https://openairdocs.org/ntsb-findings/01035510/cases.md) - [Object/animal/substance: animal(s)/bird(s)](https://openairdocs.org/ntsb-findings/03022045): Environmental issues › Physical environment · Not specified (probable cause); cases with it: [Piper PA-23-250, 3 cases](https://openairdocs.org/ntsb-findings/03022045/cases.md?model=7102308), [All aircraft, 358 cases](https://openairdocs.org/ntsb-findings/03022045/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Birdstrike](https://openairdocs.org/ntsb-events/901) (defining event); cases with it: [Piper PA-23-250, 2 cases](https://openairdocs.org/ntsb-events/901/sequence.md?model=7102308), [All aircraft, 253 cases](https://openairdocs.org/ntsb-events/901/sequence.md) ## Analysis The pilot reported that the airplane was in cruise flight at 2,500 ft above mean sea level (1,920 ft above ground level) when he heard a "bang" and felt a jolt in the flight controls. He noted no abnormal flight characteristics, so he continued the flight and landed without incident. After landing, minor damage to the leading edge of the left horizontal stabilizer was observed. Microscopic examination of the damaged area revealed several feather barbs consistent with remnants from the Columbidae bird family, which includes doves and pigeons. ## Factual narrative On August 27, 2015, about 1110 central daylight time, a Piper PA-23-250, N900AM, sustained minor damage when it was struck by an unknown object while in cruise flight at 2,500 ft above mean sea level (1,920 ft above ground level) about 4 nm north of the Joliet Regional Airport (JOT), Joliet, Illinois. The commercial pilot was not injured. The airplane was registered to and operated by Aerial Imaging Inc. under the provisions of the 14 Code of Federal Regulations Part 91 as a positioning flight. Visual meteorological conditions prevailed at the time of the incident, and no flight plan was filed. The airplane departed the Aurora Municipal Airport (AAR), Aurora, Illinois, about 1100 and landed without incident at the South Bend International Airport (SBN), South Bend, Indiana. The pilot reported that he heard a "bang" and felt a jolt in the flight controls while he was completing the cruise checklist. He did not see any objects before the noise, and he did not see any damage to the airplane. The engines were operating normally, the flight controls felt normal, the landing gear indicated up and locked, and the cargo did not appear to have shifted. He continued the flight to SBN. No abnormal flight characteristics were noted during the flight. After landing, damage to the leading edge of the left horizontal stabilizer was observed. The damage included about four dents spanning approximately 13 inches from left to right with the inboard dent piercing the aluminum skin. The damage also included multiple scratches and cuts in the deicing boot that overlies the leading edge of the left horizontal stabilizer. The damaged section of the deicing boot was removed from the leading edge of the left horizontal stabilizer and shipped to the National Transportation Safety Board's Materials Laboratory for examination. The NTSB examination using an ultraviolet light indicated that insects impacted the deicing boot, but there was no widespread area that fluoresced under exposure to ultraviolet light consistent with an exposure to larger volumes of biological materials. The tears in the deicing boot revealed exhibited features consistent with failure from overstress. The deicing boot was subsequently examined at the Feather Identification Laboratory, Division of Birds, Smithsonian Institution National Museum of Natural History. Several feather barbs were removed from the tears in the boot during the microscopic examinations that were consistent with remnants from the Columbidae bird family (doves and pigeons). ## Aircraft - Registration: [N900AM](https://openairdocs.org/aircraft/N900AM), registered now, S/N 27-7954014, built 1979 (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 IO-540 series](https://openairdocs.org/engine/lycoming-io-540-series) (registry code 41530, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 27-7954014 - Year built: 1979 - Airframe hours: 3715 - Engines: LYCOMING IO-540-C4B5 250 horsepower reciprocating; LYCOMING IO-540-C4B5 250 horsepower reciprocating - Damage: Minor damage - Flight: Positioning, Part 91 - Operator: Aerial Imaging Inc - Registered owner: Aerial Imaging Inc - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 16, 2014 - Departed: AAR, Aurora, IL - Destination: SBN, South Bend, IN - Equipment: Auto-pilot, Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 31; injuries: none; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review January 20, 2015; seat: left; restraint: 3-point; flight hours: 725 total, 43 in this make and model, 635 as pilot in command, 91 in the last 90 days, 23 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 100° at 4 knots - Visibility: 10 statute miles - Temperature: 68 °F, dew point 55 °F - Altimeter: 30.20 inHg - Observed at: JOT, 4 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). - [Incident 20150827013459I](https://openairdocs.org/incident/20150827013459I), Aug 27, 2015: Piper PA-23-250, Joliet, IL, Minor damage. Piper aztec, N900AM, was operating at an indicated airspeed of 140 knots at 2500 feet mean sea level (MSL) approximately 9 nautical miles from the Joliet VOR… ## Docket (3 files) The files NTSB released with the investigation on September 24, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=91877. 6.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 4.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432160&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Materials Laboratory Factual Report (item 2, .PDF, 5 photos, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432161&FileExtension=.PDF&FileName=Materials%20Laboratory%20Factual%20Report-Master.PDF - Photos (item 3, .PDF, 10 photos, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432162&FileExtension=.PDF&FileName=Photos-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.