# NTSB NYC08LA029: Piper PA-25-235, N131AB, Hollywood, FL, November 10, 2007 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: November 10, 2007, 16:56 local (21:56 UTC) - Place: Hollywood, FL - Coordinates: 26, -80.241668 - Nearby events: https://openairdocs.org/map.md?lat=26.0000&lon=-80.2417&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report March 5, 2009 - Report: Approved by Office Director - Parties: FAA/FSDO - NTSB case key (mKey): 67059 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC08LA029 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/67059/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=67059 - Page: https://openairdocs.org/ntsb/NYC08LA029 ## Probable cause The pilot's failure to maintain adequate airspeed, resulting in an aerodynamic stall. Contributing to the accident were an inoperative stall warning system and an erroneous airspeed indicator. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, maneuvering - turn to reverse direction - aircraft control - not maintained, pilot in command (cause) - stall/spin - inadvertent, pilot in command - airspeed indicator - inaccurate, unknown (contributing factor) - miscellaneous equipment - unavailable, unknown (contributing factor) - In flight collision with terrain/water, descent - uncontrolled - terrain condition - ground ## Analysis The pilot of the Piper PA-25 completed the local banner-tow mission and successfully released the banner. While maneuvering for landing, the airplane stalled at low altitude. The airplane was substantially damaged when it impacted flat terrain on airport property and the certificated commercial pilot sustained serious injuries. The airplane was equipped with a stall warning system that consisted of a vane-activated switch on the wing and a light in the cockpit. Electrical continuity testing and x-ray examination of the switch revealed that the internal contacts were fused, which prevented the switch from functioning in accordance with the design. The stall warning light was not illuminated at impact based on an analysis conducted by the Safety Board's Materials Laboratory. Calibration testing of the airspeed indicator revealed that the indicator read approximately 8 mph high at speeds up through at least 90 mph. The pilot had approximately 450 total hours of flight experience and approximately 130 hours in the accident airplane. Visual meteorological conditions prevailed and the reported winds were 9 knots. ## Factual narrative **This report was modified on 4/5/2012. Please see the public docket for this accident to view the original report.** HISTORY OF FLIGHT On November 10, 2007, about 1656 eastern standard time, a Piper PA-25-235, N131AB, was substantially damaged when it impacted the ground on airport property while maneuvering for landing at North Perry Airport (HWO), Hollywood, Florida. The certificated commercial pilot sustained serious injuries. The local banner tow flight was operated by Aerial Banners Inc, and was conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed. According to the Federal Aviation Administration (FAA), the flight originated at HWO, and was returning for landing after completing its banner towing mission. According to air traffic control recordings, the pilot reported to the HWO air traffic control tower (ATCT) that he was inbound for landing, and that he had obtained the current automated terminal information service (ATIS) weather and landing information. The controller instructed the pilot to report again when he reached the airport "boundary." When the flight arrived at the southwest airport boundary, the controller instructed the pilot to "proceed to the northwest corner for the north drop," and then told the pilot to plan on landing on runway 36 right. The pilot acknowledged the banner drop instruction, but questioned the controller with "that'll be a right turn for three six right?" The controller responded with "right turn between the parallels for three six right, cleared to land." According to witnesses, while headed north, the airplane dropped its banner in the assigned location west of runway 36 left, and then reversed course to the right. The airplane crossed over runway 36 left, and remained west of runway 36 right. The airplane began a left turn to align for landing on runway 36 right, then descended rapidly and impacted the ground. There was no postimpact fire. PERSONNEL INFORMATION The pilot held a commercial pilot certificate, with airplane single-engine land, multi-engine land, and instrument ratings. According to his pilot logbook, he had accumulated approximately 450 total hours of flight experience, and approximately 130 hours in the PA-25. His most recent first-class medical certificate was issued in March 2007. AIRCRAFT INFORMATION According to the type certificate data sheet, the PA-25 was a single-seat, low wing monoplane designed for aerial application of chemicals for agricultural purposes. The accident airplane was manufactured in 1965, and registered to Aerial Banners Inc in May 2004. The airplane was built and registered as a PA-25-235, but the engine installed at the time of the accident was a Lycoming O-540-G1A5, which is a 260 horsepower engine. The maintenance records did not document this airplane modification. The last 100 hour inspection was completed on September 8, 2007. The type design was no longer supported by Piper Aircraft Company; the type certificate was transferred to an Argentine company "LATINO AMERICANA DE AVIACION (LAVIA)" on April 15, 1998. METEOROLOGICAL INFORMATION The HWO 1653 surface weather observation reported winds from 340 degrees at 9 knots, clear skies, temperature 24 degrees Celsius (C), dew point 12 degrees C, and an altimeter setting of 30.04 inches of mercury. AIRPORT INFORMATION The airport was configured with four runways: 9 left, 27 right; 9 right, 27 left; 18 left, 36 right; and 18 right, 36 left. The airplane impacted in the area bounded by the four runways. Each runway was 100 feet wide and approximately 3,300 feet long. The centerlines of each pair of parallel runways were approximately 1,450 feet apart. The published traffic pattern altitude for HWO was 808 feet above mean sea level, which was 800 feet above the airport elevation. A grassy area that bounded the west edge of runway 36 left was used for banner drops, and extended approximately 1,000 feet wide in the east-west direction. WRECKAGE AND IMPACT INFORMATION According to information provided by FAA inspectors, the nose, including the engine, cowling and associated structure, exhibited crush and displacement damage. The propeller exhibited bending and chordwise scratching. The cockpit area was partially deformed. The wings were partially separated from their attach points. The left wing was crumpled and displaced aft, and the right wing had crush damage and wrinkling. The flaps were found in the retracted position. The aft fuselage and empennage appeared intact. SURVIVAL ASPECTS The pilot sustained serious head injuries. The right side of the instrument panel exhibited impact damage consistent with being struck in the aft-to-forward direction. The pilot seat remained attached to the seat tracks at all four attach points. The pilot's lapbelt restraint was intact, and the latching clasp exhibited positive engagement when tested by investigators. The cable that connected the shoulder harness to its inertia reel was fractured and separated at the swaged fitting closest to the shoulder harness webbing. The cable was examined by the National Transportation Safety Board materials laboratory, which stated the following in its report: "the broken individual wire ends...exhibited a cup and cone appearance. All features on the cable pieces were consistent with overstress separation. There was no evidence of corrosion or wear." The Safety Board was unable to determine whether the cable was an FAA-approved component, or if it was in compliance with the airplane manufacturer's design specifications. ADDITIONAL INFORMATION Pitot Tube A stainless steel tube approximately 1/8 inch in diameter served as the pitot tube. The pitot tube was bent aft, outboard, and approximately 90 degrees up from its normal orientation. The standoff distance of the pitot tube inlet below the wing surface was determined to be approximately 3 5/8 inches in its pre-accident condition. Measurements on four of the operator's other PA-25 airplanes yielded pitot tube inlet standoff distances ranging from 2 1/2 to 4 3/16 inches. Variations in standoff distances can affect the ram air pressure provided to the airspeed indicator. The Safety Board was unable to determine the airplane manufacturer's minimum or maximum standoff distances for the pitot tube, or the effect of the measured standoff distance on the accuracy of the airspeed that was presented to the pilot in the accident airplane. Airspeed Indicator The airspeed indicator (ASI) outer scale was marked as "MPH," while the inner scale was marked as "KNOTS." The white arc extended from 60 to 109 mph. The green arc extended from 67 to 124 mph, and the yellow arc extended from 125 mph to the red line at 156 mph. The airspeed arcs were congruent with the applicable airspeed limits specified in the airplane type certificate data sheet. A calibration test of the ASI was performed. The indicator was tested in 10 knot increments between 40 and 150 knots, inclusive. The ASI read higher than the input reference value at every test point. At the 60, 70, and 80 knot test points, the ASI read 68, 76, and 87 knots, respectively. Converted to mph, the test point values were 67, 78 and 89 mph, and the ASI indicated 76, 85 and 97 mph, respectively. An ASI from another of the operator's PA-25 airplanes, N169AB, exhibited values similar to those obtained on the accident airplane ASI. Stall Warning System The airplane was equipped with a stall warning system that consisted of a vane-activated switch mounted on the wing, and a light in the cockpit that was wired to the switch. Although some minor impact damage to the vane was noted, the vane moved freely. The switch was equipped with three electrical terminals labeled "COMMON, NORMALLY OPEN, and NORMALLY CLOSED." One wire was connected to the NORMALLY OPEN terminal, and one wire was connected to t ## Aircraft - Registration: [N131AB](https://openairdocs.org/aircraft/N131AB), registered now, S/N 25-3693, built 1965 (OpenAirDocs) - Reported make and model: PIPER PA-25-235 - Registry model: [Piper PA-25-235](https://openairdocs.org/model/piper-pa-25-235) (registry code 7102504) (OpenAirDocs) - Registry engine: [Lycoming 0-540 series](https://openairdocs.org/engine/lycoming-0-540-series) (registry code 41532, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 25-3693 - Airframe hours: 7602 - Engines: Lycoming O-540 235 horsepower reciprocating - Damage: Substantial damage - Flight: Banner tow, Part 91 - Operator: Aerial Banners Inc - Registered owner: Aerial Banners Inc - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, September 8, 2007 - Departed: HWO, Hollywood, FL - Destination: HWO, Hollywood, FL - Airport: HWO, Hollywood North Perry, runway 36R, 3,260 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 25; injuries: serious; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review August 3, 2007; seat: single; flight hours: 450 total, 130 in this make and model, 290 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 340° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 54 °F - Altimeter: 30.04 inHg - Observed at: HWO ## Docket (16 files) The files NTSB released with the investigation on January 25, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=67059. 7.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 601 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40306763&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - FAA-Provided Documentation (item 2, .PDF, 311 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40306765&FileExtension=.PDF&FileName=FAA-Provided%20Documentation-Redacted.PDF - Witness Statement - Hinman (item 3, .PDF, 71 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40306766&FileExtension=.PDF&FileName=Witness%20Statement%20-%20Hinman-Redacted.PDF - Broward County Report (item 4, .PDF, 7 photos, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40365194&FileExtension=.PDF&FileName=Broward%20County%20Report-Redacted.PDF - Communications Transcript (item 5, .PDF, 39 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40306767&FileExtension=.PDF&FileName=Communications%20Transcript-Master.PDF - PIC Logbook Excerpts (item 6, .PDF, 438 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396855&FileExtension=.PDF&FileName=PIC%20Logbook%20Excerpts-Redacted.PDF - Airspeed Indicator Calibration Results (item 7, .PDF, 50 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40306770&FileExtension=.PDF&FileName=Airspeed%20Indicator%20Calibration%20Results-Redacted.PDF - Additional Factual Information (item 8, .PDF, 18 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40306771&FileExtension=.PDF&FileName=Additional%20Factual%20Information-Master.PDF - Materials Laboratory 15 - Factual Report 08-039-Inertia Reel Assembly (item 9, .PDF, 22 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40293696&FileExtension=.PDF&FileName=Materials%20Laboratory%2015%20-%20Factual%20Report%2008-039-Inertia%20Reel%20Assembly-Master.PDF - Photograph - Overview (item 10, .PDF, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40306783&FileExtension=.PDF&FileName=Photograph%20-%20Overview-Master.PDF - Photograph - Instrument Panel (item 11, .PDF, 586 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40306784&FileExtension=.PDF&FileName=Photograph%20-%20Instrument%20Panel-Master.PDF - Photograph - Airspeed Indicator (item 12, .PDF, 584 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40306785&FileExtension=.PDF&FileName=Photograph%20-%20Airspeed%20Indicator-Master.PDF - Photograph - Pitot Tube (item 13, .PDF, 632 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40306786&FileExtension=.PDF&FileName=Photograph%20-%20Pitot%20Tube-Master.PDF - Photograph - Shoulder Harness Cable Fracture (item 14, .PDF, 843 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40306787&FileExtension=.PDF&FileName=Photograph%20-%20Shoulder%20Harness%20Cable%20Fracture-Master.PDF - Materials Laboratory 15 - Factual Report 08-131 Stall Warning Vane assembly (item 15, .PDF, 180 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40306847&FileExtension=.PDF&FileName=Materials%20Laboratory%2015%20-%20Factual%20Report%2008-131%20Stall%20Warning%20Vane%20assembly-Master.PDF - 4/5/2012 Revisions to Factual Report (item 16, .PDF, 59 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40365630&FileExtension=.PDF&FileName=4%2F5%2F2012%20Revisions%20to%20Factual%20Report-Master.PDF From the NTSB's public API. 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