# NTSB CEN09CA358: Aerostar International RX-9, N9116M, Marathon City, WI, June 14, 2009 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Data collection · Final report - Date: June 13, 2009, 20:00 local (Jun 14, 2009, 01:00 UTC) - Place: Marathon City, WI - Coordinates: 44.975555, -89.81639 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.9756&lon=-89.8164&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Hard landing](https://openairdocs.org/ntsb-events/092) - Highest injury: Serious injuries - Injuries: 1 serious, 3 minor, 1 uninjured - Status: Completed, report September 10, 2009 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA-Milwaukee FSDO - NTSB case key (mKey): 74049 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN09CA358 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74049/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74049 - Page: https://openairdocs.org/ntsb/CEN09CA358 ## Probable cause A hard landing as a result of unexpected high winds and gusts. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Wind: high wind](https://openairdocs.org/ntsb-findings/03034055): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Aerostar International RX-9, 1 case](https://openairdocs.org/ntsb-findings/03034055/cases.md?model=7487010), [All aircraft, 112 cases](https://openairdocs.org/ntsb-findings/03034055/cases.md) - [Performance/control parameters: descent/approach/glide path](https://openairdocs.org/ntsb-findings/01062040): Aircraft › Aircraft oper/perf/capability · Capability exceeded; cases with it: [Aerostar International RX-9, 1 case](https://openairdocs.org/ntsb-findings/01062040/cases.md?model=7487010), [All aircraft, 809 cases](https://openairdocs.org/ntsb-findings/01062040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Hard landing](https://openairdocs.org/ntsb-events/092) (defining event); cases with it: [Aerostar International RX-9, 1 case](https://openairdocs.org/ntsb-events/092/sequence.md?model=7487010), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) - [Landing: Dragged wing/rotor/float/other](https://openairdocs.org/ntsb-events/093); cases with it: [Aerostar International RX-9, 1 case](https://openairdocs.org/ntsb-events/093/sequence.md?model=7487010), [All aircraft, 319 cases](https://openairdocs.org/ntsb-events/093/sequence.md) - [Landing: Cabin safety event](https://openairdocs.org/ntsb-events/110); cases with it: [Aerostar International RX-9, 1 case](https://openairdocs.org/ntsb-events/110/sequence.md?model=7487010), [All aircraft, 151 cases](https://openairdocs.org/ntsb-events/110/sequence.md) ## Analysis The pilot and four paying passengers departed in a free air balloon. The local area surface weather observations indicated that the winds were consistently from the northwest at 6 – 8 knots. Around the time of the balloon launch, the winds were observed to be 300 degrees at 6 knots. About 3 minutes after liftoff, the balloon was heading 180 degrees at 10 knots about 800 feet above ground level. The winds on the ground suddenly increased to about 25 mph, and the balloon experienced strong wind gusts. The pilot reported that about 9 minutes after takeoff, a big wind gust “caved in” half the balloon and the mouth was “almost shut.” The pilot decided to get the balloon on the ground at the nearest suitable field, and instructed the passengers to prepare for a hard landing. The balloon hit hard, bounced in the air about 30 feet, and traveled about 200 feet before it hit the ground again. The balloon tipped on its side and one of the passengers partially fell out of the basket, but was restrained by the pilot and a passenger. The wind dragged the basket about 125 feet where the passenger fell out the basket and into a ditch. The basket was dragged about another 60 feet before it came to a stop in another field. The passenger was seriously injured. The balloon sustained minor damage. ## Factual narrative The pilot of the hot air balloon reported that he had made numerous calls to weather services prior to the balloon launch to ascertain the current and forecast winds. The local area surface weather observations indicated that the winds were consistently from the northwest at 6 to 8 knots. Around the time of the balloon launch, the winds were observed to be 300 degrees at 6 knots. The weather observations after the time of the accident indicated similar wind conditions. The pilot and four paying passengers departed in the balloon. About 3 minutes after liftoff, the balloon was heading 180 degrees at 10 knots about 800 feet above ground level (agl). The winds on the ground suddenly increased to about 25 mph, and the balloon experienced strong wind gusts. The pilot reported that about 9 minutes after takeoff, a big wind gust “caved in” half the balloon and the mouth was “almost shut.” The balloon was traveling about 45 mph and was about 1,500 feet agl in an up draft. When the pilot got the balloon to about 500 feet agl, he informed the passengers that he intended to land at the nearest suitable field, and instructed them to prepare for a hard landing. The pilot reported that he turned off the gas and pilot lights at 100 feet agl and the balloon was descending at 500 fpm. The surface wind was about 25 mph. At 20 feet agl, he pulled the vent line to open the top. The balloon hit hard, bounced in the air about 30 feet, and traveled about 200 feet before it hit the ground again. The balloon tipped on its side and one of the passengers partially fell out of the basket, but was restrained by the pilot and another passenger. The wind dragged the basket about 125 feet where the passenger fell out their arms and into a ditch. The basket was dragged about another 60 feet before it came to a stop in another field. The pilot and passengers were taken to area hospitals for observation and care. The balloon sustained minor damage. ## Aircraft - Registration: [N9116M](https://openairdocs.org/aircraft/N9116M), registered now, S/N RX9-3013 (OpenAirDocs) - Reported make and model: AEROSTAR INTERNATIONAL INC RX-9 - Registry model: [Aerostar International RX-9](https://openairdocs.org/model/aerostar-international-rx-9) (registry code 7487010) (OpenAirDocs) - Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs) - Category: Balloon - Serial number: RX9-3013 - Airframe hours: 348 - Damage: Minor damage - Flight: Other work use, Part 91 - Operator: Handcrafted Furniture Balloon Rides LLC - Registered owner: Handcrafted Furniture Balloon Rides LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 27, 2009 - Departed: Marathon City, WI - Destination: Marathon City, WI ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; commercial; medical: class 3; last flight review May 8, 2009; flight hours: 1,323 total, 78 in this make and model, 9 in the last 90 days, 7 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 300° at 6 knots - Visibility: 10 statute miles - Temperature: 70 °F, dew point 48 °F - Altimeter: 29.96 inHg - Observed at: AUW, 10 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 20090613054199A](https://openairdocs.org/incident/20090613054199A), Jun 13, 2009: Arostr RX9, Wausau, WI, Minor damage. The balloon took off in 6 knot winds. Within a few minutes the pilot noticed groundspeed increasing to over 35 knots. The envelope started collapsing forcing… ## Docket (3 files) The files NTSB released with the investigation on July 24, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74049. 1.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 731 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40316100&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Witness Statements (item 2, .PDF, 191 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40316101&FileExtension=.PDF&FileName=Witness%20Statements-Master.PDF - Weather Information (item 3, .PDF, 96 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40316102&FileExtension=.PDF&FileName=Weather%20Information-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.