# NTSB WPR12LA138: Raven Industries S-66A, N57194, Avra Valley, AZ, March 16, 2012

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: March 16, 2012, 08:00 local (15:00 UTC)
- Place: Avra Valley, AZ
- Coordinates: 32.434841, -111.31562 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=32.4348&lon=-111.3156&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Defining event: [Approach-VFR pattern final: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490)
- Highest injury: Minor injuries
- Injuries: 3 minor, 6 uninjured
- Status: Completed, report August 29, 2013
- Report: Approved by Office Director
- NTSB office: Western Pacific Region
- Parties: Federal Aviation Administration
- NTSB case key (mKey): 83146
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR12LA138
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/83146/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=83146
- Page: https://openairdocs.org/ntsb/WPR12LA138

## Probable cause

The pilot's improper decision to partially open the balloon's vent before clearing a power line while landing, which resulted in the balloon descending too soon and contacting the power line.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Performance/control parameters: descent/approach/glide path](https://openairdocs.org/ntsb-findings/01062040): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Raven Industries S-66A, 1 case](https://openairdocs.org/ntsb-findings/01062040/cases.md?model=7480612), [All aircraft, 809 cases](https://openairdocs.org/ntsb-findings/01062040/cases.md)
- [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Raven Industries S-66A, 1 case](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=7480612), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md)
- [Object/animal/substance: wire](https://openairdocs.org/ntsb-findings/03022032): Environmental issues › Physical environment · Not specified (probable cause); cases with it: [Raven Industries S-66A, 1 case](https://openairdocs.org/ntsb-findings/03022032/cases.md?model=7480612), [All aircraft, 588 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Approach-VFR pattern final: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) (defining event); cases with it: [Raven Industries S-66A, 1 case](https://openairdocs.org/ntsb-events/490/sequence.md?model=7480612), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md)

## Analysis

The pilot reported that the balloon was traveling 5 to 7 knots west toward a road oriented north-south with a power line running along the east side of the road. Beyond the power line and road was a large area of open desert where the pilot planned to land. When the balloon was about 100 yards from the lines at an altitude of about 300 feet above ground level, the pilot began setting the balloon up for landing by cracking open the vent-top of the envelope. The pilot operated one of the two burners to compensate for the expected loss of lift from the partly open top; however, the balloon began a slow descent instead of maintaining altitude, and the descent rate seemed to accelerate. In response, the pilot operated both burners and looked up at the top of the balloon, which he found was over a third open instead of the expected 2- to 3-foot crack. Realizing that the balloon’s glidepath would now result in the basket impacting the upper wire of the power line, the pilot decided to fully open the top of the balloon and land short of the power line. The balloon descended and impacted the power line wires with the basket suspension cables contacting more than one wire, which resulted in electrical arcing. The envelope folded over the wires, and the basket came to rest on the ground. The pilot stated that the accident could have been prevented by initiating the set-up for landing only after crossing the last obstacle before the landing area.

## Factual narrative

On March 16, 2012, about 0800 mountain standard time, a Raven Industries, Inc., S-66A balloon, N57194, was substantially damaged when its envelope contacted electrical transmission lines during landing near Avra Valley, Arizona. The commercial pilot and two passengers received minor injuries, and the other six passengers were not injured. The balloon was registered to an individual, and doing business as Southern Arizona Balloon Excursions, under the provisions of 14 Code of Federal Regulations Part 91. A flight plan had not been filed for the local area sightseeing flight, which had originated from Marana, Arizona, about 0630. Visual meteorological conditions prevailed at the time of the accident. The pilot reported that the balloon was traveling west at a speed of 5 to 7 knots towards a road oriented north-south with a power line running along the east side of the road. Beyond the power line and road was a large area of open desert where the pilot planned to land. When the balloon was about 100 yards from the lines at an altitude of about 300 feet above ground level (agl), he began setting the balloon up for landing by “cracking open the vent-top of the envelope to set up a “heavy” condition for landing.” The pilot operated one of the two burners to compensate for the loss of lift from the partly open top; however, the balloon began a slow descent instead of maintaining altitude, and the descent rate seemed to accelerate. In response, the pilot operated both burners and looked up at the top of the balloon, which he found was “over a third open instead of the expected 2-3 foot opening.” Realizing that the balloon’s glide path would now result in the basket impacting the upper wire of the power line, he decided to fully open the top of the balloon and land short of the power line. The balloon descended and impacted the power line wires with the basket suspension cables contacting more than one wire resulting in electrical arcing. Pieces of burning balloon envelope material rained down into the basket. The envelope folded over the wires, and the basket came to rest on the ground. Three suspension cables were separated and several envelope panels were damaged. In the section of the National Transportation Safety Board Pilot/Operator Aircraft Accident Report titled “Recommendation (How could this accident/incident have been prevented?),” the pilot stated, “when operating LTA [lighter than air] aircraft initiate set-up for landing sequence only after crossing last obstacle prior to landing field/area.”

## Aircraft

- Registration: [N57194](https://openairdocs.org/aircraft/N57194), registered now, S/N S66A-115, built 1980 (OpenAirDocs)
- Reported make and model: RAVEN INDUSTRIES INC S-66A
- Registry model: [Raven Industries S-66A](https://openairdocs.org/model/raven-industries-s-66a) (registry code 7480612) (OpenAirDocs)
- Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs)
- Category: Balloon
- Serial number: S66A-115
- Airframe hours: 336
- Damage: Substantial damage
- Fire: On-Ground
- Flight: Other work use, Part 91
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, September 27, 2011
- Departed: AVQ, Marana, AZ
- Destination: Avra Valley, AZ

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 62; injuries: none; commercial; medical: class 3, without waivers/limitations; last flight review April 14, 2010; flight hours: 2,280 total, 10 in the last 90 days, 3 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 100° at 5 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 55 °F, dew point 14 °F
- Altimeter: 30.03 inHg
- Observed at: RYN, 20 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 20120316004789A](https://openairdocs.org/incident/20120316004789A), Mar 16, 2012: Raven Industries Inc S-66A, Marana, AZ, Substantial damage. Balloon N57194 approached an open field for landing but the wind changed and the balloon was being blown toward some power lines. He climbed up above the power…

## Docket (5 files)

The files NTSB released with the investigation on June 24, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=83146. 3.1 MB in all.

- Pilot Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 802 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40395484&FileExtension=.PDF&FileName=Pilot%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF
- Owner Aircraft Accident Report, NTSB Form 6120.1 (item 2, .PDF, 262 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40395485&FileExtension=.PDF&FileName=Owner%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF
- Photo 1. Balloon envelope over wires (item 3, .PDF, 656 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40395487&FileExtension=.PDF&FileName=Photo%201.%20Balloon%20envelope%20over%20wires-Master.PDF
- Photo 2. Basket beside the road (item 4, .PDF, 639 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40395488&FileExtension=.PDF&FileName=Photo%202.%20Basket%20beside%20the%20road-Master.PDF
- Photo 3. Balloon envelope over the wires (item 5, .PDF, 719 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40395489&FileExtension=.PDF&FileName=Photo%203.%20Balloon%20envelope%20over%20the%20wires-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.

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