Thursday, February 23, 2017

Thunder & Colt AX10-180S1, Air Carriage LLC, N709TC: Accident occurred February 20, 2017 in Albuquerque, New Mexico

Aviation Accident Final Report - National Transportation Safety Board: https://app.ntsb.gov/pdf

NTSB Identification: CEN17LA118
14 CFR Part 91: General Aviation
Accident occurred Monday, February 20, 2017 in Albuquerque, NM
Probable Cause Approval Date: 09/06/2017
Aircraft: THUNDER & COLT AIRBORNE AMER AX10 180, registration: N709TC
Injuries: 10 Uninjured.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

The commercial pilot of the balloon was performing a local sightseeing flight. The balloon took off from a field, climbed, and drifted southeast. As the balloon approached an interstate, the pilot began a descent to land on a field near a university campus.

About 100 to 140 ft above ground level (agl), the balloon entered a rapid descent. The pilot applied maximum fuel to the burner system to arrest the descent; however, the descent continued. The pilot stopped the descent about 50 ft agl and the balloon began to climb again; upon reaching 75 ft agl, the balloon gondola contacted power lines. The contact caused electricity to arc through the gondola, severing two of the four suspension cables. The pilot “hand-removed” the power line from the gondola, applied heat to the burner system, and climbed away from the power lines. The pilot subsequently made an uneventful landing on a soccer field at the university about a mile away from the power lines.

The National Weather Service (NWS) surface analysis chart depicted a cold front, which was located immediately south of the area at the time of the accident and moving across the state. The front resulted in a shift of the prevailing wind to the north-northwest with an increasing pressure gradient behind the front. Some lifting would be associated ahead of the front and then would subside but wouldn’t be classified as strong downdrafts near the accident site. Though not conclusive, it is possible that the shifting wind and changing weather conditions could have affected the performance of the balloon, causing an increase in its descent rate during the pilot’s landing approach.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The pilot’s delayed reaction to the balloon’s increased rate of descent during an attempted landing, which resulted in impact with a power line.

The National Transportation Safety Board did not travel to the scene of this accident.

Federal Aviation Administration / Flight Standards District Office: Albuquerque, New Mexico

Aviation Accident Factual Report - National Transportation Safety Board: https://app.ntsb.gov/pdf

http://registry.faa.gov/N709TC

NTSB Identification: CEN17LA118 
14 CFR Part 91: General Aviation
Accident occurred Monday, February 20, 2017 in Albuquerque, NM
Aircraft: THUNDER & COLT AIRBORNE AMER AX10 180, registration: N709TC
Injuries: 10 Uninjured.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

On February 20, 2017, about 0845 Mountain Standard Time, a Thunder and Colt, AX-10-180S1, lighter than air balloon with airborne heater, N709TC, struck power lines while approaching to land near the University of New Mexico, Albuquerque Campus, Albuquerque, New Mexico. The commercial pilot and 9 passengers on board were not injured. The balloon was substantially damaged. The balloon was registered to and operated by the pilot as a 14 Code of Federal Regulations Part 91 business sight-seeing air tour flight. Visual meteorological conditions prevailed and no flight plan was filed for the local flight that originated from a field in northwest Albuquerque, New Mexico, about 0745.

The pilot reported he had established a stable level flight approach to a field near the university campus. About 100 to 140 ft. above ground level (agl) the balloon entered a severe downdraft. The pilot applied maximum heat to the burner system to climb out of the downdraft; however, the balloon continued to descend. The pilot arrested the descent about 50 ft. agl and began to climb again. However, on reaching 75 ft. agl, the balloon gondola contacted power lines. The contact caused electricity to arc through the gondola severing two of the four suspension cables. The pilot "hand-removed" the power line from the gondola, applied heat to the burner system to burn a new hole in the envelope throat that had collapsed during the power line contact, and climbed away from the accident site. He then made an uneventful landing on a soccer field at the university about a mile away from the power lines.

Several passengers on board the balloon reported that as they approached Interstate 25, they were descending and the pilot was applying the burners continuously. One passenger said as they cleared some high rise building she saw the power lines. The pilot was applying the burners and continued burning as they approached the interstate. The balloon did not ascend and it struck the power lines.

The pilot held a commercial pilot certificate with a lighter than air with airborne heater rating. On September 1, 2016, he received a second-class medical certificate limited by a requirement for corrective lenses.

The pilot's logbook showed that he had flown 647 total hours, 19 hours of which were in the 30 days before the accident. The logbook also showed that the pilot successfully completed a flight review in a Cameron N-133 balloon on March 21, 2016.

The 11-place ride balloon, serial number 2444, was registered to the pilot and used for business. The envelope had a 180,000 cubic-foot (of air) capacity and was 76 ft. tall and had a diameter of 74 ft. The gondola or basket was a single t-configuration dividing it into three compartments, two for passengers and one for the pilot, the four 15-gallon propane tanks, and the fuel lines to the double burner system that provided heat to the envelope. The complete system had a maximum gross weight 3,197 lbs.

The balloon underwent an annual inspection on July 22, 2016, with a total time of 408.3 hours. The balloon's total time at the accident was 490 hours.

An examination of the balloon showed that two of the four suspension cables were burned through and separated. The gondola showed thermal damage to the wicker vertically along where the cables ran inside the basket structure. The envelope skirt, several load tapes, and several lower envelope panels were charred and melted. (See Figure 1 for a photograph showing the gondola damage, and Figures 2 and 3 for photographs showing the failed suspension cables.)

Figure 1. A photograph showing the damaged balloon gondola.

Figure 2. A photograph of one failed suspension cables.

Figure 3. A photograph of a second failed suspension cables.

Examination of the burners, fuel system, and vent line system showed no anomalies.

At 0852, the automated weather observation station weather at Albuquerque International Sunport, 1 nautical mile southeast of where the accident occurred, recorded wind 290° at 3 knots, visibility 10 miles, few clouds at 4,000 ft., temperature 46° Fahrenheit (F), dew point 33° F, and altimeter 30.22 inches, with remarks; automated surface observation sea level pressure 1021.0-hPa, mountain tops obscured northeast and southeast.


The National Weather Service (NWS) surface analysis chart for 0800 depicted a cold weather front moving across New Mexico and was located immediately south of the Albuquerque area at the time of the accident. The front resulted in a shift in the wind to the north-northwest with an increasing pressure gradient behind the front. For more information see the report, "NTSB Senior Meteorologist's Weather Summary" in the public docket for this accident.

NTSB Identification: CEN17LA118
14 CFR Part 91: General Aviation
Accident occurred Monday, February 20, 2017 in Albuquerque, NM
Aircraft: THUNDER & COLT AIRBORNE AMER AX10 180, registration: N709TC
Injuries: 10 Uninjured.

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

On February 20, 2017, about 0845 Mountain Standard Time, a Thunder and Colt, AX-10-180S1, lighter than air balloon with airborne heater, N709TC, struck power lines while approaching to land near the University of New Mexico, Albuquerque Campus, Albuquerque, New Mexico. The commercial pilot and 9 passengers on board were not injured. The balloon was substantially damaged. The balloon was operated by the pilot without a flight plan under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorology conditions prevailed for the local business sight-seeing air tour flight that originated about 0745.

The pilot reported he had established a stable level flight approach to a field near the university campus. About 100 to 140 ft. above ground level (AGL) the balloon entered a severe downdraft. The pilot applied maximum heat to the burner system in an attempt to climb out of the downdraft; however, the balloon continued to descend. The pilot arrested the descent at about 50 ft. AGL and began to climb again. However, on reaching 75 ft. AGL, the balloon gondola contacted power lines. The contact caused electricity to arc into the gondola severing two of the four suspension cables. The pilot "hand-removed" the power line from the gondola, applied heat to the burner system to burn a new hole in the envelope throat that had collapsed during the power line contact, and climbed away from the accident site. He then made an uneventful landing on a soccer field at the university about a mile away from the power lines.

At 0852, weather conditions reported at Albuquerque International Sunport were wind 290 degrees at 3 knots, few clouds at 4,000 ft., 10 miles visibility, temperature 46 degrees Fahrenheit (F), dew point 33 degrees F, and altimeter 30.22 inches.

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