Aviation Accident Summaries

Aviation Accident Summary DEN08LA004

Albuquerque, NM, USA

Aircraft #1

N7179Z

Aerostar S-66A

Analysis

The hot air free balloon was participating in a balloon fiesta. Wind velocity had increased, and several balloons were seen to go by at high speed and low altitude. The pilot stayed low to keep right of the congested areas, but two of his passengers said they were flying too low. The pilot became distracted when he saw another balloon hit a house. The next thing he realized was that the wind had forced the balloon into power lines (the pilot told state troopers that he saw the power lines and activated the burners in an attempt to fly over them, but he told the FAA that he was on a landing approach and was in visual contact with the power line when he encountered a downdraft and was unable to clear the power lines). The balloon's basket struck the top static line of a 3-phase high voltage transmission line. The wind began to collapse the envelope and the pilot activated the burners in an attempt to maintain inflation and break loose from the power line. The basket slid down the wire and the wire became entangled in the basket's skid plate. The pilot threw a drop line to his chase crew in hopes they could pull him free. This attempt failed. The chase crew then attached the drop line to a pickup truck and tried to tow the balloon free. This attempt also failed. The braided static wire sawed through the wicker basket. The balloon finally came loose from the power line and started to rise. The drop line broke and the balloon "shot up in the air like a rocket." A propane tank fell from the basket, and then the passenger fell out. Estimates of the balloon's altitude varied from 70 to 200 feet. The pilot felt one corner of the basket drop and saw the hole. He looked up through the balloon's throat and could see blue sky because the dilation vent had become unseated. The balloon drifted east, and then descended. The pilot said the balloon came down faster than terminal descent speed and landed hard.

Factual Information

On October 8, 2007, approximately 0742 mountain daylight time, an Aerostar S-66A, N7179Z, registered to Star Trail, Inc., and piloted by a commercial pilot, was substantially damaged when it became entangled in power lines shortly after taking off at Albuquerque, New Mexico. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under the provisions of Title 14 Code of Federal Regulations Part 91, and no flight plan had been filed. One passenger was fatally injured, two passengers were seriously injured, and the pilot and one passenger were not injured. The local flight originated approximately 0730. The pilot was sent NTSB Form 6120.1/2, Pilot/Operator Aircraft Accident Report, by U.S. postage, and asked to complete it. The pilot did not respond and has failed to return telephone calls from both NTSB and FAA. The following is based on the New Mexico State Police report, an FAA report, and interviews with pilot, and witness statements. The hot air free balloon was participating in the Albuquerque International Balloon Fiesta. A witness said wind velocity had increased, and he watched several balloons go by "at high speed and low altitude." The pilot told an FAA inspector that he had been flying in a southwest direction (state troopers determined the balloon had been flying in a southeast direction) and that he had "stayed low to [keep] right of the congested areas" (two of his passengers told state troopers that they were flying "too low"). The pilot became distracted when he saw another balloon hit a house. The next thing he realized was that the wind had forced the balloon into power lines (he told state troopers that he saw the power lines and activated the burners in an attempt to fly over them. The FAA report indicated that the pilot was on a landing approach and was in visual contact with the power line. As the balloon got closer, it encountered a downdraft and the pilot activated the burners but was unable to clear the power lines). The balloon's basket struck the top static line of a 3-phase high voltage transmission line. Witnesses said the wind began collapsing the envelope and the pilot activated the burners in an attempt to maintain inflation and break loose from the power line. The basket slid down the wire and the wire became entangled in the basket's skid plate. The pilot then threw a drop line to his chase crew in hopes they could pull him free. This attempt failed. The chase crew then attached the drop line to a pickup truck and tried to tow the balloon free. This attempt also failed. The FAA report said, "The wire cut through the wicker gondola and became entangled with the handle on one of the fuel tanks." Video footage taken by witnesses showed the braided static wire sawing through the wicker basket. The FAA report continued, "The combined force of the truck and balloon lift, pulled the fuel tank through the wicker gondola creating a large hole." The balloon finally came loose from the power line and started to rise. The drop line broke and the balloon "shot up in the air like a rocket." Witnesses saw a propane tank fall from the basket, and then saw a passenger fall out. Estimates of the balloon's altitude varied from 70 to 200 feet. The pilot felt one corner of the basket drop and saw the hole. He looked up through the balloon's throat and could see blue sky because the dilation vent had become unseated. He did not know he had lost a passenger until the other passengers started yelling, "She fell out! She fell out!" The balloon drifted east, and then descended. The pilot said the balloon came down faster than terminal descent speed. It landed hard at the intersection of Comanche Road and Vassar Road. Passerby tended to the pilot and passengers until emergency personnel arrived. The FAA inspector examined the balloon and basket and noted several discrepancies, to wit: (1) the installed propane tanks bore serial numbers different than the ones listed in the aircraft maintenance records; (2) the drop line had been improperly installed. Another FAA inspector, with the assistance of an Aerostar representative, later measured the deflation strap (p/n 52264-05) and found it to be 116 feet, 2 inches in length, about 10 feet shorter than specifications (126 feet). A photograph taken by a witness while the balloon was still entangled with the power line showed little slack in the deflation strap. The inspector wrote, "This could account for the inadvertent opening of the deflation port [on top] of the envelope when the balloon was suddenly released after the drop line failed. The envelope . . . experienced major contortions and grew in length beyond the normal operating parameters." FAA's review of annual inspection criteria for the deflation strap was to check only for "abrasions, cuts, burns, and routing." There were no entries of repairs to, or replacement of, the deflation strap. At the request of FAA, Aerostar tested the drop line. It failed at 4,450 pounds. The break occurred in the stitching used to form a loop at one end, but not in the parent material itself. The FAA inspector said he had been unable to contact the pilot who "had dropped from sight. Even his own family does not know where he is!"

Probable Cause and Findings

The pilot's failure to maintain adequate visual lookout and clearance resulting in an in-flight collision with power lines, and the ground crew's improper assistance. Contributing to this accident were the high wind, the pilot's diverted attention, low altitude, transmission wire, and the subsequent partial failure of the basket and envelope.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports