story from denver post
Dec. 17 - The Columbia AirLife helicopter that got snared by power lines and crashed late Sunday had no apparent defects in its steering or engines, pointing investigators away from mechanical error.
"To the best of our knowledge, it was a good ship," Jim Struhsaker of the National Transportation Safety Board said Tuesday.
Two other factors may have come into play, Struhsaker said.
First, the pilot used a different route for take-off than he did for landing. Generally, helicopters follow their landing path when taking off to avoid obstacles.
"He came in one way and went out another, which is not normal," said Struhsaker. "I don't know why he chose to do that." Second, a curtain designed to shield the pilot from interior lights in the back of the chopper was not drawn, exposing him to glare, Struhsaker said. The emergency scene at the four-car accident to which the chopper had responded would have put off light as well.
"The pilot did not have the advantage of allowing his eyes to be adjusted to night vision," Struhsaker said. "There can be what we call a 'black hole' effect when you go from brightness to darkness."
Pilot Peter Abplanalp, 50, of Thornton, lifted off with two nurses and one patient - the driver who barreled through construction barriers into oncoming traffic and started the pile-up on South Santa Fe Drive.
The Bell 407 helicopter got tangled in 230,000-volt power lines and nosedived onto Centennial golf course, killing all four aboard. Autopsies indicated they died from the impact, not from electrocution.
Some witness accounts back up Struhsaker in pointing to the take-off path and the glare as a problem.
Littleton Police Officer Robert Tarnoff said he noticed the glare inside the helicopter.
And Officer John Fangman reported that the helicopter began to follow its incoming path on the way out, but changed course.
"The helicopter at first started to fly backwards as if it was going to back out along the same route it approached," Fangman wrote. "When it was about 20 feet off the ground, the helicopter, still facing south, started to move to its right ... "I then observed a large shower of sparks over the helicopter and heard a loud pop."
Friends said Abplanalp was a very careful pilot, and witnesses said he made the customary circling of the car-accident site to look for trouble spots before landing.
That orientation would typically help a pilot locate and avoid obstacles. But, Struhsaker said, the power lines were 90 feet up and as much as 900 feet away from the accident site and might not have been spotted.
"They could have been out of the original scope of his survey," Struhsaker said.
Struhsaker is not the investigator on the case. But he has been in touch with Investigator Norm Wiemeyer, who was working on the wreckage Tuesday at a hangar in Erie.
Littleton fire engineer Fred Turner guided Abplanalp in for a landing at the car crash site, pointing out a backhoe in a construction area, nearby power lines and a street light. But he didn't point out the high tension wires across the South Platte River and some 300 yards away.
"Our job is to make sure there's a safe place to land," Turner said Tuesday. "I pointed out the obvious things I saw within 100 feet of the landing area." The AirLife helicopter was on site for 15 to 30 minutes, loading up Jerry DeHerrera, 23, of Englewood, whose black sports car caused the accident. The helicopter was bound for Denver Health Medical Center.
Turner said he assumed Abplanalp would go out the way he came in, and didn't point out further dangers.
"He was very, very calm, very collected," Turner said. "It wasn't any hurry. It's a routine procedure for those guys. He didn't appear to be rushing. I said, 'Have a nice trip, have a nice day.' And he said, 'Thanks a lot, friend, nice meeting you.' A minute later, he's dead. It's hard to take." The helicopter took off to the south and west - toward the power lines.
"I was a little surprised he wanted to go that way," Turner said. "But he's in charge of the ship. He must have seen something I was unaware of." When the helicopter went to turn left, circle round and head for Denver, it snagged the power lines.
"He went up into the wires," Turner said. "It would have shredded the rotors. Without the rotors he more or less rolled over and fell to the ground." As to why the pilot didn't take the safer route out, Turner said, "There's only one person who knows that, and we'll have to wait to see him in heaven to find out."
KOA radio pilot Al Verley - a friend of Abplanalp who flew with him in the Wyoming Army National Guard - said Abplanalp "wasn't a hot dog."
"For some reason, after he took off, he turned back," Verley said. "The Bell 407 has three times the horsepower we have. Why didn't Pete take off straight up, go up 500 feet ... and then head to the hospital?"
The Bell 407, which AirLife put into service less than a year ago, can rise 1,000 feet a minute, Verley said. "It's got enough horsepower that with seven people on board it can fly to the top of Pike's Peak and still climb at 1,000 feet a minute."
Verley said that at night helicopter pilots can "barely make out powerlines. You are coming in almost blind." He said Abplanalp may have suffered spatial disorientation, a condition in which pilots turn their heads quickly and can confuse lights on the ground with the light from stars.
"If you fly for a long time, you say it can't happen to me," Verley said. "But it does happen to good pilots. If you fly often enough, the odds increase."
Witnesses were at a loss to guess whether Abplanalp, an experienced and careful pilot, noticed the power lines and thought he was clear of them or was unaware of them.
"Maybe he just flat didn't know," said Littleton Fire Capt. David Christ. |
