NTSB looks into possible pilot error in fatal copter crash

Two weeks after a fatal Aurora helicopter crash, authorities examining its cause have not found any evidence of mechanical failure, suggesting possible pilot error.

In a preliminary report released Thursday, the National Transportation Safety Board did not speculate what caused the Air Angels helicopter to clip a radio tower support wire Oct. 15 and crash into a field on the east side of Eola Road.

So far, an examination of the helicopter's main components did not reveal any pre-existing problems. But experts said they can't rule anything out given how badly damaged the helicopter was due to the crash and post-impact fire.

"We didn't see any defects that we could say were pre-existing, but it was severely fragmented," said John Brannen, the NTSB investigator-in-charge. "We can't entirely rule it out, but we didn't see anything."

The ill-fated crew - pilot Del Waugh, 69, of Carmel, Ind; nurse William Mann, 31, of Chicago; and paramedic Ron Battiato, 41, of Peotone - was transporting 14-month-old Kirstin Blockinger of LeLand. All four aboard were killed while on their way to Children's Memorial Hospital in Chicago.

Brannen said a lot of work remains ahead. A final NTSB report still is months away.

As the probe continues, Brannen said investigators will delve into the pilot's medical and flight history, including an in-depth look into his final 72 hours.

Waugh did not make a distress call before impact and he did not express any concerns minutes earlier when speaking with DuPage Airport officials. Moreover, radar plots show the chopper was flying steady at around 1,400 feet - low but still within the legal limit - which belies a possible medical emergency theory.

Investigators still are awaiting the pilot's autopsy and toxicology reports, some of which are being generated at the Federal Aviation Authority's medical flight center in Oklahoma and make take months.

A review of footage from two nearby security cameras earlier confirmed two sets of strobe warning lights on the radio tower were flashing properly before the crash, contrary to some witness reports.