Comments about technological history, system fractures, and human resilience from James R. Chiles, the author of Inviting Disaster: Lessons from the Edge of Technology (HarperBusiness 2001; paperback 2002) and The God Machine: From Boomerangs to Black Hawks, the Story of the Helicopter (Random House, 2007, paperback 2008)

Monday, November 15, 2010

High-Rise Fires and Helicopter Rescue

A fire that engulfed a 28-story apartment in the Jing'an District of Shanghai early today appears under control, but 42 people died and over one hundred were injured. 

Initial reports indicate that some residents made it onto the roof and three helicopter crews were orbiting in hopes they could pull people off, but few if any people made it off the roof in helos due to smoke that blocked the way.

After 9/11, the mere mention of helicopter roof-rescue brought down criticism from the Fire Department of New York (FDNY), which under operating rules put into effect after the 1993 WTC bombing (and controversial use of helicopters there) would have to approve and supervise such any such effort by the NYPD's aviation unit.

Does it ever work? Yes, sometimes. Rescue helicopters have participated at more than two dozen high-rise rescues worldwide since 1963. Each of these rescues was unique, and most proceeded under difficult circumstances. Not all went as intended, but helicopters did pluck 1,200 people from roofs, ledges, and balconies.

Two of the earliest and most spectacular fires with elements of helo rescue happened in downtown Sao Paulo, Brazil, in 1972 and 1974. The first to burn was the 330-foot-high Andraus Building, a concrete-framed structure that held offices and a department store. The fire began in a pile of combustibles stored near the fourth floor and went up via the exterior walls, touching off furnishings with heat radiated through the windows as it climbed. Crowds gathered on the street, blocking fire apparatus, to watch. At its peak the wall of flame was 350 feet high, burning with the fury of an oil well fire. 

Three hundred occupants climbed the stairs to the rooftop heliport (coincidentally, the first of many heliports built in Sao Paulo, today the world's most helicopter-friendly city). But after they reached comparative safety, someone in that group went back and blocked the steel door from opening, apparently fearing that those already on the roof would run out of foot room.

Problem: there were two hundred more occupants still in the stairwell, and they jammed against the obstruction. Whether or not those below could be called in a state of “panic” (a subject for another post) they were very upset and pushed hard. They couldn't imagine why a flow up the stairs had stopped all of a sudden.
Help was on the way. A helicopter with firefighters approached, then banked away when the crowd charged it. But the helicopter came back and hovered out of reach to drop off firefighters, who quickly took control of the crowd. This allowed helicopters to land safely. 

Here's my point: The helicopters’ biggest contribution toward survival at the world-class disaster at Andraus that day was not getting people off the roof, but getting firefighters to the roof so they could break open the stairwell door. This action certainly prevented many dozens of people on the stairs from being crushed or asphyxiated by the upward pressure. As it was, some in the stairwell had broken bones or lay unconscious from smoke inhalation when help arrived. Survival was a very close thing. 

In the end sixteen people died at Andraus, but the toll would have been much higher had the rooftop doorway remained blocked.

Sao Paulo suffered another skyscraper fire two years later, at the Joelma Building, and helicopters also fluttered to that scene. But the rooftop area available to helicopters was so small, and the fire and smoke so intense, that 90 people died before the aircraft could move in. Some survivors told investigators afterward that they had remembered how helicopters had lifted people off the Andraus roof two years earlier and said that this memory persuaded them to go up the stairs instead of down, because they assumed a similar rescue would be possible. Such false hopes are one reason why the FDNY has been, and remains, very skeptical about relying on helicopters to pull people off high rises.

High-rise emergencies continued worldwide after the twin fires at Sao Paulo, each offering unique lessons in high-angle rescue. A 1980 fire at the 26-story MGM Grand Hotel in Las Vegas prompted the biggest gathering of helicopters at any high-rise emergency, before or since. Here's the NFPA write-up. Police helicopter pilots were the first to see the smoke and sent out a radio alert. Thirty public and private helicopters mobilized to move 300 people from the roof. 

Coincidentally and remarkably, Air Force rescue helicopters and crews were close at hand, having staged at nearby Nellis Air Force Base for an exercise. Fearing that the roof deck was about to catch fire, the pilots organized their ships into a racetrack pattern: approaching from the east side, picking up hotel guests on the roof, departing on the west, then dropping people off in a parking lot. Some who waved for help were on balconies well below the roof level, which ordinarily seem to be out of reach for helicopters; but rescues proceeded even at that difficult location after a flight engineer lowered himself on a “jungle penetrator” seat at the end of a cable, and tossed a rope to those on the balconies. The hotel guests then pulled the engineer to their balcony and, one by one, joined the engineer on the rescue seat. One volunteer pilot was Mel Larson, then a vice president at Circus Circus Casino and owner of a helicopter charter service. I interviewed him later.

It was not orderly,” Larson told me about his first view of the roof, where people were trying to grab hold of the landing skids as helicopters departed. “It was panicky. We had to have police to get control. ” At one point a police officer drew his gun to make his point. Eighty-four people died at the MGM Grand, but none of the fatalities happened on the roof. (For years afterward, and at his suggestion, the management of Circus Circus cached evacuation equipment on the roof in case of such an emergency.)

One solution to unruly crowds and smoke obscuring the roof, it seemed to fire chiefs at the time, was to keep the rescue helicopter high above fire and smoke where pilots might lose their orientation, sustain aircraft damage from the heat plumes, or suffer loss of power. And rescue pilots have assured me that power loss -- even flame-outs -- due to oxygen starvation has happened. 

McDonnell Douglas took the fire chiefs' suggestions and created a sort of steerable, aerial lifeboat to be hung from a line under a helicopter. It was called the Suspended Maneuvering System. The SMS was a device of amazing abilities but was never put into regular use. A subject for a later post.

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