Wednesday, November 1, 2006
Search and Rescue: HOIST OR HOVER LOAD? YOU DECIDE
Understanding flight options and answering key safety questions can make the difference in rescue ops.
ALL CATEGORIES OF HELICOPTER OPERATIONS ALLOW for pilot discretion on how best to complete the mission. But what happens when a helicopter aircrew has two viable and safe flight options for a rescue mission?
Each helicopter rescue is different, even if it occurs over and over at the same location. Safety is paramount to success of the mission. The U.S. Forest Service is chartered with administering aviation safety protocols and training for a variety of government and private helicopter operators. It defines safety as "transforming the severity and likelihood of risk, which is inherent in all human activity, to lower, acceptable levels."
Cliff rescues are a perfect example of a mission that often requires the use of helicopters for support and or technical rescue by air. Let's face it. Cliff rescues fall on the high side of a risk continuum. Lowering the risk of mishap is everyone's responsibility.
Understanding the flight options and asking oneself a few key safety questions can make the difference. Many helicopter safety programs use Socratic questions as prompts for rescue decision-making. Important in all decision trees are two basic questions: Is there a safer way to complete the rescue? Is the perceived urgency I feel as a pilot the same as the realistic urgency determined by others?
Remember, nearly all flight techniques have alternative maneuvers that we can use when facing tough helicopter rescues on cliffs or steep terrain. They include short haul (ropes), hoisting, hover loads (toe in, one skid), and skids down.
|Ventura County, Calif. Sheriff's hoist-equipted Bell 212HP on the job. The lost hikers were on a remote cliff with a 500-ft exposure, and camouflaged by the terrain and vegitation.|
|Pilot-in-command Ken Williams(top,right) and Fire Capt. Fred Burris (top,left) monitored the mission as the author, as rescue specialist, helped position the aircraft, then exited to brief the hikers and keep them at a safe distance from the approaching helicopter (middle and bottom).|
This popular area is known for its spectacular sandstone and volcanic cliffs. After a lengthy search, our pilot in command, Ken Williams, located the lost hikers, who were isolated on a remote cliff with a 500-ft exposure. During mission debrief, we discussed the safety aspects. Our helicopter crew talked about a variety of issues regarding the rescue. A main one was the fact that the victims were so camouflaged by the natural terrain that we must have flown over them three or four times during the search phase. In addition, we collectively determined (Williams and the three rescue specialists) in less than 2 min after we located the victims to complete the rescue as a hover load versus hoist evolution. We later completed a pinnacle hover load of the stranded hikers.
But why a hover load? Would a hoist have been an acceptable option? The luxury of the pilot in command and rescue crew having the ability to pick any of the appropriate technical-rescue maneuvers immediately lowered the risk and artificial sense of urgency that can often develop.
Risk and urgency! Jim Hall, former chairman of the U.S. National Transportation Safety Board, was often called upon as a pundit of helicopter safety. In a speech at Heli-Expo in 1997, he discussed the rescue helicopter's unique capabilities and emphasized to pilots that "helicopter operations-so susceptible to pressures to push the limits of the envelope-should, in fact, always incorporate a large margin of safety."
Our cliff rescue was no different. There was almost no intercom chatter as we made our typical clockwise recon pattern around the victims. During the assessment passes, each crewmember had a different function. The tasks were divided by rescue specialty as the crewmembers intensely evaluated their responsibilities.
The pilot in command was busy flying, gauging winds, escape routes, power and performance issues. The hoist operator, Glenn Grossman, and paramedic Chris Rosa were methodically assessing the location of the victims, visual signs of casualties, and terrain factors. Through my position on the hoist side of the open deck, I established visual communications with the victims and gave them the universal "extended right-hand closed fist" that most victims understand as, "Stay put."
One by one, each of us gave an intercom synopsis of our concerns and planned course of action.We quickly developed a verbal Incident Action Plan, complete with communications failure procedures specific to the incident. The pilot asked the final rescue question:
"What do you guys think, hoist or hover load?" Like a three-man choir, the response came back. "Hover load."
Short haul is most commonly used when a hoist is not available or when a hoisted dynamic load (victims) during a swiftwater rescue may create a center-of-gravity issue between the hoist and the helicopter.
In our case, a skids-down maneuver was out of the question. Surely a tail strike would have occurred. The Mediterranean climate of the Santa Monica Mountains covers the rugged mountains with dense, impenetrable brush and trees.
There was no need to short haul our victims and we knew that there was not a c.g. issue with a potential hoist evolution. Our two best options were then focused on a hover load or hoist scenario.
Hoisting is common both in military and public rescue operations. We complete about 450 hoist evolutions a year, rescuing more than 70 stranded and injured citizens. Hover loads account for about 20 percent of all our technical rescues.
After our safety power check, we decided to that I, as the rescue specialist, would hover-jump the cliff on a pinnacle separating the helicopter from the victims by about 100 ft of nearly impenetrable chaparral. The reason for the safety separation between copter and victims was based on crew experience. We had all seen victims try to self-rescue at the very last minute. We wanted to avoid that scenario.
Typically, in latent self-rescue, unattended victims will try to jump on a skid while the pilot is still maneuvering into position. During the final approach into a hover maneuver, crewmembers are focused on tail- and main-rotor clearance. In our case, hovering on their pinnacle would have led them into a sense of security and they might have prematurely climbed out on the cliff face and fallen 500 ft to their deaths.
The hover jump went smoothly. Using my portable radio, I contacted the 212 crew. They were maintaining the helicopter in a 500-ft agl pattern for safety, observation and noise abatement. The aerial crew used their recon pattern to direct me from the pinnacle to the victims through the dense brush. The four victims were uninjured.
Our urgency continuum was then lowered dramatically. Time was now on our side. As rehearsed in training time and time again, I gave the group a safety briefing. Remember, the briefing is required and makes sense.
You have an obligation to reduce the risk factors. Our victims were located, uninjured and stable. The first victim was assisted through the brush, navigating steep cliff faces. The other victims were kept back at the isolated pinnacle, a safe distance from the arête used for the hover load. Keeping those young victims isolated from the hover zone ensured their safety had a total mishap occurred.
I gave the first victim a final safety and "expectation" briefing just prior to our final approach to the helicopter. Skid management and assistance by both me and the hoist operator was paramount to avoid a mishap while the victim stepped on the skid. I always remember my training officer telling me to have the victims visualize that they are walking barefoot on glass when they step onto a hovering skid. That pearl of rescue wisdom has worked well in quickly educating victims in hundreds of rescues. Once again, it worked this time.
All four victims were flown to awaiting National Park Service rescue personnel and another safe mission was completed. Remember to always balance your sense of mission urgency and risk with that of actual conditions.