In the past, many search and rescue (SAR) agencies had an informal motto of ‘you have to go out, but you don’t have to come back’, and while this attitude undoubtedly produced dramatic rescues, it also cost lives. Today, safety programmes and risk assessment tools have greatly reduced the number of casualties among rescue crews. Nighttime, though, is one element that greatly increases risk during helicopter rescue missions; so much so that some aviation rescue agencies do not even perform missions during the hours of darkness. For those that do, policies and procedures have been deployed that minimise the risk to crews and victims.
Work, rest, repeat
“For organisations looking to begin night operations, there are several key decisions that must be made,” explained Brice Twombly with Priority1 Air Rescue.” The first is crew work time. A 24-hour shift is very tiring, even if there is time for crew rest. If they are flying missions during the day, night missions can be very fatiguing, while even if a crew works only at night, most people are not used to being up all night, so the issue of fatigue will still be present. So, working out how best to manage crew rest times for a 24-hour rescue helicopter operation is one of the first steps that must be taken. Are crews going to do 12-hour shifts or 24-hour shifts? How many days off will they get between shifts? If a crew gets fatigued, is there a procedure to relieve them with another crew? Do you have written policies and
procedures to address fatigue? These factors will determine the number of crewmembers each helicopter will need to complete night rescue missions safely.
The next factor is the helicopter itself. Is it set up with an appropriate light package? Is it equipped with an effective searchlight? If it is equipped with a forward looking infra-red (FLIR) system, can the searchlight be slaved to the FLIR so the light will point at where the FLIR is looking? Is there a light on the rescue hoist pointing down so that people on the hoist can be clearly seen as they come up to the cabin? Is there adequate lighting in the cabin for conducting rescues and treating patients that will not interfere with the pilot’s night vision?
The last major decision is whether or not to use night vision goggles (NVGs) for night rescues. If they are to be used, who on the crew will use them, and under what circumstances? Will they be used solely during the search phase, or during the actual rescue as well? While the use
of NVGs certainly makes night flying safer, the cost of installing compatible instrument, cockpit and cabin lighting must be taken into consideration. In addition, the cost of the NVGs and dedicated initial and recurring training programs must be factored into the budget.
Implementing the new system
The Sacramento Metropolitan fire district, located in central California, had been doing daytime hoist rescue missions for some time when the team decided to move forwards with nighttime operations. They decided to become a 24-hour operation in order to be available as a regional resource to all of northern California, where no night rescue helicopter assets were available.
“With the increase in extreme fire activity in northern California and no helicopter rescue resources that flew at night, we felt we had to do this,” explained Montie Vanlandingham, Chief Pilot for Sac Metro Fire. “We also took into account the risk of natural disasters such as earthquakes and floods in our decision to start night rescue operations. We fly with a crew of three – a pilot, hoist operator, and a rescue technician – on our UH-1H Huey helicopters. Both
the hoist operator and rescue technician are paramedics and a full kit of medical gear is carried at all times. Another aspect of the programme is a helicopter and crew will travel around California to the large fires to act as a dedicated 24-hour rescue ship for the firefighters on the line in remote areas.”
There are other equipment packages that can increase the safety and decrease the stress of rescue missions at night. One of these is four-axis autopilot. This allows the helicopter to hover automatically at a specific altitude using either a radar or barometric altimeter, or GPS. Sophisticated flight management systems can automatically fly the helicopter on preprogrammed search patterns, making searching at night much more accurate. These systems can also fly the helicopter to a designated spot and initiate a hover into the wind at a specified altitude.
“For the rescuer leaving the helicopter, a good headlamp is an essential piece of equipment,” stated Twombly. “This increases visibility for the rescuer, allows the victims to see the rescuer, and allows the crew in the helicopter to keep track of the rescuer on the ground or in the water. Obviously, good radio communications between the rescuer and the helicopter are important. Some radios designed for rescue work have a built-in GPS device for locating the rescuer if the helicopter has to leave the area without retrieving them.
Wireless intercoms are also very helpful since they can be used inside or outside of the helicopter.”
“On any rescue mission, crew communication and co-ordination is critical for safety,” said Twombly. “At night, this is even more crucial. The use of standardised checklists is essential. The completion of these checklists should slow down and take more time.”
With an increased emphasis on safety in the helicopter world, both civil and military, a standardised risk matrix should be used on every rescue mission
As an example, hazards and obstacles during the approach, in the rescue zone, and in the departure path need to be identified. This will take more time at night with reduced visibility. To do a proper reconnaissance will probably take more passes to get an accurate assessment of the rescue scene. The detail of the information exchanged going through the checklist should increase at night. Typically, at night, communication between the pilots and hoist operator will be more detailed and frequent due to poorer hover references for the pilots.
With an increased emphasis on safety in the helicopter world, both civil and military, a standardised risk matrix should be used on every rescue mission. Some will complete the matrix before they leave their base, while others will do it enroute to the rescue scene. Once on scene, the matrix needs to be revisited with the actual conditions found entered. Also, it must be understood that a certain level of risk will mean the mission cannot safely be accomplished at night or another rescue method or technique should be used.
Practise makes perfect
Priority1 Air Rescue has training centers in Arizona and France with simulators on which the entire crew fits, so they can train to work together. There is also an indoor tower equipped with a rescue hoist and a cabin that can be configured to simulate many different helicopters. With the lights off, it can simulate full darkness, and the crews can then use the different types of lighting, communication, NVGs, and rescue devices in a safe ‘night’ environment. In the final phases of training at the simulation centers, the crews will receive a mission, have to plan and brief it, do a risk assessment, and then perform the mission in the simulator and the hoist tower.
“I think simulation can really increase the effectiveness of night rescues,” explained Twombly. “If we can simulate those same conditions, it gives us more time to talk through and simulate extremes and emergencies in a safe environment. We can also simulate situations that would never be done on an actual flight due to the level of risk to the crew and aircraft. We can recreate high-stress situations in a safe way.”
The US Coast Guard is one of the world’s most experienced night helicopter rescue organisations. Over-water night hoist rescues are some of the most challenging and hazardous helicopter missions, according to AirMed&Rescue’s contacts. “You have to trust your instruments due to the decreased visibility and lack of hover references and loss of a horizon, particularly with poor weather at night,” explained Lt Sam Ingham, an HH-65 pilot stationed at Air Station San Francisco. “You can also lose little things like the shape and direction of the waves which help as references to movement.”
Having the right avionics for the job are essential. “We have a four-axis autopilot on the HH-65 that has several modes that can be used for hoist rescues,” said Lt Ingham. “The mode we use depends on the conditions at the scene. I would say we use the autopilot about 50 per cent of the time and the rest of the time we are in full manual mode, which is a bit easier to make fine position adjustments. If there are large waves, it is better to be manually flying the aircraft because the boat or person in the water is making large vertical movements which the autopilot cannot compensate for.”
Having the right avionics for the job are essential
And it’s not just the helicopter that needs the right avionics package; the rescuers also need the appropriate tools for the job. “The rescue swimmers use chemlights at night,” confirmed Sean Goodman, a rescue swimmer assigned to San Francisco. “There is a pocket on their vest specifically for holding chemlights. We also have one attached along the top of our swim mask. This allows the hoist operator to keep track of us, see how much the wind and waves are moving us around, and keep the proper amount of slack or tension in the hoist cable. The rescue swimmer’s helmet and sleeves have large reflective panels so the hoist operator can see hand signals. They also use different hand signals at night. As an example, a strobe light at night is the emergency pickup signal whereas during the day it is waving a hand over your head. Waving a chemlight in a certain pattern at night is used to signal the helicopter.”
“Crew communications become even more important at night,” stated Nicholas Moryl, a flight mechanic and hoist operator. “The pilots rely on the hoist operator more due to the loss of hover references and a visual horizon. The hoist operator does not use NVGs during a hoist due to the lack of depth perception and narrow field of view. We also throw out chemlights for the pilots to use as hover references. The rescue swimmers carry extra chemlights and can throw them around the scene to be used as references for the flight crew.”
A big factor for ocean rescue missions at night is weather. At night, the temperatures drop and clouds and fog are more likely to develop. At certain times of the year, you can have clear days with cloudy and/or foggy nights almost every day. These conditions can be very localised, so crews need to take these factors into consideration during the risk assessment and planning phases of every mission.
Check, check and check again
One of the key factors listed by all the agencies AirMed&Rescue spoke to was standardisation and the use of checklists. This removes doubt and leads to clear communications. Another key factor was continuous reevaluation of policies and procedures by outside personnel either from another unit within the same agency, or by another agency that have similar aircraft and types of missions. Night helicopter rescue missions will always have risk, but that risk can be mitigated with proper training, equipment and procedures.
All images (c) Barry Smith