One of the keys to a successful rescue mission is constant clear communications among the entire crew. Unfortunately, once crewmembers leave the aircraft, that constant stream of information available via the intercom is lost. Several manufacturers offer wireless intercom systems (WIS) that allow that information exchange to continue when the crew is separated from the aircraft.

Identify the tool for the job

When looking to purchase a WIS, potential users need to do their homework to determine which system best meets their needs and budget. For commercial helicopter operators who only perform rescue missions on an occasional basis, the expense of a WIS might be prohibitive. The same could be true for HEMS operators, who could effectively use handheld radios for communication outside their helicopter.

There are two basic kinds of wireless intercom systems. One is fully integrated into the aircraft’s communication system, with a hard-wired base station that allows the WIS to access any of the selected radio channels on the communications panel. The other is a carry-on version. The carry-on system just plugs into an existing intercom jack and the aircraft’s intercom system thinks it is just another headset. Global-Sys offers a portable base station that can be plugged into any intercom port and gain access to the other radio channels on the communications panel.

Many of the features of WIS were first developed for the military. One of their important requirements was that the system be encrypted so unauthorized personnel cannot hear what is being said. This is becoming an important feature for law enforcement agencies as well, many of whom are switching over to encrypted communications for all of their radio systems, both ground and air-based.

Options for wireless comms systems abound

Axnes Inc., offers GPS location coordinates of the remote operator about every 10 seconds for situational awareness back to the aircraft. These coordinates can be relayed to a moving map system to give the physical location of the crew members. The location can also be relayed to the aircraft’s searchlight and camera/forward looking infrared (FLIR) unit so it can automatically point at the crewman on the ground or in the water.  So, the WIS has the ability to be much more than an intercom.

The range of the devices varies by manufacturer, but can be anywhere from 100 to 200m to several kilometers. It depends of the height of the aircraft, the local terrain, and where the external antenna, if one is used, is located on the helicopter.

Axnes offers a dual-band capability on the device worn by the crewmember. One is the radio that communicates with the helicopters and the other is a marine band radio. This would be used by rescue swimmers to communicate with the crew of a ship to which they are being hoisted. So, the rescuer is hoisted down to the deck of a ship, unhooks from the cable, and can then communicate with the ship’s crew on the bridge to find out where the victim is located, their condition, etc. without having to meet face to face. This can be very important when dealing with some of the larger ships, which may be 200m to 300m in length. With a dual-band system like this, if two or more rescuers are working on the same ship, they could all switch from the intercom system to the marine frequency to talk with each other from different locations on the ship to coordinate the rescue mission.

Integrated WIS enables new possibilities

With a WIS that is integrated into the helicopter’s communication panel with a base station, a medical crewmember who is outside the helicopter on the scene could talk to a hospital to get medical advice, treatment authorizations, or update the hospital on the patient’s condition even before the patient is loaded into the aircraft. The medical crew can also talk to each other if they are separated on the ground. They can come up with a patient care plan and prepare the equipment in the aircraft for what the patient needs.

Another advantage to these systems is that aircraft warning announcements are also heard by everyone using the WIS, whether they are inside or outside the aircraft. This keeps the entire crew apprised of aircraft emergencies as soon as they happen. As an example, a crewman being hoisted down to a ship with a tag line heard an engine warning announcement over the WIS and immediately released the tag line, allowing the helicopter to fly away quickly and safely.

Being waterproof isn’t enough

“There are several considerations that must be taken into account for positional information if the device is used in a water environment,” explained Steve Mickels, the SAR and EMS manager for Axnes. “Just being waterproof is not enough. Most of the time, the rescuer will wear the WIS device on their chest. In the water, it would remain underwater most of the time and therefore not transmit reliably to the aircraft. So, we recommend that it be worn higher up on the body, like on the shoulder, to keep it out of the water as much as possible for reliable transmission. This is especially important if the rescuer becomes unconscious or disabled in the water. It is also important that all the components, not just the WIS is waterproof. The radio connectors and plugs as well as headsets need to be made for water use as well.”

One of the challenges in helicopter rescue and emergency medical services is communicating with the patient/victim. Often, the rescuer has to remove their helmet or pull aside one ear pad to try to hear the patient. Some helicopters carry an extra headset and try to put that on the patient, but that is sometimes not possible or practical. Axnes’ product has built-in microphones so the rescuer can ask a question of the patient and then hear their response through the WIS. In this mode, the conversation does not go through the intercom and distract or interfere with communication among the rest of the crew. It is only between the patient and that crewmember.

Crew coordination key to safe rescues

“We decided to go with a wireless system because we were beginning to transition into night hoist rescue operations and felt it was critical to have a solid crew communication system,” stated Captain Bryce Mitchell, a Pilot with the Sacramento, California, Metropolitan Fire District.

“At night, the decreased visual cues make it imperative that you have excellent crew coordination and communication to keep operations safe.

“Using a WIS has changed our operating procedures to a certain extent. Before, when we were not using a WIS, it was just the pilot and the hoist operator talking to each other during a hoist evolution. Now, the pilot, hoist operator, and the rescuer on the hoist cable are able to talk to each other.” There is a learning curve on how to get the best out of the WIS, he added: “We have to make sure that only one person is responsible for locating the aircraft over the target. There is the chance for crewmembers to talk over each other and create confusion for the pilot.

It takes a disciplined crew to take advantage of the WIS. Per our standard operating procedures, if the WIS is not operable on the aircraft, it is not used for hoist rescue missions. It is that important to us.”

Mitchell pointed out that multitasking is essential for the rescuer to perform their job effectively: “Once the rescuer is on the ground and unhooks from the cable, the first two minutes after that is when we gather the information we need to continue the mission planning. The WIS allows the rescuer to do patient care and set up for the extraction while talking to the helicopter at the same time.”

Audio clarity enhanced by wired system

When the cabin crew is in the helicopter and expected to stay inside, such as when they’re on the way to the hospital after picking up a patient, they unplug from the WIS and plug into the wired intercom system. They have found the clarity of the audio is much better with a hard-wired intercom system.

“We use two different wireless systems in our helicopters," explained Captain Jeff Seabrook of the Ventura County, California, Fire Department. “We use the Jupiter Avionics wiJAC in our older Bell 205/212 variants. We now use the Axnes for the two Sikorsky Firehawks we have recently put in service. We went with Axnes due to them being waterproof and having a longer range than the wiJAC. We have been able to stay connected to the crewmembers on the ground longer and at greater range with the Axnes. In addition, we like the built-in GPS location of the Axnes that allows our crewmembers on the ground to be located on our moving map display. We believe that this feature will be very valuable for ocean rescues, where it can be difficult to visually keep track of a rescue swimmer in the water, especially in breaking waves or at night.”

Identifying why the wiJAC was chosen, Seabrook told AirMed&Rescue: “An advantage for the wiJAC is the lower cost of acquisition and they can easily be transferred from one aircraft to another. All you have to do is plug it into an available intercom port. Our Axnes system has a base station that is mounted in the ship and is integrated into the communications system of the helicopter. So, it is not transferable from one aircraft to another.”

A wireless intercom system is not needed for every helicopter that flies SAR or HEMS operations. However, for operators that perform hoist rescue missions, especially at night, a WIS can increase crew communication, awareness, and coordination to make high-risk missions safer to accomplish.