Tuesday, November 1, 2011
Coordinating Rotorcraft Communication
Communication is one of the most important elements of helicopter flight ensuring navigation, traffic flow and safety. Technology is making it easier to connect with advancements such as 3D Audio on deck.
|3D Audio technology can take advantage of a pilot’s natural ability to distinguish directional sound and improve situational awareness via channel separation and directional information. Terma|
Effective communication is one of the most essential components of safe helicopter flight. Vital information is being transmitted in a helicopter cockpit, and it must be accurately understood and complied with.
Radio communication involves a very large group of sensors within the cockpit. There are tactical radios, radios to talk to air traffic control (ATC) and radios that help navigate the aircraft, GPS, VHF nav, distance measuring equipment (DME), automatic direction finder (ADF), Satcom telephones, radar altimeters and transponders, and weather radars or weather-receiving devices. All these systems must be coordinated and correctly work together in conjunction with the helicopter’s mission.
Scott Hovelsrud, product line director of radio at Cobham Aerospace Communications, explains that the key systems that “keep aircraft from running into each other” are the GPS receiver, transponder and any traffic collision avoidance system (TCAS) equipment, along with electronic flight instrument system (EFIS) displays. The transponder/TCAS systems alert the air traffic control and the pilots of impending issues. The power output of the transponder and the quality of the antenna installation is critical, he adds. GPS quality is critical in that new FAA procedures such as LPV approaches require higher levels of GPS units that meet TSO 145c WAAS Beta III qualifications.
Communication equipment helps pilots with weather issues. Weather advisories from ATC assist in avoiding convective weather and icing levels when operating IFR. Radio communications with company operations can provide specific, local weather advisories at a remote base such as a hospital helipad.
“While navigating around complex weather systems during critical missions, weather avoidance sans a controller’s vector guidance is often the only method a low-level rotorcraft pilot has to maintain safe clearance from weather,” says Hovelsrud. “When single-pilot operations dictate the normal cockpit crew compliment, the pilot is the navigator, communicator, pilot-in-command and crew mission specialist all in one.
With WSI or ADS-B weather products, the pilot can use this as a tool to avoid costly mission cancellations or delays while enhancing overall safety.”
The audio panel is the terminal point of activity, localizing all controls and amplifiers within the aircraft. It is “the nerve center of the total communication package,” says Mark Scheuer, founder and CEO of PS Engineering in Lenoir City, Tenn. “Every time the pilot and crew speak, transmit and navigate, they are using the audio panel system. The audio panel touches the radio transceivers, navigation systems, audio alert systems and even entertainment systems when installed in business helicopters,” he adds.
“That’s why the operation of the audio panel must not only be simple, but it should be easily scanned. With so many things interfaced to the audio panel, it is vital that the pilot can take a quick read of the panel to know what he is hearing, where he is transmitting, and the state of the intercom system.”
Jerry McCawley, pilot and flight safety engineer at Lockheed Martin, notes that the audio panel “allows a pilot to communicate on the desired radio and is very important in aircraft with multiple radios. They must be simple to operate and intuitive to use.”
|Vital information is being transmitted in a helicopter cockpit, and it must be accurately understood and complied with. Eurocopter Group|
In spite of its importance, sometimes helicopter cockpit communication can be hindered and even silenced altogether. “The low altitudes that helicopters typically operate [in] tend to limit line-of-sight radio communications,” says McCawley. “Satellite communication and data link flight following help solve the problem to a degree. There also are some cell phone apps that can help in-flight following since the phone is continuously broadcasting its location.”
The main problems, as PS Engineering sees it from the design and manufacturing standpoint, “are the noisy environment, and the demands for more and more capability and flexibility required in an already busy mission situation,” says Scheuer. “To solve the noise problem, we find a number of very good noise-canceling headsets for the listening end. On the speaking end, (there is) excellent microphone filtering and our IntelliVOX intercom handles loud cockpits easily for seamless crew conversations.”
One of the sources of helicopter communication breakdown is interference created by other onboard radios. “Due to the small helicopter dimensions the distance between the antennas is quite small,” says Jean-Michel Billig, executive vice president of engineering at Eurocopter Group. “Sometimes switchable attenuators for receiving radios are used during transmission of another radio. ESD [electro-static discharge] is another source of interference. Proper electrical bonding of all metallic helicopter parts and anti-static painting of the complete helicopter skin can minimize it.” A third problem for radio communication, he continues, “is the helicopter shape and the electromagnetic barriers created by the main gear box and the engine. The impact of the helicopter generating a ‘shadow’ cannot be minimized.”
Sometimes breakdowns are a result of pilot error. According to Greg Schmidt, business development manager at Cobham Commercial Systems, these can include:
• Communicating on the incorrect frequency.
• Switching frequencies without remembering the last frequency, in case the new one was incorrect or nobody is there. Using a second transceiver or standby frequency position as a matter of good airmanship can serve as a combative measure to prevent this problem.
• Turning the volume down to listen to something else and failing to return the volume to normal levels later.
• Communicating with upper antenna radios when lower antenna radios will work better in close quarters.
• Managing multi-comm frequencies back and forth with ATC frequencies. When the TFO is available an extra person monitoring the situational awareness is important to avoid such conflicts and situations.
In the event of a total radio failure, most helicopters have a second radio. “In case of a double radio failure the pilot can squawk code 7600: lost communication,” Billig says. “Only a complete loss of communication and navigation systems is considered catastrophic.”
|During training sessions in flight simulators, pilots should be required to respond to communications just as they would in an actual flight. FLYIT Simulators|