All ground personnel, for example, can hear the flight deck on an open mic. But to minimize confusing crosstalk, only the driver can talk directly to the flight deck.
The pilot can also be heard. “We purposefully gave the pilot priority over everyone else to ensure the flight deck could be heard at all times,” Broadley says.
Overall, the system gives the pushback driver the chance to better manage his team during pushback.
“It’s often the case that individual members of the ground crew just focus on their own individual tasks,” Broadley adds. “A driver might be so focused on that towbar, for example, that he doesn’t see the wing walker’s signals. This way everyone can hear and be heard and that really helps make these individuals operate like a real team.”
After the pushback, the driver removes the ComHub from the aircraft (the bag also has a long, red flag that says “REMOVE BEFORE FLIGHT”) and displays it to the flight deck. However, a safety backup built into the system alerts the pilot if the bag remains on the plane.
One key to the Flightcom system is in the choice of technology to hear and speak without the wire. A wireless system transmits voices largely in one of two ways – either by incorporating DECT (Digitally Enhanced Cordless Telecommunications) or Bluetooth.
“The first forays with wireless systems on the ramp used Bluetooth technology,” Broadley explains.
But there are drawbacks to Bluetooth.
“Bluetooth is meant for close communications,” he adds, “typically about 300 feet.”
Bluetooth transmissions are also subject to interference from other communication devices – especially those operating on the 2.4 GHz or 5 GHz frequencies – and can even be blocked by physical barriers – something there’s quite a lot of on the ramp.
DECT, on the other hand, can offer better coverage than Bluetooth. The range of transmission can extend to 1,600 feet. The Flightcom system also uses DECT 6.0 and is less subject to interference in the 30 MHz to 1.8 GHz frequencies. What’s more, DECT can bounce its signal up, over and around objects to establish the best connection.
Flightcom’s wireless system is also full-duplex – meaning it allows communication in both directions simultaneously. Full-duplex capability is important for ground support communication since it lets all personnel speak and hear others at the same time, much like a telephone.
Half-duplex systems, such as walkie-talkies, allow communication in both directions, too – but only one direction at a time. If one person is transmitting, all other transmissions are blocked until the first transmission is over.
While the wireless headsets can be viewed as merely a better way to communicate on the ramp, Flightcom’s equipment also provides excellent hearing protection. OSHA regulations require hearing protection when the time-weighted average noise level exceeds 85 decibels.
A Noise Reduction Rating is a measurement that’s also in decibels. Simply subtract the NRR from the average noise level, and users can tell how much hearing protection they’ll get. Flightcom headsets are rated at 26 decibels. So, if noise levels on the ramp work out to 71 decibels, then the headsets cut that noise down to 45 decibels. By comparison, a normal conversation at three feet measures 65 decibels.
And lest we forget to emphasize this point, the Flightcom executives we interviewed reiterated that there’s more than one way wireless equipment can be considered “wireless.” Some wireless headsets, for example, may still require a wire to a radio or a belt pack. In addition, the transmission range for such devices aren’t likely to be as robust compared to the Flightcom system.
“Wires are a real sore spot with airlines since they are always breaking,” Broadley says.
Walsh adds that it’s a question of “when not if,” wired headsets will need to be repaired. He says the repair issue really gets the airlines’ attention when they look at their overall repair costs for wired headsets, whether they’re used for pushback or deicing.
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