For legacy fleets, the choice is not so simple and depends on many factors, including remaining useful life, cost of installation, an airline’s business model and expectations of future technology.
For previously unequipped aircraft, Wi-Fi connectivity for passengers requires several components, explains Frederik van Essen, vice president of Aviation Strategy at Inmarsat.
There is the antenna, generally but not always mounted about two-thirds the distance toward the aircraft tail. There are three “little boxes,” or line replaceable units to be installed in the avionics bay: one for steering the antenna, one for controlling transmissions and one, like a modem, for coding and decoding signals. Then wires must connect these boxes to the antenna and to wireless access points on the aircraft ceiling.
To minimise additional downtime costs, complete Wi-Fi retrofits are generally done during heavy checks. But if an aircraft already has the basic system installed and needs only a new antenna, this can be a much shorter job.
That is important because van Essen expects much more efficient flat panel antennae will be available by 2019. This new technology will at least double and possibly much more than double the Wi-Fi speeds possible from a given network, a big consideration in providing ample, high-quality and economic service.
But regulators must first test these antennae to ensure they cannot fall off, be ingested by an engine, damage a tail or otherwise endanger the aircraft.
Even when that is done, the Inmarsat acknowledges that installing anything on the surface of a jet can be a major job, requiring drilling of holes.
But he hopes the new antennae will fit on ARINC mounting systems that have been standardized to make swapping out different antennae very easy. Inmarsat is designing its own flat-panel antennae to meet the ARINC mounting standards.