Should cockpit trump cabin?
Connectivity capacity is focused on the cabin over the cockpit but should passenger enjoyment come before pilot performance? Yves Le Marquand reports
Should cockpit trump cabin?
Connectivity capacity is focused on the cabin over the cockpit but should passenger enjoyment come before pilot performance? Yves Le Marquand reports
DEMAND FOR for in-flight connectivity has taken on a new frequency over the past decade.
Once a luxury, access to the data-dependent world many of us live in today is a prerequisite on almost every flight. This explosion in demand has been reflected in the increase of aircraft equipped with satellite-based Wi-Fi services and products ready to harness those connections. Plus, you’re reading a guide to it (and we’re on our second edition).
Those products, however, have been largely focused on the cabin and therefore the passenger experience. Credible arguments can be made as to why cabin connectivity is critical to operations such as customer satisfaction and its impact on business health. But the only connectivity truly critical to safe operations is in the cockpit, right? So have cockpit’s requirements for connectivity been overshadowed? Has the rise in demand from the cabin impacted the cockpit? What is the trade-off?
Separate systems
Most business aircraft do not have a combined cockpit and cabin connectivity system, according to Josh Wheeler, senior director, Cybersecurity & Entry into Service at Gogo. There are, however, exceptions including Dassault’s Falcon 900LX and Falcon 8X. But cabin connectivity is available for the pilots using various range extenders which connect with the principal cabin router to extend the range of the Wi-Fi distribution through the aircraft.
“This is particularly useful on larger cabin, long-range aircraft that may be carrying more passengers. This extra bandwidth can be used for filing flight plans or even Synthetic ForeFlight [a hazard awareness capability for iPad],” says Wheeler.
He says Gogo estimates a split of about 90% for the cabin and 10% for the flight deck in terms of bandwidth. “Pilots are increasingly using connectivity now that data plans have become unlimited or customers are choosing higher packages. Pilots enjoy the live updating of ForeFlight and other situational alerts around weather, terrain changes and the like.”
A technician fits a connectivity system in the tail of a business aircraft.
A technician fits a connectivity system in the tail of a business aircraft.
Who needs what?
Connectivity requirements differ depending on the mission requirement. Charter operators and customers prefer connectivity that supports productivity and entertainment. This requires large amounts of data, which is invariably consumed in a rather short period of time and often over multiple devices, to be delivered to the aircraft cabin. This is where the GEO and LEO constellations are maximised, says Wheeler.
Up front, cockpit services will always be a standard very high frequency (VHF) and satellite communication combination to manage the threat of failover. The increased speed capability for all operators mentioned will have varying impacts depending on individual needs. The biggest difference is demonstrated by special missions and reconnaissance operations, where high-speed connectivity will need to be secure and reliable.
Wheeler explains: “This used to be L-band only, but most have also moved forward with Ka/Ku band to optimise connectivity solutions in terms of delivering real-time video feeds and communication in communication-critical environments such as search and rescue, military theatres, surveillance, commercial activities where aviation complements industry such as in mining, oil and gas, fishing and freight.”
However, this still remains separate to the flight deck safety systems.
Latency up front
Cockpit communication systems are classified as safety services. Both LEO and GEO satellites provide latency levels that are sufficient for certified voice and data safety applications, with round-trip latencies of 40–70ms and 600–800ms respectively.
Chris Bigwood, connectivity sales manager at Honeywell Aerospace, explains: “The difference in latency between GEO and LEO systems is not operationally significant. Both Iridium (LEO) and Viasat (GEO) safety service providers operate at the same design and certification level.”
L-band is used in the cockpit because it is more reliable than Ka-band which delivers much of the connectivity bandwidth to the aircraft cabin. Ka-band’s waveform struggles to penetrate clouds and rainfall, which is an inconvenience if you’re streaming Netflix but critical to life if talking to other aircraft in the area.
“This is an aspect of physics that none of us can change,” Wheeler explains. “The wavelength won’t allow Ka-band to replace L-band due to conditions such as weather interference. Realistically, this will not change due to a lack of reliability. Since Ka-band is highly susceptible to atmospheric conditions causing line-of-sight issues, it will be difficult for it to be considered an option for safety services.”
Ku-band is also widely used for passenger connectivity and offers somewhat better weather resilience than Ka-band, but like Ka it does not match the reliability of L-band.
Reliability and redundancy over multiple networks are a requirement for all aircraft flight decks to ensure consistent safety, he continues. “The cabin connectivity is not an inherent element of the aircraft safety management; enhanced productivity, entertainment and relaxation are much more targeted at the enhanced passenger experience not the safety of the airframe.”
Connecting personal electronic devices has become a must-have in the aircraft cabin.
RF interference concerns
Regulators and manufacturers are continually focused on potential radio frequency (RF) interference concerns between cockpit avionics and passenger devices using cabin Wi-Fi.
These organisations constantly test and audit based on the onboarding of new cabin connectivity systems. With the introduction of smaller mini antennas, which can be placed in the flight deck, there is some concern about the potential for the RF frequency to be interrupted, says Wheeler.
The FAA has also issued guidelines on the usage of personal electronic devices (PED) in aircraft. Plus, any antenna introduced into the flight deck must comply with FAA regulations and it is the responsibility of the pilot or operator to establish compliance.
Investment in the cockpit vs the cabin
Cockpit connectivity remains locked in with what options the plane has, there are very few “upgrades” that can be done, says Wheeler.
NextGen mandates are driving upgrades and changes to the existing technology and these are inherently designed around safety, he explains. Investment is often mandatory to meet these requirements, such as the development of Automatic Dependent Surveillance – Broadcast, better known as ADS-B.
“Cabin connectivity is more than an amenity (which is a nice-to-have), it has become a crucial component for the office-in-the-sky and at-home digital experience that owners and executives have come to expect.” It is well documented that when a connectivity system is down it is now considered AOG by most, he adds.
Looking ahead, even if cockpit systems and pilots themselves begin to make use of Ka-band connectivity on a more regular basis, the safety-critical nature of flight means the cockpit will keep its L-band connection because its reliability always comes first for regulators and operators alike.
