Technology has intruded into nearly every aspect of our lives. It has changed the way we shop, communicate, travel, research and work. It has streamlined preflight planning and integrated many flight tasks resulting in greater efficiency and fewer errors. It has improved the safety record of aviation but has also introduced new challenges for pilots.
Several years ago, I decided to put my economics degree to use and began writing market analyses for a financial publication. One of the sectors that I focused on was telecommunications. A new era had dawned in an industry that had predominantly considered physical property its primary asset. Phone and cable lines were tangible goods that historically defined the reach of the phone companies. The new normal (established by the proliferation of cellular devices) produced a mad scramble to own the airwaves. Wavelength spectrum was suddenly a trillion-dollar business. Two auctions last year drew over $100 billion of bidding for radio frequencies. It was just the latest of many such spectacular sales.
In the history of humanity, no other good or service is as uniformly in demand as cellular is today. Regardless of income level, profession, nationality or ideology, nearly everyone has a mobile device and a plan to go with it. Every single one of us taps the capacity of cellular wavelength in order to consume content. As data demands have morphed from the light touch of Blackberry email into the heavy load of video streaming, the industry has been forced to expand its allocation of spectrum in order to satisfy hungry customers.
The benign history of the cellular spectrum has suddenly become an important subject matter around airports. More than ever a pilot needs to understand the physical properties of these (now) billion-dollar wavelengths. Every time you tune a VOR (or a radio), you are changing the length of the radio wave that the unit receives (measured from peak to peak). Long wavelengths transmit less information per second than shorter wavelengths (this has become an important consideration for cellular providers). The most practical demonstration of wavelength capability is the scratchy and hollow audio you receive from AM radio compared to the crisper sound produced by FM. The upshot of low-fidelity long-wave is range. Cruising at FL280 at night, you can use an ADF to tune an AM radio station from Albuquerque while over Montana. Over the middle of the Pacific, the quality of the audio is going to be lousy (HF utilizes a longer, scratchier wavelength), but it is nonetheless available.
In the early era of cellular services, relatively long wavelengths reigned supreme. Pricey cellular towers could cover a large area of customers who were hardly consuming any data. Early cell phones were essentially walkie-talkies connected to traditional phone services via cellular towers. Flash forward a couple of decades and the device in your pocket is a mini computer more capable than the million-dollar mainframes which got us to the moon. The breathtaking advance in electronic capability has rapidly increased the thirst for faster download speeds. Millimeter wavelengths suddenly became worth billions. Before all of this happened, there was quite a bit of elbow room around the short wavelength. Radio altimeters had a nice little monopoly.
With cellular customers in the billions worldwide, there are two limitations to data speeds. The first is that only so much total data can be transmitted over the range of spectrum available to cellular providers. The second is that interference between cellular towers determines how many customers will have to share a spectrum in a certain location. Here is where short wavelength technology produces a neat trick. Not only can more data be transmitted per second, but the limited range of the millimeter spectrum also means that fewer consumers are fighting for data per cell tower. And this is how aviation and telecommunications finally managed to butt heads.
5G spectrum is now the shortest wavelength being offered to cellular customers. It represented $81 billion worth of purchases by cellular providers in the auction last year. Corporations do not drop that sort of mint to sit on an asset. As such, 5G is being rapidly deployed by cellular providers worldwide. The spectrum closely abuts the wavelength that radio altimeters use. The separation is tight enough that the FAA became concerned (somewhat at the last minute) that 5G cellular towers would induce false radio altimeter readings in aircraft. If you have flown much over the past few months, you have undoubtedly come across NOTAMs limiting the use of certain ILS procedures as a result of the still uncertain potential for 5G to corrupt aircraft systems.
This has mostly created a headache for approaches that determine minimums via the radio altimeter (such as CAT II and III). But on many aircraft the radio altimeter is utilized by other systems as well. Enhanced Ground Proximity Warning Systems (EGPWS) routinely utilize the radio altimeter to trigger terrain and wind-shear alerts. In some aircraft, gear and flap warnings also require a functioning radio altimeter. Traffic Collision Avoidance Systems (TCAS) can be impacted as well. Many of the devices aboard technologically advanced aircraft are now compromised to an unknown degree by frequency sharing with 5G. In bygone eras, aviation safety would have taken precedence around airports. Yet when it comes to cellular services, the pure force of hundreds of billions in spectrum auctions has placed the supremacy of aviation behind that of 5G deployment.
Procedural Dilemma
Threat and error management (TEM) combined with a forward-looking briefing is a good technique for pilots to utilize during a flight. An airport with a 5G NOTAM indicates a location where radio altimeters may be compromised (if your aircraft does not have a radar altimeter, the presence of 5G interference is largely inconsequential). In an aircraft equipped with radio altimeters, spurious terrain alerts may be encountered. Windshear detection may not be
available either. If there is any question regarding terrain clearance (or windshear), apply the appropriate recovery procedure (in most cases this involves disconnecting the autopilot, applying maximum power and pitching for an appropriate airspeed). Traffic alerts may be inhibited by a malfunctioning radio altimeter as well. See and avoid has become nearly an afterthought in the modern world of aviation. It may be a good time to brush up on some old skills.
The 5G dilemma is a microcosm of technological complacency. The rapid advance of technology has undoubtedly increased efficiency and safety, yet it has also produced hidden dangers. For better than a decade, the NTSB and FAA have been concerned about trends indicating technological dependency among pilots. One example of this is the fact that visual approaches in sophisticated aircraft have suddenly caused logjams in flight training. I have seen more than one applicant become captivated by a desire to “drive the autopilot” towards the runway. It can be easy to forget how much more responsive an aircraft is when managed through the old school of stick-and-rudder. If you ever want to butch up a visual approach, try guiding the servos to the touchdown zone through heading and vertical speed. It is an imprecise technique at best.
Humans are not very good at spontaneously adapting to an unexpected threat. Training helps to improve responses, but it can take a great deal of time for a pilot to react when startled by an unforeseen event. Technology improves safety margins when it is forward-looking, but response times vary significantly depending upon whether the pilot is aware of a threat or surprised by it. Studies have shown that alerts given within 5 seconds of encountering a risk are essentially worthless. It almost always takes a pilot longer to respond to a sudden event. Indeed, it took Sullenberger 30 seconds to fully react to his dual engine failure in 2009. I’ve done the “Miracle on the Hudson” scenario in a simulator. When you have an idea that it is coming, it is easy to make the turn back to LaGuardia for a safe landing. With a heavy dose of surprise, it is nearly impossible. It is difficult to overemphasize the advantage of anticipating a threat versus reacting to one. Forethought is central to a safe flight. If anyone hits a flock of geese over the East River again, you can bet that they will be much quicker to make a turn towards an airport. A whole generation of multi-engine pilots has been exposed to the possibility of a dual-engine failure. Forethought is the supreme weapon against surprise. Technology can either assist or hinder that effort. The difference depends on the relationship that a pilot has with their gizmos.
EGPWS, for one, has done yeoman’s work at separating metal from mountain predominantly due to the fact that it is a forward-looking device. Alerts are programmed to annunciate as much as a full minute before a potential collision will occur. EGPWS has produced a terrific track record at reducing (indeed nearly eliminating) controlled flight into terrain. Still, it is a technology that is most effective when utilized as a backup to the more traditional method of “read the chart and visualize the flight path.” EGPWS alerts are terrific safety elements for those moments when a pilot becomes disoriented in IMC or at night. Yet the safety record is filled with examples of pilots responding inappropriately (or not at all) to EGPWS alerts. As helpful as EGPWS is, it was never intended to replace airmanship. Every approach to a new runway should be preceded by a briefing. Every approach briefing should include any specific threats associated with the airport or runway. Terrain and obstacles, where they exist, always represent a threat (this information is included on approach plates for a reason). The advent of moving maps makes conceptualizing terrain a much easier task, but pilots were getting the job done well before the proliferation of the iPad. Spatial awareness and reading the charts are tried and true. When you are aware of terrain around an airport, you will be much more likely to respond appropriately in the event you receive an alert. If you form a mental image of the anticipated flight path over the terrain you will be encountering, you will all but eliminate the possibility of an adverse event. If you form the habit of pretending you do not have the device, it will mean nothing if it gets jammed by 5G interference (or merely breaks).
Technology has intruded into nearly every aspect of our lives. It has changed the way we shop, communicate, travel, research and work. It has streamlined preflight planning and integrated many flight tasks resulting in greater efficiency and fewer errors. It has improved the safety record of aviation but has also introduced new challenges for pilots. An interesting dichotomy with modern aircraft is the ability for automation to not only reduce workload, but potentially damage situational awareness. In the multi-crew environment (some years ago), a decision was made to stop referring to the second pilot as “non-flying” and instead as “pilot monitoring.” It is better to emphasize what a pilot is doing opposed to what they are not doing. Underlying this was an accident record where non-flying pilots failed to either notice or verbalize an emerging threat. With automation and technology, we can fall into a familiar trap. The electronics are controlling the aircraft and keeping us safe; we are simply along for the ride. Not only is it rewarding to occasionally ignore the electronics and go old-school, it also increases our situational awareness and facilitates safe operating practices. Trepidation at removing layers of automation is normal, but on a calm VFR day it provides an opportunity to refresh skills. If you fly long enough, you will eventually stumble onto an occasion where you will be glad to be fresh on some old-school techniques.
