Monday, May 20, 2013

Are They Sleeping Up There?

Yes. No. That would be illegal, dangerous, and stupid. We're reminded of one of the standard briefing items given by grizzled senior captains to all new copilots: "Don't let me wake up and catch you napping!"

The FARs (Federal Aviation Regulations) are somewhat ambiguous about this. While there are rules relating to the amount of rest needed before flight and the length of crew duty days, they don't specifically forbid napping on the job. However, in the spirit of most government regulations of this nature, if it doesn't specifically say you can do something, it's a sure bet that you can't. The FARs also provide a convenient catch-all regulation for dealing with any situation that is not specifically mentioned. That is the "careless and reckless" provision of Part 91 under which sleeping might be covered. And lastly, it should be generally expected by your employer that you stay awake on the job!

And yet, fatigue as it relates to aviation is a huge concern. Fatigue is now recognized as a physiological phenomenon rather than a moral failing. And the implications for flight safety are huge. Fatigue was cited as a factor the crash of Colgan Air Flight 3407 in February of 2009 though the NTSB declined to list it as a cause. While the primary cause of the crash was the captain's mishandling of the aircraft resulting in a stall, fatigue of both the captain and first officer likely exacerbated recognition and recovery of the stall. Indeed, the effects of fatigue are well known and can seriously degrade task performance and situational awareness. Studies have indicated that being awake for 24 hrs degrades performance as much as a .10% blood alcohol content. One poor night of sleep in the crash pad and your pilot may as well have a beer before coming to work.

As a result of the Colgan crash, Congress passed the Airline Safety and Federal Aviation Administration Extension Act of 2010. This law required the FAA to overhaul existing flight and duty time regulations, and also to require the establishment of a fatigue risk management plan at all commercial airlines. The new regulations, which will be implemented soon, include changes to duty hour limitations based upon when a pilot reports to work in an effort to respect circadian cycles. Fatigue is notoriously difficult to self diagnose and the new regulations acknowledge this. There's a lot to like in the new regulations, but as per normal when dealing with any political process, much mischief has also snuck into the law masquerading as safety improvements.

In any industry that is populated by older more mature companies, but also has younger, nimbler upstarts  unencumbered by legacy labor contracts, a proven strategy is to try to saddle the competition with the same burdens that exist in the older companies. Hence what one might see is an alliance between the established players, their labor unions, and ever willing government regulators to hamstring new entrants. And sure enough, that is in evidence in the new rest regulations. For instance, while the pilots of some low cost carriers may fly 80 or more hours in a month, pilots for the large network airlines fly 60 or fewer hours monthly. So rather than fight their own unions for increased work rules, the legacy airlines petition the government under the rubric of safety to make their competitors fly their pilots less thereby driving up costs. 80 flight hours at a six flight hour work day, which is not unreasonable, means about 14 days at work.

Overall, though, the new regulations should have a positive effect in lessening the exposure of the flying public to the dangers of fatigued pilots. One of the most beneficial methods of combating fatigue though, didn't make the final cut. And that is naps. It has been long recognized that a short nap can produce dramatic improvements in performance lasting up to several hours. Nasa has done extensive research into the science of naps for pilots and astronauts and has found that while there are drawbacks such as sleep inertia immediately following a nap, the benefits are palpable. The FAA however, citing a lack of data, has declined to regulate for controlled napping. This is probably one part science and two parts politics.

All the attention given to fatigue though comes down to a simple fact of life. Sometimes you just get tired and it may or may not have anything to do with how much sleep was achieved the night before. Having a bowl of your favorite chow mein followed by sitting on the sunny side of the plane in mid afternoon during a long cruise might just have you nodding off, and there's little to be done about it. So while certainly no napping in flight occurs, on occasion one pilot has been known to let the other take both the controls and radio in order to do some enhanced overhead panel study, or perhaps to check the eyelids for leaks. All in the name of safety, of course.

Friday, May 10, 2013

Do Phones Really Interfere With the Instruments?

When it comes to your phone and other electronics interfering with aircraft electronics and instruments, the short answer is maybe. Does this make them dangerous to use during takeoff and landing? Probably not. Are flight attendants, who are charged with enforcing this rule under pain of discipline from their employers, and fines from the FAA, a little overbearing at times? Sure. Wouldn't you be if the usual folks to push it are the frequent fliers who know better, and are the same ones who try to explain to you why it's a stupid rule? Does the persistence of this rule really have more to do with bureaucratic inertia and ineptitude on the parts of both the FAA and FCC than with any real or imagined danger? Absolutely.

A little background: Electronics on airplanes or avionics, have traditionally been used for communications and navigation. Any radio is susceptible to interference from another nearby radio due to bleed over. Owners of ham radios are well acquainted with complaints from neighbors who can hear their transmissions over their TVs and radios. The noise you hear on your AM radio when you drive under a power line is the same thing, as your radio is picking up the RF (radio frequency) energy from the line. For this reason, the RTCA (Radio Technical Commission for Aeronautics) which advises the FCC,  first recommended a ban on inflight electronics in 1961. 

Fast forward to today and the situation is only more complicated. While the avionics of yore were strictly analog and consisted of just radios, virtually everything on a modern airliner is controlled by digital electronics. This includes even the flight controls and engines. Aircraft manufacturers have replaced throttle and flight control cables with digital controls to reduce weight and to improve control of aircraft systems. When you look up front in the cockpit and see those large throttles, they're not physically connected to the engines at all, but simply relay signals to a computer which then electronically commands fuel valves in the engine to control thrust. All Airbus and soon all Boeing aircraft will have completely electronic flight controls, which means there is no physical connection between the cockpit and the wings. Some 737 aircraft which have been retrofitted with cargo fire warning systems actually transmit their own data to the cockpit by radio. Rewiring the aircraft was considered too cost prohibitive. Clearly, we don't want to interfere with those things.

On the other side of the interference ledger, consumer electronics have been revolutionized by digital electronics as well. While old "bag" analog cell phones might have transmitted with as much as 3 watts, modern digital phones are typically well under 1 watt and can be as low as 20 mW. They even self regulate their power output depending on the signal quality they receive. This is why leaving a phone on accidentally in flight will quickly drain the's searching for a signal at maximum power. Standard WiFi signals are also in the range of several hundred milliwatts. Most personal electronic devices (PEDs) are types of computers and while they may emit only tiny amounts of RF radiation, they are operating in the same frequency range as the computers on the aircraft. Of special concern here is the GPS signal upon which the aircraft depends for navigation. GPS satellites are in high earth orbit and their signals are quite weak, and might be blocked by closer transmitters that are bleeding over. 

The end result of the melange of electronics on board an airliner is a cacophony of potentially competing signals from a radio spectrum point of view. We remember from our military days catching a ride in the back of an electronic reconnaissance (spy) plane. The pilot explained that because the electronics in back were so sophisticated and temperamental, no updates could be made to the cockpit without extensive testing and RF deconfliction. The same principle more or less still applies, but it is nigh well impossible to test and catalog the many thousands of different types of consumer electronics being brought on board and hence the general ban during takeoff and landing. Another potential problem is devices which are misbehaving electronically due to perhaps being dropped or broken.

The entire question then simply rests on risk mitigation or "do you feel lucky today, punk?". Well, do ya? A charter flight which crashed in 2003 in New Zealand killing eight, is usually cited as one that is thought to implicate a cell phone. The pilot's own phone was connected during the last few minutes. Whether the aircraft's electronics themselves were compromised is unclear. Overall, though, while the potential is certainly present, trying to determine whether any one anomaly noticed up front was caused by a cell phone in back is close to impossible without extensive instrumentation and controlled conditions. 

While we routinely observe momentary anomalies in aircraft performance, interference in radio communications, and systems that just don't do what they're expected to do, there's no way to tell exactly why these things happen. Most are considered just annoyances, such as a bit of static on the radio, and don't impact operations at all. There are so many redundancies in systems and procedures, that only a truly major disruption in electronics would compromise safety, which we've never experienced nor heard of. Many airlines are even issuing their pilots iPads and other computers for use as approach charts and flight data computers to further reduce the weight of carrying flight book bags. These devices are required to be used during all phases of flight to include takeoff and landing.

So here is where the bureaucratic risk avoidance mechanism kicks in. Even though these devices are probably safe to use during takeoff or landing, no government bureaucrat is going to risk his job and government pension to sign off on lifting the ban...without the proper motivation. And as per usual, when dealing with a circle-the-wagons turf protecting agency such as the FAA, that motivation will come from political pressure. And sure enough, the hue and cry for relief on the use of PEDs in flight has become so great that this past August, the FAA announced the formation of an industry working group to address the issue. After that, rules will have to be written, comment periods observed, and maybe then some relief will appear. But, until such time as a consensus can be reached that both assures safety and gives the regulators some political cover should anything ever really go wrong, we'll all just have to carry along a real paper crossword puzzle for the time between pushback and ten thousand feet.