June 18, 2013
When a gain on one side requires a loss on the other, we call that a zero-sum game, and in aviation, that’s frequently what happens in the name of increasing capacity. Many people simply assume we’ll go faster and farther, carry more and cost less – because that’s the way it’s always been. But if you look closely at the aviation world, you find areas where capacity grows only by cramming more things of smaller size into the same space.
Most notoriously, that’s the way the game is played with airline seats. Seat “pitch” is the term the industry uses for the space between rows of seats, another way of defining legroom, albeit indirectly. It’s changing all the time, but the typical pitch in economy is now about 31 inches, down from 34 or more, with Spirit Airlines coming in at a shin-scraping 29 inches. Spirit, not so coincidentally, is the discount carrier that pioneered the idea of non-reclining seats. Meanwhile, all airlines will tell you that seat padding has gotten thinner, but hasn’t sacrificed any comfort because of modern cushioning materials, hence the closer spacing between rows.
Asian airlines tend to really cram people in, perhaps because the average person there is not as bulky as the rotund Westerners with their trendy obesity. Passengers gripe constantly about seat pitch, especially on long flights, but the only way for really large people — tall or wide — to find comfort is to buy it. If you dig deep into your wallet, and pay for business class and higher, the knee room goes up by as much as a foot. The seats not only recline, they’re wider and — again for a price — lie flat like a bed for long-distance flights.
Another area that’s feeling the squeeze is radio communications, and, in particular, the air band, which spans frequencies from 108 to 137 MHz. The radio spectrum is like real estate — they’re not making any more of it. In the beginning, voice communication radios had 70 channels spaced 200 kHz apart from 118 to 132 MHz, with the lower bands from 108 up to just below 118 dedicated to navigation channels. As voice traffic grew, they split the channels in half, with 100 kHz between them. In the 1950s, they did it again, down to 50 kHz, and then, as the industry boomed in the 1970s, to 25 kHz, providing 720 channels. Now the Europeans have taken to splitting each channel into three parts, with 8.33 kHz spacing. Some radios in the U.S. offer that option as well, mostly for use at high altitude. This splitting and re-splitting has been a boon for the people who make the radios, because they’ve had successive waves of obsolescence to drive buyers. It gets a little bit more expensive to improve the selectivity of a radio so that the receiver can accept only the frequency it’s tuned to, but channel splitting has been the only way to increase capacity in the air band since day one.
Now a lot of voice communication is expected to be replaced by digital text messages, which should eliminate errors and the problems of congestion that typify a busy push period at a major terminal when everybody is trying to talk at once. (You can hear the radio chatter during crazy hour at JFK here).
The ultimate scarce commodity in the aviation business is airspace, although the fact that it’s three-dimensional makes air traffic density a different problem from highway congestion. The choke points show up near major airports, and not so much in the en route airspace. All those arriving flights have to funnel into a runway or two, which means air traffic controllers have to work at sequencing the arrivals so they have enough space between them to allow for no-panic landings and their wakes don’t toss around the following aircraft. Very large aircraft attach the word “heavy” to their call signs as a reminder to Air Traffic Control that they require a larger trailing interval.
Until recently, human skill and experience provided the ideal interval between aircraft, but now computers and ultra-precision navigation promise to narrow that interval to, perhaps, the limits imposed by trailing wakes. In other words, airplanes will arrive in sequences and at intervals that are much closer than they are now. Will that alone eliminate delays in arrivals and departures? No. Only the construction of more runways near the busiest cities can do that. London is struggling with the problem right now, and may end up locating new runways far from downtown.
Capacity comes dear. And it’s wise to remember that when we gain something, something else usually has to give.
May 3, 2013
In the U.S. we have a federal Highway Trust Fund that takes money collected from fuel taxes and uses it for road improvements. And people are pretty comfortable with that. Every time you fill up with gas, 18.3 cents per gallon (or 24.4 cents for diesel) goes into the fund. Once the trust fund began to accumulate serious money, the temptation to raid it for other agendas became irresistible, so now it pays for mass transit and other stuff that doesn’t have anything to do with roads and bridges.
Partly because there are more highway drivers than users of the nation’s airspace, nobody’s objecting so far to a move by government to very quietly steal money from the Airport and Airway Trust Fund to pay for air traffic controllers’ salaries and avoid furloughs brought on by the recent sequester of federal funds. In fact, the relief at the fact that furloughs are being cancelled seems to have completely fogged the vision of those who would ordinarily be most alert to this kind of money grab.
The AATF is supposed to pay for improvements to airports and airways, to make both safer. The original intention of legislators was to create a mechanism to pay for needed improvements in such areas as navigation aids and airports. A ticket tax, fuel tax, and other excise taxes would provide for greater revenues as usage rose. For years, government officials looking for ways to patch over budget shortfalls have tried to tap the fund to pay for operations, which was not the intent of the law.
But furloughs and flight delays, regardless of the arguments over whether they are necessary or justified, have one clear result: they inconvenience people. Principles tend to go out the window when people can’t get where they want, when they want to get there. And these days, a short-term Band-Aid often looks better to politicians than a long-term solution that requires negotiation and compromise.
March 29, 2013
They are exceptionally durable machines, built of aluminum or, increasingly, composites. When properly maintained, they can provide decades of service. Commercial aircraft operated by airlines can last for hundreds of thousands of hours. Your car may give you 10 years, but after that it’s time to recycle it or ship it to Cuba.
Even the smallest airframes serve as reusable containers for new engines and electronics, upgrading as each new wave of technology washes over the stubborn structure. Wooden aircraft can rot, and aluminum can corrode, but both forms of decay can be kept at bay by care and maintenance. If that doesn’t work, there’s restoration and refurbishment. A Beech Bonanza, to cite one popular general-aviation airplane that typically is used heavily by its owners, will need an engine overhaul roughly every 2,000 hours. A smart owner will divide the dollar cost of an overhaul by 2,000 and salt away that many dollars in the bank for each hour flown as an “engine reserve” to pay for a new or zero-time engine when the inevitable replacement day draws nigh.
The virtuous durability of airframes became a vice when product liability lawsuits took off during the 1970s and ’80s. Manufacturers suddenly woke up to the fact that every long-lasting airplane represented long-term exposure to corporate liability in the event of a malfunction. After a long struggle, airplane makers were able to secure passage of the General Aviation Revitalization Act of 1994, which limited their liability to personal aircraft not more than 18 years old.
Although engines need regular attention, avionics are the best deal in the world. An owner can add them piecemeal or just yank out the whole instrument panel and replace it with technology such as that offered by Aspen Avionics: That company makes “glass cockpit” displays and systems that fit right in the old holes where the steam gauges used to sit, and it’s the very latest technology at an affordable price. Instant new airplane. And you don’t have to buy a new operating system every three years.
At small airports across the country, airplanes are handed down from one generation to another, not just as heirlooms but as real, live working modes of transportation. We’ve all complained about the programmed obsolescence of our cars, our appliances, our computers. Here’s one possession designed to last.
March 27, 2013
On March 22, an FAA press release announced the agency’s decision to close 149 control towers following the cutoff of funding more commonly known as “sequestration.” Outgoing transportation secretary Ray LaHood said the selection of towers for closing — all of them operating under contract — involved “tough decisions.” But in the aftermath of the announcement, there’s been little information about what effect the closings will have on flight operations.
Airports that have operating towers are designated as “controlled” fields. Those without towers are, simply, “uncontrolled fields.” Typically these are small rural airports, but they range in size from a single runway to former military bases with miles of paving.
FAA employees staff most airports that serve airlines and the traveling public, and those will remain open, although some may close at night when traffic tends to decline. The towers targeted for closing are staffed by non-federal controllers who work for private companies under contract to the FAA. In some cases, airports or local governments fund all or part of such a tower’s operation, and these towers too should be relatively unaffected.
How much of an effect will the closures have? Pilots of all stripes already follow established procedures for flying into uncontrolled fields. These procedures are spelled out in the Aeronautical Information Manual (formerly the Airman’s Information Manual) and are usually learned in the first few days of flight training, when the student pilot practices pattern flying and landings. If a tower is closed, inbound pilots would still tune in the tower frequency, transmit their position and intention to land, then follow that with continuing updates of position in the landing pattern; example: “States Air 43 is downwind for runway two-two, Metro Regional [Airport].”
At uncontrolled fields, pilots use a designated frequency — commonly called “Unicom” — to transmit advisories and monitor other nearby flights. An FAA spokesperson confirms that these established procedures will continue unchanged if the tower closures proceed with the first phase on April 7; the third and final phase is in May. Many airports are equipped with automatic weather monitoring and repeating transmissions that give pilots current conditions, and some also allow a pilot to illuminate the runway lights by keying the radio mike a set number of times.
Flight service facilities known as fixed base operators at some small airports voluntarily monitor Unicom and may even reply to incoming pilots with information about other aircraft known to be in the area. There are no plans to expand this service to actually control a field with a closed tower, however, probably due to questions about liability.
To sum up, the traveling public and operators of general aviation aircraft should notice little impact if the closures take effect. Pilots value the additional level of safety that tower controllers provide, but most will exercise additional caution and make good use of their radios.
March 5, 2013
Engineers who work in aviation learn to be risk averse. Change tends to happen slowly, through evolution rather than sudden breakthroughs. When a new idea comes along, it’s usually tested for years before being introduced to the fleet, and even then it usually debuts with the military—they have ejection seats, after all. Some engine components are tried out in ground-based turbines for electrical power plants before working their way into aircraft engines, a practice GE says it pursued for its latest engines.
One maxim of jet engine design is that higher power comes at a cost of greater heat. Unfortunately, heat melts metal. So anyone who can make an engine run hotter and still survive will be able to tweak more thrust out of the same amount of fuel. People have been working at the problem for years.
Early in the game, engineers tried alloys that could survive the 2,000+-degree-Fahrenheit gas that meets the first set of turbine blades. But the gas, coming straight from the combustor, put such stress on the turbines that they only lasted tens of hours. The metal would soften to a point where the rapidly spinning blades elongated, and their tips began to rub against the tip seals on the engine’s outer wall.
By combining metals such as nickel, chromium and even more exotic elements from the periodic table, engines could be made to run hotter and survive. Later, the blades were made from crystals grown in such a way that the metal’s grain aligned with the centrifugal force, lending greater strength. Another improvement was cooling the blades with tiny passages that carried cold air to the leading edge, using air from the engine’s compressor to supply the cooling flow. That stole some power from the compressor, but the investment paid off in higher combustion temperatures and improved power and efficiency.
Research into the use of ceramics in the engine’s hot section began decades ago, starting with ceramic coatings on combustors and parts of the turbine section. A NASA technical memorandum (89868) dated May 1987, authored by Gerald Knip, Jr. at NASA’s Lewis Research Center in Cleveland, Ohio, describes “revolutionary materials” applied to subsonic jet engines. It describes ceramic composites that overcome the typical brittle quality of ceramics by using reinforcing fibers in much the same way that carbon fiber reinforces modern composites.
GE and the Air Force are now going all in with advanced ceramics, which are incorporated into a research engine called ADVENT for ADaptive Versatile ENgine Technology. In tests, the engine is reported to have run hotter than any engine ever built. Ceramic matrix composites, or “CMCs,” made from silicon carbide matrix and fibers, make it possible for the engine to tolerate gas temperatures of 2,400 degrees and achieve a reported gain in fuel efficiency of 25 percent. With fuel prices so high, that kind of progress, following decades of materials research, couldn’t come at a better time.
February 11, 2013
The nattering nabobs in our nation’s capital are buzzing with speculation that National Transportation Safety Board chairman Deborah Hersman is at the top of the list to replace retiring Department of Transportation secretary Ray LaHood. Excellent choice, if it happens and Hersman accepts.
Some parting thanks to LaHood: He ran the department with professionalism and aplomb during a period of change. FAA Administrator Randy Babbitt was forced to resign only a couple of years into his watch following an arrest on charges that were later dropped. A career transportation and government exec, Mike Huerta, replaced Babbitt. LaHood was one of two Republicans in the Obama cabinet (the other was Defense chief Robert Gates), and whether the cross-party factor gets credit or not, his tenure was pretty seamless despite all the turmoil in many parts of the government during that time. Like all government agencies, the DOT is plagued by uncertainty about funding and budgets, which has had some effect on the implementation of the next generation of air traffic management.
When Hersman first took over the chair at the NTSB, she was a media dervish, which can sometimes be a red flag based on past examples. But the Virginia Tech grad (full disclosure: my daughter is a Hokie) and former Capitol Hill staffer (for West Virginia Democratic Senator Jay Rockefeller) soon made it pretty clear that her penchant for frequent public utterances was a matter of principle more than style: One never had to wonder for very long about what was going on at the Board. Besides the increased transparency, she convened hearings in Washington to involve the appropriate communities when safety issues arose, and her oversight of the recent Boeing 787 lithium battery issue has been tough but fair.
What’s different about her is that she seems to grasp the public appeal of her most startling credentials: a commercial drivers license with an air-brake endorsement and a motorcycle operator’s license. If push ever came to shove, she could always find work in the cab of a tour bus, and the bikers can’t say she doesn’t know their world if there’s some safety advice they don’t like. But what’s most interesting about that aspect of her CV is the fact that both spheres, buses and motorcycling, demand operator smarts and are highly visible to the public in terms of highway safety issues. That she chose to dive in and participate in both heavy vehicles and cycling says she leavens intellectual curiosity with a touch of fearlessness.
No, she’s not a pilot, although in a recent interview with AOPA Pilot editor Thomas Haines, she said she’ll pursue that when she has time. That may not be soon.
January 23, 2013
The Boeing’s 787′s problems with onboard lithium-ion batteries led to the FAA’s decision to ground the fleet. That’s hardly surprising. But some erroneous information has found its way into public forums concerning the nature of these high-tech but somewhat touchy batteries.
To begin with, the kind of battery used on the 787 is rechargeable, which makes it different from the small lithium batteries sold in AA sizes at the hardware store. Those get used up and thrown away. The 787′s rechargeables also are different from the lead-acid batteries commonly used to provide start power for automobiles. About 20 years ago, it was common to add water to lead-acid batteries when the quantity of electrolyte, a dilution of sulfuric acid, dropped too low. Today the batteries are sealed and vented.
Lithium undergoes a spontaneous chemical reaction in the presence of water, which is one reason water is not a component in its electrolyte. The electrolyte is not an acid, nor is it corrosive. The liquid used in lithium-ion batteries is made up of organic chemicals — more specifically, hydrocarbons. The greatest risk, therefore, is that the electrolyte might ignite and burn; despite some news stories to the contrary, corrosion is not a concern.
The battery also relies on an ultra-thin plastic membrane perforated by tiny openings to allow ion migration between the positive and negative poles. Maintaining battery integrity relies heavily on the precision manufacture of that component and others, as well as on the quality of materials used in fabrication. One potential weakness of lithium-ion batteries is a kind of thermal runaway in which voltages get too high and create high temperatures in one cell, which can break down and affect adjacent cells, causing a destructive cascade.
The current investigation appears to be narrowing to the manufacture of the batteries and of the battery charging systems that control rate of charge, and thereby ensure safe operation. Meanwhile, because Airbus reportedly plans to use lithium-ion batteries on its new A350 family of airliners, it is following developments closely.
January 15, 2013
The people who manage airline companies are torn between two opposing ideas, both driven by cost concerns: having the very latest technologies in their aircraft, on the one hand, and sticking with the time-tested and proven on the other. If you don’t think airlines are a capital-heavy industry, just take a look at what’s parked on the ramp at any terminal airport. Even at a smaller regional airport, the airplanes and hardware have a total value in the millions. And that’s where the cost concerns come from. It takes a steady stream of revenue from passenger and freight operations to service the debt on all that stuff.
When fares were regulated, the numbers were stable and predictable, but deregulation arrived in 1978. Before that, airlines marketed mainly on their images as reliable or glamorous — or even hip (Braniff’s “the end of the plain plane”). With competition, the only marketing tool an airline had was the price of a ticket, and fares fell. Throughout the 80s, 90s — and even into the new century — major airline companies collapsed by the dozens, leaving merged giants that dominated in certain regions to survive.
Price competition will inevitably drive cost cutting, and airlines have turned to the suppliers of their aircraft for help. The manufacturers have to attack not the list price of the aircraft but the life-cycle cost of the airplane’s operation, which will total many times its purchase price by the time it is retired from service.
So when Boeing’s 787 Dreamliner makes headlines because of an equipment bay fire, as it has recently, it should hardly be surprising. In order to produce an airplane that would save its customers on the order of 20 percent in cost of operation, the company had to turn to completely new technologies in materials, propulsion and electronics. When you promise that kind of savings to a customer, you do one thing: you reduce the airplane’s weight. Which helps to explain why the 787 has a completely new type of battery that uses lithium instead of lead and acid or nickel-cadmium in an electrochemical closed system that produces a direct-current voltage. The battery is lighter, and it’s the same type that invaded the laptop computer market for the same reason — and occasionally with the same result: Sony made some laptop batteries back in 2006 that overheated and had to be recalled. There’s little difference between what happened to some unlucky laptops and what occurred in the battery of a 787 parked at Boston.
Airlines and their suppliers expect some birthing problems when any new type enters service. If there are new technologies aboard, those problems are almost guaranteed. The Boeing 747 had new large-fan engines, and after some time in service, their internal housings distorted from perfect circles to ovals, causing catastrophic wear. For a time, Pan Am’s global fleet carried spare engines in pods that were added near the fuselages of the jumbos. The airborne “pool” of replacements minimized the schedule delays when an airliner went out of service.
The introduction of so many new technologies at once in the 787 is almost unprecedented, and prospective passengers can take comfort in the fact that the problems have everyone’s attention. After all, these changes have the ultimate goal of keeping the price of a ticket low.
November 26, 2012
With the heightened political sensitivities during the presidential campaign season, it was fairly predictable that an invitation from Boeing to some of its suppliers to attend a workshop on aerospace manufacturing in Mexico would set off a rhubarb among the various stakeholders. Boeing is not affiliated with either U.S. political party, and the invite had no partisan implications.
But Boeing is a political hot button in itself, and both political parties know that. What voters need to know is that there has been low-level aerospace manufacturing in Mexico for a long time, and placing work there is no different than the offsets in other countries, where Boeing has spread its 787 program, in particular, all over the map. It does this for competitive reasons, and so does Airbus. By sharing the work with customer nations, Boeing “offsets” some of the cost to its customers when they buy its airplanes. Japan has been a loyal Boeing customer since World War II, and its heavy industries build the wings, the center wing box and parts of the fuselage for the 787, while its airlines, Japan Air Lines and All Nippon, were the first to order the airplane and put it into service, with the first JAL flight from Tokyo to Boston last April.
Mexico is a part of the North American Free Trade Agreement, and has been manufacturing parts for U.S. automobiles as well as assembling VWs (and soon, Audis) along with Isuzus for domestic consumption.
Cessna Aircraft, a division of Textron, operates a facility in Chihuahua that makes sheet metal assemblies and wire harnesses for Citation jets. MD Helicopters, owned by Patriarch Partners, a New York holding company, uses parts made by another Patriarch company in Mexico.
Boeing has a long history of testy labor relations, and the unions that represent some of its workers are strident in opposing any work share that’s not performed by their members. But the heavy final-assembly work at Boeing is, has been, will be located in the United States for some time to come.
November 13, 2012
There was a time when a trip of more than 300 miles had you reaching for the Official Airline Guide (remember those?) for the winged alternative to driving, but times have changed. The high fares and the hassle of airline travel have conspired to move more folks onto the roads and out of the airways.
How do I know this? I don’t. But I drive a lot in my travels, and I see a lot of license plates from faraway places. I’ve also noticed that traffic moves along at about 75 to 80 mph on roads that are posted for speeds that would have had my mom screaming for my father to slow down. And it’s amazing how fast you cover ground on the Interstates.
Having been through the air-travel crunch one too many times, including nights on airport floors when they cancel flights and there are no hotel vouchers (or hotel rooms), I’m now an inveterate driver.
Look at the advantages of driving: You get to take along as much as your car can hold — and there’s no additional fee. You can even pack a nice lunch to savor at a rest stop along the highway. Instead of high anxiety and stress during security check-ins, you’re cocooned in a capsule served by a high-end stereo and all your favorite music. If you’re like me, you look at what you’ve saved in air fares and spend it instead on an overnight stop at a hotel (I’m partial to Hampton Inns and their free breakfast). And you get to see the country–which is absolutely beautiful–close up.
Mind you, if I absolutely, positively had to be there for something on the West Coast, I’d swallow hard and buy a ticket, but a trip of 1,000 miles on the road is no longer out of the question.
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