Drones? Meh.

drones

They go by many names: UAVs, drones, remotely piloted vehicles. Whatever you call ‘em, more and more of the aviation news these days seems to focus on this segment of the industry. Blogs and podcasts exclusively dedicated to UAVs have been popping up left and right, and there’s certainly no shortage of enthusiasts and businesses waiting to put these advanced flying machines to work. Or play.

It’s easy to understand the excitement. These drones are small, relatively inexpensive, easy to fly, and — thus far, at least — free from certification hassles and other regulatory burdens. They require no conventional fuel, maintenance, or infrastructure, yet can carry high-definition cameras and other payloads while exploring areas at low-altitude that even a helicopter would be hard-pressed to get to. They can loiter with less noise and disturbance than a rotorcraft, too. In short, they represent a fresh canvas for the operator’s creativity.

New models and capabilities spawn almost continuously from the designers of these micro-aircraft. It’s something those of us in the traditional aviation sectors wish we could lay claim to. I imagine the early days of the 20th century must have felt quite similar to aviation’s pioneers. The future looked limitless. “Just Do It” could have been aviation’s slogan; if you could dream it, you could build and fly it. Today? Not so much. The regulations and paperwork weigh as much as the pilot flying the darn airplane. If they aren’t, you’re probably not “airworthy”.

Drones, on the other hand? From delivering cold beer or your Amazon order to keeping humans out of harms way while fighting fires, collecting intelligence, capturing exciting video footage, and engaging in national defense, they hold the promise of improved safety and convenience for all. It’s hard not to be impressed by displays like this:

But (you knew there had to be a “but”, didn’t you?) at the end of the day, it doesn’t matter. Every time I see a video, article, or link about drones, my response is “Eh. Who cares?”. I’ll probably offend some folks by saying this, but there’s something about these autonomous devices that turns my blood cold. It’s not that I hate them. I just don’t care about them.

When I think about flying, drones never enter the picture. In fact, I don’t consider operating a drone to be “flying” at all. In my mind, it’s on par with falconry, paper airplanes, kites, and sailboarding. That’s not to say it’s bad; on the contrary, some drone operators look like they’re having the time of their lives and there’s nothing wrong with that. I hold no animosity toward those who view drones and UAVs as the most exciting thing since the integrated circuit. But while there are aviation elements present, it’s not flying in the way I know and love it.

For one thing, the operator/pilot has a much different experience and perspective on flying. There’s no skin in the game when the worst that can happen is the loss of the drone. Operators are solidly anchored to terra firma, looking up at their craft the same way men have looked skyward at the birds since the dawn of time. That awe-inspiring ability to literally transport yourself and others across time and space? Gone.

There’s no physical connection to the flight controls or the invisible fluid through which the craft sails, no seat-of-the-pants experience. And how much satisfaction can you get from a smooth landing when the craft does all the heavy lifting through gyro-stabilization and computer technology? I guess I feel about drones the way some sailboat owners feel about engine-driven boats.

Perhaps the thing I see most lacking in the proliferation of drones is the sense of pride that comes from operating within any community of highly-trained professionals. Pilots definitely fall into that category. On the other hand, it’s difficult to see random individuals who happen to purchase a remote-controlled flying device as belonging to that same cadre. Especially when a typical story reads like this:

After saying “the FAA has got to be responsive to the entire industry,” [FAA UAS office chief] Jim Williams referred to a pair of incidents in which drones caused injuries to people on the ground. One came at an event at Virginia Motor Speedway in which an “unauthorized, unmanned aircraft” crashed into the stands, and in the other a female triathlete in Australia had to get stitches after being struck by a small drone.

Then, Williams segued to a pilot’s recent report of “a near midair collision” with a drone near the airport in Tallahassee, Florida. The pilot said that it appeared to be small, camouflaged, “remotely piloted” and about 2,300 feet up in the air at the time of the incident.

“The pilot said that the UAS was so close to his jet that he was sure he had collided with it,” Williams said.

Or this one:

UAV Causes Medical Helicopter Landing Delay

The landing of a CareFlight helicopter approaching Miami Valley hospital in Dayton, OH was delayed by a small UAV flying in the area, according to the company.

Television station WDTN reports that a CareFlight nurse aboard the helo was the first to spot the small aircraft flying in the vicinity of the hospital. The helicopter reportedly had a “significantly hurt” patient on board at the time.

The company notified both local police and hospital authorities in an effort to find the person operating the UAV before allowing the helicopter to proceed with its approach. The operator was taking aerial photos of a park in the Montgomery County Fairgrounds, which is near the hospital.

By all accounts, heavier-than-air flight had a definite Wild West quality about it in the early days, too. I’ll freely admit that it’s easy to paint with a wide brush where UAV antics are concerned, so maybe I’m simply being closed-minded about drones. Or more accurately, drone operators. But I feel the way I feel about it. I suppose that’s one thing drones and traditional aircraft pilots have in common: they both develop a reputation — deserved or not — based on the media’s incessant bleat of any sensational or negative news.

I’m curious to know if others have a similar reaction to the burgeoning unmanned aircraft industry. What’re your thoughts?

Back to the (Supersonic) Future

Spike Aerospace S-512

Despite wars — both hot and cold — abroad and social upheaval at home, the 1960s must have been an incredible time for those in and around the aerospace industry.

Over the course of a single decade, the United States went from being unable to reliably launch a rocket (nearly half of the twenty-nine attempts in 1960 were failures) to putting men on the moon and bringing them back to Earth in one piece. In the realm of atmospheric flight, the 1960s saw the development and construction of the first supersonic passenger aircraft, the stratospheric cruising and futuristic-looking Concorde.

That was a half-century ago. I wonder, who could have predicted that the year 2014 would see the U.S. unable to launch a man into space on its own? Or that Concorde would be a dusty museum piece replaced by aircraft which lack the speed, altitude, and glamor of that legendary delta-winged craft? Anyone prescient enough to make that call would have been laughed out of the room. By 2014 we were going to be colonizing Mars!

While the march of computer technology has certainly eclipsed anything we could have dreamed of in the 60s, aerospace has, in many ways, stagnated. Visit any airport this side of Mojave and tell me I’m wrong.

Business Aviation Leads the Way

The space program has some promising “green shoots” with the Orion/SLS program and the emergence of third-party spaceships from companies like SpaceX and Sierra Nevada’s Dream Chaser. When it comes to atmospheric flight, the most exciting developments are no longer taking place at Boeing or Airbus. Over the past couple of decades, competition and market demand for ever more capable business aircraft has revolutionized that segment of general aviation. The VLJ sector has brought small, quiet, efficient business jets to market, while on the ultra-large cabin side, today’s airplanes fly higher, faster, and further than ever before.

But we’re pressing up against the limits of what’s possible through the continuing evolution of current designs. It begs the question: what comes next? I believe we’re headed back to the future. I’m talking about the return of supersonic aircraft to general aviation. Well, perhaps “return” isn’t the proper word, because GA has never had them. More like the return of supersonic passenger aircraft. There’s nothing on the horizon in that department from the airlines, but for the corporate/charter folks, there is plenty of research and development taking place.

Spike Aerospace has designs on one, and Gulfstream worked with NASA on a project called Quiet Spike in 2006 and 2007 where they retrofitted an F-15 with a 24 foot-long retractable nose spike to experiment with reductions in the sonic boom footprint. The goal was to find ways to make transonic flight possible over the continental U.S.

What's stranger than a 24 foot spike on the front of an F-15?  A Gulfstream logo on an F-15.

What’s stranger than a 24 foot spike on the front of an F-15? A Gulfstream logo on an F-15.

The Quiet Spike project has/had an offshoot called the Gulfstream X-54, which could very well be in development at this very moment. The X-54 is rumored to be an experimental stab at overcoming the challenges of domestic supersonic passenger flight.

Sukhoi also partnered with Gulfstream on a potential Mach 2+ business jet called the S-21 in the early 90s. They determined that there wasn’t enough of a market to proceed. But that was twenty years ago.

The Marketplace Is Ready

So what has changed to make supersonic flight a potential reality for passengers? After all, we’ve had supersonic aircraft since the late 1940s, and airliners capable of the feat for half a century now. A level of skepticism is understandable, especially in an industry known for physical vaporware, but I believe the elements are now in place to make this a reality.

For one thing, Gulfstream is now owned by General Dynamics, a conglomerate with deep pockets and significant experience with supersonic flight. If you were going to partner a bizjet manufacturer with organizations that could help it overcome the technical hurdles of a Mach 2 passenger aircraft, could there be any better synergy than Gulfstream, General Dynamics, and NASA?

Then there’s Gulfstream itself, which has become one of General Dynamics’s primary revenue sources. As always, just follow the money. In years past, the idea of a $120+ million corporate aircraft wold have been laughable. Airliners didn’t even cost that much. But today, Gulfstream is building $75 million business aircraft and buyers are lined up around the block to purchase them. Boeing manufactures corporate versions of the 747 and 787. Airbus has the ACJ. Clearly, price is not a show-stopper. With that in mind, maybe there is a market for a supersonic airplane.

From a technical standpoint, you can’t go much faster without exceeding the speed of sound. We are already flying around at Mach 0.9 and the G650 was dive tested to Mach 0.995, where plenty of transonic airflow must have already been present.

Profit and Loss

The primary reason I’m bullish on supersonic passenger flight now is because it makes far more sense for the corporate/charter market than the airlines. An airliner needs to make money for the owner. That’s their business, and the only reason those aircraft exist. If the jets don’t turn a profit, the airline goes bankrupt. As glamorous and enchanting as Concorde may have been, it was a money loser. And with fuel prices headed skyward faster than a ballistic fighter jet, the economics only got worse as time went on.

Corporate airplanes don’t have to make money. They aren’t profit centers in and of themselves, but rather a means to an end: a way to get more business done. Supersonic speeds would allow the transcontinental traveler to quite literally put more than 24 hours into a day. Imagine being able to hold a lunch meeting in Europe and have another one in North America on the same afternoon. Take a look at a map of the sheer number of aircraft crossing the Atlantic on a given day. It’s dramatic.

There’s another reason supersonic bizjets could work when an an airline version would not. Airliners carry hundreds of people and tons of cargo, catering, baggage, etc. A typical business aircraft might have 4-5 passengers on board, so there’s far less need for a big cabin or massive payload capability. The one thing every Mach 2 design has in common is the general shape: long and very slender. A space that would be cramped for 100 airline guests would feel far more luxurious if it was only occupied by a half-dozen businessmen. The needs of the corporate/charter market are simply a far better match for a supersonic design.

In conclusion, all the elements necessary for a successful supersonic business aircraft are in place. Now someone just has to build it. Between their Sukhoi partnership, the NASA Quiet Spike research, and the X-54, Gulfstream is obviously serious about taking the next step. They have General Dynamics’ resources, large market share, and deep-pocketed clientele.

My prediction: Gulfstream Aerospace will deliver a supersonic bizjet within the decade.

The Double Standard

The Stearman is a World War II-era, fabric-covered radial engine tailwheel trainer.

Last July, an Alabama resident unhappy about the noise generated by an antique Boeing Stearman biplane decided to take matters into his own hands. According to the FBI, at least one witness on the ground saw Jason Allen McCay fire “several shotgun blasts” at the aircraft as it attempted to land at Campbell Field.

The plane was at an altitude of about 75 feet and was about 300 feet from touching down when McCay fired the shots.

Fred Campbell, who built the airstrip in 1963, bought the Stearman biplane in 1976 and, since that time, he and friends have completely rebuilt the plane. The plane had not flown for 30 years when they took it up on test flights June 22. The plane was concluding its third test flight of the day when McCay fired his shots.

McCay previously had filed numerous complaints with various agencies about airplanes flying over his house. He told investigators he fired when the Stearman biplane flew over his home because he wanted to scare the people on board.

The punishment? McCay was indicted by a federal grand jury on a single count of “attempted interference with an aircraft”.

This strikes me as a woefully inadequate charge. Aside from cases of self-defense, any time a firearm is intentionally and repeatedly discharged directly toward humans, an aggravated assault or attempted murder charge seems more appropriate.

The classic Stearman biplane:  wood structure covered in fabric skin.

The classic Stearman biplane: wood structure covered in fabric skin.

I’d argue it’s especially so in this case because it involved an aircraft in mid-flight. Even if the occupants were unharmed, any hit to the Stearman itself could have brought the entire plane down. That sounds like a hell of a lot more than just “attempted interference with an aircraft”.

McCay pled guilty and was sentenced to one year of probation. Though unconvinced of the sincerity of McCay’s apology, the judge somehow came to the conclusion that jail time was not warranted.

Perhaps the prosecutor or judge were sympathetic to the defendant’s antipathy toward aircraft noise. Or maybe there’s something in the law that made interference with an aircraft the strongest charge they could make stick. Either way, there’s a double standard here, folks.

I’ve never understood the logic that allows Harley-Davidson to build (and/or their owners to modify) motorcycles with straight pipe exhausts in order to generate as much noise as possible while in general aviation we spend untold hours and fortunes modifying aircraft with mufflers, new prop designs, hush kits, and adjusting takeoff and landing procedures, flight paths, and more to minimize our noise footprint.

The Stearman is a World War II-era, fabric-covered radial engine tailwheel trainer.

The Stearman is a World War II-era, fabric-covered radial engine tailwheel trainer.

If McCay had walked into a restaurant and fired several blasts toward people and later claimed it was “just to scare them”, would he have skated with a year of probation? Of course not. It would have been national news on TV and a trending topic on Twitter for a week.

What if he was unhappy about highway noise and had fired at a car or the aforementioned Harley from an overpass? Forget probation, he’d be looking at a very long prison sentence. So why are pilots less worthy of protection under the law?

Yes, pilot Fred Campbell and his airstrip are going to be the cause of some noise. But it’s worth noting that the airport has been there for half a century and that McKay built his home adjacent to an operating airport. If those of us living near roads and highways have to deal with the constant buzz of vehicular traffic going by, it’s only fair that those near GA airports do the same, especially when users of such airfields are doing as much as reasonably possible to mitigate the noise.

Being a good neighbor goes both ways. It’s just a shame the law isn’t enforced in a way that reflects it.

Selling an Airplane

sale

I periodically browse through my web site’s referrer logs to see who’s been posting links to The House of Rapp. It’s also a useful tool for finding new aviation-related content on the Internet, something I always enjoy.

One of the sites that recently showed up in the logs is SellThatPlane.com, a blog dedicated to GA aircraft sales tips. If you’re trying to dispose of an aircraft in this challenging market, you could do worse than to spend a few minutes perusing the author’s suggestions.

The site got me thinking about the airplanes which languishing for month after endless month on Controller, ASO, Barnstormers, Trade-A-Plane, and even on the ramp at a local airport. Sometimes the airplanes are continuing to fly, but just as often it’s a dusty derilect with flat tires and a faded “for sale” banner hanging from the propeller. Each of these aircraft represent a monthly net loss for the owner as storage, insurance, property taxes, maintenance, loan payments, and other expenses mount.

On the other hand, if the aircraft can be sold, it’s a win-win for everyone. The seller gets out from under the financial obligations of owning, the buyer gets a new toy, and the airplane benefits from regular care and use.

So why do some change hands quickly while others do not? Sometimes the owner doesn’t really want to get rid of the plane but for whatever reason (financial distress, lack of use, divorce, etc) feel they should put it up for sale. I’ve actually seen sellers price the airplane too high in order to ensure that it doesn’t sell. But aside from unusual cases like that, in my experience when a plane sits on the market for a long time, it’s because the seller is neglecting one of what I call the “five golden rules”:

  • Photos sell airplanes
  • Be honest
  • Know the market
  • Appeal to the senses
  • Get the word out

Let’s look at these one at a time.

A Picture is Worth a Thousand Words
I’d say that photos are by far the most important thing you can put in an advertisement. For better or worse, human beings are visual creatures, and whether you’re selling a plane, automobile, or real estate, your ad is likely to be passed over completely unless it contains some photographs to illustrate what’s being offered.

As the old saying goes, a picture is worth a thousand words. An accurate description of the airplane is always worthwhile, but it’s no substitute photographs because it’s impossible for a textual representation to cover every aspect of the airplane, and you never know which items will be of greatest importance to any particular buyer.

For example, I’m currently looking at RV-6 aircraft, but I want a specific configuration: tailwheel, tip-up canopy, constant-speed prop, and at least a minimal IFR panel in a standard “T” layout. Photos are not only pleasing to behold but also allow me to judge the relative merits of the aircraft with minimal effort. I can also discount those with military-style paint schemes, which I dislike.

It’s extremely rare for me to click on any aircraft advertisement when I know it does not contain photos. Barnstormers.com is one of the few exceptions. I used to discount Barnstormers as a less sophisticated site for aircraft sales because of the site’s design, but over time I’ve realized the brilliance of their set-up: ads are placed sequentially on a single page, so those without photos are as likely to be seen as ads with them.

It’s not enough to have photos, however. They need to be high quality images or you’re not showing off your asset at it’s very best. That means they’re taken from an appropriate perspective with the proper lighting and edited to correct any deficiencies in brightness, contrast, color, etc. I’m always amazed at how many badly-sized, grainy, and/or improperly oriented pictures appear in aircraft listings. Lighting in particular makes all the difference in the world; you want your subject to be well-illuminated and free of shadows. It reminds me of the Seinfeld “two-face” episode:

Step number one is always to pull the plane out of the hangar before photographing it. There’s nothing worse than a dark environment under fluorescent lights. Position the airplane so that the sun is at your back. The best time of day for shooting your aircraft is typically going to be early morning or late afternoon when the sun is lower on the horizon. Most of what I learned about photographing aircraft came from browsing ads for high-dollar turbine equipment. If you want to learn from the best, just search for Gulfstreams, Falcons, etc. and you’ll find a limitless supply of professionally-staged photos.

A compelling and well-crafted photo.

As for how many photos to take and which angles to use, my metric is simple: pretend you’re the buyer. What parts would you want to see? At a minimum, a few exterior shots, the interior, and the instrument panel. Which angles are the sexiest? Usually this is going to be a front-quarter view.

As amazed as I am about the poor quality of many aircraft photos, the problem seems far worse in the real estate world. A typical GA aircraft might cost $100,000, but the average piece of Southern California real estate is several times as expensive. The photographic sin is less forgivable in those cases because the listing is usually handled by a real estate professional who ought to know better.

Honesty is the Best Policy
There’s nothing worse than pursuing a lead on an aircraft only to find it’s been outright misrepresented by the seller. Purchasing an plane often involves travel and logistical challenges with regard to mechanical inspections, ferrying, and transition training. Discovering that the aircraft is not what was advertised can be expensive even if the sale is not consummated.

Naturally, everyone wants to show their aircraft’s equipment, capabilities, and history in the best possible light. But outright dishonesty rarely pays off. There are already plenty of things that can torpedo a sale without adding to the list by misrepresenting your aircraft. Besides, if you wouldn’t want to be treated that way as a buyer, why do it when you’re selling? The aviation world is a small place and word gets around quickly, especially in the Internet age. A solid reputation takes years to build but only a short while to destroy. Is it really worth it to expedite a sale or gain a few dollars off a buyer who will feel burned?

Deception is not only a bad idea from an ethical standpoint. Hiding damage history, logbook entries, and component times & conditions can expose a seller to legal liability. In the event of an accident, even one where the deception was not a factor, the participation of attorneys and FAA personnel in the process cannot help but give a previous owner sleepless nights. For these and many other reasons, honesty is the best policy.

Know Your Market
I sold my Skylane in 2004 for a little more than what I’d paid for it a few years earlier. On the other hand, I recently saw that airplane up for sale again at less than 1/2 the price I got for it only eight years ago. While it’s nice to know I got out while the getting was good, it brings little joy to see a fine aircraft sitting on the market at such a depressed price.

It doesn’t matter how well you present the aircraft, if the price is too high it simply won’t sell. You have to know your airplane and how it fits into the current market. Not the market of six years ago, or even six months ago. Not the market as you wish to see it, but the actual demand for what you’re selling.

Many sellers feel that their airplane is worth a specific amount because that’s what they paid for it. I’ve also heard valuations based on money spent on improvements, previous values, and so on. As the real estate crash has taught millions of people around the globe, this is wishful thinking. Any asset — stock, gold bullion, currency, tulips, aircraft, real estate, — is only worth what a buyer is willing to pay for it today. The sooner one accepts that truism, the faster a buyer can be found.

Knowing your airplane means knowing what it’s worth, and to figure that out you have to look at comparable listings. Which ones are moving? Which aren’t? How does your offering compare to others in terms of airframe/engine times, equipment, condition, and so on? When prices are falling, coming up with an accurate market value for your airplane can be a painful experience, especially as owners frequently have a large emotional investment in their aircraft. But in the words of the Corleone family: it’s not personal, it’s just business.

Appeal to the Senses
At some point, a potential buyer is going to come out to your airport and look at the airplane. This is the make-or-break moment, and many sellers don’t realize that they have a tremendous level of control over the buyer’s experience. A few simple tips can help seal the deal at this time.

First and foremost, the plane must be clean, inside and out. Windows, seats, carpets, cowling, prop, belly, fairings, antennas, you name it. A major detailing job is called for when your airplane is up for sale. Even if the paint’s not perfect, get it to shine where possible.

This is a poor photo. The angle is not flattering, little detail is apparent, and the shadows cause the airframe to blend into the ground.

I like to stage the aircraft outside where it can be viewed in its best light. The buyer will be looking hard at every little thing, and your focus on the details will be interpreted as the same attention you give to things like maintenance and adherence to operating limitations.

The interior should be tidy, free of cords, headsets, charts, junk, and should not smell like a pile of dirty laundry. The sense of smell is a powerful one, but often we become accustomed to whatever scents may be present in our aircraft just as we do in our homes.

Let’s face it most airplanes could smell a bit better. It’s just that no one seems to want to talk about it.

Without air conditioning we sweat in those seats, be it from summer heat or the winter IFR approach down to minimums. If you are the typical male pilot I’m willing to bet that you occasionally let out a bit of gas as you continue to climb in that un-pressurized cabin. Then there are those who fly with us. No matter how smooth you fly there will be someone who has the unfortunate experience of loosing their lunch at 5500 feet. If you have kids you can also expect all the smells that go with your typical mini-van, sans fast food maybe.

In the Gulfstream, we’ll often place dryer sheets in the crevices of the leather seats after a flight to help absorb foul odors. Ozium and Fabreze are two other commonly used products. If it looks and smells good, your airplane is far more appealing to everyone — even if you’re not trying to sell it!

Aircraft records are important. If they’re out of order or data is missing, a buyer may assume there’s something to hide.

This is also the time to have all your records in order. Logbooks, invoices, airworthiness directives, service bulletin lists, etc. all neatly organized for the buyer. I went a step further and digitized all the records for my aircraft, creating PDF files which could be emailed to potential buyers. Think that’s overkill? Imagine you’re the buyer and are looking at two potential airplanes. One guy thinks that AD was probably complied with, the other emails you full PDF copies of the aircraft logbooks while you’re on the phone with him. Which one made the better impression?

Get the Word Out
This last one is based on my personal experience. A well-crafted advertisement and photos are worthless unless your intended audience can easily find them. Today, that’s done via the Internet. I recommend putting together a web site with all pertinent data, high resolution photos, and perform some basic search engine optimization on the site.

Next, the ad should be posted on various aircraft sales web sites, as well as posted in the appropriate online forum for your aircraft-specific pilots association (COPA, VansAirforce.net, Cessna Pilots Association, etc). Many of these entities also have print publications with classified sections.

Next, post your ad on Usenet newsgroups, Craigslist, EAA & AOPA forums, with local airport associations, and finally at the airports themselves. Most airfields have a bulletin board at an FBO, flight school, or airport restaurant for things like this. I’ll fly around with printed versions of the ad (full color, with photos and a link back to the web page) for distribution to as many places as possible.

Think creatively about the market for your aircraft. Selling an aerobatic airplane? Visit an IAC contest location. If your airplane is a single-engine Cessna or Piper, try a flight school. Graduating students often venture into aircraft ownership rather quickly. If you’ve got an Experimental aircraft for sale, ensure the local EAA chapter(s) know about it.

If you’re involved in any kind of aviation community (and most of us are), odds are you can get the word out through friends. Don’t overlook this avenue, as friends can vouch for you on a personal level and probably know your airplane as well. The “six degrees” effect, combined with general aviation’s relatively small size, means that from a mathematical standpoint, even a few contacts can put you in close proximity to a substantial percentage of the market.

Aircraft Tire Pressure

Jet aircraft nose gear

Every aviator has their soapbox issues, and when it comes to maintenance, my top two are constant-speed propellers and aircraft tires. I may touch on the former in a future article, but for now let’s focus on the latter.

Tires are one of the most vitally important — yet frequently ignored — parts of an aircraft. It’s easy to see why: they’re relatively simple elements which work day in and day out without problem, and as such are taken for granted. In addition, some of the typical pilot’s attitude toward tires is transferred from the way they treat their automotive counterparts. Be honest, how often do you inspect your car’s tires? When was the last time you checked the pressure on all four wheels? I’m about as anal as a person gets when it comes to car maintenance and upkeep, and I might check the tires once every couple of months at best.

In a light GA aircraft, tire failure on the takeoff or landing roll can lead to loss of directional control, runway excursion, and/or a ground loop. These things are unlikely to be fatal but are frequently embarrassing and inconvenient as they’ll shut down the runway for a while. I’ve had several of those in my career. Ironically, it always seems to happen during a student’s softest, smoothest 3-point landing in the Decathlon. Well, almost always.

Not what you want to see on a deserted runway in the middle of nowhere as the sun is going down.

I once lost a tire — literally — while taxiing a Pitts S-2C. I had stopped for cheap fuel in Limon, Colorado, a paved but little-used strip on the edge of a small town near the Nebraska border. After a great landing in a 25 knot crosswind, I refueled and started to back-taxi on the runway when the left main tire slowly deflated. I shut down and opened the canopy, but as soon as my feet came off the brakes, the airplane weathervaned into the wind, taking the tire right off the rim as it pivoted. Now I couldn’t even move the plane.

Oh, and did I mention the sun was setting soon and the runway had lights? Suddenly the flat tire was less important than ensuring some wayward pilot didn’t attempt a night landing with my disabled, unlighted biplane sitting on the runway.

Light aircraft flats are more often caused by the failure of the tube than the tire itself. The Pitts incident taught me the value not only of proper tire inflation, but also of alighting at airports with maintenance services when flying cross-country. Making that trip today, I’d at least carry a spare tube.

Of course, that won’t always save the day. I once had to rescue a friend from Death Valley when his underinflated aircraft tires melted into the tarmac on a 120+ degree day. Tire condition can be difficult to judge on fixed-gear aircraft on account of the fairings which often hide 90% of the rubber from view.

Jet aircraft nose gear

In turbine aircraft, improperly inflated tires are more likely to lead to expensive damage, if not outright catastrophic consequences, due to the higher speeds and heavier weights of those aircraft. There’s simply a lot more kinetic energy for the tires to absorb. This is why turbine aircraft tires are stronger and more advanced than those found in their lighter brethren. It also explains why those tires are filled with nitrogen instead of air. Nitrogen doesn’t expand at altitude the way air does. It has a low moisture content so it doesn’t freeze, and it will not support combustion.

The FAA recently issued Safety Alert for Operators (SAFO) bulletin 11001, “The Importance of Properly Inflated Aircraft Tires”, which notes:

Research has shown that transport-category airplanes can lose as much as five percent of tire pressure per day under typical operations. At a pressure rate loss of five percent per day, it would only take a few days before they require servicing.

Tires not serviced within an acceptable range may require tire replacement due to under inflation limitations specified in the maintenance manual. Additionally, servicing of underinflated tires without proper protection such as a tire screen or other protective devices may cause damage to the aircraft or injury to the individual servicing an underinflated tire.

The FAA’s not alone in their crusade to get us to pay more attention to our tires. Last week, Gulfstream reviewed tire safety “best practices” in their weekly Breakfast Minutes publication. It referenced the Goodyear Aircraft Tire Care and Maintenance publication. It’s an excellent read.

The Antonov 225. How long would it take to check the tire pressures on this aircraft??

A bit of research revealed that tire failure has caused a variety of high-profile jet accidents, including Air France flight 4590, Nigeria Airways flight 2120, Mexicana flight 940, and most recently, the 2008 crash of a Lear 60 in South Carolina.

That last accident was cited in their SAFO bulletin. In fact, the FAA recently issued an Airworthiness Directive for the Lear 60 which requires a tire pressure check no less than 96 hours before any flight.

Obviously it’s not possible to prevent every instance of tire failure, but we can skew the odds in our favor by paying more attention to them. That means checking the tire pressure at appropriate intervals. Mounted tube-less aircraft tires lose significant pressure every single day, and underinflated tires cannot necessarily be detected by simply looking at them. If nothing else, proper inflation leads to longer tire life and better ability to survive FOD damage should it be encountered. Remember too that the landing and takeoff distances listed in the Aircraft Flight Manual are predicated on proper tire inflation!

To show the importance of proper tire pressure, consider that as a tire leaves the deflected area (aka the ground) as it turns, it attempts to return to its normal shape. Due to centrifugal force and inertia, the tread surface doesn’t stop at its normal periphery but overshoots, thus distorting the tire from its natural shape. This is called a traction wave. Assuming the tire is turning at 250 mph:

At this speed, it takes only 1/800 of a second to travel 1/2 the length of the footprint (CX). In that same time, the tread surface must move radially outward 1.9 inches. This means an average radial acceleration of 200,000 ft./sec./sec. That’s over 6,000 G’s! This means the tread is going through 12,000 to 16,000 oscillations per minute.

Tires are designed to withstand traction waves… but only while inflated to the appropriate pressure. Under or overinflation will magnify the effect of traction waves. Suddenly the AFM recommendation on tire pressure seems pretty important, doesn’t it?

This Hawker was severely damaged after tire failure caused by repeated takeoff aborts.

Speaking of the AFM, the landing gear may have other limitations which must be observed. In 2007, I witnessed first-hand what happens when those limitations are exceeded.

Whatever you call them — tyres, hides, skins, rolling stock, stickers — aircraft tires are certainly one of the most highly-stressed yet least respected parts of an aircraft. Next time you fly, think closely about the punishment they take and whether you’re sure those babies are truly airworthy.