Tom Horne Archive

Skew-T fever

Thursday, August 29th, 2013

In last month’s AOPA Pilot I wrote my Wx Watch column about some of the dynamics behind frontal formation ( It’s a complicated subject but I tried to explain it as simply as possible given the space available. Believe me, entire volumes have been written on the subject.

My whole idea behind Wx Watch is to provide a mix of practical information with occasional introductions to some advanced concepts. Concepts that can help further an understanding of how weather works, as well as help better understand briefing products (such as Convective Outlooks). I take the same approach when giving my presentations on aviation weather at AOPA Summit. The audiences seem to enjoy knowing more about the weather than is provided in traditional pilot training materials. Seems logical to me. After all, we fly in it–be it good VMC or miserable IMC. Besides, weather-related accidents tend to have a disproportionate level of fatal outcomes.

And yet, the private pilot knowledge exam has remarkably few questions on weather. Last I checked, you could get all eight weather questions wrong, and still pass. No wonder pilots feel that weather is their weakest subject–a feeling that often can persist throughout a flying career. That said, I think that, at heart, most pilots want to know more. They ask questions that indicate an intellectual curiosity. But tune out when the explanations come.

Some are apparently defensive about this. One member wrote to say that the front formation article was aimed at meteorologists, and too esoteric to be of any practical use, adding that he is a VFR-only pilot. Oh, the irony.

Then there are those wanting more. One member wrote to ask for more coverage of Skew-T Log-P charts. Another wanted more talk about things like convergence, divergence, and vorticity. Proof that our membership is a diverse batch indeed.

Those not feeling the urge to better their understanding of weather may think of it as existing in the realm of entertainment. I like a good “there I was” or “Never Again” yarn as much as anyone. But many of them serve as poor substitutes for learning experiences. Sometimes you get the idea that these first-person accounts come from pilots who were genuinely surprised by horrific weather–even though its occurrence could have been predicted during the preflight phase. That is, if the pilot knew where to look, and what signs to watch.

So where do you stand? Do explanations of weather dynamics have a place in discussions of aviation weather, or do generalizations suffice? I suppose the answer is a mix of both. But for the squeamish, be forewarned: A Skew-T chart will appear in October’s Wx Watch! It will show a temperature profile of freezing rain, and there will be no quiz!



Volts to the Rescue?

Monday, August 19th, 2013

Let there be no doubt: Anti-noise and anti-carbon-footprint forces have teamed up with escalating fuel prices to make for challenging times. The future of general aviation may well depend on a new, cleaner, renewable source of power–electricity. Today, electrically-powered aircraft are in their infancy, but this is bound to change. As newer generations of lithium batteries continue to boast longer flight times, shorter charging times, and the ultimate in green technology–charging via electricity generated by solar cells–takes hold, it’s time to take electric aircraft seriously.

Tian Yu, Chairman of Shanghai-based Yuneec International, parlayed his fortune as a manufacturer of electrically-powered, remote-control toy airplanes, helicopters and cars into real airplanes such as the GreenWing International eSpyder and two-seat e430. Now, the eSpyder has been certified in Europe under Germany’s expansive ultralight rules as set out by the Deutscher Ultraleichtflugverband (DULV)–a branch of tthat nation’s Federal Ministry of Transport. U.S. Light Sport Aircraft certification is on track to follow, and more European and other nations are bound to reciprocate as well.

For a complete report on the state of the electric-aircraft movement, be sure to check out AOPA Pilot’s latest report on engine technology entitled “Electric Instead” in the September issue–and already released in digital form.

What are your thoughts on the subject? Are electrically-powered aircraft a passing fashion, or do they hold real promise for what could be a new technology that helps preserve general aviation’s future?


Wings Over Afghanistan

Friday, June 21st, 2013

Do we have great AOPA Sweepstakes winners, or what? If you recall, airline pilot and AOPA member Eric Short won 2011’s “Crossover Classic” Sweepstakes. He’s now the proud owner of that terrific airplane–a fully restored, totally modernized 1974 Cessna 182M. But Eric’s son, Allen, also flies the airplane. But probably not as much as he’d like.

That’s because Allen is a Captain in the U.S. Air Force. He’s based at Offutt AFB in Nebraska but deploys to Afghanistan, where he flies RC-135 reconnaissance aircraft. The RC-135 is a highly modified variant of Boeing’s C-135 Stratolifter. The Air Force gives Allen’s ships the “RIVET JOINT” handle. They perform signals intelligence and electronic warfare missions. Here’s what a RIVET JOINT looks like:


On one of his missions, Allen took along an American flag. Just yesterday, a package was resting against my front door. It was from Offutt, so I knew it had to be from Allen.

Inside was the flag, a certificate, and three patches. One patch bore the logo of the 379th Air Expeditionary Wing, one represented the USAF Central Command, and one was for the 763rd Expeditionary Reconnaissance Squadron. As a weather nut, I especially liked 763rd’s patch. It says “Always On The Hunt,” and has a sun with two sundogs. Sundogs–or parhelions–are halos in the form of a colored spot, at the same angular elevation as the sun.

When I delivered the Cessna to the Shorts, it was to an airport near Offutt. I gave checkouts to both Eric and Allen, and on Allen’s ride I happened to look up and see sundogs. “Hey, look, sundogs,” I said, to which Allen responded “that’s our unit’s nickname.” And now I have a Sundog patch. Cool.

Ther certificate reads:

“This American flag was proudly flown for AIRCRAFT OWNERS AND PILOTS ASSOCIATION aboard an RC-135 RIVET JOINT Reconnaissance Aircraft, tail number 62-4132, over the hostile skies of Afghanistan in support of OPERATION ENDURING FREEDOM on the 5th day of June, 2013, by the men and women of the 763rd Expeditionary Reconnaissance Squadron.

Allen E. Short, Captain USAF

Aircraft Commander”

Now here’s a look at the flag, certificate, and patches:

Part of Capt. Short's payload over Afghanistan

Part of Capt. Short’s payload over Afghanistan

Thanks so much Allen, and here’s hoping we meet you and your father at AOPA Summit this October in Fort Worth.


Debonair Sweeps: Panel Sneak-Peek

Friday, November 30th, 2012

N232L Radio Panel

N232L Radio Panel – click to see bigger image.

Ok, so the last Debonair post was a tad troubling…I mean, will that torn-up old instrument panel really make the leap to state-of-the-art?

Fear not! Santa Fe Aero Services has come up with a plan. And a drawing that shows their vision of the Deb’s panel-to-be. Click on the accompanying image and it will enlarge.

Take a look at the illustration and see if you like what’s planned. It’s a display-rich panel with a clean look and a load of new avionics. Again, check for subsequent posts–and the sweepstakes article in the January issue of AOPA Pilot magazine–for updates.

But for now I just wanted to give you a peek into the very near future. What do you think?

Debonair Sweeps: No Turning Back!

Tuesday, November 27th, 2012


The Debonair Sweeps' gutted panel

Yikes! The Debonair Sweeps’ gutted panel


I’ve shepherded three AOPA Sweepstakes airplanes through their restorations, and there’s something that shocks me each time.

What is it? It’s seeing a photo like one posted here! Yep, this is the stage where all the old avionics have been yanked, and then unceremoniously tossed or traded in to the avionics shop for credit (what little that might represent) against their labor.

But look at it…chaos incarnate. NO WAY the old panel is ever coming back! The point of no return has passed!

Even though you may intellectually grasp the idea, at this stage of a panel restoration the mind cannot fathom the concept of a full-on upgrade. How can any normally-endowed person have the ability to put things right after seeing such a mess of wires and gaping holes? You or I couldn’t, of course. So take a look, ladies and gentlemen: The Humpty-Dumpty metaphor, made manifest!

Good thing that Santa Fe Aero Services has been there, done that. Many times over. Before long, we’ll see a three-screen Aspen Avionics installation, along with Garmin’s GTN 750 and GTN 650 navigators, an Alpha Systems angle of attack indicator, an R.C. Allen backup attitude indicator, a PS Engineering PMA8000BT audio panel, a CO Guardian carbon monixide detector, a JP Instruments EDM 900 engine and systems monitor, and much, much, much more. Like a panel-mounted iPad Mini, USB charging ports, and new annuciators.

Check out the January 2013 issue of AOPA Pilot for more information about the Debonair Sweeps’ panel transformation.

And don’t worry. The gutted-panel look may prompt despair, but that will fade as the new panel springs, Phoenix-like, into the 21st century.

Debonair Sweeps: Flying D’Shannon’s tip tanks

Monday, November 5th, 2012

Time for an update on the Debonair Sweeps’ progress–and the news is big! After buying the airplane at Hartford’s Brainard Airport, I flew it to AOPA headquarters at the Frederick, Maryland Municipal Airport–a flight of two hours. From there, I flew it another five and a half hours to Buffalo, Minnesota (stops were made at the Muncie, Indiana and LaCrosse, Wisconsin airports). Buffalo is D’Shannon Aviation’s home office. At Buffalo, D’Shannon went to town, installing its 20-gallon tip tanks, a new “Speed Slope” windshield, tinted side windows, and aileron and flap gap seals.

For those who may not know, D’Shannon is all about fixing up Bonanzas, Barons, and Debonairs. They have Supplemental Type Certificates (STCs)–98 of them!–that run the gamut. If you want your Debonair, Bonanza, or Baron to look better and go faster, then D’Shannon’s the place. Scott Erickson is D’Shannon’s president, and he’s your point person. He’s at 800-291-7616.

D’Shannon’s more aerodynamically-shaped windshield replaces the stock windshield, which has a kind of bubble shape. But the main advantages of new windshields and side windows have to do with visibility and noise reduction. The old windshield and side windows were scratched and milky. Believe me when I say that flying into the sun made forward visibility a challenge. The new windshield and windows are also thicker than the originals–3/8-inch thick versus the original 1/4-inch thick glass. So there is also a noise reduction factor.

The tip tanks come with two methods of determining fuel level. First, there’s a clear slot in the side of the tanks, so you can directly observe the fuel level. There are fuel quantity markings–1/4, 1/2, 3/4, and full–and each corresponds to five gallons’ worth of fuel. In the cockpit there are digital fuel gauges that give both numerical and graphic fuel quantity indications. The gauges are on the same small panel that contains the transfer pump switches. To use tip fuel, you burn down the main tanks first, to make room. Then you turn on the transfer pumps to move the fuel from the tips to the mains. It’s an in-flight fill-up!

I first got a chance to check out the tip tanks on a flight from Buffalo to Wichita’s Jabara Airport. The takeoff from Buffalo was definitely sporty, with direct crosswinds out of the west gusting to 27 mph. And the turbulence on  climbout was a solid moderate–if aviation had a Richter scale, it would have rated a seven I’d think.

I hear you asking about the effects of all that weight out on the wingtips. Yes, I was busy in the turbulence, and even with just five gallons in each tip tank, there was a noticeable moment-arm from those 30 pounds sloshing around out there. How would it be with the full, 120-pounds-worth of fuel in each tank? I’ll find out one of these days, and I hope it will be in smoother air!

The tip tanks certainly have benefits: seven- to eight-hour endurances, for example. And the tip tanks come with a 200-pound hike in max gross takeoff weight. It’s now a 3,200-pound airplane, which helps in the useful load department.

The Debonair’s empty weight now stands at 2,028 pounds; useful load is a decent 1,172 pounds. But fill up all the tanks and useful load shrinks to 488 pounds. So for two people and light bags, the Debonair Sweeps is ideal for long trips or tankering lower-cost fuel. Of course, the airplane’s weight will change during the refurbishment process, and  by “change” I mean increase in weight. So the winner will probably need to modify the fuel load on typical flights.

That’s it for now, with some 20 hours logged on an airplane that has yet to experience its biggest work packages.

In the next post I’ll show you a photo and a drawing that’ll give you a fair idea of the goings-on at the Debonair’s current stop–at Santa Fe Aero Services, where its avionics will get a complete do-over. Stay tuned!

The Sweeps Debonair: Sign of a Trend?

Thursday, October 25th, 2012

Now that AOPA’s Debonair sweepstakes is under way, I’ve been thinking about the previous owners of this very special 1963 airplane. Our/your Debonair was previously owned by two partners. One was 90 years old. The other wanted a newer airplane–an A36 Bonanza, I understand. The 90-year-old is still flying, by the way, and the day I checked out the Debonair I watched him taxi out in a Skyhawk with an instructor. For him, the Debonair was too much expense for too little flying. For the past five years he averaged just 20 hours per year in the Debonair. Keeping it made no sense.

This sounds a lot like the previous owner of the 2011 sweepstakes airplane–a 1974 Cessna 182 we dubbed the “Crossover Classic.” The owner was in his late 70s and only flew his Skylane 10 hours per year. Though he couldn’t justify keeping the Skylane he, too, kept flying. He purchased a Piper J-3 Cub, restored it with a partner, and now flies it under Light Sport Aircraft rules.

Let’s go back further, to AOPA’s 2004 “Win-A-Twin” sweepstakes airplane–a 1965 Piper Twin Comanche. Same deal: an ex-airline pilot rarely flew the airplane. He was getting out of the twin because, you guessed it, he didn’t fly so much any more.

It strikes me that these pilots represent a groundswell in sales of older general aviation airplanes. All three owners were deeply involved in GA flying, and emotional about parting with their beloved airplanes. In each case it took years for the owners to come to the decision to sell. And in those years, I might add, each deferred essential maintenance. They became inured to their airplanes’ signs of wear and tear.

I’ll bet that there are hundreds, maybe thousands of owners and airplanes out there in the same situations. And guess what. Those owners and airplanes were part of GA’s glory years, which ran roughly from the early 1950s to the late 1970s. That’s when more GA pilots were trained, and airplanes built, than ever before–or since. It was the apex of GA’s bell-shaped activity curve.

Now many of those older owners are getting out of “conventional” GA and into light-sport flying. Others are simply walking away. No surprise here, but my point is that there aren’t enough younger pilots entering GA to compensate for the older ones leaving. That’s why AOPA’s many initiatives designed to promote growth of the pilot base–our flying club iniative being the latest–will be so essential in the years to come.

Ride-sharing, wherever you want it

Wednesday, October 3rd, 2012

Let’s say a pilot is flying a cross-country, but has an empty seat or two. Doesn’t it seem a waste not to fill a seat or two with someone needing a lift? Now, Edouard Kohler of AOPA-France, has come up with a way to match pilots with potential passengers–or other pilots wanting the experience. Kohler’s website gives you a way to see which willing pilots are going where, and lets prospective pilot/passengers sign up. It’s a new program, just launched a month ago, and Kohler is hopeful that more pilots and passengers will sign up for ride-sharing.

Sounds like a great way to spread the word about GA. We’ll see how the concept evolves over the coming year. And remember, this ride-sharing program is intended to be available in both the United States and Europe.

Caution: Catfish on ramp!

Monday, September 10th, 2012

We’ve all heard the expression ‘raining cats and dogs.’ Now let’s add to that ‘raining catfish.’ Let me explain.

I had just landed at the Vero Beach, Florida airport and was cleared to taxi to Paris Air’s ramp at the east end of the field. It rained heavily the day before, and off and on for several hours before my arrival. The rain was heavy. So heavy that the airport’s storm drains–grass swales, really–filled to the brim. I came down the taxiway paralleling Paris Air’s ramp, hung a right, and–hey, what’s that? One, two, three black, curved shapes flopping around on the ramp.

Catfish taxiing at VRB

Yep, catfish. They had apparently washed out of the swales and were now trying to walk–er, flop–somewhere. It was a first for me! After taking a picture I went to check on them again but they were gone. A Paris Air employee snatched them, ostensibly to put in a pond at his home. That, or perhaps there was catfish for dinner that night!


The Mega-Derecho

Monday, July 2nd, 2012

Last Friday a monster wind took out houses, hangars, and electricity from Indiana to Delaware. The highest wind speeds at the surface reached 90 mph, or more! What caused this mayhem? A derecho (pronounced de-RAY-sho), something that’s fairly common in the central U.S., but rare in the east. A derecho isn’t a thunderstorm per se, although convection is at its heart. Nope, it’s a wind event, and a long-lived one at that.

The trouble starts when strong outflow winds from a thunderstorm complex–and yes, this could be a mesoscale convective complex (MCC) which we touched on before–form huge bow echos. Easily visible on infrared satellite imagery, I might add (I’m becoming more of a fan of IR images, BTW). Strong winds aloft, meanwhile, impart energy to the bow echos and start them moving. So now you have the forward motion caused by the outflows themselves, plus the windspeeds added by winds up near jet stream altitudes deep in the flight levels. It’s a two-fer! And it means big, destructive winds at and near the surface. Straight-line winds, by the way, not tornados. Derechos are not tornadic events. Although the wind damage matches what you’d expect to see with tornado activity.

How big were the winds? Reagan National Airport in D.C. recorded gusts as high as 71 mph, although surface winds as high as 80 to 100 mph have been recorded elsewhere in areas under the derecho’s influence. In yet another testimony to aviation safety, there were no accidents related to the derecho, at least not yet. Presumably because all received adequate warning, and any pilot with a particle of brain tissue made sure he/she stayed on the ground while the derecho did its thing. Hey, it’s not like it snuck up on us easterners–you could see it coming nine hours and 600 miles before it hit the Baltimore-Washington area.

Now you know why the Storm Prediction Center’s website, , is right up there on my favorite websites list. Not that I was logged on when the bottom fell out Friday night; I’m understandably afraid of a lightning hit. (I’ve lived through hits in two houses I’ve lived in, watched lighting go down a tree about five feet from where I was standing, lost numerous TVs and weather instruments to lightning hits, and watched lightning strike a barn on a farm I lived on, which subsequently burned the barn down, burning all the animals inside alive, and sending those living in the barn’s adjoining apartment screaming across open fields toward my house. In the dead of night. With the animals, trapped, bellowing in pain.) This was on December 1, 1974, the same night that  TWA 514 hit Mt. Weather on approach into Dulles International–but that’s another story.

So last Friday I was looking out the window, not surfing the net for cool Nexrad images.  I live very near AOPA HQ and the lightning was coming fast and furious–most of it cloud-to-cloud. Sure, there were wind gusts and plenty of rain, but thankfully no damage of the sort that happened in the Washington and Baltimore regions some 35 miles to my southeast and east, respectively.

As of Saturday some 750,000 were without electrical power. 911 services in Falls Church, Virginia and other nearby Virginia communities were out of service. Today I hear that the outages are down to 500,000 or so–but 911 still doesn’t work in those parts of Virginia. Traffic signals are out. Governments and schools

June 29, 2012 derecho progression

 are closed. Liberal leave is in effect. Clearly, the Boswash corridor is unprepared for derechos.

Meanwhile, friend and AOPA Pilot contributor Pete Bedell is meeting with an insurance adjuster this morning. Seems his Baron’s hangar roof departed the scene during the storm (no damage to the Baron, thankfully). I’m sure his situation is being duplicated all over the region. Not to mention the airplanes flipped over in their tiedowns, or, gasp, left unsecured. Those airplanes can be found in the nearest creek I suppose.

All because of a storm that began in Illinois. Though I didn’t capture any images during the derecho, here’s an image from the NWS that gives you the big picture, along with a chart showing the climatology of derechos.