Thomas Block

Full Circle: Wind Dilemmas

Lessons learned about wind and mountain waves. 

As I sit to write this, the major theme in my life these past few weeks has been wind. I say that because, first and foremost, we are right now involved in cleaning up our Florida horse ranch from the effects of Hurricane Irma—which, thankfully, amounted to only a half-dozen fallen trees and, literally, an infinite number of tree limbs scattered across our acreage. 

The second reason these past few weeks have involved wind is that I was concurrently producing an audiobook version of Harrison Jones’ nonfiction book “Miracle on Buffalo Pass: Rocky Mountain Airways Flight 217.” Reading for the audio version got me to thinking about experiences with wind-induced dilemmas from my own aviation past.

The book itself is an in-depth analysis and interview with nearly all the survivors of the Rocky Mountain Airways Twin Otter turboprop that crashed in a blinding blizzard at the very top of one of the most inaccessible spots between Denver and Steamboat Springs, Colorado on Dec. 4, 1978. 

We follow the passengers and crew through their experience, and then the bands of rescue personnel who mobilized immediately to attempt to locate the wreckage and any potential survivors before they would invariably freeze to death on that desolate mountaintop.

As the NTSB later concluded, the Rocky Mountain Twin Otter encountered an unforeseen severe mountain wave which, when combined with some airframe icing, prevented the commuter airliner from climbing above 13,000 feet (the MEA in that area was 16,000 feet) and the airliner was then gradually forced down into the terrain, just barely clipping the top of the mountain at Buffalo Pass. 

The first miracle was that everyone survived the initial impact with the crest of the mountain, but if rescue folks didn’t locate them quickly (no one knew for sure where they had gone down, and it was the middle of the night in a driving blizzard), none of them would survive.

As the NTSB pointed out in the accident report, one of the things that disguised what was happening was that the mountain wave the flight was involved with was quite smooth. With no wind-induced turbulence to tip the crew off, the initial symptoms of decreasing climb performance seemed to be more related to either engine power output or airframe icing. When the pilot in command is not understanding why something is happening, it’s far more difficult to come up with a reasonable plan to correct the problem. 

My own experiences with mountain waves were certainly nowhere near as dramatic, but they were personally attention-getting. Being more of a flatland pilot, my initial exposure to the effects of wind across undulating terrain came from those small bumps in the earth around Kentucky and West Virginia that we Easterners call mountains.

About 50 years ago I was skittering around Eastern Kentucky in, if my memory serves me correctly, a Cessna 140 with a 90 hp engine. It was a breezy day—nothing too outlandish—and I was giving a student some dual in the art of crosswind landings at an outlying grass field we often used. 

After a half-dozen acceptable takeoffs and landings in the quartering wind that was 20, with maybe gusts to 25, we left the airport for a little local flying up higher to get away from the bumps. 

After a few steep turns and whatever else I thought the student could use, I figured that we’d top off our day with a simulated engine failure, then head back to the barn. I chopped the power and announced: “Engine failure.”

The student picked a field below in a reasonably wide valley between two rows of hills, and set up an approach to a large pasture. Down to about 300 feet everything looked fine, so I announced, “The engine is working again; just go around and head back to the airport.” The student complied.

Sort of. 

He did everything right. So did the airplane. But Mother Nature did not. The student pushed the power up to max; 90 horses surged into the prop, and he turned us toward the airport that was on the far side of the next ridgeline. But we were, I figured out later, on the leeward side!

At max power and max climb speed, we were barely holding altitude—and the ridgeline in front of us was getting nearer! I was getting less comfortable with every passing moment, until I finally said, “I’ve got it.” 

Suspecting there was something now wrong with our engine, I did a snappy one-eighty to head back for our simulated emergency landing field—one that I figured we might need for real. Partway back—and, it turns out, away from the effect of the downward wash of wind over the ridgeline—we began climbing normally again. We climbed to a higher altitude, then crossed that ridgeline far above the mini-mountain wave effect beneath us.

Many years later I was in a light twin flying between northern Colorado and Montana, where there are some real mountains by anyone’s standards. It was a breezy, clear day and I was flying at the MEA, enjoying the view of the ridgelines and canyons that passed below. 

What I noticed first was the airspeed slowly trickling away as the autopilot kept pitching us up a little more as it tried to hold our altitude. Again, my first thought was that something was wrong with the power output from the engines, or at least one of them.

Yet all the engine gauges were middle of the green. They sounded fine, too. So what could be happening? It took me a few moments to see the obvious: the line of higher mountains to the northwest of my location were at a right angle to the prevailing wind. We were apparently in a downwash of wind from them. 

I requested a higher altitude from ATC, pushed up climb power and while the rate of climb was a little lower to begin with, a few thousand feet of climb later, the performance numbers went back to normal as we got above the downward effect of the distant mountain wave.

But don’t think that only smaller airplanes are susceptible to this sort of wind-induced dilemma. About 30 years ago I was the captain of a Boeing 737-400 headed westbound to San Francisco over the middle of the biggest rocks in the Rockies. We were at FL310 on a windy day, with our ground speed being clobbered by the constant westward flow. Still, the sky was smooth—so all was well, right?

First clue: the sense of the airliner trying to climb, the autopilot rolling in nose-down trim and pulling off engine power to keep us at altitude. I commented to the copilot something insightful, like, “What the hell?” 

I disconnected the autopilot, reduced the power on both engines until they were back at idle—and we were still being propelled upward at over 2,000 feet per minute! It was hard to believe what the gauges were saying. I pulled out full speed brakes, and still we were climbing! 

The copilot told ATC that we couldn’t hold altitude; that we were being pushed up. We got to 35,000 feet and I began to seriously worry because, even thought the sky was still smooth, if we went much higher the air would be (in a manner of speaking) too thin to keep the wings from stalling—“coffin corner,” it’s called.

Then we hit the turbulence, which started at severe and quickly got worse. Our big Boeing airliner was simultaneously being pushed upward and churned all around the sky! We needed to get down—quickly—before the wings decided to do the job for us. 

I was just about to call for gear down (at this airspeed, it would have probably done some gear damage) to get more drag to stop us from climbing when, in the blink of an eye, the washing-machine sky we were in went dead calm.

We had popped out of this mountain wave-induced wind machine at 35,400 feet. We stopped climbing, the airspeed began to drop, and I then pushed engine power to a low cruise setting. After coordinating with ATC, we turned off our route that had us headed toward the highest mountains and eventually drifted back down to our assigned altitude of FL310.

So that’s what I spent Hurricane Irma doing: narrating the book “Miracle on Buffalo Pass,” which is about the results of a wind-induced accident, while listening to the winds howl around my own home. 

Like an old captain once told me nearly 60 years ago, “Son, don’t fool too much with Mother Nature. She can win anytime she wants to.”


Full Circle: A Controller Speaks, Part 3

Highlights from “Spinning at the Boundary: The Making of an Air Traffic Controller” by David Larson.

This month I’ll be continuing a series that highlights the interesting and entertaining memoirs from an FAA air traffic controller (one of the aviation-themed audiobooks that I’ve produced and narrated), David Larson’s “Spinning at the Boundary: The Making of an Air Traffic Controller.” 

“Spinning at the Boundary” is an insider’s view—with lots of iconoclastic observations and irreverent opinions—from an experienced controller’s career path and the ATC happenings during that long (and often tumultuous) period in our aviation history. With the author’s permission, here are more highlights from his years in the Miami (KMIA) tower and radar facility.

The old airplanes that flew out of the northwest corner of the Greater Miami International Nuthouse hauled more than just pigs and chickens around the world. Sometimes they hauled race horses, and sometimes they hauled other exotic animals from one zoo to another.

One day we’re going about our air traffic control thing in the tower and the guy working local had rolled a DC-6 off 9L. 

“Hey,” the controller said as he flipped his radio to speaker mode, so everyone else could hear it. “This guy keeps whispering to me. Can any of you understand him?”

“Say that again,” he said to the pilot, as we all listened intently to the radio.

“96BL needs to come back and land,” the pilot said in
a voice so soft we could barely hear him with the radio on
full blast.

“96BL, enter a left downwind, cleared to land Runway
9 Left,” the controller said. “What’s the nature of your

“Cleared to land,” was the whispered response. 

“What is the nature of your emergency? Say your fuel remaining, and souls on board.” (We always asked how much gas they had and how many people… or souls. There is a lot of speculation as to why we were required to ask that, but at Miami we assumed that it was because the fire department wanted to know how big the fire was going to be, and how many bodies and survivors to look for. Consequently, supervisors would tell the controllers to ask the captain for bodies and burn time every time they worked an emergency. We never put that out on the air.) 

There was no immediate answer. “We are going to need an animal handler,” the pilot eventually whispered.

“What did he just say?” the controller asked.
“Say again, 96BL.”

“We… will… need… an… animal… handler… Out.” 

We all got that message loud and clear. He had no more to say. 

We got everybody out of his way, called the fire equipment out, told them the “animal handler” thing, and sat back to see how things played out. 

The DC-6 made a giant, slow, gentle turn to final and touched down on the runway ever so gently. Even as the plane turned off the runway he was shutting down all four engines. As the big silver dinosaur slid to an almost imperceptible stop, the escape hatch opened, ropes uncoiled down to the pavement, and the whispering crew climbed down to the ramp. 

As the story goes, this particular DC-6 was taking a giant anteater—along with other cargo—to a zoo someplace in the Midwest. At some point as the plane sat on the ramp getting ready to leave, the Vermilingua extricated itself from the cage and ambled up front to spend some quality time with the crew. 

Oddly enough, as soon as it got in the cockpit it crawled up on the pedestal (the console between the pilot seats that has the throttles sitting on top of it) and fell asleep. The crew was whispering because they didn’t want to wake up the giant long-nosed dog that had three-inch razor-sharp claws. 

While we’re on the subject of flying wrecks at Miami, several stories come to mind. My wife, Christy, was working south local one day. The south runway on an east operation at Miami is usually only used for arrivals. Some of the cargo hangars were fairly near the approach end of that runway, and you might get one or two of these departures in the course of working that position.

One of the things that you need to know about the wonderful world of air traffic control is that almost all of the rules were written by lawyers after some type of heinous crash or screwup. Way back in the day, our rule book was known as the ANC, or Army, Navy, Civilian—and it was about 10 pages long. 

Then a few years passed, a few pilots died along with a lot of passengers, and the ANC became the ATP or Air Traffic Procedures. This book was several hundred pages long. Today, this book is called the 7110.65. I keep a copy next to my bed to knock intruders unconscious.

Among other stupid things that have arisen from having bureaucrats make rules is the odd fact that we can’t tell a pilot what is happening to his/her aircraft without first saying “it appears.” That led to a hilarious story about a Cessna 402 that took off without having the door latched correctly. The copilot went back as they became airborne—and the door fell open just as the guy grabbed it, dragging him out into the atmosphere with it.

“Ah, it appears your aft door is open, and someone is hanging onto it screaming.”

Another story is that a cargo DC-8 taxies to the approach end of 9R, and calls ready to go. Christy waited for a gap in the arrivals on the final, and then puts the DC-8 into position, telling him to be ready to go. Once the runway was clear, takeoff clearance was given, black smoke rolled up behind the big jetliner, and it slowly started creeping down the runway.

Just past the tower the wings on the big DC-8 generated enough lift; the nosewheel lifted off the ground, followed closely by the main wheels, and the eager craft was committed to the commerce of aviation. 

That was when one of the engines fell completely off the aircraft, slammed into the runway, and slid down the centerline like a Japanese torpedo at Pearl Harbor.

“It appears you’ve lost an engine,” Christy told the pilot as she watched the engine lazily come to a halt on the runway.

“I know,” said the pilot. “We’re trying a restart but we want to come back and land.”

“No,” she said. “I mean, it appears you have LOST an engine.”

“I know that!” he said, obviously irritated. “We’re coming back.”

“Roger,” she said calmly. “Cleared to land Runway 9L; Runway 9R is blocked by your engine. I suggest you look out the window.”

The scary part is that when the airplane got back to the ramp they found that when the engine flew the coop, it hit the engine next to it, knocking that one loose from its pylon, and it was swinging freely in the breeze just waiting to make a break for it at the earliest possible moment.

Here’s another story. As I said before, we worked a lot of really old airplanes back then, and one of the biggest examples was the Boeing 377 Stratocruiser. I admit that working this flying museum was pretty cool, and there was no place else in the United States that you could actually see this many working examples of this type of aircraft moving in and out of a major airport. 

The downside was that these aerial crates were really starting to show their age, and anytime you saw one crank up on the ramp, you knew it was just a matter of time before you had some type of emergency on your hands.

This was the case late one night—well, actually, early one morning—on the midnight shift. An inbound B-377 called the approach controller, and shortly after that declared the not-so-surprising emergency of having one of its engines out of service. The radar controller got the “bodies and burn time” numbers from the pilot and passed the information on to the tower controller.

At some point prior to the aircraft getting to the airport, the crew tried to lower the landing gear. Aircraft with retractable gear have a series of lights (usually three) that show green when the gear is safely down, and red when the landing is going to be really noisy and the pilot will need full power to taxi to the ramp. 

The indicator lights in this aircraft showed the crew that the nosewheel was being timid and refused to come out of the safety of its little house under the flight deck. The pilot informed the approach controller; the approach controller informed the tower controller; and the tower controller informed the crash equipment, which immediately raced out to the runway and waited.

The pilot lined up his eager craft on final approach to the runway, and the approach controller instructed him to change to the tower radio frequency.

Now, the guy in the radar room was a little… high strung, so he kept calling the guy in the tower on the override feature asking what was going on with the inbound emergency. 

The guy in the tower was very laid back, and kept trying to work the emergency, feed information to the crash and fire chief, work other traffic he had, and answer the radar guy’s incessant questions. 

Finally, just before the Boeing touched down, the radar guy called again and the tower guy said something to the effect of, “Get XXXX out of my ear!” Shortly after that, the Boeing touched down safely with what was apparently a faulty light in the cockpit, and taxied to the ramp with crash trucks in tow.

Unfortunately, at some point on final the captain had asked one of the crew to go down a ladder in a trap door that was in the floor of the flight deck so he could check the nosegear with a periscope that was installed there for that purpose. 

The crew member verified that the nosegear was actually down, and was on the way back up the ladder as the Boeing touched down. The shock of the landing jarred the crew member’s grip loose from the ladder, causing him to fall back down the trap door—and breaking his arm and a few ribs.

This single incident turned a nonevent into an “aircraft incident with injuries,” which in turn got the NTSB involved.

In the course of the NTSB investigation, they requested all of the pertinent data from all air traffic facilities that had worked the ill-fated Stratocruiser. That included the interphone transcripts from Miami tower. Both of the controllers got some time on the beach for that one.

The full story is available in print and e-book from Amazon, while the audio version can be found at Amazon, Audible and in Apple’s iTunes Library. (Note: this book contains a measure of salty/profane language—be forewarned if you prefer not to hear/read that sort of thing.)

Next time: Some final incidents from DTW and MIA.

Editor-at-large Thomas Block has flown more than 30,000 hours since his first hour of dual in 1959. In addition to his 36-year career as a US Airways pilot, he has been an aviation magazine writer since 1969, and a best-selling novelist. Over the past 30 years he has owned more than a dozen personal
airplanes of varying types. Send questions or comments to



Full Circle: A Controller Speaks, Part Two

More excerpts from David Larson’s “Spinning at the Boundary: The Making of an Air Traffic Controller.”

The last time we were together I began a series highlighting one of the aviation-themed audiobooks that I produced and narrated: the interesting and entertaining memoirs from an FAA air traffic controller.

Retired after 36 years of working traffic—initially at some small and then on to several very large ATC facilities—David Larson’s “Spinning at the Boundary: The Making of an Air Traffic Controller” is available in print and e-book from Amazon, while the audio version that I narrated can be found at Amazon, Audible and in Apple’s iTunes Library. (Note: this book contains a measure of salty/profane language—be forewarned if you prefer not to hear or read that sort of thing.)

“Spinning at the Boundary” is an insider’s view—with lots of iconoclastic observations and irreverent opinions—from an experienced controller’s career path and the ATC happenings during that long (and often tumultuous) period in our aviation history. Continuing with our selected excerpts from the audio script, and with the author’s permission, here are a few highlights from his years in the Miami (KMIA) tower, beginning with one particularly boring night shift:

I was working the midnight shift with a friend of mine and nothing was going on, so—idle minds and all—I made up a tag for an aircraft that didn’t exist. To keep it from dropping off the radar, I put it into a handoff status to an unused scope (a target in that mode will sit on a scope indefinitely).

Then I called the tower and told him a C-130 was going to make low approaches over Runway 09/27. I moved that tag by using the reposition function so that it would appear to be moving when the controller in the tower watched it on his radar display.

I ran the tag out to a 10-mile final and started to move it down the final approach course. When the tag got to a seven-mile final, I used the backup radio and called the tower. Disguising my voice, I said, “Metro Tower, Air Force five-six-nine on a seven-mile final for Runway 27; low approach.”

The controller cleared “Air Force” for the approach, and I moved the target slowly down the final, “flew” down the runway, and out the other side.

Needless to say, the tower guy never saw anything.

I kept up the approaches for the next hour or so while I told the guy in the tower it was a top secret test the Air Force was doing on super stealth aircraft that were really, really quiet.

I kept at it until the guy upstairs realized that the voice on the radio was me. Oddly enough, he didn’t think it was near as funny as I did. Go figure.

Another story within “Spinning at the Boundary” came from the radar room in Miami. It happened while Larson was training a new controller on approach control and other controllers in the room were carrying on very loud and raucous personal conversations with each other:

The incident that pulled the bottom card out of our card house wasn’t the mistake that was eventually made; the final straw was the action taken to fix a mistake. A British Airways heavy B-747 (callsign “Speed Bird”) filled with happy Brits winging their way to beautiful South Florida was on the final approach for 09L, descending out of 2,800 feet, 10 miles from the airport and already on the control tower frequency.

My trainee had turned an American heavy jet north from the south side of the airport for a visual approach to 09R. American had called the airport in sight, and the trainee cleared him for the visual approach.

So, although American was pointed directly at Speed Bird—and also at the same altitude—it didn’t matter because American would turn toward the runway before he became a factor for Speed Bird—in theory.

But instead of hearing the visual approach clearance directed to him, the pilot heard a bunch of yelling in the background of the facility from that bunch of bored controllers, so he kept winging northward—ready to T-bone Speed Bird.

Luckily, visibility was good and American eventually said, “Would you like us to turn onto the final?”

Now picture, if you will, standing on a pitcher’s mound. In front of you are 20 people with their hands behind their backs. All at once, all 20 of them fling a softball at you, and as they release them, someone yells, “Catch the red one, or everybody dies!”

That’s exactly how much time you have to fix this problem involving hundreds of people coming together with a 400-knot closure rate.

My guy had an instant fix: Speed Bird was at 2,600 feet, and he needed 1,000 feet of separation to be safe, and since American was descending, he told that pilot to descend immediately to 1,500 feet. The downside was that American was still at 3,000 feet, so to get to 1,500 he had to descend through Speed Bird’s altitude.

I took the frequency over at that point, stopped that, and let American pass behind Speed Bird.

Even though they would miss each other by less than half a mile and 100 feet of altitude, it was the best alternative I had. It was technically illegal, but by using that option, everybody got to go on living.

Unfortunately, that was when something else turned really sour.

Once I took the position over, I began transmitting at a hundred miles an hour. The fact that 300 or 400 people nearly died at my hand didn’t help my mental condition at all—but I still had to keep ‘em separated.

At the time, I had 15 to 20 aircraft on my frequency, all going between 250 and 150 knots, and all trying to get to the same spot on the earth. I was talking nonstop as fast as I could, not even taking time to unkey my radio so the pilots could answer me.

After every instruction I would tell the pilot to “ident to answer”—that would cause a little “ID” to show up on the scope, so I knew they were doing what I told them. I was now “vectoring for Jesus,” as the expression goes.

All things considered, events were actually going pretty well at that point. The rest of my wards were adequately separated, and I could see a glimmer of light at the end of the tunnel. The light quickly turned out to be an express freight train headed directly toward me.

I looked up into the northeast arrival corridor, and noticed that an Air Canada Airbus and a Comair regional jet were winging their way down the arrival chute at the same altitude—but luckily, three miles apart, side by side. I thought I should pull these guys apart a little more.

As a refresher, on any radar scope little “tags” follow each aircraft. A “position symbol” sits over the actual aircraft (this symbol is the letter of the scope that is working that traffic: “S,” “A,” “V,” “N;” whatever).

Then a line called a “leader line” extends, usually about one-fourth of an inch, to the “data block.” The data block contains the flight information, callsign, aircraft type, altitude, etc.

This automation also has a cute feature called “auto offset.” This feature will offset a data block that is laying on top of another one, so the controller can read it.

Back to our hapless duo in the arrival corridor. As you may remember, I was going to help them out by pulling them farther apart. The tag for Comair was on the east side of the corridor, and the tag for Air Canada was on the west side, so I turned Comair 20 degrees to the east and Air Canada 20 degrees to the west.

As I’m sure even the slowest of you have already figured out, the tags had auto offset, and instead of giving the pilots some breathing room, I tried to fly them up each other’s noses.

All Comair had time to say was “Hey!” as he ripped right behind the Airbus.

The history that was made at this point was this: two “deals” (ATC system errors) in one session that weren’t even related to each other.

I politicked for my trainee, who had done a smashing job (no pun intended) right up until the deals occurred. So the instructor—me—was decertified with a double deal, and the trainee was checked out.

Next time: The weirdness of KMIA prevails.

Editor-at-large Thomas Block has flown nearly 30,000 hours since his first hour of dual in 1959. In addition to his 36-year career as a US Airways pilot, he has been an aviation magazine writer since 1969, and a best-selling novelist. Over the past 30 years he has owned more than a dozen personal airplanes of varying types. Send questions or comments to .