Cue The Towering CUs


It’s raining. The “it” refers to the growling sky that hinted I should land, put the airplane away, and further discussion was pointless if not downright stupid. Although, the risk of appearing stupid has rarely dissuaded me from making the wrong stab at the Go/No-Go coin toss. Any pilot who ventures beyond the runup area has experienced a moment of, “Perhaps, I shouldn’t have done this.”

Such as the time, decades ago, when I was flying an A36 Bonanza, and ATC said, “Area of weather, twelve o’clock …” The controller suggested a minor deviation to avoid columns of towering cumulus clouds (TCUs), yearning to become thunderstorms. Being younger and flying with another commercial pilot, also young, we decided to see what it would be like to punch through the enticing pile of Cool Whip, because—by our collective logic—if you never experience something, how will you know how bad it can be? Other than, perhaps, reading NTSB reports about idiots punching through developing convective weather. So, I tightened my harness, slowed to maneuvering speed (VA), disengaged the autopilot and requested a block altitude in case of deviations. In case … sheesh. This had stupid spray-painted all over it.

(Side note: Having two technically qualified pilots on board does not double decision-making acuity. It often halves it. Unless you’ve trained as a crew with defined duties, being PIC is not a roundtable exercise.)

For those fortunate enough not to have experienced penetrating any stage of thunderstorm life cycle, imagine a Rottweiler shaking the stuffing from a rag doll in its jaws. You’re the doll. The dog usually wins and feels no guilt with the results. You can’t yell, “Bad thunderstorm!” to deadly weather standing sheepishly over a crumpled Bonanza.

What saved us from our own boneheadedness was limited exposure. We were inside the CU-tube for only about a minute, but I’d learned my lesson in the initial three seconds, and the subsequent 57 seemed an eternity as I used rudder—not aileron—to keep the airplane upright and intact. Altitude excursions were undetectable because the instrument panel was a nightmarish blur.

My PIREP of “extreme turbulence” might’ve been debatable, since extreme by AIM standards says the aircraft is “violently tossed about.” This ride qualified, but the AIM also says extreme turbulence makes the aircraft “practically impossible to control,” and “may cause structural damage.” I was practically amazed how stupid our decision was but grateful that Beechcraft had made such a tough airframe. It creaked and moaned but didn’t break. Sounds like an ad slogan back in the Sixties: “Creaks and moans but never breaks! (Might not apply to V-tails; discontinue use in thunderstorms).”

The wimpier “severe” turbulence rating was more appropriate, as we seemed only “momentarily out of control” and adhered to the AIM’s advice to “discontinue food service,” given that I was about to lose my lunch. But whatever the label, I’m inclined not to repeat the experience, although I remain fascinated by TCUs, a sight enjoyed while maintaining proper social distance from threats composed of seemingly harmless vapor droplets.

Bonanzas are in my past, and today I mostly fly light sport airplanes. Getting somewhere isn’t nearly as important anymore as simply being up there. With the side window open on a summer day, I’ll throttle back to ride a thermal as it spawns a particularly seductive cloud that’s giving me its Siren’s come-hither gaze, while I remain 2000 feet clear of its hips. Students ask, “How do we know we’re no closer than 2000 feet?” I tell them to imagine our home base 2000-foot runway stretched between us and the cloud. “Plus,” I add in a professorial tone, indicating I don’t know what I’m talking about, “if we weren’t 2000 feet away, we’d be in violation of 91.155 Basic VFR minima. Therefore, we must be 2000 feet clear.”

I rarely operate my Aeronca Champ at or above 10,000 feet MSL, where horizontal cloud clearance increases to one mile. Heck, I rarely operate above 1000 feet AGL, so I’m usually inside Class G—so-called “uncontrolled”—airspace, where in daytime airplanes must remain clear of clouds, and their pilots can swear there’s a mile visibility. The question begs from no one: Does “clear of clouds” mean the whole airplane need be clear or just the cockpit? Does poking a wingtip into a cloud violate the letter if not the spirit of the reg? If you can see a perfectly focused airplane shadow (yours, it’s assumed) highlighted by a circular rainbow on the cloud, are you too close? If you see a converging second shadow, is it too late?

A preemptive clarification: The FAA no longer wants CFIs to call our clients “students,” an apparently demeaning term, and instead refer to them as “learners.” So, instructors are “learnees” or “certificated learnerators?”  I’ll let others dissect any possible merits to that change.

Now, though, as the rain soaks the runway, and my airplane is dry inside her hangar, I can reflect on the developing TCUs that earlier had invited us up to explore. The approaching colonnade of brilliant white against blue prairie sky, had coalesced with complete indifference to my plans, into a mesoscale thunderstorm that filled the windshield. It was breathtaking, and I undoubtedly would’ve taken my last if I hadn’t 180’d and headed for home.

I’ve made and survived a wad of dumb decisions over 45+ years of flying and am not proud of many but learned from some. I try not to repeat the worst but will always take the opportunity to stare a Rottweiler TCU in the snout … while leaving plenty of room—way more than 2000 feet—to turn tail and run before the “it” hits my fan.

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  1. Thanks Paul for the seasonal reminder and another enjoyable read. Students are no longer students? I hadn’t heard.

    My worst ever ride was through a thunderstorm during the mid 1970’s as a passenger in the aft most row of an Air Cameroun 707 from Kinshasa to Douala. The 707 had come from Addis to Kinshasa where the weekly flight normally took on some fuel prior to proceeding to Douala, but this day they did not refuel because they were required to pay in US$. Payment in US$ being a non-starter, they decided to continue to Douala sans refueling. This precluded deviating for weather. It was literally a rodeo bull ride complete with deafening thunder outside and amber flashing inside to the extent that I said what I thought were my last prayers. Our descent into Douala began way late, presumably to make the entire descent at idle power which we did. Flaps, gear, flaps and even boards came out in a final long idle power dive to the runway. The “it” nearly hit my fan that day.

  2. Paul..

    A nice walk down “ there I was” boulevard.. Truly a nice skill set of experience, created by a history of trying different things.. Wonderful correlation to the GA and Air Carrier world.. You may spot CU’s on airborne radar, but everybody goes around the bad stuff.. No penetration.. If you can’t see around a CU, then by all means, go all the way around the WX,.. Or you’ll wish you did..!

  3. You’ve reminded me of the time back in the 70’s we got SO tossed around in an early 50’s V-tail over eastern Kansas that the airplane got upside down … and we weren’t IN the TCU. An old heavy mike came off it’s perch and boinked the PIC/owner who was spurting blood from his lip. I experienced total loss of control over my body and actually “saw” the newspaper article announcing my demise. I could barely tune the radios I was so nervous. The knothead I was flying with continued on into the clouds — illegally — with the help of some guy in a 400 Cessna w/ radar. When we landed in Burlington, IA, I actually kissed the ground. Not only did I learn not to fly near a TCU, I learned that they have powers that you can’t even see miles away … just like we learned as students.

    BTW: The PIC killed himself and his whole family in Colorado a couple of years later in that same airplane.

    I think every pilot either has — or maybe should — experience terror to learn that all those warnings we got as a student aren’t just words … they’re a credo to pay attention and … “Don’t do that.” We don’t have to touch a hot stove to know it’ll burn us.

    Over three decades of living in the Mojave desert, I’ve heard of probably a half dozen V-tails coming apart in extreme turbulence over the Tehachapi’s or even IN the desert during bad WX.

  4. Even student (implying the ability to study by your-self and to decide whether or not to listen or even attend the lecture) is out of place when learning how to fly.
    Surely good old teacher and pupil is more accurate?
    (Don’t call me Shirley — sorry could not resist).

  5. Yea. Younger, stupider (or not), had to try it just once “just to see”. I had just gotten my double eye, myself and pilot friend were in a C172 on a tower enroute IFR in the L.A. basin. We were VMC but saw a very nice and very pretty Cumulous right ahead. Tops not too bad and size of it not too bad. Would be through it pretty quick if I didn’t like what was inside. Could have turned 15 left or right and missed it easily. But, I was a double eye now! Go for it. As happened to you, we plunged into it and all hell began. I think the color of the interior was maybe yellowish. We didn’t have quite the ride you did, but for us it was a ride only because I certainly was not in control of this up and down tossing and turning airplane anymore. Was before encoding altitude transponders, because if I had one then, ATC would have seen us up and down about 1000′ off our assigned. We finally popped out the other side, and I have never, never done that again. And that was actually just a baby Q.

  6. During UPT in west Texas one afternoon, my T-38 IP taught me a lesson I will never forget. He had me dive to the bottom of the area aimed at a TCU that was growing like a mushroom on high quality horse-stuff. As I started my pull he had me slide into flull blower while just short of Mach 1. My goal was supposed to be passing that growing cloud. Popping out the top of the area at 350 I still hadn’t even come close. The lesson, well and permanently learned was: you can’t out climb’em.
    Another lesson, not personally learned of course, was the result of the C-141 fatal accident in England in 76. That airplane tried penetrating weather in England without radar, it had failed in flight. That aircraft landed in a farmers field in 4 large pieces, all personnel dead. Compact European storms are just as nasty as the 70K footers in TX.

  7. I always love these ‘There I was…’ stories. I’ve always said that I learned more at the bar talking about flying, than sitting in the airplane (I learned to fly in the military). Now I use forums like this.
    Anyway, I was flying an F-4 cross country from Nellis in Nevada in the 70’s. We were headed towards just such a cloud as described above – and asked ATC for a deviation for weather. Their ‘Standby’ call took WAY too long, and before we knew it, we were in said formation. Fortunately we were strapped in tight, with helmets, in a plane that could take a lot of G’s. We used all the design margin of each of those systems as we went through the horizontal, vertical and rotational thrashing. In an eternity or so, we popped out the other side, about 3,000 feet lower than we went in, ever grateful to the great job McDonnald Douglas and GE did building such a tough airplane. It was a personal life long lesson that never needs a refresher course. Read and heed … Try to only make NEW mistakes!

  8. If you are going to penetrate cu-nim–you need better equipment. Here’s a link to South Dakota School of Mines research into thunderstorm penetration.

    It is a heavily armored T-28 aircraft. The leading edges were reinforced–the bubble canopy was broken up into multiple pieces to withstand hail strikes. Armor plate was added in front of the cylinders, which were beat up by the hail.

    I’ve spoken at length with the former pilot–at the time, he had just retired from the Air Force, where he was an F-100 driver–trolling North Vietnamese missile sites to fire on them so they could be taken out by other aircraft. The man was fearless. Multiple lightning strikes on the T-28, and when they had a good understanding of thunderstorm dynamics, they went LOOKING for hail shafts!

  9. When you see photographs of hail stones (boulders?) ranging in size from grapefuit to footballs, it gives you a clue to the power of the winds inside a TCU. Anything that can hold a chunk of ice up long enough to grow to that size would have no problems manhandling an airplane. Years ago, having seen the beat up remnants of a friend’s plane after he flew too close to the underside of an anvil head, I decided to never temp the same fate. That’s not to say I haven’t pulled other dumb stunts in an airplane, but at least I did learn one lesson from someone else’s misfortune.

    Speaking of learning, if students are now learners, I think the FAA has things backward. An employER has employEES, so shouldn’t the learnER be the teacher and learnEES be the students?

  10. Paul Berge maybe many things, such as a fine pilot and an excellent writer. But above all, Paul appears to be an expert polisher of aircraft windshields. Not a splattered bug anywhere in the picture!

  11. The pics, the writing, some comments, all moved my perspective back to growing up in the Heartland near Chicago in the best ways. Green everywhere, rivers and towns with airport restaurants, ‘water towers’, and ubiquitous farms laying out beautiful, unintentional patchworks of terrestrial quilts.
    And, that rarest of rare sky events we in the Southwest call WX, or Weather.

    As much as I’d love to fly into the center of the Sun to experience the roiling furnace firsthand, as in “if you never experience something, how will you know how bad it can be?”, I tend to avoid the rare CB’s and T-storms like the true wuss I am now.

    But ohmygoshisthelandFLAT! …Lovely though, thanks for the trip, Paul, hmm…maybe buy a few riverfront acres somewhere to park my motorhome on to escape our desert summers…but where to keep the plane? :-]

  12. Paul…you make me smile. I absolutely, flat out enjoy your writing. Especially when you become even more creative than your normal creative self.

    “The FAA no longer wants CFIs to call our clients “students,” an apparently demeaning term, and instead refer to them as “learners.” So, instructors are “learnees” or “certificated learnerators?” My vote is for certificated learnerators. AAAHL B Baaach steely eyed, sage, wisdom filled, awe inspiring certificated learnerator. If you cannot learn from a certificated learnerator, you cannot be taught. Sort of like “if I have to explain it, you wouldn’t understand” mentality.

    I was one of the few enlisted backseat qualified maintenance personnel in the Navy T2C Buckeye back in 1984. I often flew to the mechanically downed birds with a particular Marine Major who was an ex-Vietnam A-4 driver ( 2 combat tours) and Top Gun instructor. He was also a gear head owning a very quick 65 Falcon goading me into many drag races with my 70 Rebel Machine leaving NAS Kingsville. While most officers were running high dollar European sports cars, he was all American, hard-core, muscle-car street racer. He also knew that I was a Cessna 150 ace. He loved to get dirty with me when repairing an airplane, demonstrating his own excellent mechanical skills. I had joined the Navy at 28, so he was only a couple of years older than me. So, we had a unique bond from a couple of mutual interests. He thought it was unfair that enlisted had to barrack in the “low rent” side of any airbase, plus the inconvenience of having to pick me up, normally a distance from the officer’s quarters. So, he fixed me up with my own green LCMDR flight suit. I enjoyed the benefits of the officer quarters. While carefully, and with great detail, told me he would deny any involvement in this ruse if caught, it worked quite well for the many rescue missions we flew together. I just had to remember to salute back to my suspicious enlisted brethren.

    We suited up after getting a call from Cherry Point, NC from an instructor with a student pilot on a cross country training mission when they suffered hydraulic pump failure. Just to the west of Cherry Point was a developing front drifting slowly, but steadily east. The idea was to get to the downed airplane in time to repair, and then launch in formation from Cherry Point back to NAS Kingsville before this building line of T-storms with expected tornadoes over ran Cherry Point requiring an over-night or longer stay. The flight in would help us get a handle on how fast the storms were building. The return flight would require a fuel stop en-route back to NAS Kingsville. He was an expert and welcome hand when changing both pumps making this one of the fastest hyd pump changes ever performed on a Buckeye. Our PMCF (post maintenance check flight) would be our return flight.

    While taxing out in a mostly now very green sky, the tower controller closed the field to any more incoming traffic including sending a very close C-130 to his alternate field much to his dismay, then ordering us to expedite our formation launch…like right now or taxi back to the parking area. The wind sock was limp, the gages in the green, the stick wiggled, and we launched together. We went into this pea green overcast about 800 feet. I also noticed we were doing a max rate climb. In short order, we spread out from the normal, almost trading paint formation flying to seeing the other airplane occasionally at a wingspan or so distance away. All was eerily quiet, smooth, and very green.

    First, the Marine Major switched to a hot mike. I could clearly hear his breathing and usually, if he did this, it was somewhat of a warning that something is not right requiring rapid fire communication without pressing mike buttons. Of course, he could also hear me breathing, and any other sounds I might emit as well…no mike button needed. Soon after, the command ejection seat light came on which allowed him full control of ejection. If he punches out, I automatically go out with him a split second behind. Two very strong signs things could and most likely will rapidly change. I looked over my shoulder and could see faintly the outline of the other T2C and it’s glowing nav lights and flashing beacon in the still green clouds. We were actually in a left hand, sort of a cork-screw max climb, definitely not a normal departure procedure. One must remember, this is a basic IFR panel, not equipped much differently than a C150 IFR trainer. No radar or anything other than what was learned during the per-departure weather brief and some inbound PIREPS before base closure.

    At 14,000 feet my helmet hit the canopy causing me to bite my tongue…really bad. Although I had really cinched down my belt in anticipation of violent turbulence, it was so bad in an instant, I still hit the top of the canopy while the airplane literally seemed to be falling not as if in a free fall. Instead it was being forced down violently. Our attitude was still nose up, but in a matter of what I perceived as a split second or slightly more we bottomed out around 7,000ft. The skin outboard of the fuel tanks inboard of the tip tanks sheared off a row of rivets as it buckled upward as we pulled now violent positive G’s. At the same time, our headsets are filled with my yelp when hitting the canopy and a now bleeding tongue, followed with lots of weird grunting noises as we pulled a bunch of positive G’s. Ex-military knows what these bizarre sounds are like when in high G air combat maneuvers or during high stress traps ( excluding my yelp…that was one of a kind…nor am I proud of it).

    This cycle of climbs to 14K or so met with a down-force hammer blow back to around 6-7K repeated itself three times in rapid succession. On the fourth climb out, we seemed to be heading toward light rather than the pea green. The turbulence was awful and almost indescribable. The rain unrelenting. I was convinced the engines were going to be drowned out. But things were way better than three previous hammer blows down. Somehow, that Marine Major managed to keep the rubber side down. Somehow the other pilot did likewise and we did not hit each other. As I remember, the service ceiling of a T2C was somewhere around 41,000 feet.

    At around 42,000 feet we broke out into the most surrealistic scene I have ever witnessed. The visuals were close to what a psychedelic album cover would have looked like composed by someone on LSD. At those altitudes, a lot of stick movement needed to sort of herd the airplane around rather than the usual precise flying characteristics. It was all my pilot could do to maintain that altitude and not drop back into this cauldron like mess very close to our belly. Tall spires of still building T-storm clouds overshadowing what looks like a maelstrom of swirling green, gray, and black clouds beneath us with an almost blinding sunlight as a backdrop of amazing colors. The only thing missing was seeing the angelic choir singing the Hallelujah Chorus as we slowly turned left and right, with the other Buckeye doing likewise about a mile ahead of us, we looked like two drunken pinballs in an old arcade game navigating around these spires of ever changing colored clouds. No words were spoken but a lot of Tim Allen type of grunting. Other than the now slightly lifted top skin out board of the fuel tanks waffling up and down a little, and a significant scuff above my helmet to the canopy, it seemed like the rest of the airplane was all together. My cockpit was a mess. Amazing what lies in the bowels of an airplane when one pulls that many repeated, violent negative G’s. As we burned fuel we were able to maintain this altitude for a few more miles as the morass below slowly began to descend allowing us to follow that contour to a thicker altitude.

    At our fuel stop we assessed ourselves and the airplane. My legs were severely bruised just above my knees from repeated whacks to the instrument panel. My tongue had stopped bleeding but so swollen I talked like I had a mouthful of marbles. My back was sore from the pounding of positive G’s when we bottomed out. My glasses were bent. My Frito bag had exploded. My camera damaged. The wing skin’s top rivet heads were sheared quite neatly but seemed to pose no structural problem according to the North American tech rep as long as we did no more high G maneuvers. It appeared to have forced an unknown amount of Jet A out of the tops of the fuel caps. And a bunch of paint had eroded off the leading edge of the engine’s intakes.

    I could not imagine going into a building CU in Bonanza. Our escapade lasted but a few brief but almost lifetime like slo mo minutes. I was in a stout, well designed Navy trainer flown by one of America’s best. While we expected rough, no one anticipated what really happened as we thought we were not in the middle of anything but at the fringes of this storm. We had a fresh PIREP from the C-130 pilot who was inbound on our intended outbound route. We were advised it was still very smooth. That proved to be partially true. We purposefully did not attempt a direct cross through. We thought we were on the fringes and felt by getting to our normal cruising altitude as soon as possible, we could avoid a significant part of what we thought we knew of the storm. As it turns out some of our assessment was true. However a larger part was not even close. Handling any nav or communication duties was impossible. The panel was a violent, shaking blur. How, the Marine major kept the greasy side down still amazes me. And I have never, ever attempted to go through or near anything that looks like building CU.