Flat hatting, part deux

Point Hadji

You can be going mach 2.0 in a fighter at 40,000 feet, and feel like you’re pasted in the sky. To really get the sensation of moving quickly, it’s important to have reference to the ground. The lower you go, the better that reference is visually defined, and the more gratifying the feedback.

Once you get down low, your eyes quickly acclimatize themselves to the rushing blur of the terrain sweeping under your nose. In time, the temptation to regain the feeling of speed by going just a little lower is hard to resist. You have to resist it though, because at some point you go past the point of just fooling around, all-in-good-fun, no harm/no foul buffoonery and well into the territory of “how fricken stupid could he be, flying into the ground like that?” Because you can only tie the low altitude record. You can’t beat it.

But there is, I am told, one other way to regain the sensation of speed.

Just to the east of the Edwards Dry Lake Bed , east of the Sierras in the high desert of California, there’s a neat little canyon, little more than a rugged cleft in the mountain face, which plunges quickly from the high escarpment down to the Panamint Valley floor below.

It is a sort of miniature “Star Wars Canyon ,” right in our own back yard. I’m told that you could scream above the desert floor at 450 knots and a couple of hundred feet, and then, having reached the opening to the canyon, flip your jet upside-down, and thrill for the course of seven or eight seconds to the sight of the zigzagging rock walls perhaps a hundred feet away from either wingtip. Which sounds like a lot, but trust me, it isn’t, not moving at those speeds. The folks who’ve done it? They say it’s a blast.

Dangerous, though.

Low performance planes, puddle jumpers, bug smashers and bombers, for example, often get themselves in trouble flying into box canyons. Sometimes they “turn the corner” and rather than see a path ahead leading ever onward, they see a sheer rock wall, staring them in the face with grim indifference. In far too many cases, it will be the last thing they ever see. They haven’t got the excess thrust to rapidly generate a rate of climb sufficient to get above the terrain, and usually don’t have the turn radius to go back the way they came. Running rapidly out of time and out of ideas, the hapless pilots of these craft will often try to convert their pitiful supply of excess airspeed into altitude. But since they don’t go very fast anyway, it’s mostly not enough, and they end up hitting the canyon wall right at, or even just past stall speed. Which is just barely fast enough to kill you.

In a fighter, with afterburning engines and knots on the jet, you’ve always got the “up” option to clear the canyon. Except when you don’t.

Like when you’re flipping the jet from turn to turn around the zigzagging terrain. You see, lift is generated perpendicularly (in the normal plane) to the wing planform. In level, unaccelerated flight (no excess g on the jet), all of the lift opposes gravity’s pull. Since gravity is pulling you right now at 1g in the negative y -axis, 1g in the positive y-axis is required to remain level.

As you roll the jet into increasing angles of bank (AOB), increased g is required to maintain level flight: The relationship of required g to maintain level flight can be expressed as g= 1/Cos AOB. From this you’d determine that at a sixty-degree angle of bank, the g required to maintain level flight is 2.0.

And it’s probably intuitively obvious to all of you (right?) that since we’re talking about inverse relationships and cosines, that as you increase the angle of bank past 60 degrees the g required increases very rapidly – from 60 to 75 degrees, for example, it doubles to 4.0 g. In fact, at 90 degrees angle of bank, the g required to maintain level flight would essentially be infinite, which I think we can all agree would be painful for the pilot to endure, even if the airframe could generate it.

Which it can’t.

So.

You: “What if you went over 90 degrees angle of bank, Lex?”

Me: “Well then, gentle reader, at the altitudes we’re talking about? Your lift vector would be taking you rapidly towards the site of your fatal accident.”

You: “Oh.”

Just one more thing, and that’s AOA: Angle of attack can grossly be described as the difference between where your airplane is pointing, and where it’s going. (And yes Lamont, I know it’s actually the measure of the angle of the wing’s incidence to the relative air mass, measured from the wing’s mean aerodynamic chord line, but this is for everyone else.)

(Lamont, gentle reader, is the omnipresent voice of my guilty conscience in all things technical.)

So the point is that even when your nose is pointing into the clear air mass, it’s not at all impossible that your frail craft is hurtling towards the unyielding and dispassionate earth, carrying with it your fragile pink body. Depending on the breaks.

So with all that said, you can no doubt understand why flying down Point Hadji was so thrilling. The sensation of speed was incredible (you’ll never, no never get used to terrain on three sides of your machine), the skill required to navigate successfully (I do not say safely here, it doesn’t quite fit) under those conditions of altitude and speed was significant, and best of all, from the standpoint of the thrill seeker personality type, was the fact that there was a Very Real Chance of killing yourself. Why that always seemed to go hand in hand with good clean fun (ok, fun? clean fun, anyway?) and aviation is something that is still a mystery to me.

And as fun as it was navigating down the precipitous canyon to the valley floor below, it was probably equally exciting (again, I’m told) to fly the route in reverse, up the escarpment. Why, I know of a fellow who did so, or said that he did, and appeared at the top a mere (redacted) feet above a parked tour bus, which had stopped in order to give a group of eco-tourists a photo opportunity at the charming, entirely barren desert. (Isn’t it cute?)

With the sound of his approach muffled by the folds and wends of the canyon walls until really, the last possible moment, our hero essentially materialized above the gathered crowd scant hundreds of (redacted) above their heads, upside down, in full afterburner, like some screaming, carbon-epoxy bird of prey. With a Plexiglas, bubble canopy.

They were quite surprised, I should think. This was a sight I do not think that any of them had even hoped for, when they booked the tour.

When he looked down from his aerial perch into the amazed, (not to say shocked-almost-to-death, because really, who can say at this point?) faces of the eco-tourists, danger boy reflected that the item of the first importance was to keep the plane upside-down. By doing so, he hoped thereby to obscure from the cameras only now being retrieved from the dust below to hands that had moments before been stunned into momentary lifelessness, the blazon on the vertical tail identifying his squadron.

Because without an identifying mark, the plane could have belonged to anyone, anyone at all.

Yes. Yes, he was a rather wicked man, that danger boy. I scarcely ever see him, any more.