Thursday, April 10, 2014

Intimations of Mortality*

We three. We merry three. We three polished and experienced aviators on our way to sunny Sao Paulo, looking so forward to its succulent grills and its cold cerveja, were about to discover that the failure of just a tiny piece of old aviation technology can still make us squirm like nervous Nellies on our dollar ride.
 

Before the trouble even started we had done a thousand miles of cat-and-mouse battles with those dangerous and deceitful offspring of the inter-tropical convergence zone—the dry cell thunderstorms. The X-band needed a skilled touch to tweak it for dry cell detection, and we three knew how to do that. But we seethed with resentment over the bedamned moon. It was AWOL. It could have helped us see with our Mark-1 eyeballs the frosty white tops of the titans. Our dispatcher had forewarned of the moon’s conspicuous absence in our pre-flight briefing. We would receive no succor from Luna.
 

Since I had opted for the last break and was yet to take it, my eyelids were growing heavy with the work of straining to watch the dark expanses for tell-tale lightning flashes. The man to my right, Mac, mitigated my sleepiness with constant chatter about his days flying F-16s and other such hair-raising tales as could be trusted to have some measure of truth. I had flown with him before and knew, despite his bluster, he was a solid and trustworthy airman. Suddenly I interrupted him, pointing at the center instrument panel. “Look at that!”
 

We had been so occupied dividing our attention between the dark unknown out ahead of us and the radar’s ominous sweeping motion on the scope in front of us, that we had not noticed the Standby Attitude Indicator (SAI) had died. In all my years I had never seen one go bad, except once on pre-flight. If you see a bad one before take-off you cannot go until it’s fixed.
 

The SAI on the 767 is an ancient relic of an instrument—it’s a
Dead SAI in top center. Primary display (blue over brown) at left.
gyro-driven ball sitting in a chamber. A line across the ball represents the horizon. Drop your nose into the black below the line and you’re descending. Raise it into the gray and you’re climbing. It also shows the bank angle of your wings. It runs off of standby power.
 

The SAI is an important but under-appreciated piece of equipment. It sets there waiting for that one-in-a-thousand chance that you might lose your primary attitude references and need it to keep the blue up and the brown down. Or in our case that night, the black up and the black down.
 

In your initial training you fly an approach in the simulator using the SAI as sole reference. It’s so hard to do because of the 767’s control sensitivity and the fact that it sits in the center of the panel—not right in front of either pilot—the accepted technique is to split the tasks. The captain manipulates the flight controls and the first officer works the throttles. After that once in the sim, you never do it again. Shame. I was wishing I had demanded to practice with it more often.

Mac uncharacteristically turned sullen. His stare bore into the SAI lying on its side like a beached whale. “Strange,” he said. “No red flags. It didn’t lose power. It just rolled over and died.”
 

I nodded. “Internal failure.”
 

I reached over and re-caged it, then let it go. “Let’s see if it will stay erect long enough for us to use it for a while if need be.” Instantly it started to roll over again.
 

Mac shook his head. “No good!” He gestured out the windows at the blackness. “No moon. No horizon. No lights below us. Just that lightning over there.” He pointed, then swung his forefinger another direction. “And over there. And who knows where else!” He leaned forward to get a better overhead view. “And only a few stars overhead—all dim.” He looked back at me with wide, troubled eyes. He pecked his forefinger at me to emphasize a point that needed no emphasis. But I let him vent. “If we take a lightning strike that knocks out our electrics—” He swung his finger toward the SAI. “—that damned thing is worthless. We’re screwed!”
 

I nodded. He was right. With not even a turn coordinator that even common light planes have, I doubted our combined skills and experience could keep the touchy 767 rightside-up under these conditions. With a loss of all our electrical power, we might be able to hold her steady for a few minutes using the few visual ques we had—the dim stars and the lightning flashes—but eventually we would have an upset that would beguile our senses into unpardonable control inputs and we would become unrecoverable.
 

I sank back and looked out front. Doubly alert now for weather demons, I remembered the story about the 767 that lost all its generators on this exact route about five years ago. Fortunately for them their SAI was on duty and the battery lasted long enough for them to thread the gauntlet of the menacing Andes and touch down unmolested at Bogota. That crew deserved medals.
 

An edgy half hour later Bill came up from his rest period. We showed him the dead SAI. He uttered an imprecation as he settled into the right seat that Mac had vacated for him. “If you feel us get into a graveyard spiral, you’ll know what happened,” Bill called to me, grinning, as I prepared to go back. He had a hundred or so night Hornet traps aboard a boat and seemed a bit less concerned about the dead SAI than us USAF products.
 

I went back, burrowed into the rest seat and brooded. What would it feel like to lose control of this massive jet and spiral down into the blackness, your mind playing fatal tricks on you all the way to the crater? In spite of such nightmarish ponderings sleep came quickly.
 

Three hours later they woke me up. I went up to the cockpit to be greeted by a brilliant sun and two cheery jocks, free from the night’s concerns and ready for the approach into Sao Paulo.
 

That evening, over a savory grilled meat array flanked by an ice bucket stubbed with bottles of Antarctica beer, we talked and laughed about the dead SAI.
 

As I listened to their banter—the intensity of which became inversely proportional to the decreasing number of bottles of Antarctica in the bucket—I thought about how we always have a back-up plan, or a back-up method. When the primary goes down and we have to revert to the back-up, we think nothing of it; it’s the way things work. All is cool.
 

But when the back-up suddenly goes down and we’re left with only the main and the familiar, we feel like naked men trying to hide. We become shifty-eyed anticipators of trouble—until the sun comes up, or some other providential deliverance presents itself, and we know our salvation is at hand. And then like pardoned felons thumbing our noses at the gallows we land and drink and commence to brag about our consummate domination over the elements and the technology.
 

We three. We fortunate three. We gullible trio of lucky sons-of-bitches.

* The title of this post was shamelessly stolen from and slightly modified from Wordsworth.

 
 
My buddy Pete "Squatch" VanStaagen took this. Moontown Airfield, Huntsville, Alabama, March 2014.

13 comments:

Capt. Schmoe said...

Fate is the hunter.

Frank Ch. Eigler said...

Do y'all carry any portable electronics that could substitute as a backup backup?

jsterner said...

Captain,in this blog you sound a lot like Ernest Gann. And that is as nice of compliment as I can make.

Jerry

Bradley Smith said...

Great post as usual! They just don't come often enough.

Anonymous said...

If both engine generators fail, does the APU provide enough of the proper juice to run the electronics?

wayne in louisiana

Anonymous said...

Looks as though Vans Air Force is right there on your field!

Alan Cockrell said...

Wayne: If both generators fail the APU generator can provide full aircraft power, but you would still need to land at the nearest suitable. The battery is only good for 30+/- mins.

Brian Mee said...

Hmm.. would the level feature on an iPhone be of any use? I uses accelerometers so with G's on it might not work too well.

During development of the Lear 31a we made a few returns on the standy "peanut" gyro when the tubes or signal generators had problems--but that was in clear air.

Brian Mee said...

Hmmm would the level app on an iPhone do any good? It uses accelerometers so with any G's on it might not be too good either.

During development of the Lear 31a we made a few returns on the "peanut" gyro when the displays or signal generators had issues, but that was in clear air over flat ground.

Alan Cockrell said...

I'm not familiar with a attitude app that works without a network connection. If you know of one I would like to have it on my Andoiod.

Frank Ch. Eigler said...

I've been tempted by http://www.aviation.levil.com/ilevil-sw-1.html

Frank Ch. Eigler said...

I've been tempted by this portable AHRS unit.

Alan Cockrell said...

Yes, oh yes. I have been tempted of late by that also.