Wednesday, July 15, 2009

I, the Guinea Pig

A guinea pig is a cute little rodent commonly used in lavatory tests. But in the world of commercial aviation a guinea pig is any pilot who first ventures up to test questionable weather before others takeoff. And thus, so are his trusting passengers. But sooner or later somebody has to do it, lest the airport remain at a standstill. Last week at Denver I became the pig, or rat, or whatever the thing is.
  There were a dozen planes lined up behind us. We were number one to takeoff, but I had an uneasy feeling about the threatening weather. A gigantic thunderstorm inched its way eastward south of the airport. Its arms of turbulent cloud weaved overhead like an octopus’s probing tentacles. But the main body of the beast was ten miles away, which gave us plenty of room to turn away from it.

Confident that his ride in the tower cab would be a smooth one, the tower controller cleared us for takeoff. I lined up the 757 on runway 17R, but only for a look/see. Our radar verified the storm was a safe distance away, however the gunmetal clouds billowing and curling overhead boded an atmosphere ripe for windshear.


Suddenly, with the urgency of an air raid klaxon, a voice blared at us: “WINDSHEAR AHEAD! WINDSHEAR AHEAD! WINDSHEAR AHEAD!”
The voice was that of “Bitching Bob,” our own plane shouting to us. I looked down at the electronic horizontal situation indicator. A splotch of bright red marks sat two miles ahead of us. Its unspoken message: Fly through here lads and they'll weep at your wake

 
I told Mike to inform the tower. The busy tower controller, who was managing operations on three runways said, “Who’s reporting windshear?” He sounded annoyed, as if the news was now severely complicating his life. Or was he agitated that his own windshear detection system had not seen what our plane’s gear saw? 
But seconds later he too got on the bandwagon. “Okay, our equipment sees it now. ATTENTION ALL AIRCRAFT. MICROBURST ALERT! DENVER, RUNWAY 17 RIGHT!”\
Long minutes passed as we sat poised for take-off. I tried to relax but couldn’t. No pilot enjoys sitting on an active runway, unable to check his six. We watched and listened as a 737 approached Runway 8, which was perpendicular to us. “That guy ought to have his head examined,” said Mike, a seasoned Naval aviator. I agreed. As if hearing our comments, the 737 pilots wised up and went around. 
Many jets were waiting behind us. We could see them to our right front on the parallel taxiway. I knew they were watching to see what we would do. Windshear is a fickle thing. It comes. It goes. When would we roll? We waited. They waited.
 “You want to take precautions?” Mike asked.
“Yeah!” I said. “We’ll use maximum thrust. And work me up an increased Vr.”

Mike nodded and calculated a rotation spe
ed based on our maximum runway limit weight. Using the extra momentum of a longer takeoff roll we would slingshot ourselves into the turbulent sky—the theory being if we hit windshear we should have the energy to punch through it. But we still had to wait until the warnings subsided.

I thought about the Pan Am flight at New Orleans in 1982. They took off with a thunderstorm nearby and hit a microburst. They all died. Nobody knew then what a microburst was, mu
ch less how to predict it and prepare for it. A microburst happens when a thunderstorm spits its windy wrath straight down. In the aftermath of the New Orleans disaster the excellent predictive windshear system embedded in the nose of our jet was developed. It uses Doppler radar to detect horizontal wind movement.

Windshear reports began to flow in from other parts of the airport. On the west side the shear was 50 knots. I looked at the windsock bes
ide our runway. It hung limp―not enough to fly a kite. Creepy. Finally the warnings stopped—both ours and the towers. Tower cleared us to takeoff.

At that very moment we heard a “ding,” the forward flight attendant calling. Mike let out a big “Phsew! What now?”
I answered the call. A passenger had to go to the lavatory―couldn’t wait. I couldn’t believe what I was hearing. The whole airport was waiting for us, and some guy had to tinkle. I said, “No way. He stays down!” But before she hung up her handset I revaluated. “No. Wait! Okay. Tell him to get it done QUICKLY and report back when he’s seated!”

The tower wanted to know why we weren’t rolling. Mike told them. I could almost hear his frustrated sigh, along with the chuckles of the other pilots waiting.


The sky ahead boiled and flowed with menacing tendrils emanating from the storm but the windshear warning stayed silent. I worried our window of opportunity might close.
Finally another DING. He was down. I kicked the parking brake off and shoved the two big Pratts to maximum power. The roar of 75,000 pounds of raw thrust catapulted us forward. We heard a clattering crash of metal in the galley behind us. The flight attendant had not secured the galley drawers and the acceleration emptied them onto the floor. We ignored it and concentrated on the takeoff.

The wind sock kicked out with a direct crosswind as we rolled. I held the yoke into the wind but not too much, less the spoilers, which aid the aileron function deploy and impede our acceleration. The speed picked up fast but hung up at 90 knots for a few troubling seconds, then increased again. I concentrated
on the white stripes racing at us while Mike hunched over staring with shifty, suspicious eyes at the engine instruments watching for a malfunction. I waited for the windshear warning. I was ready. If it came prior to V1 I would abort. 

A high speed runway abort is one of the most dangerous maneuvers airline pilots are called on to do. The decision has to be made instantly, the physical reaction must be instantaneous and it must be done right. A hundred and eighty-five breathing, frightened bodies back there would get slammed forward against their seat belts while hearing the engine reversers belch a hellacious roar. Ever heard the old saying ‘There are no atheists in a fox hole’? I submit to you that there are also none riding out a high speed abort.

The expansion joints in the concrete thumped under our nose wheel like machinegun fire, ever faster and faster. Finally, Mike said, “VEE ONE.” I kept the nose down gathering even more precious speed, far more than we needed under normal circumstances. Then, “ROTATE!” I gingerly raised the nose, not too much—didn’t want to dissipate energy.
The runway fell away and our ride turned smooth. Mike raised the gear, then the flaps. We turned east, away from the storm.

As we climbed out I wondered what the guy who had to pee thought when the engines exploded with a tearing roar, kicking us ahead like a lit afterburner, just as his butt hit his seat.


And another thought: I distinctly remembered hearing a quick transmission during our takeoff that must have come from one of the aircraft waiting behind us. I was sure is sounded like “Oink oink!”


The other planes watched us climb away. One by one they fed onto the runway and followed their guinea pig into the restless sky

15 comments:

Marc Cote said...

I'm sure you mean "laboratory" tests.

Wayne Conrad said...

You've got the ability to put me there in the jumpseat behind you. Great story. And what a menacing picture. I wouldn't even want to drive beneath that, much less fly under it.

Capt. Schmoe said...

Capt. Cockrell,
Is a shifty, suspicious eyed FO part of the MEL? Or will a regular-eyed FO do?

Amazing post, words and pics.
Thanks

limonlima said...

Great post(s). New to your blog but have managed to read many of your posts. Thanks for giving us a peek into a world that demands an amazing combination of responsibility, hard work and experience.

bradcockrell said...

I was riveted on this one pop! Very good stuff... more... you must write more!

Rambler said...

It should be noted that the slightly more heroic term for the first aircraft off the field in the face of weather is "pathfinder". :-)

Alan Cockrell said...

Thanks Marc for the correction.
Capt. Schmoe, I would much prefer an MEL item that specified a shifty-eyed suspicious F/O who might be better positioned to save my erring ass.
Rambler: You are also correct, but imagine the guy who was having a little fun with us punching his mike button and whispering, "Path, path, path."

Flying Kites Mom said...

Thanks for a brilliant post! With treacherous weather and PIC decisions having a high profile at the moment your post illustrates the meshing of knowledge, experience and tech aids which you bring to your job. And humour with it- just the cherry on your postings!! LHSPF1

David said...

Good story brother-n-law. More, more, more.

andy softley said...

Alan,
I agree,a great story...i could sense your heart pounding out your chest..cause mine was right there also.

D.B. Cooper said...

Nice.....

Seneca said...

Excellent story, thanks for sharing!

And please keep them coming!

Best regards from EDDH..

Ron said...

Awesome blog, great post.

One nit, if I may -- I believe "less the spoilers..." should be "lest the spoilers...".

I look forward to going through and reading all your back posts.

Alan Cockrell said...

Thanks, Ron. Your the second one to catch me in a grammar error on this one.

--Alan

PltFlyng said...

Hey, i have been following your blog for a while now although this is the first time i am commenting. I had an experiance the other day which i blogged about on my own blog that reminded me of an old post of yours which i ended up quoting, i hope you dont mind. I have cited the source appropiatly and added a link back to your blog.
You can find it at http://islandsinthesky.wordpress.com/2011/02/09/guinea-pig/
If your interested.

Keep blogging, love your posts.

-Daniel