Archive for the airliner take off Category

All in a Pilot’s Day: Thunderstorm Zen and the Captain’s Firewall.

Posted in air travel, airline, airline delays, airline pilot blog, airliner, airliner take off, flight crew, passenger bill of rights, pilot with tags , , , , , , , , , , on September 29, 2012 by Chris Manno

Head pounding. Look down at your right calf: a liter bottle of water, mostly full.

Stupid.

Just flew 3 hours from DFW to DCA–should have paid attention to hydration. Now, sitting near the end of runway 1 at Reagan national, it’s too late: the damage is done.

Been sitting here for over two hours now. In a thunderstorm. Which has hit the tower with a lightning bolt that fried their primary radios–so now they’re using a weak backup radio that sounds like the controller is using a tin can on a wire.

More delay while the radio situation gets fixed, plus the hand-offs from tower to departure ain’t working. Wait.

Call the tower: “Tower, American 445.” Wait.

“American 445, go.” Sounds like her head is in a bucket.

“We’re wondering about a take-off time, as we’re bumping up against some Passenger Bill of Rights time constraints.”

Like three hours–an hour from now–then we need to go back to the gate and probably, cancel the flight. Passengers have a right to not go anywhere, rather than sit on a plane waiting to go somewhere.

“We don’t have any information,” comes the tinny reply. Thanks for your help.

Ignored several phone calls from the cabin crew already, saying passengers are antsy, wondering what the latest is. When I ignore the interphone chime, the F/O has to field the questions to which there are no answers anyway. I prefer to isolate myself to focus on weather, fuel, timing, the departure procedure to the north (the FAA will violate you for even a tiny stray from the radial) and a clear path on radar. Which I can’t see because our nose–and our radar dish–is facing south. I make a PA every thirty minutes or so, telling passengers what I know: westbound departures are on hold due to weather on the departure routing. The lady in the tower sounds like her head is in a bucket. I don’t tell them that, but still.

Already tried to negotiate a departure to the south or even east in order to air file a route west–craftily uploaded an extra 3,000 pounds of fuel before pushback, after seeing the storm front marching on Washington as we landed.

No dice.

More calls from the back: passengers want to use their cell phones; they’re getting up . . .

Tell them no–if they use phones, the cabin crew has to make another aisle pass to ensure they’re off for take-off (FAA regulation) and if we’re cleared, we need to take the runway, check the weather–then go.

Sure, they have connections and people waiting. But that can wait till we get there. What I want to attend to is a new and higher power setting that creates less time on the runway; an optimum flap setting that gives a better climb gradient, and a wind correction to stay on the safe side of the departure radial.

That’s where the “firewall” comes in: if I let connections, cell phones, Passenger Bill of Rights or even my own next flight tomorrow (not going to be legal if we keep delaying) mix with the important considerations like fuel, weather, radar, performance and power settings, something’s getting messed up.

It’s not that I don’t care–I really do. But if I don’t attend to the latter set of considerations, the former won’t matter, will they? Drink some water, rehydrate. Relax. Run through your list of priorities for right now. Pay attention to right here, right now. Be ready to do “now” right; worry about later, well, later.  That’s the thunderstorm zen, the captain’s firewall.

It happens fast: “445, start ‘em up–you’re next to go.”

Fine. I reconfirm with the F/O the heading plan (310 is good–but 305 is better. If we have to correct back right to the radial, fine–but we do not stray east . . . a full radar picture before we roll, static.”

Raining cats and dogs, hard to see, swing out onto the runway and grab every inch. Stand on the brakes, full radar sweep–decide.

“You good?” I ask the F/O as a formality–because I’m looking at him and I can tell from his face whether he is or isn’t from his look no matter what he says. And if he isn’t okay or doesn’t look okay, if maybe his firewall or zen are under seige, I’ll know and we won’t go until everything adds up.

We roll; relief when we’re past abort speed; mental chant “engines only, engines only” reminding myself of which of the hundreds of warnings I’ll abort for on that rain-slicked postage stamp of a runway; throttles speedbrakes THEN reverse, amen. The jet rockets into the whipping rain undaunted; love the big fans at a high power setting. We climb, buck, dodge, weave and finally . . . cruise at 40,000 feet above all the turmoil as the lights of the nation wink out.

Landing after midnight, home finally at 1:30am. Crew Schedule calls: “Sleep fast, we’ve slipped the departure of your Seattle turn just long enough to keep you legal. You’re still on it.”

Eight hours in the cockpit today; another eight tomorrow. Plus a few hours to sleep in between.

Erase today–it’s over, safely and smartly done. Rest, and save a little zen for tomorrow. No doubt, you’re going to need it.

Airline Flying 101: Anatomy of a Take-off.

Posted in air travel, airliner, airliner take off, jet flight, pilot with tags , , , , on January 2, 2012 by Chris Manno

Take-off? That’s easy, right? You fasten your safety belt, move your seat fully upright and stow your tray table. Ready. Right?

Not even.

But if that’s the full extent you prefer to be aware of, fine. Otherwise, read on as we take apart this very complex, important maneuver.

The planning starts long before you strap yourself into your seat in the back of the plane, and here’s why.

Take-offs come in all sizes and shapes because of several variables–so there’s no “one size fits all” logic or protocol. What are the variables? Well, aircraft weight, runway length, winds, runway surface condition and temperature are the basics, and each has an effect on performance.

You might think runway length is the great reliever, right? Miles of runway, like at DFW or Denver mean simple, low-risk performance, right?

And you might think a short runway or nasty weather are the “problem children” of take-off performance. But let me give you the pilot answers: no, no, and furthermore, no.

Throw out what you’ve been thinking about take-offs as a passenger, and strap in tight (is that tray table up? is Alec Baldwin playing “Words” in the lav while we all wait for His Highness to finish?) because you’re about to test drive some “pilot think:”

I don’t worry about taking off–I worry about stopping.

Why? This sounds so simple that when you think about it, you’ll have to agree: aircraft are made to fly–not drag race.

Huh?

Look, accelerating 85 tons to nearly 200 miles per hour builds tremendous kinetic energy. Not a problem for the landing gear if you take off because it’s simply rolling. But if you must stop, the brakes and wing-located speed brakes have to dissipate that energy within the length of the asphalt ahead.  The runway length is finite, the aircraft weight is unchangeable once you’re rolling. So where is the point of no return, the point after which there’s not enough runway to stop?

Brakes are key--and checked visually before EVERY take-off.

As a pilot–particularly as the captain who makes every go-no go decision no matter which pilot is actually flying–you must know when that instant occurs. That magic point is not a distance down the runway but rather, a maximum speed: “Refusal Speed.” In other words, the maximum speed to which we can accelerate and still stop within the confines of the runway if we choose to abort the take-off.

But there’s a catch, of course.

Refusal Speed is only half of the go-no go decision. Part Two is just as critical: what is the minimum speed I must have in order to take-off if one engine fails, continuing on the other. I can hear this already: why the hell would you want to continue the take-off on one engine?

To which I’d answer back, what if the failure happens above Refusal Speed? In other words, there’s not enough runway ahead to stop your high-speed tricycle.

Okay, that minimum speed–the speed you must have in order to continue the take-off in the remaining runway on one engine–is called “Critical Engine Failure Speed.”

All of the performance numbers for each unique take-off are computed, with corrections for the many variables to be made by the pilots.

Now you have the two controllers of the go-no go decision; one a minimum speed (you must have Critical Engine failure Speed achieved to continue safely into the air) and one a maximum (if you attempt to abort in excess of Refusal Speed–you ain’t stopping on the runway).

So which is the deciding factor? Well, in modern day jets under average circumstances, the “max” speed is normally way in excess of the “min” speed. In other words, you normally achieve the min required for single-engine continued take-off before you reach the max allowed for stopping. So, in ordinary circumstances, Decision Speed–which we call V1–is Refusal Speed.

In other words, we know we’ll secure adequate flying speed for a single-engine take-off before we hit the max abort speed. So we use the max abort speed–Refusal Speed–for V1.

Pilot-think lesson one: it’s easier to deal with a single-engine aircraft in the air than it is to stop a freight train on the runway. Which goes back to my earlier point: airliners fly great but make only adequate drag racers, stopping on the drag strip remaining being the challenge.

Single-engine take-off, or high speed abort?

Add to that the wild card: the captain must decide in a split second as you’re rolling toward V1 if any malfunction that occurs will affect the ability to stop the jet: did an electrical system failure kill the anti-skid system required for max braking? Did a hydraulic failure eliminate the wing spoilers figured into the stopping distance?

Some jets require very little system support to fly–but a lot of factors to stop: the MD80 will fly all day without hydraulics, electrics or pneumatics–but it ain’t stopping on a “balanced field” without electrics and hydraulics.

Hydraulically actuated wing spoilers are figured into the stopping distance.Get my pilot-prespective regarding my preference to take a wounded jet into the air rather than wrestle it to a stop on a runway?

And remember, those speeds are “perfect world” scenarios. But on your flight–like every flight–despite the engineering numbers from which the stopping distance is computed, there are the real life factors which screw them up: wet or icy runway, tailwind, old tires, old brakes, rubber on the runway because of aircraft touchdown on landings.

Not a problem on an average day, but corrections to the numbers and your pilot-think must be made if any of those variables are present.

Now, have you deduced the worst-case scenario with the two controlling speeds, Critical Engine failure Speed and Refusal Speed? That is, you will exceed the max speed for stopping before you attain the minimum speed for single-engine flight?

That’s simple: you can’t take-off. In practice, we adjust the flap setting or even reduce the gross weight: back to the gate–some cargo and/or passengers must come off. Hardly ever happens that we return to the gate because we plan ahead–and that’s why you hear of a flight being “weight restricted,” meaning some seats will be empty by requirement before you even board. Now you know why.

But really, that’s not even the worst case scenario from a pilot’s perspective (sorry about your trip, if you’re one of the passengers left behind on a weight restricted flight–but you probably got some compensation for it). Rather, it’s when the two numbers are the same.

That is, the minimum speed required for flight is equal to the max speed for stopping.

That’s called a “Balanced Field:” the runway distance required to accelerate to minimum single-engine take-off speed is also the maximum velocity from which you can safely abort and stop on the runway.

That’s a “short runway” problem, like in LaGuardia, Burbank, Washington National or Orange County, right?

Wrong–it’s everywhere, like Denver’s 14,000 feet of runway (compared to LaGuardia’s 7,000) on a hot summer day; ditto DFW; also Mexico City even on a cool day because it’s at 7,500 feet elevation. And it can occur anywhere due to rain, ice or snow.

So here’s your plan, and as pilot-in-command, you’d better have this tattooed into your brain on every take-off: once you enter the high-speed abort regime (by definition, above 90 knots), know what you will abort for–or continue the take-off. Be ready for both–without hesitation.

LaGuardia: 7,000' between you and Flushing Bay.

It’s easier to decide what you will abort for than won’t–because the “must stops” outnumber the “can stops” and remember your pilot think: it’s often safer to continue than stop. And here are my Big Four Must Stops: engine fire, engine failure, windshear or structural failure.

So rolling past 90, I’m thinking over and over, “engines, engines, engines,” zeroing in on any malfunction in order to assess if it’s an engine problem–if not, it’s likely not a “must stop” situation; I’m aware of windshear but don’t even start the take-off roll with any of the conditions present; structural damage we’ll deal with as necessary. Otherwise, we’re flying, folks.

Got all that? Good deal: now you understand the important interrelationship between Critical Engine Failure Speed, Refusal Speed and the all important concept of V1.

And now that you understand the complex, split-second conditions surrounding the go-no go decision on your next take-off, you can relax and just put all of those crucial factors out of your mind.

Because rest assured, they’re at the forefront of mine, or that of whatever crew into whose hands you’ve entrusted your life.

Special Note:
Coming in 2012–The JetHead Podcast! Interviews with real pilots, hands-on first-person  descriptions of airline piloting and aircraft flying from the folks on the front lines of commercial aviation!

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