After the storm: fly home–but not so fast.


After the divert to Wichita Falls, time to gas and go: Flight Dispatch says DFW is accepting arrivals. That’s all we needed to hear–we’re refueled and refiled with Air Traffic Control. As soon as we’re released by tower, we’re in the black night and headed south to DFW at 280 knots.

Would be flying faster, but 280 is the best turbulence penetration speed and though the ride’s not overly bumpy, the latticework of cloud to cloud lightning straight ahead promises roughness. We’re making a beeline for one of the four arrival corner posts for DFW at 10,000 feet.

Things will happen fast on a 70 mile flight, and the First Officer is flying: he’s sharp, and that allows you as captain to oversee all of the preparation, the checklists, the navigation and most importantly, the radar. Approaching midnight, we’re now 12 hours into our pilot duty day, but regardless, there is still the same roster of tasks to be accomplished–and they don’t care how tired you are, they must be accomplished correctly.

Getting a good look at the current radar sweep and things look ugly. The cells have broken up and are scattered like mercury all over the place. The DFW airport arrival information is automated: weather, winds, runway–all printed out from the on-board data link printer. The DFW info says landing south–so you set up frequencies, courses and descent altitudes in both sides of the Flight Management System, as well as both pilot panels. While he flies, you brief the approach.

Have to swing wide around storms–request a descent to get below scud blow-off you can’t see on radar, but which you detect because it’s blocking the pattern of ground lights you know should be Denton. As soon as we begin descent, the master caution light glares in front of your face, along with a pressurization clue. A quick glance at the pressurization control panel above the F/Os head shows we’re holding cabin pressure fine, it’s just that we never reached the programmed cruise altitude and the computer is confused.

“Off schedule descent,” you say, punching off the warning light. Reset the cruise altitude to 5,000, which is lower than where you are, to let the computer recalculate and catch up.

“Radar vectors to 35 Center,” says the air traffic controller. Dammit–we set everything up for a south landing per the DFW info.

“ATIS says DFW landing south,” you say, making sure there’s absolutely none of the annoyance you feel in your voice.

Pause, wherein you can imagine the controller saying to someone the ATIS is wrong. “I’ll check on that, but plan north.

Redo the courses, rebrief for the F/O, reinsert the proper approach in the FMS and extend the centerline for intercept. Complete the checklist down to configuration, validate the Heads Up Display Data. Staring at the lights of The Ballpark in Arlington miles south, doing the math on descent rates versus final turn altitude based on a left turn thereabouts. Looking good.

A loud snap as the autothrottles kick off. “I’ve got them back on,” you say, reaching up to reinstate the system. F/O nods, concentrating on flying.

Now ask yourself why they tripped off. No failures annunciated–they wouldn’t have reinstated with an internal failure. And it’s not that choppy. Has to have been a power interruption. Glance up–sure enough, there it is.

The left generator bus source is gone. Is it the generator or the bus that’s failed? Regardless, we’re flying with only one electrical source–the right generator. Not good.

First instinct is to start the Auxiliary Power Unit (APU), a small jet engine in the tail that can provide electrical power and pressurization air–but wait.

If the fault is in the left electrical bus, adding the APU generator could either cause a fire, or take down the APU generator. Be patient.

Although you know the right generator has assumed the power load–so the bus must be okay–why take chances?

“We’ve lost the left generator,” you say, reaching for the Quick Response Handbook. “I’ll take care of it. “F/O nods.

The procedure confirms what you deduced. Within a couple minutes, you have the APU running and power restored. Follow the QRH procedure exactly; better to have two electrical sources–if you’re down to one, if it fails, it’s going to get dark and ugly: flying with limited instruments and systems on 30 minutes of battery back up. In the weather, at night. We can do it–but would rather not.

Left base turn from an angling downwind. Mike’s doing a good job–he sees the bad angle and is slowing and calls for dirtying up with flaps and gear. The runway’s coming into view on my side. Good altitude and speed; the intercept of glideslope and course will be fine.

Tower calls the winds “130 at 18.”

Dammit. The limit is 15. With the 50 degree offset, we’re close. Legal, but you don’t like flirting with limits. Even on a long runway.

“Continue,” you say to Mike’s inquiring look–he’s done the math too. But you’re just about decided to abandon the approach. But no need to rush anything. Rushing is never good.

“I’ll rebug you to 40″ you say, changing configuration as required by the tailwind, “and brakes 3.” He nods.

At a thousand feet, it’s clear that the tailwind is unstable and variable–you can tell from our ground speed versus the airspeed.

No good. “Let ‘s take it around,” you say. He nods, adds power–the descent stops.

“Here comes flaps 15,” you recite the litany for him,”positive rate, gear coming up. Missed approach altitude set.”

“American 245 is on the go,” you tell the tower.

“Fly runway heading, maintain two thousand,” says the tower.

Fine; nearly there–reset the throttles from N1 to speed, reset both FMC from climb to capture. Reset both course windows and MDA–because we’re going to land south. Reprogram the FMS for the 17s.

“I’m going to teardrop you out to the east, then bring you around for a final to the south,” says the controller. “Can you do that?”

Eyeballing the radar: nastiness to the northeast, but there’s some room.

“Give us five miles,” you answer. No need to rush–make this correct, hit every step. F/O nods. “Then turn us back in.”

Slowing, getting dirty. Left sweeping turn.

“Do you see the runway?” asks tower. You do–you give a thumbs up to Mike. He nods.

“Affirmative,” you answer.

“Cleared visual approach, cleared to land, 17 Right.”

Confirm the Right runway freqs, MDA and courses set. “I’ll bug you back up to 30,” you say, changing configuration again: don’t need a whole lot of drag without the tailwind and with a possible wind shear. Mike nods.

Glideslope is rough. You’re on a hair trigger to go around again–there’s plenty of fuel to hold or go north to Oklahoma City or south to Austin. Be alert, be patient.

Increasing wind; good sign–but it has to stay within controllable limits. Mike’s doing a fine job wrestling the jet onto glidepath. The Boeing is a steady machine–an MD80 would be a bucking bronco in this.

Below 500 feet–you’re call: it’s stable enough, we’re good. If Mike wants to go-around, we sure will, but we’re good.

Over the threshhold, Mike puts it down; speedbrakes deploy, he yanks in full reverse, the jet slows.

“Nice job,” you say, taking over as we slow to 80 knots.

After landing checklists, taxi in. Careful, do the job right all the way to the chocks. Engine shutdown.

Passengers deplaning, our shutdown checklists complete. You’re writing up the left generator in the maintenance logbook, a mechanic is already on the jetbridge waiting.

“You can take off, Mike,” you say, “I’ll finish up here.” Meaning you’ll do the final “after all passengers have deplaned” checklist items to power down the aircraft. That’s a courtesy you do–you’re the captain, you leave last. He did a great job tonight–respect that.

We fist bump, he leaves.

You finish up: packs off, recirc fans off, cockpit power off. Grab your bags. Slip out of the gate area past the 160 passengers who have no idea what transpired between Wichita Falls and their safe landing a few minutes ago. Nor should they–that’s what they pay you for.

Fresh air feels good, outside waiting for the employee bus to the parking lot. Nearly 1am, got to get home and get some rest–flying again tomorrow.

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14 Responses to “After the storm: fly home–but not so fast.”

  1. James Albright Says:

    Chris,

    Another great “There I was” flying lesson — I am always learning here.

    From our bag of tricks flying the white rocket:

    If the crosswind is 30 degrees off heading, the magnitude is equal to one half the full value. On runway 360 a wind of 030/20 gives you a ten knot cross. (The engineer says the sine of 30 is 0.5, the pilot says “half.”)

    If the crosswind is 45 degrees off heading, the magnitude is about 3/4 of the full value. On runway 360 a wind of 045/20 gives you a 15 knot cross. (The engineer says the sine of 45 is the reciprocal of the square root of two, the pilot say “What? Call is 3/4.)

    If the crosswind is 60 degrees off heading, the magnitude is about 90 percent. On runway 360 a wind of 060/20 gives you an 18 knot cross. (The engineer says the sine of 60 is the square root of 3 divided by 2, the pilot says “get real, it is about 90 percent.)

    James

    • That’s a great rule of thumb. Not a chance in hell my non-mathematical brain could figure out a sine, but the 60, 45 and 30 numbers are smart to have in your hip pocket. Many thanks!

  2. That was an awesome read Captain Chris! Thanks for sharing, I love your blog :)

    Bas

  3. Very interesting! Quick question, why would ATC advise you to land with a tailwind, if you could make an upwind approach? Sounds like ATIS had the correct information! Thanks!

    • Hah! You should fly a jet into O’Hare: flights landing in all different directions, but “nobody has a tailwind.” Yeah, right.

      It’s not unusual to have some tailwind, especially when storms are passing through and they can’t switch the traffic pattern as quickly as the wind shifts. Have to be heads up and know your aircraft’s limitations.

       Chris

      Sent from my iPhone, so please pardon the typos.

      • As long as there is no microburst activity in the area, right?

        I have to say, reading your blog, I have a much increased respect for you pilots. I was living in MSP when the NWA flight crew overflew the airport all the way into Wisconsin and missed several ATC calls along the way. Honestly, I can’t imagine how it was possible for those guys to be fooling around with their laptops when I read all the stuff you have to do! This frequent passenger says “Thank you”!

      • Thanks! And windshear is a whole different set of problems.

         Chris

        Sent from my iPhone, so please pardon the typos.

  4. I really look forward to your posts Chris. They remind me that I’m in the baby class and I learn a lot from them. Turbulence is something else in a half ton aircraft. Inertia is a wonderful thing I’m told.

  5. Great reading as I’m waiting in MSP for Delta to send us another plane since the one at the gate had a cabin pressure problem coming from Whichita.

    Are pilots required to “drive” a plane from the hangar to the gate?

  6. Duh! Never mind: stupid question. They use a tractor.

  7. Scott W. Says:

    Sorry I missed you the other night JH. Look forward to hearing from you again..Hope my counter parts took care of you..

    • They sure did. I’ve been doing the late afternoon rocket to LaGarbage, then the last flight home which gets back to The Jethroplex around midnight after the LGA delays. Have been getting cleared direct to the inboard OM shortly after LIT at that late hour.

      Same trip in July, so I’ll give you a shout.

       Chris

      Sent from my iPhone, so please pardon the typos.

  8. Thanks for another great post, Chris. Obviously, the brain must remain in gear for the entire flight. Duh? I think this post is also an excellent example of the need for TWO fully qualified pilots in your small office, not one and a trainee. CRM at its best. Thanks.
    -Craig

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