Friday, January 17, 2014

That Sinking Feeling

One of the most frequent questions I get from non-pilots - after "what route do you fly" - is "don't you ever get bored up there?" The quick, obvious answer is "of course." Modern airline flight is thankfully routine and devoid of frequent surprises, and a certain amount of enroute ennui is inevitable. I've written before about ways that I combat that, such as talking to crewmembers and following our route on a road atlas. But there's a big difference between being occasionally bored enroute, and being completely bored with the job. I've known more than a few people who find airline flying terribly dull. I see where they're coming from, but I also think it's what you make of it. I would probably find it tiresome as well if I didn't bid different routes every week, make an effort to get to know my crewmembers and do things with them, and make sure I get out of the hotel and explore our layover cities. Those things keep the job fresh, and every once in a while something even happens in flight to shake up the routine a bit. Of course, I'm seldom appreciative at the time.

Last Friday I flew a daytrip to Steamboat Springs, Colorado (actually Hayden, KHDN) and back. Now, in the winter I tend to bid more 3- and 4-day trips to cut down on the driving and get out of the snow for a few days a week, but the computerized Preferential Bidding System (PBS) that builds my schedule determined that staffing required I fly one daytrip, and added it to my January line. I hadn't flown to Steamboat in two years, partly because we only do it in the winter and I avoid winter daytrips, and partly because I avoid Steamboat specifically due to the low credit time (4.5 hours roundtrip) and operational challenges associated with it. Fortunately, when I looked at the weather before heading to the airport, Steamboat Springs had clearing skies and it was forecast to be a nice day.

When I got on the airplane in MSP, mechanics were on board clearing an MEL. One air cycle machine ("pack") had been deferred, limiting the airplane to 31,000 feet, but now it was fixed. I called our dispatcher to take the MEL off of the release and get the phone briefing that our company requires before all flights to Steamboat Springs. On a bad day, some of the issues I would discuss with the dispatcher might include snow removal and runway braking status, maximum landing weight considering contamination and climb performance limitations due to terrain and icing, permissible load out of MSP considering our landing weight, weather at alternate and second alternate airports, and potential problems getting into Steamboat considering that we can only land on Runway 10 with a 3 knot or less tailwind when it's snowing, and the fact that 28 is served only by an RNAV approach with relatively high minimums. Besides that, we might also talk about performance limitations for the return flight, and whether the booked payload out of Steamboat might require taking a reduced fuel load and a tech stop to refuel in Denver on the way back to MSP. This day, however, there were no such troublesome matters to discuss. "There's a little bit of snow just moving out of the front range now," said our dispatcher, "but Steamboat and surrounding area should stay clear. No alternate needed." He added that though he had planned the flight at FL300 for the now-removed MEL, we could go up to FL360 to save fuel. With that he cheerily wished us a good flight. I briefed the First Officer - who I had flown with several times - on what we had talked about, and continued with my preflight routine.

We were about 55 minutes into the flight when "MESSAGE RECEIVED" popped up on our FMS screens. It was a text from our dispatcher. "New Hayden TAF just out would require an alternate. Are you ok continuing without one?" Per the regulations and our Flight Operations Manual, the well-known 1-2-3 rule (alternate airport required if within +/- 1 hour of arrival, less than 2000' ceiling and 3 miles visibility is predicted) only applies to preflight planning. If we take off and then the predicted weather goes below 1-2-3, we are permitted to continue without an alternate if the Captain determines it is safe to do so. The FO and I eyed the amended TAF. It was drastically worse than the original, showing 1/2 mile visibility in snow until after our ETA, and winds picking up heavily from the west around then. "I'm pretty sure that's below minimums at Hayden," said my FO. We flipped through our Jepp plates. Sure enough, the minimums for the special ILS Z Rwy 10 are 3/4 mile visibility. If the winds from the west were more than 3 knots - a seeming certainty - the RNAV Rwy 28 approach requires 1 & 3/8 mile vis, with a MDH of 514' above touchdown elevation. I used the ACARS "Weather Request" function to pull up the most recent METAR. Sure enough, it was 1/2 mile visibility in moderate snow with 8 knots of wind from the west. Clearly, continuing without an alternate would be sheer madness. My FO agreed vigorously.

I decided to do a little homework before responding to our dispatcher. I pulled up the weather for Denver; it was fine. Laramie and Cheyenne are closer and the weather was good at both, but a quick review of their 10-7 (Company Info) pages showed that neither is a regular line airport, and a divert to either would involve sitting on an FBO ramp and depending on them for services they may or may not be able to provide in a timely manner. If a divert was in the offing, I'd best avoid those two. I checked our fuel and did some quick calculations. Thanks to our higher-than-planned cruise altitude, we would be arriving with about 600 lbs more fuel than originally planned. If we diverted to Denver, I wanted to land there with no less than 3500 lbs (2640 is official reserve but it would be foolishness to land at a busy airport with that little, especially with unforecast, unsettled weather around). We had just enough fuel to fly one approach at Steamboat Springs, go missed approach, and divert to Denver. If the weather was still below minimums when we got to Steamboat, we had no more than five minutes of holding fuel.

I typed a message back to our dispatcher. "New TAF and METAR shows below minimums at HDN. Request Denver alternate, FOB 9.2, show 6.4 on arrival at HDN, bingo to DEN 6.0. Also, please call HDN ops and request most recent MUs." Hayden is a designation Special Winter Operations Airport (SWOA), which is the reason we can't land with no more than 3 knots tailwind when it's snowing. It also requires runway friction numbers (MU being one type) or a braking report from a transport category aircraft less than an hour before our arrival. The dispatcher replied promptly: "Hayden MUs 39/41/33 as of 5 minutes ago. A320 just landed reported good braking." We were landing in only 40 minutes, so that met the requirement. "Denver alternate looks good, add that to your release, sending numbers to your printer." The ACARS printer spit out a new flight plan page with amended fuel required numbers that roughly matched my calculations, though a bit less conservative.

With that the FO and I set about reviewing Hayden's 10-7 sheets, which are a full eight pages long as opposed to most airports' 1 or 2 pages. About half of these applied to our arrival, and included quite a few review items we had already considered and a few we had not (e.g.: call CTAF 15 minutes out to get all the snowplows off the runway!). We briefed the ILS Z Rwy 10, noting that the missed approach procedure is different than the normal ILS in our FMS, as well as the RNAV 28. Runway 10 also had a Complex Special procedure to consider for an engine failure during missed approach. While discussing these items, we kept requesting a new METAR on the ACARS every five minutes. Special METARs kept coming out, but showing little improvement. Denver Center issued a descent clearance and we started down. I silently cursed myself for not requesting more fuel with any snowfall anywhere in the mountains. I know from experience just how unpredictable mountain weather can be. Oh's not helpful to dwell on that now, I told myself, and concentrated on the task at hand.

We were passing through 18,000 feet when Denver Center triumphantly informed us that Hayden's new weather was 6 miles in light snow, ceiling 2200 broken, wind 230 at 4, and asked us which approach we would like. The weather at the airport was good enough for the RNAV Rwy 28, but I suspected it would be worse east of the airport, where we would be approaching from. The southwest wind was just light enough to land on 10. My FO requested the ILS Rwy 10. The controller immediately cleared us direct to the Hayden VOR, 12000' until established, cleared for the ILS Rwy 10 approach. I called for the approach checklist a bit early, overflew the VOR, joined the backcourse, and passing INEDE hacked the timer for a good-ole-fashioned freight-dog-style procedure turn onto the ILS. We broke out of the clouds right at INEDE inbound, and the sight was about what I expected: a clear airport with a wall of snowfall immediately east, over the town of Steamboat Springs. The snowplows confirmed on CTAF that they were clear of the runway, and we landed on the nicely plowed runway without incident. We did have to wait a few minutes for the gate, as the [nameless major airline] A320 that had landed 45 minutes prior was still loading up for its return to Salt Lake City.

Thankfully, it snowed only lightly for our departure and our outbound load was light enough to fill up on gas without a Denver tech stop. Our winter considerations did not stop with departure: it was snowing with low ceilings in Minneapolis. Still, with multiple long runways, oodles of snowplow capability, no performance restrictions, and Cat II approaches, Minneapolis is a walk in the park after Steamboat Springs. I smiled and relaxed as we cruised northeastbound over Nebraska with absolutely nothing to see on the ground and little chatter on the radio. Sometimes, a little enroute boredom is a wonderful thing.


Dave W said...

I bet the PAX would give you funny looks if you walked onboard with that road atlas under your arm!!

Great post, thanks!

Dave from the UK

D.B. said...

Interesting post & flight. I thought part 121 operators couldn't start an approach if the weather is reported below mins for that approach? So I was a little confused by the part about having enough fuel for one approach at Steamboat (great skiing there) and then divert to KDEN. If the METAR hadn't improved, would have been able to do an approach at all? We part 91 fliers can do whatever we want, sometimes with disastrous results. My own SOP's are closer to yours, since I like staying alive, and approve of caution in the air.

Joe said...

Very cool to see your input on flying into a SWOA. I always enjoy the EGE turn in the sim, but that has a better credit time than the HDN turn out of MSP. Rocky Mountain flying is certainly a challenge, and I give a lot of credit to the SKW crews that constantly do those routes (especially ASE) day in and day out. Doing multiple legs in those conditions with delays is extremely draining. Does CPZ only operate HDN as a single day turn?


Tom B. said...

Great article Sam!!

Dave said...

Quite a workload.. don't think I would enjoy the snow conditions.

Sam Weigel said...

D.B.-- We can't start the approach until reported surface vis or RVR meets approach minimums. My fuel calculations were *assuming* the wx came up enough to start the approach - we could do one, but would have to go to DEN immediately if we didn't get in for whatever reason (at mountain airports, for example, there can be huge differences in vis over the airport vs the 1-2 miles away when you arrive at MDA/DA). If the weather hadn't improved to mins, we would have had only enough fuel for one turn in holding before bugging out.

Joe, yes, no HND overnights, only daytrips. Otherwise I would bid it!

Peter Allen said...
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Pete Templin said...

Can you explain the linguistics of the term MEL? I understand the term, in that there's a minimum list of equipment necessary for flight, and that for a variety of reasons (service improvements, redundancy improvements, whatever) aircraft often have more "stuff" than their minimum. However, I don't understand the usage of the term, especially in verb form. For example, here in That Sinking Feeling, you say the mechanics were "on board clearing an MEL", and (back in Feb '09) in Saying No the DM sputtered "I just know that it's all in the same module and that module can be MEL'd". Is it treated as an "Extraneous Equipment List" and anything "MEL'd" can be treated as unneeded for legal flight? Thanks!