Monday, June 12, 2006

A Bad Day in Montana

In my post about Butte, I mentioned that we had "a heck of time" getting in on Friday. It was a pretty ugly day to be flying in Montana, and we were definately glad to be done by the end of it.

We were supposed to do two legs on Friday, Portland to Seattle and Seattle to Butte. There, another crew would normally pick up the airplane and continue to Bozeman and then back to Seattle, since this flight is always operated as a triangle.

As we prepared for the flight to Butte, a few items in the NOTAMs (notices to airmen) caught my eye. First, there was no fuel available in Butte - the fuel truck was broken. Therefore, under no circumstances could we land there unless there was enough fuel for the next crew to get to Bozeman. Indeed, our dispatcher put a note on our release informing us that the next crew needed a minimum of 4800 lbs onboard. Secondly, the ILS and LOC-DME approaches at Butte were out of service, as was the RNAV approach and GPS overlays. The only approaches available to us were two non-precision circling VOR approaches. The weather in Butte was OK, but the forecast noted the possibility of thunderstorms.

While we were still about 100 miles from Butte, we heard another airplane on Salt Lake Center's frequency as they twice attempted VOR approaches at Butte, went missed approach, and ended up diverting to Bozeman. Butte's AWOS was reporting three miles' visibility and a broken ceiling at 1500', which is above minimums for the VOR-B approach, but they were also reporting a thunderstorm overhead. We weren't too interested in trying an approach during a thunderstorm, particularly after our weather radar painted heavy rain directly over the airport. We began holding over Coppertown VOR and waited for the storm to pass.

We'd taken plenty of fuel from Seattle, and could've held for over an hour before dipping into our alternate and reserve fuel. However, the unavailability of fuel in Butte meant that we couldn't risk beginning the approach with less than 5200 lbs lest we turn the airplane into a pumpkin upon landing. We held for nearly a half hour, watching the storm slowly move southward. Finally, our fuel state reached the point where we had to land in Butte now or go somewhere else. The airport looked like we could maybe get in, and it was tempting to try, but we both knew it'd be foolish. We diverted to Bozeman, zigzagging around several thunderstorms on the short flight there.

Upon arrival in Bozeman, we began crunching the numbers. We needed to put on enough fuel to get to Butte (around 1000 lbs) plus enough fuel for the new crew to get to Seattle - nearly 8000 lbs of fuel. We had 55 passengers going from Bozeman to Seattle, plus 15 of our original passengers who were going to Butte. A full load of passengers and bags plus 8000 lbs of fuel puts the Megawhacker very close to max takeoff weight. The problem is that there is a 2750 lb difference between max takeoff and max landing weights, and we'd only be burning off 1000 lbs on the way to Butte. We couldn't leave behind fuel, so the only option was to offload passengers and/or baggage.

Skywest Airlines came to the rescue by offering to let our Butte passengers ride along on a bus they had chartered for one of their own flights that had diverted from Butte. With those 15 passengers gone, our landing weight was below the maximum. Butte was reporting good weather again, so we did the paperwork, closed the doors, fired up, and took off for Butte.

Once airborne, our weather woes weren't over; we had to dodge several big cells on the airway. The captain listened to Butte's AWOS over a period of several minutes, which painted a picture of rapidly deteriorating weather. Although there were no thunderstorms, the clouds were getting lower and rain was reducing visibility. By the time we began the VOR-B approach, it was down to 3 miles' visibility - the minimum for the approach - with a 1400' ceiling.

Of all the things I wanted to do this week, a "dive-and-drive" non-precision approach to minimums in the mountains definately wasn't on the list. Ameriflight lost a Beech 99 on this particular approach a few months ago (they apparently continued on the 127 radial after Coppertown rather than turning to the 097 radial); that thought contributed to the white-knuckle factor. As we reached minimums, we weren't seeing anything other than I-90 beneath us. We kept trucking along through the driving rain, waiting for 5 minutes to expire on the timer. Eventually, recognizable landmarks around Butte began appearing in front of us, and the forward visibility increased a bit. Finally, the airport appeared three miles ahead and slightly to our right. We both breathed a sigh of relief as the Captain began the final descent to landing.

It's funny how my perceptions have changed. As a flight instructor and freight dog, I shot non-precision approaches to minimums fairly regularly. Now it's a rare event. This approach induced enough adrenaline that we were almost shaking after we got on the ground. "That was one tight approach," my Captain exclaimed to the crewmembers taking the plane over. They shrugged indifferently, as if to say "Well, at least you finally brought us our plane."

That was day one of this trip. I figured after that, the trip would go smoothly. Right? Right.....?

Update: Airline flying really has turned me into a total wuss. I'm catching up on Aviatrix' recent postings and I'm getting embarassed that I actually whined about shooting a real VOR approach. I think Aviatrix is a good hundred miles from the nearest VOR.


Aviatrix said...

That's about right. It's all NDBs up here. Most of the time I just use the trackbar on my HSI as an extra heading bug.

But you're not a wuss. I'd be a little nervous if I had to shoot an ILS approach tomorrow. Do I still remember how?

Sam said...

Heh, I actually shot a real live NDB approach into Boise a few months ago. The ILS and VOR were both out of commission, and I was flying with a new captain who hadn't completed his FMS approach initial experience yet, so the NDB approach was our only option. It was almost comical, we were both reciting old crutch-phrases from our CFII days ("lead the head, lag the tail!" etc).

Aviatrix said...

I taught "push the head, pull the tail." Was everyone in this industry once a flight instructor?

Sam said...

Everybody who didn't buy SIC time in a Be1900 at Gulfstream, heh.