Weather and Static Systems


"Three things in life are overrated," I was told in medical school. "Home cooking, out of town sex and the Johns Hopkins Hospital." Envy was surely at work. When I became an intern in the great Midwest, the saying was similar, but regionalized. "Three things in life are overrated: (HC, OOTS) and the Mayo Clinic." I'm confident that similar aphorisms in the West disparaged Stanford or maybe UCLA. In any event, the message was about those overrated but highly regarded facts of life.

Labor Day weekend. The usual is planned: Tampa to Lebanon, New Hampshire, in our Cheyenne. The weather? Lousy in Florida (thunderstorms) and crummy in the Southeast (low ceilings and visibilities), improving towards the Northeast, but lowering in New Hampshire. It looks doable.

Off we don't go. As we taxi out, the airport is closed for thunderstorms. It is not yet noon, a bad sign. I open the oil cooler doors, expecting an indefinite hold, as it is hot, very hot. In time the aerodrome opens and we are cleared to take off to the south. I notice the Nexrad is "unavail." We go.

Without Nexrad, I negotiate a series of buildups, some visually, some by onboard radar. (Remember that? That used to be, before Nexrad, as good as it got.) At one point I ask for and receive an intermediate altitude of 15,000 feet. I can see low-hanging anvils everywhere; 15,000 seems very comfortable in the meantime.

Clear of the weather, I ask for FL 250, which is where the fun begins. Out of 200, the airspeed indicator on the pilot's side starts a slow slither towards zero. The altimeter jumps around, assessing our altitude in 500-foot jerks. What the devil? I look to the often ignored, never closely watched, copilot's instruments. They show a climb of 1,000 feet per minute and a gradually increasing altitude consistent with what I think we're doing. But staring at an airspeed indicator falling to zero is not a reassuring experience. Should we retreat to Tampa? I'm reluctant. We've just worked our way through this unpleasant weather.

The GPS altitude on the Garmin 430 is consistent with the copilot's gauges. JAX center agrees with our altitude when I think we're at Flight Level 230. I admit to a "static system partial problem" to the center. JAX voices no concern.

I decide to continue. The airplane is running normally; the encoder, the copilot's altimeter and the GPS agree about our altitude. The copilot's airspeed indicator seems about right. My wife is uneasy. How is it, she wonders, that we can be sure of our altitude as we transgress some of the busiest airspace on earth? Trust me, I say. Though, truth be told, I'm uneasy myself. I switch to the alternate static source, without any change in any instrument. Should I land? We'd be shipwrecked, somewhere, with a large Labrador Retriever. On we go.

As we approach the Northeast, I am deprived of the metars usually supplied by XM Weather. I have no reception on our Avidyne. Signal strength is "low," indicating that the box is working, but no adequate signal is being received. I call flight service over Virginia. I barely remember how. Raleigh radio replies. The weather at our destination is 2,000 overcast, three miles, rain and mist. The fact that Lebanon (KLEB) is in a nonradar environment reminds me that an ILS without radar supervision in mountainous terrain with an unreliable altimeter is the kind of thing Peter Garrison likes to write about in Aftermath. This concept enters my distracted, vaguely displeased mind. I decide to default to Manchester, New Hampshire. They have maintenance there, at Wiggins Airways, where I've had things done before, and they are reporting better weather (3,000 scattered, 4,000 overcast), at least according to the nice man at Flight Service. The terrain is more hospitable. We can rent a car there and get to Lebanon in an hour and a half.

We start down into a pretty thick overcast. Vectored onto the ILS 35, I note we're still IMC at 2,000 feet. So much for the forecast. But the ILS does bring a big bouquet of relief: I can receive a glideslope, great reassurance for a man with an altimeter staring him in the face that reads height in 700-foot gulps. I'm quite grateful when we break out with infinite runway before us. We'll sort out the maintenance tomorrow, a Saturday.

To my surprise and gratitude, Wiggins has weekend maintenance. I talk to John Danis at 9 a.m. and by 11:30 he calls me back, announcing that he's located both pitot tubes on the fuselage and recommends bringing the airplane into the hangar for a static leak check and a leak check of the air data computer. I'm very grateful for Saturday service. I also talk to Bill Turley, our airplane's constant gardener, and ask him, given his intimate knowledge, to talk directly to John at Wiggins.

The two mechanics talk. It is much like asking two plumbers to clean your pipes. Each has a different view of things. In the end, Bill Turley arranges for an air data computer to be flown from Duncan in Omaha to Manchester. This is not the first air data computer that I've bought for this airplane from this vendor. There's a certain sense of familiarity. Delivery is scheduled for Sunday afternoon at 4:36. John will be there until 10, so chances of having a workable airplane in time to fly home on Labor Day are good. I go to sleep expectant but wary.

No word on Sunday, but by Monday morning John is on the phone. The air data computer didn't arrive at 4:36; it got there after 10. John was gone. He's there with it now, though. I make reluctant backup reservations on Southwest's 8:20 p.m. to Tampa. The arrival is close to midnight. I've got a big day the next day and the late arrival doesn't sound appealing.

I figure that a signed off, safe airplane by noon will make it possible for us to get home. Later than that, I've got to go home on the airlines and my wife and dog will get to stay in the cool air while I return to work. My hopes don't last long. There's a Northwest Airbus stranded at MHT with a fuel leak in an engine. John is called away. We're understandably on the back burner. I try to adjust. Not many times has this airplane stranded us. And it is definitely not safe to start out on a 1,000-nautical mile plus IFR trip. Not for me, at least.

The airline trip home and week at work are all satisfactory, but leave me with a sense of life unlived, of flights unflown. On the following Saturday, I board Southwest and track back to MHT. The work is done. The bill is reasonable. I pick up the airplane and fly VFR to KLEB. Everything, except the XM Weather, seems to work okay, but I don't get high enough for a real reassurance. A generous homecoming awaits.

Next morning we prepare for the trip home. The weather is not what I'd pick for a takeoff in a newly repaired airplane: 600 overcast, visibility three miles. There are numerous convective cells about. I put MHT in the box in case something happens on takeoff, oblivious to the fact that there is a thunderstorm right there, right now.

We depart without difficulty and I and Cathy, but not the dog, are relieved to break out on top around 14,000. Now all we have to do is circumnavigate the tropical storm (Gabriel) pounding the Outer Banks and deal with the summertime afternoon thunderstorms in Florida. Everything is working perfectly, including the recalcitrant Nexrad. The dog shows no hint of concern.

Though we could make it nonstop from LEB to TPA, there would be no margin for weather or a hold. I decide to stop in Columbia, South Carolina, at Columbia Air Service, where jet-A is at least $1 cheaper than the other FBO. By midafternoon we're homeward bound after a fill up. The Nexrad, working perfectly, shows smooth sailing.

On the Dades One arrival, I see a few cells, but deviations are easy to come by. Everybody is getting requested headings without difficulty. There are holds into Orlando, though. Soon we're descending out of Flight Level 220. Then, the fun. There's a cell right over the Tampa airport. I see it first on the Nexrad, then confirm it with onboard radar. Tampa Approach is busy. A US Airways crew gets into a tiff with approach. Approach asks whether the crew wants to try the approach or head for the hold. The crew is indecisive. Approach is reassuring: "Heavy rain, smooth ride on final," he says. This is common in Florida but not a trustworthy phenomenon in other parts of the world. US Air says, "Then why are we vectored 360 degrees if the airport is landing to the south?" "Because you're on the downwind," comes the answer. Disdain drips from the headset.

British Air is having none of it. "Speedbird 2167 heavy is painting magenta over the airport. We'd like a hold. Speedbird doesn't do magenta." Apparently they've got very good radar on those 777s. Me, on the other hand, I'm game. Several Southwest flights have reported rain and smooth sailing on the ILS. I accept an ILS to 18 L, five in trail to Southwest 332, in bound from Providence, though I don't know that.

Established on the ILS at three miles from the outer marker, the tower says, "Wind Shear alert." It is getting very dark ahead, no longer gray, but a green-gray blue. You know. I plan to continue VFR to the marker and recheck the winds with the tower. Then I hear Southwest say, "Onboard wind shear alert, we're going around." I look at the Avidyne. The go-around track is into the worst of it.

"2458 Whiskey is breaking this off to the east," I say. We're at 1,000 feet. I can see daylight to my left. Gear up, flaps up. We're turned over to Tampa final and vectored away from the storm. I see sunlight. I am glad.

Twenty minutes of vectoring later, the cell has moved north and we're on the downwind for Runway 9. In 24 years of being based at Tampa, I've probably landed on this bit of pavement twice. It looks really good on final, I think. We land, aware that stopping for fuel gave us the luxury of not diverting and aware that the time it took to refuel gave the thunderstorm time to build in just the wrong spot. A paradox.

Taxiing in, I thought about the broken airplane, its competent repair, my reliability on Bill Turley to see to the communications and my trust in several Wiggins mechanics whom I've never met. I thought about my decisions to depart in marginal weather in mountainous terrain, to land for fuel, to accept an approach that British Airways declined but Southwest accepted.

That night's martini tasted especially good. Flying has a way of sharpening the taste buds. Some things in life are not overrated. I'd list competent out of town maintenance, a reliable expert mechanic at home, functioning Nexrad, helpful controllers and luck among them.