Hi, I’m Bruce Landsberg and welcome to the Leading Edge. We’ll discuss safety-of-flight issues, procedures, techniques, and judgment. With the convective nature of Internet misinformation, and so much content that is over weight and out of balance, you need an experienced and trusted source. So, strap in and let’s go fly!

Tiptoeing ‘round the Boomers

May 21, 2014 by Bruce Landsberg
Boomers Fig 1

                    Figure 1

Last week the Weather Channel was predicting Meteorological Apocalypse as they almost always do whenever a strong cold front hits the Midwest. A 25-degree temperature spread across the air masses often makes for a few tornadoes and copious thunderstorm activity.

A business meeting in Kansas City offered the chance to fly from the East coast with a friend in his Cessna 441. We launched early afternoon for the 3.5-hour ride. At 30,000 feet the view was impressive, and it was obvious from several hundred miles away that “direct” was no longer in the cards. We climbed to FL340 for a better view. Not many 32-year-old turboprops can do that.

In Figure 1, you’ll note a significant northwest deviation as we worked around the end of the first line. Datalink radar told the story as did ATC. Visually, however, it looked better down to the southwest. That’s because the line was trailing away from us and was hidden by the closer storms. Got to watch those illusions or get taken for a ride!

Boomers Fig 2

                    Figure 2

Arrival into MKC required onboard radar because the flight was in and out of lower clouds and much closer to the cells. Timing is everything. FlightAware’s snapshot at 2:50 pm is a midflight picture—not actually what was happening when we arrived. It shows us going through a cell, which we did not (Figure 2).You may notice a “buttonhook” sort of turn as we got onto the downwind. Tracon asked if we’d like a scenic detour since heavy rain was moving across the final approach course. It’s bad karma to be on final in heavy precip, so a 5-minute delay allowed a much less exciting arrival.

The return trip two days later was equally interesting but in a completely different chariot—another friend’s Cessna Caravan. Since many of us don’t routinely fly the flight levels, it’s fun to compare the differences. It was VFR, low and slow, to St. Louis for a three-hour business stop.


Boomers Fig 3

                    Figure 3

The mid-afternoon launch had us into the backside of the front, which had meandered into the Ohio Valley (Figure 3). Again, the image shows the mid-trip picture, so the cells are not exactly as they appear at the time of our passing.

The first part of the trip, being in the cold sector, precluded cruising at the odd 5,000 feet altitude due to icing—4,000 worked well until the temperatures warmed eastbound.

Late afternoon is about the worst time to tackle something that requires heat as an engine, but there we were. In convective weather one should never rely on just one source of information. We had five: visual (much of the time), datalink, onboard radar, lightning detection, and ATC (the ARTCC duplicates datalink, but most tracons have real time weather). Each has its strength and weakness, but collectively they provide a good picture of where not to go. The whole trick is not to get painted into a corner, and a wide yellow stripe down your back doesn’t hurt either!

One point about deviations: On the return trip, even though there appear to be significant deviations (and there were), the mileage didn’t change much—699 nm direct, 757 nm as filed, 761 nm as flown. Those were quality miles, and despite all the vertical clouds light turbulence was all we encountered and not enough rain to wash the bugs off.

Join the Air Safety Institute during Storm Week, June 8-14. Each day during Storm Week look for ASI’s convective-weather related safety products, including a  new “Flying the Weather” video, and register now for our “Datalink: Cockpit Weather Do’s and Don’ts” webinar to be held on June 11, 2014, at 7:00 p.m. ET, as we discuss important safety considerations when flying with cockpit weather.

Learn how to keep thunderstorms at bay with ASI’s “Weather Wise: Thunderstorms and ATC” course, which explains the finer nuances of how to effectively communicate with ATC, how controllers describe precipitation, and what radar services they can offer.

Bruce Landsberg,
President of the AOPA Foundation

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Air Pockets or Worse !

May 14, 2014 by Bruce Landsberg

wavesToo many airlines think we can’t handle the truth, and so the flight crew refers to “bumps” rather than turbulence. You’ll even hear media types occasionally mention “air pockets,” a long outdated terminology. For light GA, turbulence is often uncomfortable and occasionally dangerous.

The Air Safety Institute, working with the FAA and the NTSB, is highlighting turbulence this month as part of our 2014 weather education campaign. Turbulence comes in a variety of forms and can be merely aggravating or really bad news.

Convective turbulence from thunderstorms is probably the worst and disassembles aircraft about six times a year. It often takes the form of the pilot first losing control, and then the hardware starts to come apart after all speed limits are exceeded.

But sometimes the bounces are in the form of waves and rotors. If you’ve done much flying in any sort of mountainous or hilly terrain you’ve likely experienced the wave—sometimes visible with lenticular clouds but not always, especially when the air is dry.

My first exposures to the wave were perplexing at best. In cruise flight with the autopilot in “altitude hold,” the airspeed was going up and the A/P was trimming nose down. Pretty cool—free lunch? You know the deal on lunches, because a few miles down the road just the opposite happened as the nose went up and the airspeed just went to pot. Thinking a navigational error had placed me into the Bermuda Triangle I called ATC to ask for a block altitude. It was, of course, the smooth part of the down wave.

However, altitudes below the smoothness can be a dentist’s delight—rough enough to jar loose fillings. Airspeed control is the key, and on descent in those types of conditions one should be well acquainted with VAmaneuvering speed. VA is one of those counter-intuitive concepts. As the gross weight declines, the slower the maneuvering speed. The published number in the handbook or on the placard is appropriate at max gross. If you’re lighter than that—slow down.

Airspeed bumps around a good bit in turbulence, and if everything is stable “right at” VA, a gust can increase the speed by 10 knots in the blink of an eye. When flying an older aircraft there is no comfort knowing that if the bozo that flew it before you exceeded VA, and got into heavy turbulence, some of the margins built into the structure when new have been used up. How much? Good question. Slow down.

Pay attention to pireps and Center Weather Advisories—the loss of a modified Cessna P210 is instructional. Even moderate winds over big mountains deserve to be treated with great respect. Maybe there’s something to this air pocket thing after all.

Bruce Landsberg,
President of the AOPA Foundation

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A few questions in SD

May 7, 2014 by Bruce Landsberg
9D0 sectional and turbine inset

                                      MEF 2,700 feet

There was a tragic accident in South Dakota last week when a PA-32R (Piper Lance) collided with a wind turbine. There aren’t that many people in South Dakota, so the loss of four prominent young men in the cattle business is really unfortunate. Losing anyone in an aircraft accident is unfortunate.

An accident chain seems clearly present here, but the usual caveat is that this is preliminary and there might be a completely different causal factor:

1) Fatigue? The accident is estimated to have occurred shortly after 9 p.m. CDT. Based on distance from the departure point in Texas, the flight would have been approaching four hours or more depending on headwinds. That means departure was made at the end of a long day and facing difficult weather. Better to leave a couple of hours earlier?

2) Weather? According to the NTSB preliminary report “The closest official weather observation station was…Pierre, South Dakota, 37 miles west of the accident location. The routine aviation weather report…, issued at 2124,..wind 010 degrees at 19 knots, visibility 10 miles, sky condition broken clouds at 1,000 feet, overcast at 1,600 feet, temperature 06 degrees Celsius (C), dew point temperature 05 degrees C, altimeter 29.37 inches, remarks, ceiling variable between 800 and 1,200 feet.”  Technically it was VMC but this really is IFR weather. Why no IFR flight plan?

3) Low Level? The impact with the wind turbine was about 300 agl. The tower itself was measured at 215 agl or 316 agl depending on which symbol you choose. The blades may extend well above that. Tower symbols are charted south of the airport about 10 miles. Why fly that low…to avoid ice perhaps, or to maintain ground contact?

From what we know now, subject to change, there was no IFR flight plan filed even though the pilot was instrument rated. Don’t know if he was current. There was no reported communication with ATC. The weather system was widespread, so it’s unlikely that the pilot was surprised by the rain and fog. The temperature/dew point spread tells the story. It’s a “fur piece” from Texas to South Dakota especially at low altitude and bucking a 30-knot headwind. There is no indication they stopped for fuel, so could fuel exhaustion be an issue?

Armchair quarterbacking would say “controlled flight into tower (CFIT)” and VFR into IMC. Possible fatigue, possible fuel shortage, definite low ceiling and visibility, definite dark night, definite towers and apparently a strong desire to get home after a weekend in Texas: If all that is as it appears, it’s a risky proposition.

TAP—The Air Safety Institute has a Terrain Avoidance Plan Safety Brief that will keep you out of the rough. In this case the absolute bare minimum altitude for VFR is charted at 2,700 feet msl (Maximum Elevation Figure) with the tops of the turbines around 2,500 feet msl. Personally, I’d add several hundred feet to that.

The question none of us will be able to answer is why? Those that we lost can no longer explain. Would sure like to better understand the human mind. Too many smart, capable people are lost this way.

Free aviation safety programs from the Air Safety Institute—including ASI’s Do The Right Thing: Decision Making for Pilots online course—are available to all thanks to support from pilots everywhere. Help us to keep educating pilots on safety issues by donating to the AOPA Foundation today.

Bruce Landsberg,
President of the AOPA Foundation

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