Wx Watch: Convective Calamaties

For the time being, let's do away with any deep theoretical discussions concerning thunderstorms. Besides, we should all know by now that thunderstorms are caused by moist, unstable air rising under the influence of frontal, terrain, or upper-air lifting forces. We should also know to look for advance warning about thunderstorms from National Weather Service products such as the convective outlook, radar summary charts, radar reports (rareps), TAFs, area forecasts, pireps, and low-level significant weather prognosis charts, among others. Of course, the diligent pilot will also obtain a complete preflight weather briefing from flight service or DUATS. That should go without saying.

With those sound government-issue bits of advice out of the way, it's time to look at a few examples of how things went terribly wrong for several general aviation pilots who flew in convective situations. No theory here. We're talking about the realities surrounding thunderstorm accidents.

The following accident synopses are instructive because they are so typical in their unfolding. And the lessons are so clear that there's no need for pontification.

• June 15, 1982. A 2,500-hour commercial, noninstrument-rated pilot flying a Piper PA-32 Saratoga on a cross-country flight near Hartshorne, Oklahoma, was advised in flight of a severe thunderstorm and tornado watch along his route of flight. The pilot had not received a preflight weather briefing. At 4:13 p.m., flight watch told him of a line of radar returns 10 miles ahead. The pilot said that it "looks like a soft spot through there just to the north of our position," and flew on. Eight minutes later the pilot radioed that he had an emergency. He said that the engine had quit and that he had lost an aileron; 25 seconds later he said that the airplane was hard to control, and that he was at 2,500 feet and descending. Then he reported the loss of the right wing. An examination of the wreckage indicated that the airplane hit the ground in a flat spin. The pilot and his two passengers were killed.
• July 13, 1994. An instrument-rated Cessna Skyhawk pilot received two preflight weather briefings — one on the day before the flight, the other prior to departing — before taking off on a cross-country flight from Janesville, Wisconsin, to Mount Pocono, Pennsylvania. During the second briefing the pilot was told to expect conditions in Pennsylvania to be 4,000 to 5,000 broken, with tops to 10,000 feet. Widely scattered thunderstorms, with tops to 35,000 feet, were also forecast. Where thunderstorms were forecast, the pilot was told to expect ceilings and visibilities in the 1,000-and-one mile range. While en route, the pilot made a fuel stop at the Wood County Airport in Bowling Green, Ohio. But he didn't receive a weather briefing prior to leaving Bowling Green. By 5:23 p.m., the pilot and his passenger were over western Pennsylvania, and a radio call to flight watch was made. The pilot was told of a severe thunderstorm watch in effect for parts of eastern Pennsylvania, as well as thunderstorms in progress northeast of Wilkes-Barre. In a second transmission, flight watch told the Skyhawk pilot, "...You are definitely going to have problems with that area [Wilkes-Barre, Mt. Pocono] with weather." A discussion about route deviations ensued. The pilot then called the New York Air Route Traffic Control Center, saying, "I'd just like vectors for the closest airport ... sounds like we're going to be running into some storms here and I'm going to wait those out." Vectors for an approach to the Williamsport (Pennsylvania) airport were issued. While flying toward Williamsport, the pilot radioed, "...This is pretty bad for us right here. Do you have any vectors for us?" The controller said that his radar didn't paint weather very well, then asked for radar information from another airplane in the area. Seconds later, the Skyhawk pilot said, "We're flying into some heavy lightning here, and, ah, decreased visibility." The controller then said, "There's an airplane at your twelve o'clock and ten miles.... He says it's pretty good to the southwest if you want to take a turn to the south or get away from the weather." The pilot acknowledged that transmission, then was told to switch frequencies. He checked in on the new frequency, but the controller didn't acknowledge the callup at first. When he tried to call the Skyhawk pilot, there was no reply. The airplane crashed 14 nm northwest of the Williamsport airport, where the latest surface weather observation included a report of 6,000 broken and a visibility of seven miles. In the remarks section of the report it was noted that there was a thunderstorm northwest of the field, moving southeast, with occasional lightning in clouds. The pilot and passenger were killed.
• September 9, 1985. During his preflight weather briefing, a 2,000-hour, instrument-rated Mooney 201 pilot learned of the possibility of thunderstorms along his planned route from Beaumont, Texas, to New Orleans. On the morning of the accident flight, the pilot had a Stormscope installed in the Mooney. That evening, while en route, New Orleans approach control warned the pilot that convective activity with VIP (Video Integrated Processor) Level Three radar returns was along his flight path. The pilot didn't acknowledge this information. During his descent into the New Orleans area, ATC radar logs showed, the Mooney's descent was normal at first, but then went vertical. At about 10:05 p.m. the airplane crashed in a swamp near Kraemer, Louisiana, in a vertical attitude, killing the pilot.
• October 31, 1995. The pilot and three passengers in a Beech A36 Bonanza were killed during a takeoff in a thunderstorm from the Colonel James Jabara Airport in Wichita. A seven-year-old boy survived the crash with serious injuries. Before the flight, the instrument-rated pilot received a weather briefing and filed an IFR flight plan to Colorado Springs. During the 5:37 a.m. briefing, the pilot was told of a severe thunderstorm watch north of his route, a "pretty severe line of thunderstorm activity," and a convective sigmet. The briefer said, "...It looks like you should be able to slide around the southern edge, uh, south of the Dodge City area to get around that area." At 8:30 a.m. a severe thunderstorm with Level Six radar returns and gust front winds of up to 63 knots was approaching Jabara from the northwest. Linemen busy tying down aircraft noticed the Bonanza taxiing out for takeoff. Just as a northwesterly gust arrived, the Bonanza took off. As several airport employees watched, the Bonanza climbed to about 50 to 75 feet, pitching and banking severely. One witness said that the nose then pitched up and the left wing dropped as though the airplane were entering a spin. The airplane crashed 1,000 feet from the departure end of Jabara's Runway 18.

Most accident reports provide a number of lessons. The common thread weaving through the previous four is a foreknowledge of convective weather. Although these pilots knew what might await them, they pressed on. Sure, the pilot in the Oklahoma crash wasn't instrument-rated, and apparently attempted to continue flying VFR into deteriorating weather — a major cause of many, many thunderstorm accidents. But he knew to call flight watch for inflight updates, and he was accurately warned of severe weather ahead. In the Pennsylvania crash, the pilot became well informed of the convective situation he was entering, and was executing a diversion to an alternate airport. This case may have been one of just plain bad luck.

It happens. The pilot was trying to avoid storms but appears to have flown into a cell that developed suddenly as he approached his alternate airport. He was acting in great diligence but got trapped. It would be easy to blame him for not doing a 180-degree turn, but in this case — as in so many others — that may not have worked. The pilot was working with, and trusting, all the information he could get and was doing just what he should have done. But he crashed anyway. What's the lesson here? Stay on the ground if storms are ever mentioned in a briefing? That would work, but so many times it's just not practical. And in any event, the go/no-go decision is composed of a blend of factors: your qualifications, experience, and comfort level; your airplane's performance; your weather avoidance equipment (if any); and the region you're flying in.

The New Orleans crash carries a special warning about the risks of flying at night in thunderstorm season. At night it's more difficult to see and avoid clouds with convective potential. A bright moon certainly helps, but not if you're picking your way along through cloud conditions that favor embedded thunderstorms. Flying VFR in IMC in areas with Level-Three weather? Not a good idea.

Finally, the Jabara accident. Here we enter the realm of mystery that surrounds so many weather-related crashes. Why did the pilot decide to take off? We'll never know. He must have known, on a purely intellectual level, about the dangers he was about to face. But he never put that knowledge into action. Figure out the disconnect between pilot knowledge and judgment, and we'll be well on the way to ending these sorts of crashes.

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