January 27

January 27, 1998

Flying Real-World Weather

G.A. pilots are taught to stay on the ground when the weather briefing doesn't look good. That advice may be Politically Correct, but it doesn't cut the mustard if you use your airplane as a serious long-range transportation tool. The author has flown dozens of coast-to-coast trips by lightplane in all sorts of weather, and offers one experienced instrument pilot's perspective on how to deal with real-world weather.

By Mike Busch

Airmanship Several decades ago, my primary flight instructor taught me that being a safe pilot meant staying on the ground when the weather didn't look good. When I got my instrument rating a few years later, my CFII cautioned me against flying when icing or thunderstorms were anticipated.

Such advice may be okay for pilots who fly for recreation, but it's simply unrealistic if you fly for business and use your airplane as a serious transportation tool. This is doubly true if you fly transcontinental distances, as I do several times a year. It's seldom possible to fly 2,000 nautical miles without having to traverse at least one major weather system.

Naturally, there are times when the weather is bad enough that staying on the ground is the only prudent course. Even the airlines occasionally cancel flights due to weather. But unless we can operate with a fairly high probability of getting where we need to go when we need to be there, the airplane can't be counted on for serious business travel.

We've all heard the cliché: there are old pilots and bold pilots, but no old bold pilots. Unfortunately, it's not that simple. Weather flying requires a certain measure of boldness. The question is: how much is too much?

Flying Ice

The NTSB has ruled that forecast icing conditions are considered to be "known icing," which means in theory that most light planes are grounded whenever the forecast calls for a chance of ice. Get real! If we stayed on the ground whenever ice was forecast, we couldn't fly for 4 or 5 months out of the year in many portions of the country. And so far as I can determine, the FAA has never pursued a volation against an airman for flying a non-known-ice airplane in forecast icing conditions except when an accident occurred.

While I'm not prepared to accept the NTSB's guidance on ice flying, it is necessary to establish some basic rules. For example, I have no reservations about descending through an icing layer at my destination, especially if it's above freezing at the surface. On the other hand, a departure that requires me to climb through an icing layer gives me considerable pause. I have to be darned sure that I can get on-top without picking up much ice before tackling such a departure. This is one of the few situations where a twin has a big advantage over a single, because although twins don't cruise significantly faster than singles, they do have a lot more climb capability.

Cessna 182 The scariest ice experience I ever had occurred in the winter of 1970 while I was heading home to California from Minneapolis in my Skylane. I wound up getting stuck in Rapid City, S.D., for several days while I waited out a big snowstorm. Finally, the snow stopped and I headed out to the airport and went to the FSS for in-person briefing. I asked about icing PIREPs, and the briefer told me about a Cessna 150 that was practicing holding patterns at 6,000' and reporting only occasional light rime ice. He also said that a United 737 was due in shortly and might be able to provide information on tops and icing.

The United flight landed as advertised, and as soon as the last passenger deplaned, I ran up the airstair, headed for the cockpit, and asked the first officer if he could give me an in-person PIREP. He replied that the tops were about 12,000 and that he hadn't noticed any icing during the descent into Rapid City.

"It's essential to take immediate action at the first sign of icing. Don't just sit there in denial... do something!"

Armed with that information, I returned to the FSS, filed an IFR flight plan westbound, and launched into the soup. Although it was below freezing on the surface that day, I experienced no icing during the climb until passing about 7,000' at which point I started picking up a little. By the time I reached 8,000' I realized my rate of climb had gone to zero and the engine was starting to lose power. The only way I could restore power was to use full carburator heat. It became clear that there was no way I was going to be able to climb on-top.

I advised Center that I was picking up moderate ice, couldn't maintain altitude, and needed to return to Rapid City. The controller gave me a clearance to return and descend. By the time I reached the outer marker, I realized that my windshield was totally iced over and completely opaque. The defroster managed to clear only a dime-sized hole right above the hot air outlet. I wound up shooting the ILS and feeling for the runway. The landing was a little "firmer" than usual, and the impact caused a large quantity of ice to fall off the airplane.

Upon taxiing in and shutting down, I discovered that there was 3/4-inch of ice on the wing leading edges and wing struts, and that the induction air filter was completely iced over. I pulled a foot-long piece of ice from the wing and plunked on the FSS counter, saying "here's my pilot report". I then checked back into the motel, at which point my knees went weak when I realized just how close I'd come to getting in serious trouble.

Could I have made this flight successfully had I been flying a known-ice-equipped Turbo 310 instead of a Skylane? Maybe, but maybe not. I'm sure I could have climbed higher than 8,000' in the T310R, but whether I could have made it to on-top is unknowable. If not, the windshield hot-plate would have come in handy when landing back at Rapid City!

I learned several things from that close call:

No matter how thoroughly you brief, you can never be sure about icing until you fly it.
Trying to climb through an icing layer in a light plane is sometimes impossible.
Most important, it's essential to take immediate action at the first sign of icing.

(I also learned that a Skylane can haul quite a load of ice without falling out of the sky. I hate to think of what would have happened had I been flying a Mooney!)

The same time-is-of-the-essence attitude is important when ice is encountered enroute. Don't just sit there in denial...do something! There are three possible ways to escape from an icing encounter:

Climb (if you think you can get on-top)
Descend (if you think you can get below the freezing level)
Make a 180 and retreat

If you can't decide whether to climb or descend, try climbing first because you can always descend later (but necessarily not vice-versa). A turbocharger often makes climbing the preferred option: if you can't climb to on-top, you still may be able to climb into cold enough temperatures that icing is no longer possible. (Icing rarely occurs below -20°C).

As soon as you've resolved your immediate icing problem, be sure to file a PIREP so that other pilots can benefit from your knowledge. It's even more important to file PIREPs when you find that there's no ice despite the forecast. If you think about it, reports of ice-free altitudes are precisely the sort of thing that other pilots need to know about.

About the Author ...

Mike Busch is editor-in-chief of AVweb, a member of the technical staff at Cessna Pilots Association, and in a prior lifetime was a contributing editor for The Aviation Consumer and IFR Magazine. A 6,000-hour commercial pilot and CFI with airplane, instrument and multiengine ratings, Mike has been flying for 36 years and an aircraft owner for 33. For the past 14 of those years, he's owned and flown a Cessna T310R turbocharged twin, which he maintains himself. In his never-ending quest to become a true renaissance man of aviation, Mike's on the verge of earning his A&P mechanic certificate. Mike and his wife Jan reside on the central coast of California in a semi-rural area where he can't get DSL or cable TV.