Why VFR into IMC?

January 1, 2004

ASF Executive Director Bruce Landsberg tells it like it is by filing pireps when he flies.

Some accidents aren't. That is, they do not fit the definition of being unexpected or unforseen events.

The results of pilots flying VFR into instrument meteorological conditions, or VFR into IMC, really are no surprise. The most recent Nall Report, the Air Safety Foundation's annual review of accidents that is published each spring, noted that there were 33 accidents in 2001 where the NTSB reported pilots getting into clouds when they weren't on an IFR flight plan.

In a few cases there might be some extenuating circumstances resulting from unforecast weather. It's rare but it happens. In many more cases there were clear warning signs that the pilot overlooked out of ignorance or carelessness. In the majority of these crashes it appears that the pilots made the decision to launch, or continue, into weather that was clearly inappropriate for their skills or the flight rules under which they chose to operate.

An interview after the crash might unravel the thought process behind what has to be one of the highest-risk activities in aviation. Unfortunately, we don't get to talk with many of the pilots because very few survive the experience. Some possible answers: "I couldn't see the clouds into which I was flying because other clouds were obscuring my vision;" or, "The layers were pretty thin and I felt I could get on top (or underneath) before losing control;" or, "I've always been a little foggy about that temperature/dew point relationship;" or, "I've done this many times and never had a problem, until today." This last one might be the most popular.

There are two scenarios regarding the impacts: out of control, typically in a spiral or with the aircraft disassembling itself after the flight exceeds V NE; and in level flight and in control, right up to the sudden stop. An example of each is offered. They occurred a few days apart in January 2000.

Out of control

IMC prevailed for the cross-country flight from Montrose, Colorado. The noninstrument-rated Cessna 421B pilot did not file any flight plan. Radar documented the airplane's departure from Montrose at approximately 9:15 a.m. At 9:46, the airplane began a 1,792-fpm climb from 14,300 feet msl to 16,600 feet msl. Nineteen seconds later, the airplane lost 4,000 feet of altitude, a 12,631 fpm rate of descent. The airplane then climbed back to 13,300 feet msl at a rate of 1,448 fpm. One more primary radar return was recorded at 9:48 (no altitude was documented), and then the airplane disappeared from radar.

At 9:53 a.m., the weather conditions at the Cortez Municipal Airport, Cortez, Colorado, (elevation 5,914 feet) 22 nm south of the accident site, were: wind 240 degrees at 5 knots; visibility 5 statute miles with snow showers; broken clouds at 2,400 feet, overcast at 3,200 feet; temperature and dew point 28 degrees Fahrenheit.

The wreckage indicated an inverted 30-degree nose-low, 25-degree right bank that points to a graveyard spiral. There were no indications of pre-impact malfunctions and there was no fire.

Snowmobilers near the crash site reported snow showers and visibility of less than one-half mile at approximately 9:50. Telluride Regional Airport (elevation 9,078 feet), 045 degrees and 33 nm from the site, reported 6 to 8 inches of snow throughout the day. A pilot departing Telluride at approximately 10:15 said that it was clear right over Telluride but on climbout he entered clouds at 12,000 feet msl, and he didn't break out until 22,000 feet msl. He experienced no icing or turbulence.

The pilot's original flight logbook (his current logbook was never found) indicated a private pilot certificate issued in 1970. The pilot purchased the 421B in November 1998, and attended Cessna 421B ground and flight training school in Tucson, Arizona, in January 1999. At that time, he reported 1,500 hours of single-engine flight time and 1,500 hours of multiengine flight time. Instructors at the school described the pilot as having "good natural flying skills and a quick learner but somewhat weak with instrument reference." On the pilot's last insurance application, less than a month before the accident, he listed 3,700 hours total flight time and 200 hours in the Cessna 421.

Sudden stop

Scenario two: A noninstrument-rated private pilot departed Louisville, Kentucky, at 3:32 p.m. in a Beechcraft P35 Bonanza and crashed less than an hour later into a mountain near Rogersville, Tennessee. During the flight he requested multiple altitude changes to either maintain VFR or to improve the ride, we don't know which.

Instrument conditions prevailed in the area. The Tri-Cities Regional Airport surface weather observation at 3:53 p.m. was 1,300 feet overcast, with visibility of 10 miles. While the weather was technically VFR and possibly adequate for flight in flat terrain, it was not sufficient for safe flight in mountainous terrain. Witnesses at Hawkins County Airport, the pilot's intended destination, stated that on the day of the accident, the ceiling and visibility had been low and the airport was closed because of the weather. The Bonanza was in level flight when it struck Clinch Mountain, about 6.7 nm from Hawkins County Airport, 50 feet below the top of the 2,400-foot peak.

The pilot had attended a Bonanza initial training course in September 1999, four months prior to the crash. The flight experience on the pilot's application was 700 hours total time, 400 hours in a Bonanza, and 400 hours of instrument flight experience. How does a VFR pilot manage to log that much instrument time? Most GA instrument pilots average 10 to maybe 20 percent instrument time relative to total flight time. There are exceptions, perhaps in the Northeast, but having more than 50 percent instrument time falls into the "whopper" category. The pilot completed a flight review, with "satisfactory" performance during the two VFR flights. The flight instructor could not specifically remember whether the pilot either did not request instrument training or stated that he was not instrument-rated, and thus was not given instrument flight training during the Bonanza course. The pilot's private certificate with an airplane single-engine land rating, no instrument rating, was issued on August 30, 1989.

A recurrent theme

The similarities of these crashes should give us reason to pause. Both involved fairly experienced pilots, flying high-performance aircraft, who had recently trained, likely because of insurance company pressure. Neither had an instrument rating but both appeared to be competent VFR pilots, at least according to the instructors who flew with them last. A while back we looked at another high-time VFR pilot flying a complex aircraft, a Piper Arrow, who also disregarded the rules regarding VFR (see " Safety Pilot: Drilling Hills," April 2002 Pilot). It is a recurrent theme and one that should not be ignored by any VFR pilot.

In many cases the pilots involved in similar accidents did not receive an official weather brief. They may have looked at The Weather Channel or gone to the Internet to get what they needed, but it was not tallied anywhere. Maybe the attitude was: "Why bother to check the weather? We're going anyway." For pilots of light aircraft, even with an instrument ticket, that is not a long-term survival strategy.

Complex and high-performance aircraft are designed for cross-country flight and are naturally exposed to more weather. Noninstrument-rated pilots who operate these aircraft seem to have disproportionate tangles with instrument conditions. It appears that they have been successful for years operating outside the system and arriving at point B in perfectly fine shape. It's highly unusual to get nailed the first, second, or tenth time unless you're very unlucky.

It also seems that these pilots have a cavalier disregard for the collision potential with a legitimate IFR flight. I have observed other aircraft between layers, when I was IFR, and not far away. ATC, when queried, reported the target on a VFR transponder code. That's a hanging offense in my book.

The losses from these accidents total millions of dollars annually, and more important, lives are needlessly wasted. More regulation isn't the answer — we have enough of that. In every case at least two rules were broken. But why do pilots put themselves, their passengers, and other IFR aircraft at such risk, and what should be done about it? You likely have some thoughts — let us know.

ASF has one small suggestion that may help. If a briefer tells you VFR is not recommended (VNR) and you decide to take a look, which some of us do because that particular warning is grossly overused according to an FAA/industry study done several years ago, call in a pirep to report what you find. If it's a bad forecast and the weather is good, let's get it corrected — we need truth in forecasting, and the National Weather Service agrees. The NWS will amend a forecast with a few contrary pireps. Nothing beats having a timely observation out the windshield. If you do indeed find the bad weather, turn around or land as appropriate, and call back to flight service to tell them what you found.

Here's why this is so critical. VNR does no one any good when it's false, and it encourages pilots who are inclined to push the edge to go and to compile a list of successes before they get into trouble. How much better would it be if, when the pilot got a briefing, he or she were advised that forecast was VNR and, by golly, there were several pireps from both VFR and IFR flights confirming that the bad stuff was actually there. It won't stop those hellbent on going, but for the skeptical yet rational crowd it could make a significant difference.


For information on pirep training, see SkySpotter online. Keyword search: pirep.