Features  / 04.11 /

Exit strategy

IMC ahead? Four steps to get you in the clear


One person a week. That’s how many people, on average, don’t make it home from a flight because they flew VFR into instrument conditions. Over the past 10 years, 311 accidents can be categorized as VFR into IMC, an event that claims lives 86 percent of the time. The worst part? Most of these accidents were avoidable.

How—why do these tragic accidents occur? After all, every private pilot applicant is required to receive at least three hours of flight training under simulated or actual instrument conditions before their checkride. But these three hours of training are merely a very short introduction to the demanding and complex procedural and mental requirements of conducting a flight in IMC. While seldom mentioned during initial flight training, the real purpose of this training is to prepare the pilot to survive an accidental IMC encounter, should they ever find themselves in that predicament. Statistics prove that surviving an accidental IMC encounter demands much more than just a basic ability to fly the steady heading and altitude that was required during the checkride.

Why would a pilot on a visual flight rules (VFR) flight allow an airplane to enter IMC in the first place? Good question. According to accident analysis data taken from the Air Safety Institute’s Nall Report, the most common type of weather-related—

and deadly—accidents result from VFR flights that continue into IMC. One could logically conclude that the training these accident pilots received in preparation for an IMC encounter was insufficient; or the skills achieved were not retained or reviewed frequently enough to be useful when they were needed.

Unless a pilot decides to proceed to instrument training after receiving his or her pilot certificate, typically very little additional time, effort, or thought is given to improving or even maintaining the meager instrument skills obtained during primary flight training. Unfortunately, the next time a newly minted pilot dons a hood to simulate IMC may very well be during a flight review some 24 months later. But even the flight review’s one-hour minimum flight training requirement does not stipulate that any instrument training be provided. The FAA’s Airplane Flying Handbook reminds us that a pilot whose instrument skills have eroded will lose control of the airplane in about 10 minutes upon entering IMC.

Flight instructors often advocate a 180-degree turn as the first line of defense upon encountering IMC. It is much more appropriate to consider the 180-degree turn an avoidance maneuver—not an escape tool. In the history of aviation, there has never been a case where IMC has suddenly snuck up on, overtaken, and completely enveloped an airplane without warning. Instead, it is the pilot who, through poor judgment, chooses to continue flying into the IMC. Once encountering IMC, making a 180-degree turn is unwise if the pilot has been attempting to maintain VFR by descending lower and lower until the presence of terrain and/or obstacles prevented any further descent. Accomplishing a 180-degree turn at this time, without losing altitude, is challenging to a pilot facing intense anxiety and workload. Even worse would be a pilot’s decision to descend further, in spite of the knowledge that terrain exists immediately below.

So, make your 180-degree turn well before getting into IMC. Failing that, a much safer course of action once IMC has been encountered is to aggressively escape the immediate danger by executing the “Four Cs." If you’ve allowed very poor judgment to get you into this mess, successfully executing these four Cs can and will get you safely out of it.

CLIMB! Begin climbing immediately to a safe altitude, even if this means remaining in IMC. Climbing puts as much distance as possible between you and the ground which, as an added benefit, increases your chances of obtaining effective assistance from ATC. VHF radio communications and radar services require line-of-sight capability to be useful, and these are precisely the two types of immediate assistance of which you are in desperate need.

Avoid, at all costs, the natural temptation to begin looking out the windows to reacquire visual cues. Gazing out the windows almost guarantees entering an extreme unusual attitude from which even a trained instrument pilot would have difficulty recovering. Focus all of your attention on maintaining a wings-level attitude as you apply full power and climb.

Don’t look at sectional charts or reference manuals as a means of determining your location or what ATC facility to contact. Digging for charts or information only distracts you from successfully accomplishing the only task that really matters right now—flying the airplane. If you are fortunate enough to be equipped with a reliable autopilot system, activate it to climb on a steady heading.

COMMUNICATE! All you need to recall are the two emergency numbers your instructor was so adamant that you memorize: 7700 and 121.5. No matter where you are in the United States (almost), these two numbers will get you the most immediate and effective help. And now that you are climbing to a higher altitude, squawking 7700 on the transponder and selecting 121.5 MHz in the communications radio will provide you the quickest access to the help you need. Even if you are located in a remote area with few ATC facilities near your position, every airliner coursing the skies above you is monitoring 121.5, leaving very little chance that no one will hear your plea for help. If you don’t receive an immediate response to your first calls, don’t panic—just keep climbing; each additional foot of altitude you gain will increase your chances of being heard, and observed on radar. Don't allow your attempts at communication to distract you from your primary task of maintaining steady control of the airplane’s attitude as you climb. (If you are receiving VFR traffic advisories, don’t change frequencies—explain your situation and ask the controller you’re already talking with for help.)

CONFESS! As with nearly everything in life, when it comes to confessing that you have gotten into trouble and need help, there is usually a special word that aids in that effort. In aviation, that magic word is the “M” word: “Mayday, mayday, mayday!” By beginning your transmissions in this way, there will be absolutely no doubt in the receiver’s mind as to the nature of your communication. Avoid calls to ATC that sound as if everything’s cool, and you’re requesting some sort of routine assistance like flight following. On IFR days, a busy controller might automatically tune out these types of requests and respond with a curt, “Unable VFR advisories.” However, if you begin your transmission with the M word, ATC will immediately understand your situation and place you at the top of their priority list. Achieving “number-one-customer” status without delay or confusion will reduce your stress level and get that needed flow of assistance from ATC moving more quickly. Once ATC communications have been established, all that remains is for you to carry out their instructions.

COMPLY! This particular C is what those initial three hours of instrument flight training was intended to prepare you for. But that might have been quite a while back. Plus, without successfully completing the first three Cs in the equation, there is probably little need for compliance, since you’d still be attempting to find your way out of the IMC on your own. Get help with the first three Cs and then survive by complying with the instructions provided.

Compliance is simply your ability to follow heading and altitude instructions provided by ATC. If you can accomplish that task, the controller will lead you either to VFR conditions or to an eventual descent out of the IMC while lining you up with a nice, long, well-lit runway. However, even the very best air traffic controllers in the world cannot fly the airplane for you, so your survival demands that training and recent practice allow you to accomplish this critically important task.

Take everything very slowly. Make turns at very shallow banks (10-degree maximum) while keeping the pitch attitude of the airplane fairly close to the horizon as viewed on the attitude indicator, even for climbs or eventual descents. If larger turns are required, consider breaking them into smaller 30-degree segments; don’t combine turns with climbs or descents. Take these tasks one at a time to reduce your workload. Most of your attention should be on the attitude indicator as you scan the other flight instruments as needed. While in IMC, your clearest and most immediate view to the outside world is through that essential instrument.

If you’re still preparing for your private certificate, discuss and practice the four Cs strategy with your instructor before your checkride. If you’re already instrument rated, you should still be practicing the four Cs to enhance your skills. At some point during your practice flights, get your hood in place and complete the life-saving four-Cs drill, step by step:

1. Immediately begin climbing.

2. Once established, tune in 121.5 on your communications radio and simulate that you’re selecting 7700 on the transponder.

3. Addressing your safety pilot, announce: “Mayday, mayday, mayday! I’m in IMC and need radar vectors to VMC and land!”

4. At this point, your valued safety pilot can play the role of ATC by issuing various headings and altitudes, simulating ATC-provided radar vectors to your favorite airport restaurant destination. It’ll be the best investment in a $100 hamburger you’ve ever made.

And don’t worry if your early attempts aren’t very impressive. No matter how ugly it gets, all you have to do is slip off your hood. Just be thankful that you’re discovering your weaknesses on a nice VFR day in simulated conditions. Don’t give up; these critical skills will return. Maintaining the knowledge and skills required for escaping an accidental IMC encounter do not come easily or naturally, but must be reviewed and practiced routinely to ensure they will be available if needed.

Bob Schmelzer is a Chicago-area designated pilot examiner and a United Airlines Boeing 777 captain and line check airman. He has been a flight instructor since 1972.


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