The graveyard spiral, or "spiral dive," has claimed the lives of many pilots. In my years as a flight instructor, I've come to find that graveyard spirals are not well understood by many pilots. That's part of the reason graveyard spirals continue to kill people. I believe education is the answer to managing risks in flying, so I'd like to provide some information about spiral dives and how to respond to them and, more importantly, how to prevent them in the first place.
First of all, what is a graveyard spiral? Graveyard spirals usually occur in instrument conditions when the pilot becomes spatially disoriented. The pilot's spatial disorientation could be the result of turbulence, instrument failure(s), lack of instrument training, or simply cockpit distraction. Whatever the case, the pilot loses control of bank attitude and one wing begins to drop. As the bank steepens, the nose falls through the horizon and the aircraft begins descending. The airspeed increases and the bank angle and rate of descent continue to increase. The pilot senses a descent and pulls back on the yoke or stick in an attempt to arrest the descent, but this only steepens the spiral. The load factor increases dramatically and the descent rate becomes incredibly steep. Often in fully developed graveyard spirals the aircraft suffers an in-flight breakup before it reaches the ground. Other times the aircraft strikes the ground in a nose-low attitude at extremely high speed. Accident sites of graveyard spirals are usually breathtaking... Thousands of aircraft fragments (and other things) scattered around as though a bomb went off.
Recovery from a fully developed spiral dive is sometimes impossible. Once the airspeed exceeds a certain value, structural failure will occur during any type of recovery attempt. For this reason it's very important that we never allow a spiral dive to fully develop. The answer to preventing the formation of a spiral dive is to avoid situations where we might become spatially disoriented. Never fly in instrument conditions unless you're instrument proficient, not just instrument current. Minimize cockpit distractions and always remember keeping the airplane under control is your top priority. Never conduct other cockpit tasks during turns because there is a higher risk of losing control of bank during a turn. Use an autopilot, and always maintain a proactive instrument cross-check to detect instrument failures. Luckily, instrument failures are much lesson common now with glass panel systems and laser gyros. We don't have to rely on undependable vacuum pumps anymore for attitude information.
If a spiral dive starts, rely on your unusual attitude recovery training. Reduce power to idle, level the wings FIRST (that's very important because leveling the wings reduces load factor exponentially), and slowly recover from the resulting dive. The most important component of attitude during flight is bank. If you control bank, there's very little pitch can do to hurt you. If the wings are level, positively stable airplanes will fix pitch on their own and the nose will eventually return to a safe attitude after oscillation cycles. Some new airplanes are being built with a "wing leveler" feature for this reason. If the pilot feels like he's losing control of the airplane, he hits a button and the autopilot levels the wings. If the wings are level, a spiral dive can't develop. Remember, spiral dives are the result of runaway bank. Maintain control of bank, and you won't find yourself in one of these terrible situations.
