Page 14 - Volume 17 Number 11

TheChallenge Visual Appby LeRoy CookDescending into a terminal environment when the weather’s adequate for a visual transition to the runway would seem to be a welcome release. Slipping the fetters of an IAP (instrument approach procedure) allows air traffic controllers and pilots to shave minutes and save fuel. Your affirmative response to “Do you have the airport in sight?” can be followed by “Okay, go there”, or official phraseology meaning much the same thing.So, what’s the downside of accepting a visual arrival? Maneuvering in visual meteorological conditions should be easier and more flexible than jumping through the hoops of an approach procedure. It’s not uncommon, however, for pilots to execute visuals poorly or even destructively. What’s the problem here?It may begin with the fact that clearance from obstructions and terrain becomes the pilot’s responsibility, often in difficult conditions. The definition of “visual” only means that the weather meets VFR criteria, as low as three miles visibility and 1,000 feet of ceiling. It’s probably not CAVU, and keeping the airport in sight in marginal visibility takes up much of the pilot’s attention. Without electronic guidance, there’s ample opportunity to let the airplane slip into hazardous speed and attitude regimes.It’s difficult to refuse the offer of a visual arrival, especially with comforting vectors from approach control. Saving time and money, and thereby avoiding the stepdowns and heading changes of an IAP, create an attractive inducement. However, there can be times when you may want to ask for the full approach. In any case, you should have the likely approach procedure for the expected runway loaded and ready, so there won’t be a mad scramble to dial and punch inputs close to12 • TWIN & TURBINEthe ground. Air Traffic Control wants to know your intentions early on, so if you don’t like what you see when you start breaking out of the cloud layers, begin the process of requesting a full approach right away.Are Pilots Visually Qualified?Have we have grown so comfortable with coupling the autopilot to a charted procedure, designed to bring the airplane close to the threshold, that having to steer it and configure it on our own has become an abnormal circumstance? Some of the notable accidents of late seem to point to this lack of familiarity. When on a visual, you should be prepared to actually FLY the airplane.Visual arrivals to an airport with multiple runways assumes that the pilot has a runway assignment and probably will accept a vectored line-up on a downwind, base, or straight-in leg, often with traffic-to-follow in sight if not seeing the airport. It may be necessary to adjust speed to maintain spacing without direction, or even to S-turn (carefully) if overtaking. The opportunity to perform a downwind entry or extended base leg gives a bit more ability to adjust spacing before stabilizing on final, but one has to take advantage of that opportunity, not miss it.You need to be familiar with the power settings required to hold the aircraft in a stable speed and/or altitude condition in various configurations, remembering that maneuvering adds some drag as well. The goal is to align the aircraft on a stabilized final, ready to land, which means you shouldn’t carry so much power that excess speed results, yet not so little that the aircraft settles below a visual glideslope or, worse yet, begins to decelerate dangerously. The process of stabilizing the approach should be completed no lower than 500 feet above ground level. Using approach slope lights to stayNOVEMBER 2013r