Vintage Instructor THE
BY Steve Krog, CFI
That turn to final
any of you reading this article are experienced pilots and have excellent flight safety records, while others are relatively new to the world of Classic, Antique, and Contemporary tailwheel flying. However, both groups are probably thinking, “Who is this guy and what does he know about flying old airplanes?” I have had the pleasure of flying airplanes and providing flight instruction for more than 40 years. For the past 25 years I’ve focused almost exclusively on tailwheel (conventional gear) instruction, providing me an opportunity to fly with a lot of individuals in a lot of different tailwheel airplanes. I offer primary instruction, tailwheel instruction leading to a tailwheel endorsement, FA A W I N G S i n s t r u c t i o n , a n d numerous FAA-required flight reviews. Most of the flying time has been uneventful, but some has proven to be quite interesting! One can always learn something new and helpful from the viewpoints of others. For those of you who are relatively new to the world of vintage tailwheel flying, you may find this information of interest as you prepare for the 2010 flying season. Perhaps the single greatest weakness I see in pilots young and old is the portion of the traffic pattern from the point of power
32 FEBRUARY 2010
reduction to landing, especially the turn from base leg to final. Why should that be so hard? It’s not! But executing that portion of the flight smoothly, safely, and comfortably can be a challenge when additional factors are added to the equation. L e t ’s t a k e a c l o s e l o o k a t a typical scenario that you may face when flying into a nontowered airport. The wind is from 260 degrees at 10-12 knots, and the active runway at our destination is Runway 29. The airplane you are flying could be any one of a dozen different models, as many have similar approach and landing speeds. In this case you’re slowing to 90 mph after applying carburetor heat and making the i n i t i a l p o w e r r e d u c t i o n . Yo u r final approach speed will be 70 mph. The traffic pattern is the traditional left-hand with a published traffic pattern altitude of 1,000 feet AGL. What’s so unusual about this? You deal with this scenario all the time at your own airport. How can this be a problem? So far, it isn’t anything unusual. But let’s add to the equation the fact that we have two additional airplanes in the pattern. The first is a slower airplane ahead of you just making the turn from downwind to the base leg. The second airplane is a light twin entering the traffic pattern behind you, and based on his radio call,
he’s in a hurry! Entering the traffic pattern using the normal 45-degree approach, you turn to 110 degrees, apply carburetor heat at the runway midpoint, make your initial power reduction to 1200 rpm, and establish your 90-mph glide attitude. While completing the pre-landing checklist assuring the fuel selector is on the proper tank, making trim adjustments, and securing maps and other loose items lying on the seat, you momentarily lose sight of the slower airplane in front of you. It takes a few seconds, but the airplane is finally located. “Man, he sure is taking his time,” you think! You’ll need to extend your downwind leg just a bit to give him more time for his approach. Now where is that twin behind you? Finally, the slow airplane is on final approach. You’re wingtip to wingtip, he on final and you on downwind, so the turn to base can be initiated. As you establish your bank angle for the turn, things don’t seem quite right. But no problem. You’ve landed this beautiful old bird many times before. Gosh, that slow plane in front of you is sure taking his sweet time. To compensate, you roll out of your base turn a few degrees early and add 100 rpm. That should provide a few seconds’ more time and better spacing. Things still don’t seem quite right. You have no worries, though. After what seems to be an
eternity, the slower airplane is finally on the ground and rolling out. You can begin your turn to final. Just as you start your turn the twin behind you radios that he is on base leg and beginning his turn to final. You think to yourself, what’s he doing? Doesn’t he know I’m here? Doesn’t he see me? While your neck is straining to look behind you, your beautiful bird is still flying the base leg heading. As you initiate your turn to final you realize that you’ve overshot the runway by a little and you’re a little too high. You need to realign yourself with the centerline and reduce the power. Without realizing it, while in the turn to final, you’ve added a little bottom rudder to speed up the turn and to help get realigned. The bank angle seems a little steep, and you apply opposite aileron to keep the bank at a comfortable 30 degrees. Straining in your seat you take a quick look over your left and right shoulder tr ying to locate that fast-approaching twin supposedly on your tail, and unknowingly, you have applied some backpressure. Wow. What started out to be a normal pleasure flight has caused some stress. Small beads of perspiration form just below the bill of your flying cap. You can’t find the airplane behind you, your airplane is too high and not aligned with the runway, and without realizing it, you’ve added even more bottom rudder to help with the alignment. This is a classic stall/spin predicament, the most common cause of accidents in general aviation. It is only then that you recognize that knot in your stomach. Your gut is telling you this is not where you want to be. Listen to it! This is neither a comfortable nor safe situation in which you find yourself. Roll out of your turn, add power, and go around! Before we go back and do a quick analysis of this situation, let’s put things into perspective. You’re
sitting at the controls of a nicely restored airplane. You’ve put your heart, soul, and a fair amount of money into the beautiful old bird. Why risk your $30,000 - $150,000 investment trying to salvage a landing for the cost of a couple of bucks worth of avgas?
What’s so unusual about this? You deal with this scenario all the time at your own airport. How can this be a problem? Now, let’s go back to the point of the pattern entry and look at what could have been done differently. First, you had an approximate 15-mph quartering tailwind from the right increasing your ground speed significantly while pushing you toward the runway. A 5-degree crab angle to the right and slightly less power would correct the downwind leg. You might even put your airplane in a slow-flight configuration extending the downwind leg by 5-10 seconds beyond the normal no-traffic approach. Then you
can make the base leg turn when wingtip to wingtip with the traffic ahead of you, which will usually provide adequate spacing when the airplanes have similar performance parameters. The turn to base also requires a slight crab angle to the left to compensate for the wind that is now pushing you away from the runway. Upon completing the base leg turn, you should have approximately 500 feet of altitude (assuming you’re not on a 2-mile final!). Due to the now left-quartering tailwind, the turn to final will need to be initiated a few seconds earlier than normal. Doing so should eliminate overshooting the runway and prevent the desire to apply additional bottom rudder pressure. From this point the approach and landing can be conducted normally and safely. As a longtime flight instructor in these old airplanes, I like to have students begin the turn to final with a shallow (15-degree) angle of bank. This provides the flexibility to either safely increase or decrease the angle of bank to align the airplane with the centerline of the runway and never exceed a 30-degree bank angle. A d d i t i o n a l l y, i t i s a g o o d practice to review slow flight in your airplane from time to time. Know your airplane and what it is safely capable of before finding out the hard way in the traffic pattern and under pressure. Steve Krog Steve learned to fly in 1968 and has been flight instructing since 1973. For the past 25 years he has focused on tailwheel flight training in all types and models of tailwheel aircraft. Located in Hartford, WI (HXF), he also owns a small flight school, training sport and private Pilots in tailwheel airplanes. Steve and his wife Sharon run the Cub Club and Luscombe Association type clubs. He has been an EAA and VAA member since 1982.
VINTAGE AIRPLANE 33