FLYING LESSONS for February 11, 2016

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1 FLYING LESSONS for February 11, 2016 suggested by this week s aircraft mishap reports FLYING LESSONS uses the past week s mishap reports to consider what might have contributed to accidents, so you can make better decisions if you face similar circumstances. In almost all cases design characteristics of a specific make and model airplane have little direct bearing on the possible causes of aircraft accidents, so apply these FLYING LESSONS to any airplane you fly. Verify all technical information before applying it to your aircraft or operation, with manufacturers data and recommendations taking precedence. You are pilot in command, and are ultimately responsible for the decisions you make. FLYING LESSONS is an independent product of MASTERY FLIGHT TRAINING, INC. This week s lessons: Pursue Mastery of Flight This week's LESSON may seem at first to be a bit of a pilot-report "fluff piece." But mastering this week's LESSON would probably do more to reduce the chances of the most common fatal crash scenario across all types of fixed-wing aviation loss of control crashes, primarily stalls than any new technology or automation ever could. Finding the Numbers A friend and flying student of mine made a great buy: a nicely updated and well-equipped early 60s Cessna 172. He flew it with another pilot 8.5 hours from the U.S. Southeast back to Wichita a couple of weeks ago (I was not available), so he had the opportunity to see how things worked and how it handled during the times the pilot not an instructor let him do the flying. Upon his arrival home, my student took a day to rest from the longest day of flying he s yet had. Meanwhile I took the 172 up at his request, to double-check all the equipment s operation. Since we had been working toward his Private Pilot checkride in a Cessna 150 (subject of the Bugsmasher chronicle of my own delivery flight from Georgia last summer), we d combine the 2016 Mastery Flight Training, Inc. All rights reserved. 1

2 rest of our time on his preparation for the Practical Test with a solid transition to the type-specific characteristics of the 145-horsepower Cessna 172B. See To expedite his transition and to establish a pattern that will serve my student throughout his entire flying career, in anything he flies I used the time also to find the numbers for this vintage Skyhawk. After spending about 40 minutes in the book, that is, the 1961 Cessna 172B Owner s Manual, to re-acquaint myself with the airplane that is very close to the 1965 Cessna T-41As in which I first trained, I preflighted the spunky Cessna and took off for some exploratory maneuvering. One key point from the Owner s Manual is the top, high-speed end of the airspeed indicator s white arc : maximum flap extended speed V FE. According to the Cessna manual, V FE is 100 miles per hour (all airspeeds for this airplane are given in mph), and this is the maximum recommended indicated airspeed for extending any of the 172B s four extended positions of the manually activated flaps: 10, 20, 30 and 40. After leveling off at a safe altitude and making a few turns to get the feel for the airplane, I began to experiment to develop a useful set of numbers for my friend s Cessna. I wanted to find a power setting that would result in a speed of 95 mph in level flight with the flaps up. Why 95? This speed would permit immediate extension of flaps to begin the descent from pattern altitude, without having to reduce power and hold altitude to slow to V FE on the downwind. Also, as additional flap is added and perhaps with a further power reduction, the airplane would easily settle into the 80 mph book final approach speed with 30 (normal landing) or 40 (short field landing) flap extension. Further, 80 mph is the book initial climb speed for this airplane. This means the trim setting on final approach would be very close to the same as the trim for climbing out on a go-around. In turn, this means pilot workload is significantly reduced in this highest-of-workload normal flight environment. In a go-around, the pilot whose trim is already set will be able to apply power and retract flaps, and the airplane will do pretty much what he or she wants while the pilot devotes attention to the larger situation. It s all part of a concept known well to pilots of larger airplanes, and which you ve probably read about in my previous articles and LESSONS in the context of flying high-performance aircraft: Power + Attitude + Configuration = Performance The PAC concept works in jets, turboprops and high performance piston airplanes. There s no reason to believe PAC isn t just as valid and valuable in smaller airplanes as well and a lot of evidence to convince us it works. So what did I find? Flaps UP, it takes about 2000 RPM for this Cessna to maintain 95 mph in level flight. I sped up and slowed down a couple of times, and slowed to about 80 mph and then added power back, to confirm that the C172B regularly and repeatedly trends to 95 mph in level flight at 2000 RPM. Except that my friend s well-equipped C172 has something not terribly common in these airplanes: a Carburetor Air Temperature (CAT) gauge. The six-cylinder Continental O-300 is fairly well known for developing carb ice when conditions are conducive Outside Air Temperature (OAT) between about 20 F and 70 F (-17 C to +21 C) in high humidity or visible moisture. It turns out that at 2000 RPM the C172 s carburetor temperature was running just into the red (extreme hazard) arc when flying with an OAT in the mid-50s Fahrenheit (10 to 12 C). The CAT is a good thing to have with a carbureted engine indeed (long ago in a 2016 Mastery Flight Training, Inc. All rights reserved. 2

3 CAT-equipped Cessna 182 I found that its engine ran in the yellow or red temperature arc almost all the time, even in cruise). I wanted an easy technique for my student (and myself). Even though the CAT makes it possible to accurately use just enough carburetor heat to keep the carb temp out of the icing range, I decided to teach using full carb heat at all times when carburetor heat is called for. That way it takes a glance at the gauge, one movement of the carb heat knob (the same every time), and only an occasional scan of the CAT thereafter to see if anything has changed. Knowing I needed the equivalent of 2000 RPM without carburetor heat, and that applying carb heat during the preflight test usually causes a roughly 100 RPM drop in power, I though it would take 2100 RPM with full carburetor heat to result in 95 mph in level flight with the flaps up. Sure enough, that was exactly right. Next was to determine the numbers in terms of flaps and power during the descent portion of downwind, base leg and final approach. With just a little more experimentation this is what I learned: 1. Establish the 2100 RPM/Carb Heat/Flaps UP 95 mph condition prior to entering the traffic pattern, and maintain that condition until abeam your intended landing spot. 2. Abeam your landing spot, add the first notch (10 ) of flaps. Then, reduce RPM to The C172 will settle quickly into a 500 foot per minute descent at 90 mph. Very predictably, if you are trimmed for 95 mph in the downwind/pattern entry configuration, after adding the first notch of flaps and reducing power to 1900 RPM, it takes one roll of the trim wheel forward (nose down) to be trimmed for 90 mph. By a roll of the trim I 2016 Mastery Flight Training, Inc. All rights reserved. 3

4 mean this: grasp the lower (or aft) end of the trim wheel where is comes out of its fairing between your thumb and forefinger, then move the trim forward/nose DOWN until your thumb and finger touch the forward/upper upholstery or housing. This is extremely easy to do without having to look at the trim wheel or position indicator, and again, is extremely predictable. 3. After turning base, extend the second notch of flaps (20 ). Leave the power at 1900 RPM. In this C172 this doesn t change the speed noticeably from 90 mph, but it requires another roll forward of the trim to maintain that speed. 4. Established on final approach, extend final flaps (30 or, in a shortfield landing, full or 40 ). Reduce power to 1600 RPM. This slows the airplane to the target final approach speed of 80 mph. Maintaining this speed requires one roll up of the trim wheel grasp the wheel with your thumb and forefinger at the point it enters the upper or forward end of the fairing, and roll the trim nose UP until you re touching the aft/lower end of the housing. 5. If you choose to go around follow the book procedure: add full power, including turning off the carburetor heat; adjust the pitch to the climb attitude as you retract all by the first notch (10 ) of flaps, and begin an 80 mph climbout. As time permits retract the flaps fully; adjust pitch and trim as necessary to climb safely to altitude. Now, I admit that this wasn t the first time I ve used these PAC settings in a Cessna 172. I recall having this all worked out (including the nose down, nose down, nose up sequence of trim changes with flap extension) when I taught full time in a Skyhawk. But that was 25 years ago. And now I have the Carburetor Air Temperature gauge to help me make a much more informed power management decision Mastery Flight Training, Inc. All rights reserved. 4

5 Here s the real value of knowing the numbers, the PAC settings for the airplane(s) you fly: Not only does using this technique tremendously reduce your workload in the traffic pattern, because you re not having to make it up every time you come in to land, but it also makes the airplane perform predictably in a manner that obtains maximum performance and maintains a comfortable margin away from stall speed and angle of attack, without you having to manage it beyond making crosschecks that pitch, power, configuration and resulting performance are what you expect. Keep the rudder in coordination and the pitch attitude where experience shows you it should be; adjust pitch slightly to maintain airspeed, including lowering the nose slightly while in descending turns to maintain airspeed, and power 100 to 200 RPM up or down as needed to maintain descent rate and glide path; and the airplane will not stall in the traffic pattern. In fact I m very proud of my current pre-private student pilot, because he s constantly saying rudder, rudder and lower the nose in the turn as he flies the pattern, and more importantly because he s actually doing what he says he needs to do, consistently. He s very rapidly made the transition from the Cessna 150 to flying this C172 because he knows how to guide it through approach and landing using PACs, instead of manhandling it randomly through the pattern. Yes, an angle of attack indicator will provide more of an advance warning of a trend toward stall than the traditional stall warning horn, but if you habitually fly using PACs you don t have to worry about an inadvertent stall. Note that warnings are often ignored when the pilot is under stress (stall warnings, gear warning horns, etc.). I m not sure the distracted pilot who stalls an airplane while the traditional stall warning horn is blaring would act any differently with an additional stall warning device. I like angle of attack indicators as a teaching tool. They would make it easy to demonstrate the types of things I m discussion here. But here s where, frankly, I personally diverge from a lot of the government and industry guidance that has come out over the past couple of years despite my admiration for all who have been trying to do something about the Loss of Control Inflight (LOC-I) record, and the FAA for making the installation of most angle of attack indicators an easy, minor alteration in U.S.-registered airplanes. I m convinced that pilots would be far better off to spend $150 - $200 on flying their airplane with an instructor for a solid hour of finding the numbers and then practicing the PAC technique in the traffic pattern, repeating the exercise once a year, than they would be to spend a few thousand dollars installing an angle of attack indicator without taking the time and effort to learn how to use it properly which includes figuring out the numbers and the PACs for the airplane, and regularly practicing in the pattern regardless. You may not have to reinvent the wheel. Most major airplane types are supported by a type club or other network of enthusiasts and experts for that type. Seek out the owners groups and associations for the airplane you fly, and get their recommendations on the numbers and the PACs for yours. In Practical Flying (1928), author Major Byron Q. Jones, who had been Chief of U.S. Army Aviation Training during the First World War, writes about approaches to landings: the student will begin to learn how far down below the horizon the nose should be pointed for a normal glid[ing turn], how quickly the plane will pick up speed if the nose is pointed down farther, and how quickly speed will be lost, and how much more slowly the controls will respond when the glide is flattened out. In the classic Stick and Rudder (1944), Wolfgang Langewiesche writes about angle of attack in gliding turns: relax the back pressure first of all. Once back pressure is relaxed, the airplane becomes again stable, controllable, and well behaved and the pilot can do just about whatever he wants. A friend in the FAA tells me that preliminary data from a study being conducted by the University of North Dakota shows that, in airplanes equipped with angle of attack (AoA) 2016 Mastery Flight Training, Inc. All rights reserved. 5

6 indicators, student pilots are lowering the airplane s nose two to three degrees during descending turns in the traffic pattern when compared to students flying similar airplanes without the AoA devices. We knew this from the very beginning of powered flight. We ve just not been teaching it effectively. Do we need another panel-mounted device to make a real difference? Or do we need pilots to be flying their airplanes using predictable combinations of power, attitude, configuration and airspeed, in coordinated flight, and adjusting pitch slightly in gliding turns to maintain airspeed and angle of attack? The first stripe of airmanship is to master the aircraft (and its technology). What better way to develop mastery than to learn, and use, the numbers and PACs for your airplane? See What do you think? Let us know, at mastery.flight.training@cox.net See I really like the "mastery" rather than "safety" concept, Tom. Thank you, and keep up the great work. I look forward to continuing to learn from you. Michael Lapore Please be a FLYING LESSONS supporter through the secure PayPal donations button at Thank you, generous supporters. Share the skies with master aviators. Forward FLYING LESSONS to a friend Personal Aviation: Freedom. Choices. Responsibility. Thomas P. Turner, M.S. Aviation Safety, Three-time Master CFI Flight Instructor Hall of Fame 2010 National FAA Safety Team Representative of the Year 2008 FAA Central Region CFI of the Year FLYING LESSONS is 2016 Mastery Flight Training, Inc. For more information see or contact mastery.flight.training@cox.net Mastery Flight Training, Inc. All rights reserved. 6