Top left - The “Airspeed Indicator” shows aircraft airspeed, usually in knots. (A knot is one nautical mile per hour—about 1. 15 MPH or 1. 85km/hr). Top center - The “Artificial Horizon” shows the aircraft attitude, that is, how the plane is inclined in all directions—whether the plane is climbing or descending and how it is banking - left or right. Top right - The “Altimeter” shows the height (altitude) of the aircraft, in feet MSL—feet above mean, or average, sea level. Lower left - The “Turn and Bank Indicator” is a dual instrument which tells how fast you are changing the compass heading (rate of turn) and also whether you are in co-ordinated flight, feeling the proper (down-in-the-seat) Gs from the turn. This is also called the “Turn and Slip Indicator” or “Needle Ball. " Lower center is the “Heading Indicator” which shows the current compass heading. Keep in mind that small amounts of friction in the heading gyro dictate that this instrument be calibrated on an ongoing basis. This is explained below in the calibration procedure. Lower right is the “Vertical Speed Indicator” which tells how fast you are going higher or lower. It gives the rate of descent (or climb) in feet per minute. Zero means that you are maintaining altitude and are neither climbing nor descending.
Your answer should have been, “The aircraft is in a slightly climbing left turn, cruising at a speed of 110 knots about 3,100 feet (944. 9 m) above sea level on a heading of 178° (almost due south). "
Throttle - A black knob - When pushed forward, the engine is at full throttle and when pulled full back, the engine is idling. Fuel Mixture - A red knob - Pushed full inward is the richest mixture (used for sea level takeoffs and landings), while full back is engine off. Only pull the red knob full out when you are on the ground and ready to shut down the engine. Carburetor Heat - Used to warm the engine air intake in icing conditions and on long descents with engine at idle - conditions where a cold engine with cold air could cause icing. Note that, for all practical purposes, this has to be either full-on or full-off. Flaps - A flat handled switch to select the wing flap positions. This will be used for slowing the aircraft to a safe speed in preparation for landing the aircraft. Note that the flaps should be advanced notch-by-notch, one position (10°) at a time. Fuel tank select - A Cessna 172 would almost always be set on “Both Tanks. " Steering wheel (Yoke) - This sets the attitude (climb and turn) and the speed of the aircraft. Use small pitch adjustments, in and out for pitch (to climb or descend). Turn the yoke left and right to bank the aircraft. Engine RPM is used for setting engine speed (power) for climbing, descending, and/or landing. Rudder Pedals - These are operated by your feet. Press the top edge of the pedals and the brakes are applied. (Of course, this only has an effect when you are on the ground. ) Pressing the lower part of the pedals allows steering while on the runway and helps do quality turns in the air. You will also use the lower part of the rudder pedals to stay lined up with the runway while on final approach. Control trim - There are two trim wheels in the panel which, when adjusted properly, give you almost hands-off control. You will not be using these in an emergency. Be aware too, if you do try to use them to trim for landing, you may not have enough pitch control to gain altitude quickly in case of a go-around. You would have to re-trim in case of a go-around, but it is way better to just stay away from these controls and consider them off limits.
Look at the gauges and see if you can determine the normal operating ranges. Then ask yourself what basic actions you would have to perform to correct for certain conditions. For, example, if you were slightly descending and wanted to get back to level flight, what would you have to do? Take a few moments to deeply think about the scenarios you imagine and visualize the correct action you might take. This will prime your mind to absorb further lessons. It is highly recommended that you spend enough time doing this to feel like you have it mastered, up to this point. You should, at a minimum, have a good feel for what information each instrument gives and how it relates to the plane position and near-term flight path.
The airspeed indicator (top left) has arcs colored in green, yellow, white, and red. Normal airspeed will, of course, be in the green and the lower edge of green indicates the flap-up stall speed. Try your best to keep the instrument in the green arc while cruising. Use the Yoke to adjust nose-up and nose-down (pitch) to set the airspeed; do not use the throttle to adjust airspeed. The red line is the “never exceed” speed line. Stay out of there! The white range is safe flap lowering speed and the lower end of white is the stall speed for full flaps down (only used when on final approach for landing). The Artificial Horizon has a miniature aircraft in the center. In straight and level flight it should stay there. If it starts to drift, use the yoke to re-center and/or level the small airplane on the horizon line. The Altimeter may start to wind or unwind. If you seek to maintain level flight, use the yoke to stabilize your altitude. You can see that you will have to scan these six instruments to maintain control of the aircraft. – That’s why the six are right together in front of the pilot. Scan them often. The Needle Ball should stay centered when you are in level flight and turning the aircraft. When turning, the needle ball graphically shows you the quality of the turn you’re making. Strive to keep your turns very shallow, less than 10°. This will keep you out of trouble. which is what you are after whenever you fly a plane, particularly for the first time, and, particularly, in an emergency. The Heading Indicator should be on the heading you are trying to fly. If not, use the yoke to make one (or a series of) very shallow turn(s) to stay on course. Don’t chase the heading too much; just make very small corrections and patiently wait for the reading to settle. That will feed back on how you’re doing and you can correct a bit again, if needed. The Vertical Speed also should be centered at zero in level flight. If not, make small pitch corrections with the yoke, don’t chase the rate of change of ascent or descent. —Make one small correction, same as above, and continue scanning the instruments.
Use the Yoke to adjust nose-up and nose-down (pitch) to set the airspeed; do not use the throttle to adjust airspeed. The red line is the “never exceed” speed line. Stay out of there! The white range is safe flap lowering speed and the lower end of white is the stall speed for full flaps down (only used when on final approach for landing).
Straight and level flight Climb Descent
Ensure that the RPM gauge is indicating a cruise setting of between 2100 and 2700 RPM. When you are in straight and level cruise (flight), you can adjust the RPM using the throttle.
The Cessna 172 can stall (in a turn) at approximately 65 knots (no flaps) so keep your turns shallow and avoid any speed below 80 knots to allow yourself a margin of safety. Remember to boost the speed by lowering the nose slightly and/or adding a little throttle when necessary. Again, use gentle corrections and stay well out of the danger zones that are indicated on the instruments.
A descent to land at a nearby airport is done by reducing the throttle to an engine speed of about 1800 to 1500 RPM while setting the air/fuel mixture at full richness (red knob fully inward). If the descent will cause you to be a long time at low engine power, then you may have to use carburetor heat to prevent icing. At reduced RPMs, the engine will not be producing as much heat and you may have to kick on the carburetor heat. Do so only if the weather indicates possible icing conditions. Here, the tower can give you guidance, so ask if you aren’t sure. If you’re descending for a landing at an airport further away, reduce throttle to 2000 RPM to descend while maintaining a higher airspeed. However, don’t get going too fast. Watch the airspeed indicator and avoid going very far into the yellow arc.
Each time you lower the flaps a notch (10°), push forward on the yoke a little to counteract the tendency of the flaps to raise the nose.
This is a hard thing to break away from, but it is absolutely critical to be able to ignore what your body is telling you because it may be wrong. Instead, when you do not have supplementary visual input, rely solely on the instruments. Switch to total reliance on the instruments once you lose your ability to see clearly. Once you lose the ability to determine your plane’s spatial orientation by using visible cues (either the horizon, a beacon, or a landmark), you must compel yourself to rely solely on the instruments and force yourself to discard what your body is telling you.
If you enter a banking turn and stay there (in co-ordinated flight) for twenty seconds or so, your body gets acclimated to the turn and thinks you are flying straight and level when you are still in a banking turn. In the dark or when visibility is limited, you have no visual cues to correct the impression your body has picked up. The “Death Spiral” starts when you notice you are losing altitude (common in banking turns) and pull up on the yoke to gain altitude. The problem comes from being in a banking turn: Pulling back on the yoke results in tightening the turn and a further loss of altitude, not in gaining altitude. The natural tendency is then to pull back even more on the yoke and that makes things even worse. Moral of the story: Trust the “Artificial Horizon. "
Be highly aware that any loss of altitude might be the result of entering a banking turn without realizing it. This will be evident on the “Artificial Horizon” and on your “Heading Indicator. “If your heading is changing, you are turning.
