Flight Four features ground reference maneuvers and introduces emergency procedures. Ground reference maneuvers are intended to develop your understanding of how the wind influences your ground track. They develop your skill and confidence to a point where you can safely maneuver the airplane while flying at low altitude and making corrections for the effect of the wind. Ground reference maneuvers are a required part of the private pilot practical test and you will need these skills when operating in the airport traffic pattern.
Before commencing Flight Four, be sure to do a thorough Preflight inspection.
Select a location where you will be able to maneuver without disturbing people on the ground and where you could safely land in the event of an emergency.
Before doing any maneuvers, clear the area by reversing course or by making two ninety degree changes of heading.
Since ground reference maneuvers are usually practiced at between 600 and 1000 feet above ground level (AGL), it will be necessary to descend prior to commencing the maneuvers. This presents an opportunity to practice the engine failure emergency procedure.
Engine Failure Emergency Procedure
To practice the engine failure emergency procedure, your instructor will simulate loss of engine power by applying carburetor heat and retarding the throttle to idle. It is not considered necessary or safe to actually cut the engine when practicing this procedure.
As soon as you detect (or in the training situation are told) that your engine has failed, pitch for the best glide speed stated in your airplane’s pilot’s operating handbook (POH) and head toward an area where you can make a forced landing.
If the engine failure occurred during cruise flight, pitching for maximum glide speed will involve slowing down as the best glide speed is usually slower than cruise. You will probably need to add a lot of nose-up trim to establish and maintain best glide speed after transitioning from cruise. Any speed above or below best glide speed will reduce the distance you can glide, so be sure to trim for the correct speed.
While you are pitching for best glide speed, look for and head toward a place you can land.
Once you are at best glide speed and heading for a potential landing area, start troubleshooting per your airplane’s emergency procedure check list.
To help remember the steps, memorize a flow pattern.
Steps usually include:
- Make sure fuel selector is on fullest tank
- Mixture full rich
- Throttle adjust
- Carburetor heat on
- Check magnetos
- Primer locked
In the Cessna 152, the fuel valve is either on or off with no tank selection choices. However, in most airplanes, there is fuel selector that can be set to different tanks. In an engine failure situation, the tank with the most fuel should be selected.
Mixture goes to full rich as required in a normal engine start. The throttle should be adjusted to see if there is a setting at which the engine will run, or if the prop is stopped, set at the normal engine start-setting whilst attempting to restart.
Applying carburetor heat supplies heated air to the carburetor to prevent or remove carburetor ice; however its ability to remove ice is greatly diminished if the engine has quit completely since the heat comes from the exhaust manifold. Carburetor heat also bypasses the air filter, allowing air to enter the carburetor in the event the filter or normal intake is blocked.
Checking the magnetos means trying left, right, and both to see if the engine will run in a different setting and, if the prop has stopped (not likely ) selecting start to turn over the engine.
Ensuring the primer is in and locked should eliminate the possibility of inadvertently flooding the engine with fuel.
Having performed these steps by memory, using a flow pattern, assuming time and altitude permit, look at the emergency checklist and verify that all recommended steps have been taken.
If you are unable to restart the engine (assuming time and altitude permit), declare an emergency.
If you are already in contact with air traffic control (ATC), declare the emergency on the frequency currently in use. If not already in contact with ATC, you can use 121.5 MHz, which is monitored by most air traffic control facilities and some aircraft. Your initial declaration of being in distress should start with the word “Mayday!” repeated three times. This will give your transmission priority over other communications and will silence all other radio traffic until your situation has been handled.
The call should include who you are calling, your aircraft type and identification, the nature of the emergency, your position and intentions, and number of “souls” (people) on board.
Mayday Mayday Mayday, Napa Tower, Cessna 12345, engine failure, over Hamilton 3500 feet making forced landing, two on board.
Once radio contact is established, ATC will provide assistance and initiate search and rescue efforts if necessary. However, they cannot tell you how to fly the airplane, which is still your responsibility and your number one priority.
If you are already in radar contact and have an assigned transponder code, keep the same code unless instructed otherwise. If you do not already have a code and cannot immediately establish communications with ATC, squawk code 7700 and Mode C.
Secure Airplane for Forced Landing
If unable to restart and you have already declared an emergency, the next task is to prepare to secure the airplane in preparation for landing. This procedure, like troubleshooting, should be memorized using a flow pattern.
Shutdown Flow Pattern
- Seat belts should be secured
- Passengers briefed
- Magnetos off
- Throttle to idle
- Mixture idle cut off
- Fuel selector off
- On final approach, doors open
- Just prior to touchdown, master switch off
The idea is to make sure the occupants are secure and ready to exit the airplane, and to minimize the chances of a fire in the event of bad landing. This means making sure seatbelts are secure, advising passengers to use soft items, such as coats or cushions, to shield their faces, and advising them to open their door on final and to exit as soon as landing is complete. Cutting off the flow of fuel and switching off sources of electrical current will reduce the risk of fire.
Power-off approach and landing
The most critical part of the whole engine failure emergency procedure is the approach and landing. The approach and landing will have a bigger influence on the outcome than any of the other steps.
As you fly toward the place you intend to land, try to determine the wind direction. Look for clues such as the direction smoke or dust moves, movement of water, or crops relative to the wind. If terrain permits, plan on landing in to the wind.
Plan your glide to arrive at the “key position” 600-1000 feet AGL downwind abeam the point where you plan on touching down.
From the key position, proceed downwind onto turn base and then final, as appropriate, given your altitude and the strength of the wind. Only after you are positive you will make it to the touchdown area should you use flaps. On touchdown, maintain a nose-up pitch attitude for as long as possible. Use brakes to stop in the shortest distance possible and exit the airplane as soon as it stops.
For training purposes, the approach will be terminated prior to touchdown by the instructor advising you to add power and go around. How low you go depends on where you are practicing, but bear in mind you are required to stay at least 500 feet away from any person, vessel, vehicle or structure.
Breaking off the approach at 600 feet puts you at an altitude from which you can practice ground reference maneuvers.
Ground reference maneuvers
The skills you develop from practicing ground reference maneuvers will be useful when flying in the airport traffic pattern and you will be expected to perform ground reference maneuvers as part of the private pilot practical test.
The three maneuvers applicable to private pilots are the rectangular pattern, turns around a point, and S turns across a road.
Select a location where you will be able to maneuver without disturbing people, livestock or wildlife on the ground and where you could land safely in the event of an emergency.
Before doing any maneuvers, clear the area by reversing course or making two ninety-degree changes of heading. The maneuvers should be flown at an altitude of 600-1000 feet AGL.
This maneuver will prepare you for working in the airport traffic pattern and will develop your understanding of the influence of the wind on your ground track.
As will be the case with all ground reference maneuvers, the first step is to determine the wind direction. Observation of smoke, dust clouds, crop movement, etc., should help establish where the wind is coming from.
Chose a rectangular field to maneuver around and approach the downwind side of the field at a 45-degree angle at an altitude of 600-1000 feet AGL. This is also the standard way to enter an airport traffic pattern.
Once the airplane is just outside the edge of the field, turn to fly parallel to the perimeter of the field. Fly just far enough away from the field that you can keep the perimeter of the field in sight. The objective is to fly around the outside of the field, keeping the same distance all the way around, while maintaining a constant altitude. You are expected to fly the airplane while, at the same time keeping alert to any other traffic in the area. Avoid fixating on any one task at the expense of another.
As you reach the end of the field and turn, you will have the wind behind you (i.e., you are downwind), and this will increase your groundspeed. This means you need relatively more bank to get around the corner without increasing the radius of the turn. The analogy of thinking about going around a corner on a motorcycle may be helpful. That is to say, the faster a corner is taken, the more bank is required to maintain a particular radius of turn. The maximum angle of bank for ground reference maneuvers should be 45 degrees, although 30 degrees is preferred. With the turn from downwind being at the highest groundspeed, any subsequent turns should require less bank.
Once on the base leg, it will probably be necessary to establish a wind correction angle so the nose of the airplane points slightly inside the rectangle to compensate for the wind trying to push the airplane away from the field. The crab is flown wings-level in coordinated flight by selecting a heading which establishes the appropriate wind-correction angle. Do not crab by yawing the airplane with rudder; instead make a coordinated turn using aileron and rudder to fly a heading which establishes the appropriate wind correction.
On completion of the base leg, you will be turning into the wind as you establish yourself on the upwind leg. This means you will have a slower groundspeed than on the previous turn (from downwind to base) and, therefore, you will need less bank angle to maintain the same radius. Once established upwind, you will be more or less headed into the wind and, as such, you shouldn’t need much wind correction.
The turn from upwind to crosswind will be the slowest and, as such, needs the smallest bank angle. On the crosswind leg the wind will be trying to push the airplane into the rectangle; and to compensate for this, you will need to establish a wind-correction angle that allows you to fly a heading that points slightly outside the rectangle. Upon completion of the crosswind leg, as you start to turn downwind, your groundspeed will start to increase and, therefore, you will need an increasing angle of bank to maintain a constant radius turn. Once established downwind, little or no wind correction angle will be needed since you should have the wind more or less directly behind you. Plan on completing the maneuver at the same position, altitude, and airspeed at which you started.
You should practice flying a rectangular pattern with both left and right turns. The skills you develop flying these patterns will prepare you for flying left and right Traffic Patterns at airports.
Having practiced rectangular patterns in both directions, the next maneuver will be turns around a point.
Turns Around A Point
Turns around a point will further develop your ability to compensate for the effect of the wind on your ground track. They involve flying a constant radius circle around a reference point on the ground at a constant altitude while dividing your attention between controlling the airplane, looking for traffic, and maintaining the desired ground track.
Select a reference point on the ground that will define the center of the circle. This could be the intersection of fence lines, a tree, or anything that will clearly mark the center of the circular ground track you intend to fly. It should not be a house or any structure where there are people or animals nearby. You will be flying at an altitude of only 600 – 1000 feet above ground level (AGL) and, therefore, you should choose a location where you will not create a disturbance and where you could land safely in the event of an emergency.
Having cleared the area, fly toward your selected point at a constant altitude between 600 – 1000 feet AGL . You should fly toward the reference point with the wind behind you (downwind) so you pass slightly to the right of the point. When the point is directly off your left wing, start a left turn in order to fly a circle around the reference point. When you start to turn, the wind will be directly behind you, so your ground speed will be relatively high. Consequently, you will need a relatively steep angle of bank. The bank angle for this initial turn from the downwind entry will be the steepest used throughout the maneuver, but still should not exceed 45 degrees. As you fly around the point, you will need varying bank angles depending on your position relative to the wind. You will need the steepest bank when the wind is behind you and the least when you are pointed into the wind.
Do not correct for the wind by yawing the airplane with rudder. Instead, adjust the angle of bank using coordinated aileron and rudder input to maintain coordinated flight as you fly around the circle at a varying angle of bank but at a constant altitude and constant radius from the reference point. If there were no wind, a constant bank angle could be maintained. The more wind there is, the more you will need to change your bank angle to compensate for changes in groundspeed as you progress around the circle. Remember, constant groundspeed at constant bank equals constant radius. If the groundspeed changes, you will need to change the bank angle to maintain constant radius.
As you fly around the point, visualize what your overall circular ground track should look like with respect to other features on the ground and visualize where you will be relative to the point as you fly around the circle. You should plan on completing the maneuver at the same position, altitude, and airspeed at which you started.
Turns around a point should be practiced in both directions. Having practiced these, the next maneuver will be S-turns across a road.
S-Turns Across a Road.
S-turns across a road, as with all ground reference maneuvers, are designed to develop your ability to fly a desired ground track while compensating for the effect of the wind and dividing your attention between controlling the airplane and looking for traffic. The maneuver consists of flying back and forth over a long, straight ground reference, such as a road, creating an S-shaped ground track, with each semicircular section being a constant radius, while maintaining a constant altitude.
Select a long, straight ground reference, such as a road or section line. You will be flying at an altitude of only 600 – 1000 feet above ground level (AGL) and, consequently, you should choose a location where you will not create a disturbance and where you could land safely in the event of an emergency.
Fly toward the reference line with the wind behind you (downwind), on a course perpendicular to the reference line, at a constant altitude of between 500 – 1000 feet AGL. As you cross the road, start a left turn and visualize a point on the reference line equivalent to the center of semicircle you will be flying and another point which will mark where you will cross the road next on completion of the constant radius turn. As you turn from the downwind entry, your ground speed will be relatively high and, therefore, you will need more bank than at any other point during the maneuver. Maximum bank angle used should be 45 degrees.
You should plan on being wings-level as you cross the road; so, when you turn upwind, you will need to start leveling the wings in order to cross the road wings level. Having crossed the road wings-level, begin a turn to the right, once again visualizing the center of your imaginary circle and the point at which you will again cross the road while maintaining a constant radius. The upwind semicircle will be into the wind and, therefore, will require less bank than the previous (downwind) semicircle. Once again, plan your rollout to cross the road wings-level all the time maintaining constant altitude and a constant radius ground track.
If your reference line is long enough, fly a whole series of S-turns in both directions. You should plan on completing the maneuver at the same altitude and airspeed at which you started.
If there is no wind, the same bank angle can be used on each semiircle. The more wind there is, the more you will need to change your bank angle to compensate for changes in groundpeed as you progress around the semicircles. Remember, constant groundspeed at constant bank equals constant radius. If the groundspeed changes, you will need to change the bank angle to maintain constant radius.
Having completed practicing S-turns across a road in both directions, you will climb back to an appropriate altitude and return to the airport. This concludes Flight Four.
Flight Five features exercises to prepare you for practicing multiple takeoffs and landings at the airport.