Leveling Off
After the climb we usually level off. An old saying among pilots is, "How long does it take a student pilot to level off?" Thirty-five hours is the answer. I have seen 500+ hour pilots who use a common VFR trim technique take as long as 15 minutes to get a 172 completely trimmed at a given altitude.

If you reduce the power in time and to the right amount the speed will remain at cruise. The trim will be correctly set perhaps with only the slightest of adjustment. It is when you don't level off smoothly with every setting of attitude, power, and trim set in anticipation of aircraft performance that IFR flight problems occur. For me, the best clue is sound. Every performance parameter or change has a sound. Learn the sound of your airplane. Sound sensitivity will transfer from aircraft to aircraft just as it does from car to car.

You should keep your hand on the throttle. Use your forefinger as a lock, a measure and control of the throttle. This is particularly important in the C-172. The power to weight ratio of the 172 is such that deceleration and sag is quite abrupt while acceleration may take several minutes if too little excess power is applied. Once the required power settings are known they must be adjusted for altitude and temperature. Up to 200 rpm difference will exist between hot and cold day operations. Numerous small changes of power will be required in most flight conditions but particularly on approach. Keep power reductions small but increases should be of 200 rpm or more soon to be followed by reduction of excess power. Learn the sound of aircraft power as well as performance. Any change in constant power necessitates trim adjustment. Plan accordingly.

The student should know for leveling off from a climb at Vy will require a certain amount of anticipation, a certain amount of trim, a certain amount of acceleration, changing amounts of yoke pressure, a power adjustment, changing sounds and some fine tuning. The trick is to put the aircraft into the desired attitude and leave/keep it there. The reason instrument flying becomes easier is because the pilot selects an attitude and leaves it there. In order to fly instruments well, you learn to note very small indications and very small trends. Doing this while leveling off is just a beginning.

Leveling off from Vx will differ from that of Vy. Leveling off requires anticipation of what the aircraft is going to do. Due to the low power to weight ratio of the C-172 you must anticipate the effect of a longer and slow acceleration. Initially lower the nose to catch the altimeter needle at altitude using the attitude indicator as primary aid. Make your initial rough trim movement that your experience and practice has shown will be about right. I prefer to hand fly while the plane picks up speed. Do not let the aircraft climb as it accelerates. If you have not trimmed enough it will begin to climb during acceleration. Correctly trimmed the nose will want to drop. You must anticipate and gradually relax any back pressure against the trim's effort to lower the nose until the increase in airspeed releases the down pressure. The 172 may take a while to gain speed but once it has reached its normal cruise speed reduce the power to 2450 rpm. Don't be satisfied to fly 50' off altitude even if you are holding it there.

Practice leveling off from Vx and Vy until you can anticipate the attitude, performance and settings required for the transition from climb to level. Mark the trim setting. Learn the sound of level cruise. Do this until you can level off and hold heading. Do this until it becomes automatic not just within 100 feet but right on altitude and heading. You must become so proficient that flying the plane will not get into the way of flying a departure or an approach.

If you level off below altitude the period of hand flying and acceleration becomes prolonged. This is just another area where flying is capable of interfering with IFR procedures. This is just the time that ATC will chose to amend a clearance or such. Everything comes unglued. This usually results in corrections that will require multiple adjustments. It is easier to do it right the first time.

You may not select the correct level attitude on the attitude indicator resulting in a climb above your desired altitude. You have two options. Lower the nose and dive down to altitude. This results in a speed increase which will result in another gain in altitude unless the power is reduced. At the higher speed the trim is no longer correct for level flight. The result is a series of altitude and airspeed oscillations until finally the desired initial settings are acquired. You will go up and down a hundred feet or so with changes in airspeed, attitude, power and trim. Essentially the same effect is created if the power is left in too long so that excess speed is acquired. Likewise, if too little trim is initially applied. These are typically flight indications of a pilot who has not acquired basic skills.

Level Cruise to Low Cruise
After leveling off at cruise we may need to hold level while slowing down to say holding speed. First reduce your power to a predetermined setting (1700 rpm) that you know will work. As the aircraft slows apply back pressure to hold altitude while trimming quickly one turn down (nose up) smoothly to the amount that you know will work. Quickly increase power to 2200 rpm before speed gets below 90 kts. If you don't know what works, repeat these changes until you do know. If you have avoided any oscillation of altitude this should be a very smooth transition. The resulting configuration will show the AI about 1/2 bar high. Otherwise, practice it until it is a very smooth transition. The highest complement you can pay a pilot is that he is very sm-o-o-o-o-th. Work on going from slow to cruise and back again until it is smooth. This speed is right at the Vx climb speed when used to conserve fuel. The name of this game is anticipation.

Descent
Descent, depending on the situation may be made from cruise or from approach speed. A smooth descent is about level on the AI for 500 fpm to 1/2 bar low for greater than 500 fpm. Work on determining the initial power settings that are required for both 500' and 1000' per minute descents from both airspeeds. Descents of 1000' and the last 1000' of any greater change are made at 500 fpm. The basic is five for five. Low cruise at 2200 rpm reduced to 1700 rpm will approximate 500 fpm descent without change in trim. It is better to set up your descents by reduction of power and not change trim. This is under the assumption that application of power will give level flight at the appropriate speed. This is especially true if the speed has been held during descent. Practice descents and these airspeeds until you determine the power reductions that give the desired performance. Again, the performance parameters of the descent and recovery must be practiced until smooth.

Your airspeed for descent is somewhat limited by the Vne redline, Vno structural meeting of green and yellow, and Va maneuvering in turbulence speed in the POH. Do not extend flaps at any of these speeds since allowable G-load is much lower. Always use some power and carburetor heat for descents to keep the manifold warm.

Level from Descent
Leveling off from a descent is somewhat different. If the descent is only accomplished by a power reduction without speed change, application of power will give you "level". From 1700 rpm to 2200 rpm. I recommend that, knowing level flight will be resumed at a lower altitude as in a step-down approach, descent be done only with power and not trim. If trim is used or a change in speed is called for, it is important to keep in mind the amount of trim change involved so that it can be reset for level later. Speed changes must then be anticipated by power settings.

Cruise Descent
Cruise descent to a destination altitude at 500 fpm can be figures by multiplying your altitude in thousands less destination altitude by two to get the descent time in minutes. Multiply by 4 if descent is at 250 fpm.

Example:
Current MSL altitude 8000'
Destination altitude 1000'
Difference is 7000'.

@ 500 fpm 7 x 2 = 14 minutes descent time.

@ 250 fpm 7 x 4 = 28 minutes descent time.

Turns
The last element of basic IFR flying is the turn. Climbs, descents and level flight will either require a constant heading or a turn to an assigned heading. Initially work on maintaining a constant heading. A constant heading is best assured if the wings are kept level. Use the attitude indicator. If the heading is changed or changing, one wing must be low. In climbs rudder application may be required to keep wings level.

An IFR turn is usually shallow compared to a VFR turn. The VFR habits of yoke pressure in the bank causes over control when IFR. No power change should be made in level IFR turns. Pilots who are frequent VFR pilots will inadvertently climb in VFR turns. Lead your desired heading by 1/2 the angle of bank. Every turn requires a lowered wing and a slight loss of lift. Even the lightest back pressure of one finger in an IFR bank must be countered with the thumb pressure when leveling the wings. Otherwise, a pop-up of some degree will occur.

If you are doing a timed turn with the compass, use a sweep second hand, set the ADF to your initial heading as an aid. Do your figuring before you start the turn. It is much easier to relate sweep hand to turning of HI. Digital watches make relating the time to the turn more difficult.

Stop the turn by reference to the top index marker on the attitude indicator. The most common error of any small turn is to reverse the turn back to where you started as opposed to stopping the turn and holding it. Making the turn with the rudder seems to focus your attention to the AI better on recovery. Larger turns are subject to same error to a lesser degree. If you have a heading bug use it. If you don't, use your mouth (say aloud) to keep the required heading actively in mind.

You must learn the angle of bank on the attitude indicator which represents the standard rate turn on the turn coordinator for your IFR airspeeds. The angle of bank for any airspeed can be determined by dropping the last digit of the airspeed; Divide by 2 and add back to first dividend.

An airspeed of 100 knots would show:
100 drop the last 0 = 10.
Divide 10 by 2 = 5
Add back the 10 = 15 degrees of bank.

Work on your skill in making small heading changes using only the rudder since those are most often required. Use half standard angle and a count system for the turn itself. For heading changes of less than 20 degrees, use banks of 5 degrees. For heading changes of less than 10 degrees, use rudder alone.

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