Instrument Flight
Constant Airspeed Climbs and Descents
Pitch: As required to maintain level flight
Lead point for roll-out: 1/3 of the AOB
TURN PATTERN
Consisting of two pairs of left and right turns, the turn pattern gives you practice in smoothly performing a
series of linked turns at a constant altitude and airspeed.
To begin the maneuver, make a 30-degree AOB turn for 60 degrees of heading change. Reverse into a
30-degree AOB turn to the original heading. Perform the final pair of reversing turns at 45 degrees AOB
for a heading change of 90 degrees each. Since there are no 45-degree bank angle scale markers on the
ADI display, you must place the bank angle pointer halfway between the 30-degree and 60-degree bank
angle scale markers. Execute the turn reversals smoothly, with no straight-and-level legs. At the end of
the maneuver, recover wings level on original heading.
Throughout the maneuver, maintain altitude and 250 KIAS, adding more aft stick and more power for each
set of turns. When reversing turns, ease the back stick as you apply reverse aileron in order to avoid
gaining altitude.
1/2 STANDARD RATE TURNS
A 1/2 standard-rate turn (1/2 SRT) is performed at 1-1/2 degrees per second. Therefore, a heading
change of 30 degrees will take 20 seconds to complete. To accomplish this rate at different airspeeds,
you will have to vary the bank angle. A good rule of thumb for determining bank angle between 15,000
and 20,000 ft is to use approximately 10 percent of indicated airspeed. At higher altitudes, you will need
more bank than 10 percent of indicated airspeed, while at lower altitudes you will need less bank than
10 percent of indicated airspeed to maintain a 1/2 SRT. For example, at 250 KIAS and 18,000 ft, the bank
angle would be approximately 25 degrees. Establishing and maintaining a 1/2 standard-rate turn at any
altitude requires that you monitor the turn needle and adjust the bank angle as necessary to achieve one
needle-width of deflection.
TIMED TURNS, 1/2 STANDARD RATE
For practice, you should start your 1/2 SRTs from a cardinal heading using a lead point of 3 seconds prior
to the clock’s second hand passing the 6 or 12 position. Roll into the turn on the ADI display
(approximately 25 degrees of bank at an airspeed of 250 KIAS) and adjust the pitch attitude to maintain
level flight. Initially, scan the ADI display for bank and pitch control, the VSI or altitude trend indicator for
pitch, and the airspeed trend indicator for speed.
Once you have made the necessary pitch and power changes, check the turn needle and adjust the bank
as necessary to maintain 1 needle-width of deflection. Check that 20 seconds have elapsed on the clock
for every 30 degrees of heading change. Always check the time when you reach the correct number of
degrees of turn (not vice versa) to ensure that you are keeping your scan on the flight instruments rather
than on the clock. Since the HSI display compass rose is numbered in 30-degree increments, it provides
a good reference when you should check the clock.
Continue to check the clock at least every 30 degrees of turn and adjust (AOB) rate of turn accordingly. If
you are ahead of the clock, decrease AOB; if you are behind the clock, increase AOB. When you have
the turn back on time, readjust your bank angle to a 1/2 SRT. Use no more than 30 or fewer than
10 degrees of bank when making your corrections.
Lead your roll-out by one-third of the angle of bank, simultaneously reducing power to the level flight
setting if it has been advanced.
Bank angle: Approximately 10 percent of IAS (25 degrees at 250 KIAS)
Rate: 1-1/2 degrees per second
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