A steep turn in

aviation Aviation includes the activities surrounding mechanical flight and the aircraft industry. ''Aircraft'' includes fixed-wing and rotary-wing types, morphable wings, wing-less lifting bodies, as well as lighter-than-air craft such as hot air ...

, performed by an aircraft (usually

fixed wing A fixed-wing aircraft is a heavier-than-air flying machine, such as an airplane, which is capable of flight using wings that generate lift caused by the aircraft's forward airspeed and the shape of the wings. Fixed-wing aircraft are distin ...

), is a turn that involves a

bank A bank is a financial institution that accepts deposits from the public and creates a demand deposit while simultaneously making loans. Lending activities can be directly performed by the bank or indirectly through capital markets. Because ...

of more than 30 degrees. This means the angle created by the axis running along both wings and the horizon is more than 30 degrees. Generally, for training purposes,DGCA - India - CA40 Form for Day/Night Check ride mentioning Steep Turn Assessment
/ref> steep turns are demonstrated and practiced at 45 degrees, sometimes more. The purpose of learning and practicing a steep turn is to train a

pilot An aircraft pilot or aviator is a person who controls the flight of an aircraft by operating its directional flight controls. Some other aircrew members, such as navigators or flight engineers, are also considered aviators, because they a ...

to maintain control of an aircraft in cases of emergency such as structural damage, loss of power in one engine etc. Entry procedure for a steep turn involves putting the aircraft into a bank (left or right), simultaneously increasing the

thrust Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that syst ...

adequately to maintain

altitude Altitude or height (also sometimes known as depth) is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The exact definition and reference datum varies according to the context ...

, while pulling back on the flight stick or flight yoke to speed up the turning process. For Jet training an increase of 7-8% of N1 caters. While doing this the pilot has to ensure no loss or gain of altitude. The pilot is expected to constantly look outside the aircraft while keeping a close check on the

Attitude indicator The attitude indicator (AI), formerly known as the gyro horizon or artificial horizon, is a flight instrument that informs the pilot of the aircraft orientation relative to Earth's horizon, and gives an immediate indication of the smallest o ...

for angle of bank. When the aircraft is in a 45 degree bank, it is common for a certain amount of opposite aileron control to be required to prevent the aircraft from slipping into a steeper bank.

Tolerances and technicalities

For purposes of testing, a steep turn is a 360 degree turn in either direction with a 45 degree bank angle while maintaining altitude, speed and bank within certain set tolerances. Furthermore, the roll out heading must be within 10 degrees of the entry heading for the manoeuvre to be deemed successful by most flight training standards and check rides. A steep turn increases the load factor of an aircraft. Simply put the aircraft feels heavier due to the effect of

centrifugal force In Newtonian mechanics, the centrifugal force is an inertial force (also called a "fictitious" or "pseudo" force) that appears to act on all objects when viewed in a rotating frame of reference. It is directed away from an axis which is paralle ...

. At a 45 degree bank angle the load factor of an

aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines ...

is 1.4 i.e. the aircraft effectively becomes 40% heavier. This requires the pilot to exert backward pressure on the flight stick or column to raise the nose, thereby creating more lift to maintain altitude. In the event that backward pressure is not exerted on the stick / column, the aircraft will tend to lose altitude. This increase in the lift required also generates what is referred to as lift induced drag which without increased power, means the aircraft will lose speed.

Parallax error based on pilot seat position

This applies to cockpits with two seats (usually pilot and co-pilot) arranged horizontally or abreast. Assuming the pilot performing the manoeuvre is positioned in the left seat (command seat) when a steep turn to the right is performed, the nose will appear to fall. Conversely, a steep turn to the left will make it seem like the nose is rising against the horizon. This is parallax error based purely on the pilot's vantage point and instinctively causes a pull back or a push down reaction on the control stick / column which is an incorrect reaction. A good way of eliminating the effect of this error is to keep an eye on the horizon and maintain the aircraft's position relative to the horizon line thereby allowing you to approximate the 45 degree angle the panel top creates against the horizon.

References

{{reflist Aviation risks Aerial maneuvers Emergency aircraft operations