Definition
A reference to the role the bank attitude plays during the entry phase of a level constant-airspeed turn on instruments, where bank is the primary control input that initiates and establishes the turn while pitch is held by other instruments to maintain altitude. In this entry phase, the attitude indicator (or its equivalent) showing bank is the primary instrument for establishing the turn, and pitch information is supported by altimeter and vertical speed cues until the turn is stabilized.
Plain English
When you first roll into a turn while flying on instruments, the bank angle is the main thing you set to start the turn, and you use other instruments to keep the nose at the right level while you do it. Once the turn is steady, the roles of the instruments shift.
Context Anchor
Seen in instrument flying turn diagrams, especially where the handbook shows which cockpit instruments guide bank and pitch during the entry to a turn.
Derivation
“Primary” comes from a word meaning first or chief. “Bank” in aviation means the airplane is tilted to one side. “Pitch” means the nose is angled up or down. The phrase is a role label: first use the instrument for bank, and use it only as backup help for pitch.
Why Pilots Care
Correct sequencing prevents unintended altitude loss or pitch excursions when rolling into a turn on instruments.
Grounding Statement
Picture rolling into a turn in the clouds: your first job with this instrument is to set the wing tilt, while also noticing whether the nose is rising or dropping.
Intuition Check
“Primary” does not mean this instrument is the only one to look at. “Supporting pitch” does not mean pitch is unimportant; it means this instrument helps confirm pitch but is not the main pitch reference.
Example Sentence 1
During the roll-in, treat bank as the primary reference initially supporting pitch, then shift your scan once the turn is stabilized.
Example Sentence 2
Establishing the primary bank initially supporting pitch kept the nose from dropping as the turn began.