Definition
In instrument flying, the role played by secondary instruments that confirm and reinforce what the primary pitch and bank instruments are showing. The supporting instruments do not lead the pilot's control inputs; they back up the primary indications by displaying related information that should agree with what the primary instruments are reporting. For straight-and-level flight, for example, the attitude indicator is the primary reference for both pitch and bank, while the altimeter, vertical speed indicator, turn coordinator, and heading indicator serve in supporting roles for direct pitch and bank control.
Plain English
These are the instruments that back up your main pitch and bank instruments. They don't lead — they confirm. If the main instrument says you're level, the supporting ones should agree. If they don't, something is wrong and you need to cross-check.
Context Anchor
Seen in FAA instrument-scan figures for straight climbs and descents, where each flight instrument is labeled by the job it is doing during that maneuver.
Derivation
‘Supporting’ here keeps its everyday sense — to hold up or back up something else. The phrase ‘direct pitch and bank’ refers to the aircraft's actual nose-up/nose-down attitude (pitch) and wing tilt (bank), as opposed to indirect indications like altitude trend or heading change.
Why Pilots Care
Knowing which instruments lead and which support keeps a pilot's scan organized under instrument conditions. If you treat a supporting instrument as primary, you tend to chase it — making control inputs based on lagging or indirect information, which causes overcontrol and disorientation.
Intuition Check
“Supporting” does not mean unimportant; it means confirming or backing up the main reference. “Direct” means the instrument shows pitch and bank themselves, not a result of pitch or bank such as a change in airspeed or heading.
Example Sentence 1
During straight-and-level flight, the altimeter and vertical speed indicator are supporting direct pitch and bank, while the attitude indicator remains the primary pitch reference.
Example Sentence 2
When leveling off from a descent, the pilot uses the attitude indicator supporting direct pitch and bank to set the proper nose attitude.