Instrument Rating ACS · Area IV
IR.IV Flight by Reference to Instruments
2 tasks and 23 knowledge, risk management and skill elements. Each code below is a link target: a code from your test report, such as IR.IV.A.K1, lands on its own line.
Instrument Rating Airman Certification Standards, FAA-S-ACS-8C (November 2023 edition), effective May 31, 2024 and incorporated by reference in 14 CFR 61.14. Text from the FAA’s ACS page, checked on 11 November 2026. If the FAA has published a newer edition since, the codes and wording may differ: the FAA document is the authority.
IR.IV.A Instrument Flight
To determine the applicant exhibits satisfactory knowledge, risk management, and skills associated with performing basic flight maneuvers solely by reference to instruments.
- IR.IV.A.K1Knowledge
- Elements related to attitude instrument flying during straight-and-level flight, climbs, turns, and descents while conducting various instrument flight procedures.
- IR.IV.A.K2Knowledge
- Interpretation, operation, and limitations of pitch, bank, and power instruments.
- IR.IV.A.K3Knowledge
- Normal and abnormal instrument indications and operations.
- IR.IV.A.R1Risk management
- Situations that can affect physiology and degrade instrument cross-check.
- IR.IV.A.R2Risk management
- Spatial disorientation and optical illusions.
- IR.IV.A.R3Risk management
- Flying unfamiliar aircraft or operating with unfamiliar flight display systems and avionics.
- IR.IV.A.S1Skill
- Maintain altitude ±100 feet during level flight, selected headings ±10°, airspeed ±10 knots, and bank angles ±5° during turns.
- IR.IV.A.S2Skill
- Use proper instrument cross-check and interpretation, and apply the appropriate pitch, bank, power, and trim corrections when applicable.
IR.IV.B Recovery from Unusual Flight Attitudes
To determine the applicant exhibits satisfactory knowledge, risk management, and skills associated with recovering from unusual flight attitudes solely by reference to instruments.
- IR.IV.B.K1Knowledge
- Procedures for recovery from unusual attitudes in flight.
- IR.IV.B.K2Knowledge
- Prevention of unusual attitudes, including flight causal, physiological, and environmental factors, and system and equipment failures.
- IR.IV.B.K3Knowledge
- Procedures available to safely regain visual meteorological conditions (VMC) after flight into inadvertent instrument meteorological conditions or unintended instrument meteorological conditions (IIMC)/(UIMC).
- IR.IV.B.K4Knowledge
- Appropriate use of automation, if applicable.
- IR.IV.B.R1Risk management
- Situations that could lead to loss of control in-flight (LOC-I) or unusual attitudes in-flight (e.g., stress, task saturation, inadequate instrument scan distractions, and spatial disorientation).
- IR.IV.B.R2Risk management
- [Archived]
- IR.IV.B.R3Risk management
- Operating envelope considerations.
- IR.IV.B.R4Risk management
- Interpreting flight instruments.
- IR.IV.B.R5Risk management
- Assessment of the unusual attitude.
- IR.IV.B.R6Risk management
- Control input errors, inducing undesired aircraft attitudes.
- IR.IV.B.R7Risk management
- Control application solely by reference to instruments.
- IR.IV.B.R8Risk management
- Collision hazards.
- IR.IV.B.R9Risk management
- Distractions, task prioritization, loss of situational awareness, or disorientation.
- IR.IV.B.S1Skill
- Use proper instrument cross-check and interpretation to identify an unusual attitude (including both nose-high and nose-low) in flight, and apply the appropriate flight control, power input, and aircraft configuration in the correct sequence, to return to a stabilized level flight attitude.
- IR.IV.B.S2Skill
- Use single-pilot resource management (SRM) or crew resource management (CRM), as appropriate.
Other areas in this standard
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Last updated 11 November 2026.