Introduction to Instrument Flying

Flight rules and weather describe different things

Instrument flight rules (IFR) describe the rules under which a flight operates. Instrument meteorological conditions (IMC) describe weather below the applicable minimums for visual flight, based on visibility, distance from clouds, and ceiling. VFR means visual flight rules; VMC means visual meteorological conditions. A flight can operate under IFR in clear weather. Entering a cloud does not automatically create an IFR clearance.

For this U.S. airplane course, acting as PIC under IFR requires the appropriate pilot qualifications, including instrument privileges. Those qualifications are needed even when the weather is clear. Under §91.173, IFR operation in controlled airspace requires both a filed IFR flight plan and an appropriate ATC clearance. Filing alone is not permission to depart under IFR.

Instrument practice can also occur in VMC using a view-limiting device. Section 91.109 sets safety-pilot, visibility, and control requirements for simulated instrument flight. Work with your instructor to arrange the operation correctly. That is simulated instrument flight; the device changes what the pilot can see, not the actual weather or the flight rules. Later lessons cover the detailed qualification, equipment, and operating requirements.

14 CFR §61.3(e): instrument privileges · 14 CFR §91.173: IFR in controlled airspace · Pilot/Controller Glossary: instrument flight rules and instrument meteorological conditions · 14 CFR §91.155: basic VFR weather minimums · 14 CFR §91.109: simulated instrument flight

Control attitude and power, then check performance

In visual flight, the outside horizon helps you judge the airplane’s pitch and bank. When that reference is missing or unreliable, flight instruments provide the information needed to control the airplane.

The attitude indicator shows pitch and bank relative to its horizon reference. Power information comes from the appropriate engine instruments, such as a tachometer or manifold-pressure gauge. Airspeed, altitude, vertical speed, and heading show what the airplane is doing as a result. Navigation indications help establish where it is and whether it is following the intended course.

1. SetUse attitude and power references to establish the intended flight condition.
2. CheckCompare airspeed, altitude, vertical speed, and heading with the desired performance.
3. AdjustMake an appropriate correction, trim as needed, and check the result again.

For example, in a planned climb, a nose-up indication alone does not establish that the airplane is climbing safely. Check altitude and vertical-speed trends, airspeed, and power as well. The correct pitch and power settings depend on the aircraft, configuration, and conditions; this lesson supplies no universal settings.

These instrument roles are part of the FAA’s control/performance method. The primary/supporting method is another way to organize the same information. The next lessons develop those methods and the cross-check used to apply them.

IFH Chapter 6: attitude instrument flying, including control/performance

Cross-check instead of relying on one indication

A cross-check is a repeated comparison of the instruments relevant to the current task. You interpret what they show, make the needed control input, and check the response. It is more than moving your eyes through a fixed pattern.

Fixating on a single instrument can hide a change elsewhere. Some indications also lag behind a control change. A reliable cross-check includes both the attitude/power information and the resulting performance. As the task changes, the emphasis changes too.

If indications disagree, use the remaining evidence and the aircraft procedures to assess what is reliable. Two screens may share a sensor or power source, so matching displays are not necessarily independent confirmation. An attitude indicator can fail; “use instruments” means use reliable, corroborated information, not follow one display regardless of other evidence. Later lessons cover failure recognition and control with reduced instrumentation.

IFH Chapters 5, 6 and 11: systems, cross-check and failures

Your senses can disagree with the airplane

Without a reliable horizon, the inner ear and sensations of pressure or motion can give a false impression of attitude. Spatial disorientation is a mismatch between the pilot’s perception and the airplane’s actual position or motion. It can affect an experienced pilot as well as a beginner.

In the leans, correcting a slowly developed bank can produce a sensation of banking the other way. Following that sensation can put the airplane back into a bank. Sudden head movement during a prolonged turn can produce another powerful false sensation, the Coriolis illusion.

If you feel banked while a reliable instrument cross-check shows the intended level flight condition, maintain control using those references. Do not make a control change simply to make the sensation disappear. Minimize abrupt head movements, keep checking the instruments, and reduce competing tasks. Darkness over featureless terrain can remove a useful horizon even when the weather meets VFR requirements.

Rest, fitness, and preparation matter. Fatigue, illness, stress, or unfamiliar displays can degrade the cross-check. Review the existing aeromedical explanation of spatial disorientation for more examples. The unusual-attitude lesson will cover recognition and recovery; this introductory lesson is not a recovery procedure.

IFH Chapter 3: human factors and spatial disorientation · AIM 8-1-5: illusions in flight

Prepare for the aircraft and the workload

Currency means meeting the applicable recent-experience requirements. Proficiency means being able to perform the operation competently now. A pilot can be legally current yet need more practice before a demanding flight or a change of aircraft.

Personal minimums should account for recent experience, weather, aircraft equipment, terrain, and available options. A rating or clearance does not make every condition suitable for the pilot or aircraft. Discuss unfamiliar avionics, aircraft handling, or a long break from instrument flying with an instrument instructor before taking on those demands.

During flight, keep aircraft control ahead of other tasks. Organize charts and brief the expected procedure before workload increases. If a clearance is unclear, ask for clarification. If you cannot comply safely because of performance, equipment, or workload, tell ATC and request an appropriate change. Do not let programming a navigator replace the instrument cross-check.

ATC is a useful resource, but the PIC remains responsible for operating the airplane. In an emergency requiring immediate action, §91.3 gives the PIC authority to deviate from Part 91 rules to the extent required to meet that emergency. Communicate the situation and assistance needed as workload permits.

ACS I.A and IV.A: currency, personal minimums, physiology and unfamiliar equipment · 14 CFR §91.3: PIC responsibility and emergency authority

What this course prepares you to study

The course proceeds from scan and attitude control to instrument systems, IFR planning, navigation, ATC procedures, approaches, emergencies, and a complete flight scenario. You will use the same Learn, Explore, and Check structure throughout.

This lesson introduces parts of ACS I.A (pilot qualifications and risk) and IV.A (instrument flight). It samples privileges, currency versus proficiency, personal minimums, reliable references, disorientation, and workload. The mapped elements receive further instruction in later lessons; this page does not complete either ACS task.

Ground study supports the knowledge and decisions needed for instrument flight. It does not replace instructor-led aircraft training, required aeronautical experience, endorsements, or the knowledge and practical tests under §61.65. A saved lesson completion is a study record, not a certification or logged flight-training credit.

14 CFR §61.65: instrument rating requirements · FAA-S-ACS-8C: I.A and IV.A

Continue studying

Connect this lesson with related concepts:

• Spatial disorientation and fitness for flight