Attitude Instrument Flying

Module 3 · Attitude Instrument Flying · Lesson 1 of 5

Control and Performance Instruments

Set an attitude and a power setting, then let the other instruments tell you what you got.

Attitude instrument flying means controlling the airplane by its instruments instead of the outside horizon. The Instrument Flying Handbook builds it on two fundamental skills, the cross-check (looking at the right instruments in the right order) and instrument interpretation (knowing what each one is telling you), which together give you aircraft control (moving pitch, bank and power smoothly to get what you want) (IFH p. 6-10). There are two ways to organize the panel in your head (IFH p. 6-2). Both are correct, and most pilots use a mix.

Which Instrument Is Primary?

The primary instrument is the one that shows the value you are trying to hold. In level flight you are holding altitude, so the altimeter is primary for pitch. In a constant-airspeed climb you are holding airspeed, so the airspeed indicator becomes primary for pitch. The attitude indicator supports everything.

The rows follow the Instrument Flying Handbook (FAA-H-8083-15B), which the ACS lists as a reference: straight and level p. 6-10, level turn pp. 7-20–7-21, constant-airspeed climb p. 7-14, constant-rate climb p. 7-14 (VSI primary for pitch, airspeed primary for power), with turns combined as on p. 7-24.

Standard-Rate Turns

A standard-rate turn is 3° per second, so 360° takes two minutes. The turn coordinator's marks show it directly. To estimate the bank angle it takes, divide true airspeed by 10 and add half again: at 120 KTAS, 120 ÷ 10 = 12, and 12 × 1.5 = 18° of bank (IFH pp. 7-19–7-20). The turn coordinator shows rate of roll and rate of turn; an older turn-and-slip indicator shows rate of turn only (IFH p. 6-8). The FAA errata for the Instrument Flying Handbook corrected page 7-7 so it says "turn coordinator," which is what this lesson uses (IFH errata, p. 7-7).

Banking tilts part of the wing's lift sideways, so a level turn needs a little more back pressure than straight flight. Watch for it in the F08 panel: roll into a turn without touching pitch and the altimeter starts to unwind.

Normal and Abnormal Indications

Performance instruments lag. The VSI shows the trend immediately, but its pointer lags a few seconds behind the actual change (IFH p. 5-8). An instantaneous VSI (IVSI) uses accelerometers to remove most of that lag (IFH pp. 5-8, 6-6). The airspeed indicator, by contrast, has very little lag: a pitch change shows up on it almost at once (IFH p. 6-6). So make a change on the attitude indicator, hold it, and give the performance instruments time before you change again. Chasing the VSI or airspeed needle leads to over-control. If an instrument disagrees with the others, suspect it: Module 2 covered how blockages and gyro failures look, and Lesson 3.4 covers flying with what is left.

Module 3 · Attitude Instrument Flying · Lesson 2 of 5

The Cross-Check

A good scan keeps coming back to the attitude indicator and never stops on any one gauge.

The cross-check (or scan) is the continuous, logical look around the panel that tells you what the airplane is doing. The Instrument Flying Handbook describes three common patterns (IFH pp. 6-11–6-12):

Three Scan Errors

The Instrument Flying Handbook lists the three common scan errors you are expected to name (IFH pp. 6-11–6-13). Each one lets a small deviation grow because you are not looking where it shows up first.

• FFixation: staring at one instrument, often the one you are correcting, while everything else drifts.
• OOmission: leaving an instrument out of the cross-check, for example forgetting the heading indicator after leveling off.
• EEmphasis: relying on one instrument you trust or understand best instead of the combination of instruments that show pitch or bank.

Trim Frees Your Eyes

A trimmed airplane holds its attitude when you look away to copy a clearance or check a chart. An airplane held by force drifts the moment your attention moves. Trim after every change of pitch or power: set the attitude, let the airspeed settle, then trim off the control pressure. ACS IR.IV.A.S2 expects you to apply pitch, bank, power and trim corrections.

Unfamiliar Displays and Avionics

A glass primary flight display puts the same information in a different place: tapes instead of dials, trend vectors instead of needle motion, a turn-rate arc instead of a turn coordinator. Your scan built on a six-pack does not transfer automatically, and neither does a scan built on glass. ACS IR.IV.A.R3 asks you to manage that risk. Get instruction on the new system in VMC or a simulator, learn its failure modes and reversionary mode, and keep your personal minimums high until the new scan is automatic.

Module 3 · Attitude Instrument Flying · Lesson 3 of 5

Spatial Disorientation and Illusions

In cloud, two of your three balance senses stop working and the third starts making things up.

Your brain works out which way is up from three systems (IFH p. 3-2). The visual system is the strongest, and in IMC it has nothing to look at except the panel. The somatosensory system, the nerves in your skin, muscles and joints, cannot tell gravity from the push of a coordinated turn. That leaves the vestibular system in the inner ear:

• Three semicircular canals sense rotation in pitch, roll and yaw. Each is filled with fluid. When your head turns, the fluid lags behind and deflects the cupula, a gel flap that bends the sensory hairs, and the brain reads that as rotation.
• Two otolith organs, the utricle and saccule, sense linear acceleration. They cannot tell acceleration apart from tilting your head.

The canals only notice changes in rotation. Hold a turn long enough and the fluid catches up with the canal: the hairs stand up again and you feel level, though you are still turning. Every vestibular illusion grows from that.

Visual illusions catch you near the boundary of IMC. A false horizon comes from a sloping cloud deck, an obscured horizon, or a dark night with scattered ground lights and stars. Autokinesis makes a single light you stare at in the dark seem to move. On the approach, a narrow runway makes you feel high, upsloping terrain makes you feel high, featureless terrain makes you fly low, rain on the windshield makes you fly low, and haze makes the runway look farther away (IFH pp. 3-7, 3-9; AIM 8-1-5b). Those come back in Module 11.

Physiology That Degrades the Cross-Check

ACS IR.IV.A.R1 asks you to manage anything that makes your body a worse instrument pilot. The main ones:

• Hypoxic hypoxia: not enough oxygen pressure at altitude for the lungs to absorb it (AIM 8-1-2a).
• Hypemic hypoxia: the blood cannot carry the oxygen, from blood loss, anemia or carbon monoxide (AIM 8-1-2a, 8-1-4).
• Histotoxic hypoxia: the cells cannot use the oxygen, for example after alcohol or drugs.
• Stagnant hypoxia: the blood is not flowing well, from heart problems, high G loads, shock or cold.
• Hyperventilation: breathing too fast removes too much carbon dioxide. Symptoms resemble hypoxia. Slow your breathing or breathe into a paper bag (AIM 8-1-3b). Talking aloud also helps slow it (a rule of thumb).

Illness, medication, alcohol, fatigue, lack of sleep and mild hypoxia all make spatial disorientation more likely (IFH pp. 3-8–3-9). The Instrument Flying Handbook's coping list comes down to this: know the illusions, get good weather information, stay proficient, avoid sudden head movements in turns and on approach, be rested and fit, and above all trust the instruments over your body.

Module 3 · Attitude Instrument Flying · Lesson 4 of 5

Unusual Attitude Recovery

Read the airspeed first. It tells you whether the nose is high or low, and that decides the whole recovery.

An unusual attitude is any attitude you would not normally need for instrument flight. The Instrument Flying Handbook lists how pilots get there: turbulence, disorientation, instrument failure, confusion, preoccupation with flight deck duties, careless cross-checking, errors in instrument interpretation, or lack of proficiency (IFH p. 7-26). ACS IR.IV.B.K2 and R1 add physiological and environmental factors, system and equipment failures, stress, task saturation, an inadequate scan, distractions and spatial disorientation (ACS pp. 10–11). Automation doing something unexpected belongs on the list too. On the checkride, the evaluator puts the airplane in an unusual attitude while you look down, then hands it back.

Recognize It

Recover in the Right Order

The Instrument Flying Handbook gives a sequence for each case (IFH pp. 7-27–7-28). The inputs come almost together, but in this order:

In a nose-low bank, level the wings before you pull. Back pressure in a bank tightens the turn and adds load factor without stopping the descent, which is exactly the graveyard spiral from Lesson 3.3. ACS IR.IV.B.R3 and R6 are about this: stay inside the operating envelope (stall speed, maneuvering speed, never-exceed speed and the load limit) and avoid control inputs that make things worse.

When the Attitude Indicator Is Gone

If the attitude indicator has failed, it may be what caused the upset. Recover with the instruments that are left:

• Pitch: the nose passes through level when the airspeed and altimeter needles stop and start to reverse. Hold that.
• Bank: wings are level when the turn coordinator shows no turn and the ball is centered.
• Then cover the failed instrument so it cannot fool you again, and fly partial panel (Module 12).

Automation

ACS IR.IV.B.K4 asks for the appropriate use of automation. Some autopilots have a level or recovery mode, and some airplanes have envelope protection. Know what yours can do from the POH/AFM supplement. But be ready to recover by hand: if the autopilot or a failed sensor feeding it caused the upset, disconnect it, fly the airplane, and troubleshoot after you are level.

Module 3 · Attitude Instrument Flying · Lesson 5 of 5

Inadvertent IMC and Loss of Situational Awareness

The windshield goes white. The next ten seconds are for flying, not for deciding.

Inadvertent (or unintended) flight into instrument meteorological conditions, IIMC, usually happens on a VFR flight that pushed on as the weather came down. Once you hold the rating it can still happen: a VFR leg, a cloud deck that closes up, or a moment of distraction. ACS IR.IV.B.K3 asks you to know the procedures to safely regain VMC.

1. Fly the airplane
   Eyes inside. Wings level on the attitude indicator, hold altitude, trim. Ignore what your body says.
   Aviate
2. Turn back or climb
   A standard-rate 180° turn toward the VMC you just left, if terrain allows. Otherwise climb to a safe altitude.
   Navigate
3. Ask for help
   Tell ATC you are in IMC. Declare an emergency if needed and squawk 7700 (AIM 6-2-2a). Ask for vectors to VMC or an airport.
   Communicate
4. Use what you have
   Autopilot in heading and altitude hold, if you know it well, to cut workload. If you are rated, current and equipped, request an IFR clearance (AIM 6-2-1b).
   Manage

Situational Awareness and SRM

ACS IR.IV.B.R9 names distractions, task prioritization, loss of situational awareness and disorientation. After an upset or an unexpected cloud, your workload jumps exactly when you are least able to handle it. Single-pilot resource management (IR.IV.B.S2) means using every resource: the autopilot, ATC, the moving map, a passenger who can hold the chart. Prioritize in order: fly, then navigate, then talk. Think about collision hazards too (IR.IV.B.R8): the 180° turn and any climb must clear terrain, other traffic and airspace. ATC can help with all three.

Module 3 · Attitude Instrument Flying · Knowledge Check

Module 3 Knowledge Check

Fourteen questions in the style of the oral exam, each tagged with its ACS element. Pass mark: 80% (12 of 14).