Flight Instruments
PHAK Ch 8 • Pitot-Static, Gyroscopic, Six-Pack Scan
Memory Aids
A TOMATO FLAMES, ANDS & UNOS, Pitot-Static, Transponder Codes
- AAirspeed
- TTachometer
- OOil pressure
- MManifold pressure (if applicable)
- AAltimeter
- TTemperature gauge
- OOil temp
- FFuel gauge
- LLanding gear indicator
- AAnti-collision lights
- MMagnetic compass
- EELT
- SSeat belts
- ANAccelerate → North — on E/W headings
- DSDecelerate → South — on E/W headings
- UNUndershoot North — turning through N/S
- OSOvershoot South — turning through N/S
Pitot = Speed, Static = Everything
Pitot tube feeds ONLY the ASI. Static port feeds ALL THREE: ASI + Altimeter + VSI. Block the pitot → ASI fails. Block the static → all three are wrong.
Transponder Codes
7500 = hijack (taken alive), 7600 = comm failure (can't talk), 7700 = emergency (going to heaven), 1200 = VFR
Key Takeaways
- •The six-pack splits into two systems: pitot-static (ASI, Altimeter, VSI) and gyroscopic (AI, HI, TC).
- •Pitot-static uses air-pressure differences; gyros use rigidity in space and precession.
- •The Turn Coordinator is electric — your backup bank reference if the vacuum system fails.
- •Realign the HI with the magnetic compass every 15 minutes (it precesses ~3°/15 min).
- •ASI color arcs: White = flaps (Vso–Vfe), Green = normal (Vs1–Vno), Yellow = smooth air only (Vno–Vne), Red line = Vne; Va is not marked.
Attitude Indicator
Gyroscopic · Vacuum/Electric
Shows: Pitch & Bank
Key limit: ±60° pitch, ±100° bank
CFI tip: Primary pitch + bank reference. If it tumbles after unusual attitudes, cage and re-erect before trusting it.
Altimeter
Pitot-Static · Static pressure
Shows: Altitude MSL
Key limit: 1" Hg ≈ 1,000 ft error
CFI tip: Set Kollsman window to current altimeter setting. Above FL180, set 29.92. "High to low, look out below."
Airspeed Indicator
Pitot-Static · Pitot + Static
Shows: Indicated Airspeed
Key limit: Vne (red line)
CFI tip: Know your color arcs: White=flaps, Green=normal, Yellow=smooth air only, Red line=never exceed.
Turn Coordinator
Gyroscopic · Electric
Shows: Rate of Turn + Coordination
Key limit: Standard rate = 3°/sec
CFI tip: Your electric BACKUP if vacuum fails. "Step on the ball" — ball left, press left rudder.
Heading Indicator
Gyroscopic · Vacuum
Shows: Magnetic heading
Key limit: Precesses ~3°/15 min
CFI tip: Realign with magnetic compass every 15 minutes in straight-and-level, unaccelerated flight.
Vertical Speed Indicator
Pitot-Static · Static pressure
Shows: Rate of climb/descent (fpm)
Key limit: 6-9 sec lag
CFI tip: Use as a TREND instrument — don't chase it; lag is normal. An IVSI reduces lag with accelerometers.
Two Systems, Six Instruments
Pitot-Static System, Gyroscopic System
Pitot-Static System
Measures speed, altitude, and vertical rate from air-pressure differences.
• ASI — pitot (ram) vs static
• Altimeter — static only (aneroid wafers)
• VSI — static through calibrated leak
Gyroscopic System
Spinning gyros sense attitude and direction via rigidity in space and precession.
• AI — vacuum (or electric) · pitch & bank
• HI — vacuum · heading (precesses ~3°/15 min)
• TC — electric · rate + coordination
Per FAA-H-8083-25C (PHAK), Chapter 8 — Flight Instruments
Airspeed Indicator — Color Arcs
White, Green, Yellow Arcs & Red Line
| Arc | Range | Meaning | Detail |
|---|---|---|---|
| White Arc | Vso → Vfe | Flap operating range | Stall speed (landing config) to max flap speed |
| Green Arc | Vs1 → Vno | Normal operating range | Stall speed (clean) to max structural cruising |
| Yellow Arc | Vno → Vne | Caution range | Smooth air only — risk of structural damage in turbulence |
| Red Line | Vne | Never exceed | Structural failure possible above this speed |
Note: Va (maneuvering speed) is NOT marked on the ASI — it changes with weight.
DPE Scenarios
The examiner will test how you recognize and respond to instrument failures. Practice these out loud.
Go Deeper
Question about flight instruments, failures, or compass errors? Ask FlightKit for a CFI-level explanation.
Ask about flight instrumentsTraining aid only — verify all data against your POH and current FAA publications.