Study the following systems in your aircraft's POH:
Engine
Fuel system
Oil system
Electrical system
Flight controls
Induction system
Anti-icing prevents ice from forming in the first place.
Think of it as protection ahead of time.
De-icing is used to remove ice that has already formed.
Think of it as cleaning ice off after it has appeared.
You will be asked if our planes are rated for flight into known icing. The answer is a simple NO, the POH says "flight into known icing conditions is not permitted."
Most trainers (Cessna, Archer, Skyhawk, Warrior) only have partial anti-ice systems, not full de-ice equipment.
Below is a list of the systems:
Airspeed Indicator: The ASI measures how fast you’re moving through the air. It compares pressure from the pitot tube (facing forward into the wind) with static pressure. The difference moves a diaphragm connected to the needle. It shows speed in knots or miles per hour and is the only instrument that uses both pitot and static pressure.
Power Source: Pitot-static (uses both pitot and static ports)
Indication: Airspeed in knots
Markings: Color-coded arcs (white = flap operating, green = normal ops, yellow = caution, red = never exceed)
Principle of Operation: Measures dynamic pressure (pitot - static)
Limitations: Requires correct pitot and static input; ice or blockage can render it inaccurate or inoperative
Errors: Position error, density altitude effects, pitot tube/drain hole blockage
Altimeter: The altimeter has sealed, flexible metal aneroid wafers inside that expand or contract based on outside air pressure. As you climb, outside pressure drops, and the wafers expand. As you descend, pressure increases, and they compress. This movement turns gears that move the needles to show your altitude.
Power Source: Static system only
Indication: Altitude above the selected pressure level
Markings: Numbered face with 20-ft intervals, barometric setting window (Kollsman window)
Principle of Operation: Expanding/contracting aneroid wafers as pressure changes
Limitations: Must be set to current pressure; tolerance ±75 feet for IFR
Errors: Incorrect setting, pressure changes, static port blockage
Vertical Speed Indicator: The VSI compares fast and slow changes in air pressure. A diaphragm inside gets pressure right away, but the rest of the instrument fills more slowly. When pressure changes quickly (like during a climb or descent), the difference causes the needle to move up or down. It has a small delay due to the restricted orifice (calibrated leak).
Power Source: Static system only
Indication: Rate of climb or descent in feet per minute (FPM)
Markings: Scale with increments typically in 500 or 1000 FPM
Principle of Operation: Measures rate of pressure change through a calibrated leak
Limitations: Has lag (~6–9 seconds), limited accuracy in rapid altitude changes
Errors: Static blockage, lag in reading
(Note: Some aircraft are equipped with an instantaneous vertical speed indicator (IVSI), which incorporates accelerometers to compensate for the lag in the typical VSI. [Figure 8-6])
Figure 8-6
Used in: Standby Attitude Indicator
Powered by: Engine-driven vacuum system
How it works: A physical spinning mass maintains orientation in space. As the aircraft moves around it, the gyro stays fixed, providing pitch and roll reference.
Why it matters: Functions as a backup if the G1000 system or electrical power fails.
Used in: AHRS (Attitude Heading Reference System)
Powered by: Aircraft electrical system
No moving parts: Uses microelectromechanical sensors (MEMS) to detect angular movement (pitch, roll, yaw).
Feeds data to: Attitude Indicator, Turn Rate Indicator, and Heading computation via AHRS.
Why it matters: Provides stable, accurate reference without the limitations of mechanical gyros (e.g., drift, precession).
Rigidity in Space
A spinning gyroscope tends to stay pointed in the same direction, no matter how the airplane moves around it.
Used in: Attitude Indicator and Heading Indicator
Why it matters: It gives you a stable reference to show pitch, bank, or heading
Precession
When you apply a force to a spinning gyro, it reacts 90 degrees later in the direction of rotation.
Used in: Turn Coordinator
Why it matters: This lets the instrument show rate of turn and roll
Power Source: Vacuum or electric, depending on aircraft
Indication: Pitch and bank relative to the horizon
Markings: Artificial horizon with pitch ladder and roll indicators
Principle of Operation: Gyroscopic rigidity in space
Limitations: Precession over time, may tumble beyond pitch/bank limits
Errors: Acceleration/deceleration errors, vacuum failure
Power Source: Vacuum or electric, depending on aircraft
Indication: Magnetic heading (must be synced with magnetic compass)
Markings: 360° compass rose with heading bug (if HSI)
Principle of Operation: Gyroscopic rigidity (rotating in vertical plane)
Limitations: Subject to precession; needs regular realignment
Errors: Drift, failure of power source (vacuum/electric)
Power Source: Electric (most commonly)
Indication: Rate of turn and coordination (slip/skid)
Markings: Airplane symbol with standard rate turn tick marks; ball inclinometer for coordination
Principle of Operation: Gyro precession (rate of turn) + inclinometer (ball)
Limitations: Only accurate for standard rate turns; not good for exact bank angle
Errors: Electric failure, slow response, instrument lag
Used in: Heading Information via AHRS
Powered by: Electrical system
Located remotely: Typically in a wing to reduce interference.
What it does: Measures Earth’s magnetic field to determine magnetic heading.
How it works with others: AHRS blends magnetometer input with gyro data to generate a smooth, drift-free heading.
Why it matters: Replaces the function of a magnetic compass within the G1000 environment.
What it provides: Gives your heading indicator on the PFD information through AHRS
Accelerometer: a solid state gyro
Used in: AHRS for motion refinement
Powered by: Electrical system
What it senses: Linear acceleration in all directions (e.g., nose-up, descending, turning).
Purpose: Helps the AHRS validate and refine the aircraft’s attitude and movement—especially during rapid maneuvers.
Why it matters: Ensures the Attitude Indicator remains accurate under dynamic flight conditions.
ADAHRS Computer
Power Source: Earth’s magnetic field (no electrical source)
Indication: Magnetic heading
Markings: Lubber line and deviation card; compass card graduated in 5° increments
Principle of Operation: Magnetized bar aligns with Earth’s magnetic field
Limitations: Only accurate in straight-and-level, unaccelerated flight
Errors:
ANDS: Accelerate North, Decelerate South
UNOS: Undershoot North, Overshoot South
Deviation (aircraft magnetic fields), Variation (true vs. magnetic)
Broadcast on 108.0 to 117.95 MHz, excluding 108.1-111.95 and odd tenths.
Full scale deflection: 10º
Must verify correct and functional VOR station
The VOR MON (VOR Minimum Operational Network) program ensures that as old VORs are decommissioned, a MON airport (equipped with ILS or VOR approach) is available within 100 nautical miles
The reference signal goes out in all directions.
The variable signal rotates like a lighthouse beam—starting from 0° (North) and sweeping clockwise.
If you’re east (090° radial) of the VOR:
The rotating variable signal reaches you shortly after the reference signal.
→ Small timing difference.
If you’re west (270° radial):
The variable signal takes longer to sweep around and reach you.
→ Larger timing difference.
Receiver Checks:
VOT: ±4º
Ground: ±4º
Airborne: ±6º
Dual: ±4º
Repair Station: ± 4º
Prominent landmark: ±6º
VOR Errors:
Cone of confusion
Area of ambiguity
Reverse sensing
Line of sight
Propeller rotation: spinning at such an RPM that it will disrupt the VOR frequencies.
962-1213 UHF
Normally tuned automatically with a paired VHF station (VOR/LOC)
The airborne DME unit transmits and interrogation signal
The ground DME facility receives and replies to the interrogation
Airborne unit calculates the slant range distance to the station based on the reply time
Due to slant range error, when flying overhead the station, DME indicates greater than zero
Slant range error is negligible at 1 nautical mile per every 1000'
Localizer (AIM 1-1-9)
Provides lateral course guidance
Frequencies: 108.1-111.95 with odd tenths only. 90 and 150 Hz signals are carried over the VHF frequency and used by the receiver to interpret the aircraft's lateral position
Width: 3º-6º with threshold at 700'
Coverage: 35º to each side of the centerline for the first 10 nautical miles and 10º up to 18 nautical miles from the antenna and up to an altitude of 4500'
Glideslope (AIM 1-1-9)
Provides vertical course guidance
Frequencies: 329.3-335 MHz (UHF). Vertical position is determined by the intensity of 90 and 150 Hz signals carried over the UHF frequency and directed above and under the slope
Width: 1.4º
Range: up to 10 nautical miles
Slope: 3º
Errors: false glide slope above normal glide slope
Global Positioning System (GPS) is a U.S.-operated GNSS (Global Navigation Satellite System).
Constellation: At least 24 satellites orbiting ~10,900 NM above Earth. At least 5 satellites are visible from any point at any time.
3 Satellites: 2D Position (Latitude + Longitude)
4 Satellites: 3D Position (Latitude + Longitude + Altitude)
5 Satellites: RAIM – Fault Detection (checks signal integrity)
6 Satellites: RAIM – Fault Exclusion (identifies and removes bad signal)
Each satellite creates a “pseudo-range” sphere.
The aircraft is located at the intersection of multiple spheres from several satellites.
Ensures GPS signal integrity by checking for faults.
5 satellites required for fault detection (RAIM).
6 satellites needed for fault exclusion.
GPS can substitute:
DME
ADF (except for NDB approaches with no GPS overlay)
Check GPS NOTAMs and use RAIM prediction preflight.
In the U.S., this is called WAAS.
Uses ground stations to monitor GPS errors and send corrections through satellites.
Improves:
Accuracy
Integrity
Availability
Enables APV approaches like:
LPV
LNAV/VNAV
LP
Previously called LAAS
Sends error corrections via VHF, not satellites
More accurate than WAAS but covers a smaller area
Supports GLS approaches with Category I or better minima
Marker beacons are part of the Instrument Landing System (ILS) used to provide position awareness during an approach. They send vertical fan-shaped signals upward that your aircraft detects as you fly over them.
Outer Marker
Final approach fix or beginning of the glide slope
Approximately 4-7 nautical miles from the threshold
Blue
Middle Marker
DA for Cat I aircraft
Approximately 3,500' from the threshold
Amber
Inner Marker
DA for Cat II/III aircraft
Approximately 1,000' from the threshold
White