Basic Stall Warning System

A stall warning system primarily relies on the angle of attack (AoA) as its main input.

• The AoA is detected using vanes on the wing’s leading edge or other sensing devices.
• When the aircraft approaches its stall point, the system triggers a warning, alerting the pilot to take corrective action.

note that modern aircraft stall warning would have more inputs so make sure you read the question carefully

Flight Data Recorder (FDR) Installation Requirement (JAR Regulations)

The Joint Aviation Requirements (JAR) mandate that the Flight Data Recorder (FDR) must be installed in the rear section of the aircraft.

Reason for Placement:

• The aft section of the aircraft is less prone to damage in the event of a crash, improving the chances of data survivability.
• It is positioned away from potential impact zones, such as the nose and wings, which are more vulnerable during accidents.

screen

EVSI

WEATHER RADAR AND EFIS DISPLAY,(BASICALLY YOU CAN USE THE EFIS PANEL TO CHANGE IT ON ANY MODE)

Principle of TCAS II

TCAS II (Traffic Collision Avoidance System) operates using the secondary surveillance radar (SSR) principle in an air-to-air role, utilizing standard SSR frequencies:

• 1030 MHz (Interrogation)
• 1090 MHz (Reply)

Protective Zones

TCAS II establishes two three-dimensional protective bubbles around the equipped aircraft:

1. Traffic Advisory (TA) Zone – Provides alerts about nearby traffic.
2. Resolution Advisory (RA) Zone – Issues vertical maneuver instructions to prevent collision.

TCAS Visibility Requirements

For an aircraft to be detected by a TCAS-equipped aircraft, it must have at least a Mode “A” transponder.

Limitations of Mode “A” Transponders

• If the transponder is switched off or unserviceable, the aircraft becomes invisible to TCAS, increasing collision risk.
• Mode “A” transponders transmit only identity and position, without altitude information.
• Due to the lack of altitude data, TCAS can only issue Traffic Advisories (TAs) but not Resolution Advisories (RAs).

When a Flight Data Recorder (FDR) is combined with a Cockpit Voice Recorder (CVR), it records both flight data and cockpit audio. The audio recordings typically include:

1. Cockpit voice – Conversations between pilots and other cockpit sounds
2. Radio communications – ATC transmissions and responses
3. Public addresses from the cockpit – Announcements made by pilots over the PA system

However, cabin voice is not typically recorded unless there is a dedicated microphone in the cabin, which is rare. The CVR primarily focuses on flight deck audio.

The correct answer is:

“Aural signals which may be supplemented by visual signals.”

Explanation:

A Ground Proximity Warning System (GPWS) primarily provides aural warnings to alert pilots of potential terrain hazards. However, these warnings are often supplemented by visual signals on cockpit displays, such as warning lights or annunciators.

The function of the altitude alerting system is to warn the pilots that the aircraft is approaching or deviating from the altitude selected on the autopilot control panel. It does this in certain height bands above and below the selected altitude.

Approaching a Selected Altitude
At 900 feet prior to the selected altitude a white box will be displayed around the current altitude display on the PFD, together with a momentary audible alert. At 300 feet prior to the selected altitude the white box disappears.

TCAS II obtains information from:

1. Pressure encoding from Mode S transponder – Provides altitude data.
2. Radio altimeter – Helps determine altitude above ground level.
3. Aircraft-specific configurations – Includes aircraft performance characteristics.
4. Inertial Reference Unit (IRU) – Provides aircraft position and movement data

The Cockpit Voice Recorder (CVR) records:

• Radio communications (with ATC and other aircraft)
• Flight crew conversations in the cockpit
• PA announcements made from the flight deck
• Ambient sounds (engine noise, alarms, switch clicks, etc.)

1. Traffic Advisory (TA) Actions:

• Alerts crew to potential collision risk.
• Begin visual search for conflicting traffic.
• Prepare to respond if an RA follows.
• Do not maneuver based on TA alone.
• If traffic remains a concern, consult ATC.

2. Resolution Advisory (RA) Actions:

• Immediately initiate the RA maneuver.
• Adjust flight path, power, and trim accordingly.
• Non-flying crew should monitor traffic visually.
• Inform ATC of any deviation ASAP.

3. When to Disregard an RA:

• Only if visual contact confirms no deviation is needed.
• If ATC instruction conflicts with an RA, follow the RA (TCAS takes priority)

TCAS PPI

Resolution Advisories

It should be remembered that it is not the job of the ACAS system to maintain standard Air Traffic separation minima. If RAs are responded to smoothly and immediately, then the intended vertical separation varies from 300 to 600 ft (700 above FL410) depending on the Sensitivity Level (SL) which decreases with altitude.

Resolution Advisories come in two forms:

• Preventative Advisories are situations where no collision risk exists unless a change of level is initiated by either aircraft. The synthetic voice advisory is “Monitor Vertical Speed”.
• Corrective Advisories are situations where a collision risk exists and a manoeuvre is necessary to avert it. The synthetic voice produces the appropriate command.

TCAS II receives input from the following sources:

1. Mode S Transponder Data – Provides pressure altitude encoding and aircraft identity.
2. Radio Altimeter – Supplies altitude data for proximity awareness.
3. Aircraft-Specific Configuration Data – Includes operational modes and performance characteristics.
4. Inertial Reference Unit (IRU) or Air Data Computer – Provides additional altitude and velocity information.
5. ATC Transponder Replies from Other Aircraft – Receives data from nearby aircraft equipped with Mode C or Mode S transponders.

As per ICAO Annex 6 and FAA/EASA regulations, aircraft registered after April 1, 1998, must be equipped with a Cockpit Voice Recorder (CVR) that retains at least the last 2 hours of recorded audio.

Why 2 Hours?

1. Accident Investigation – The last 2 hours are the most critical for understanding incidents, as most accidents occur during approach, landing, or departure.
2. Technological Advancements – Earlier CVRs recorded only 30 minutes, but this was extended to 2 hours in modern solid-state recorders for better data retention.
3. Regulatory Compliance – ICAO, FAA, and EASA mandated this change to improve safety and post-accident analysis.

JAR-OPS Requirements for Cockpit Voice Recorder (CVR) Operation

According to JAR-OPS 1.700 (Joint Aviation Requirements – Operations), the CVR must:

1. Automatic Start

• The CVR must automatically start recording when electrical power is applied to the aircraft.
• It must remain operational for the entire duration of the flight, including engine start, taxi, takeoff, cruise, landing, and shutdown.

2. Continuous Operation

• The CVR must continuously record once power is supplied, ensuring that critical flight data is captured at all times.

3. Automatic Stop

• The CVR must continue recording until electrical power is removed, which usually happens:
  • When the aircraft’s engines are shut down after landing.
  • When the electrical power is manually switched off on the ground.

For an aircraft weighing more than 5,700 kg and registered after 1 April 1998, the Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR) must record:

• FDR: At least 25 hours of flight data.
• CVR: At least 2 hours of cockpit voice and audio data.

• TCAS I: Provides Traffic Advisories (TAs) only, alerting pilots to nearby aircraft but does not issue Resolution Advisories (RAs). The pilot must visually identify and decide on any action.
• TCAS II: Provides both TAs and RAs, issuing Corrective RAs that direct pilots to adjust their vertical flight path (climb or descend) to avoid collision.

According to JAR-OPS and ICAO Annex 6, the FDR must automatically start recording when  power is first applied to the aircraft and continue recording until the aircraft is powered down at the end of the flight. This ensures that all critical flight parameters are captured, including taxi, takeoff, cruise, landing, and shutdown.

TA and RA in the vertical plane.

Explanation:

• TCAS II (Traffic Collision Avoidance System) is designed to issue both Traffic Advisories (TAs) and Resolution Advisories (RAs) to avoid mid-air collisions.
• It operates only in the vertical plane, meaning it provides climb or descent instructions to avoid conflicting traffic.
• A Mode C transponder provides altitude data, enabling TCAS II to determine the vertical separation between aircraft and generate appropriate RAs.

According to JAR-OPS (Joint Aviation Requirements – Operations), a Cockpit Voice Recorder (CVR) on a 50-seat turboprop aircraft must start recording before the aircraft is capable of moving under its own power (typically when electrical power is applied) and must continue until the aircraft is no longer capable of moving under its own power (typically after shutdown).

This ensures that all pre-flight, taxi, takeoff, cruise, approach, landing, and post-flight communications and sounds are recorded.

The Cockpit Voice Recorder (CVR) consists of:

1. Microphone – Captures cockpit sounds, communications, and alarms.
2. Crash/Fire Resistant Construction – The CVR is housed in a protective casing to withstand impact and fire.

However, the CVR does not have:

• An independent battery – It relies on aircraft power, but an underwater locator beacon (ULB) has its own battery.
• A Flight Data Recorder (FDR) – The FDR is a separate unit, though some small aircraft may have a combined CVR/FDR system.

The requirement to carry a Ground Proximity Warning System (GPWS) applies to aircraft based on their age, weight, and passenger capacity.

Applicable Aircraft Types:

1. Turbo prop – Required if above a certain weight or passenger capacity (e.g., >5,700 kg MTOW or more than 9 passenger seats).
2. Jet – Required for all jet-powered aircraft above a certain weight or passenger capacity.
3. Piston – Generally not required, unless the aircraft meets specific commercial transport regulations.