Aeroplane Equipment and Instruments — Page 70, Lesson 115

Welcome to Chapter 6 of your Operational Procedures syllabus — Aeroplane Equipment and Instruments. This is a brand-new topic, so let’s start from the ground up. This chapter is essentially a catalogue of the mandatory and recommended equipment you’ll find on a modern transport aeroplane, along with the regulatory logic behind each item. The table of contents you’re looking at gives us the roadmap: we’ll cover everything from basic cabin requirements like internal doors and curtains, through first aid kits and oxygen, to emergency evacuation markings, then into the recording systems — Cockpit Voice Recorders (CVRs) and Flight Data Recorders (FDRs). After that, we move into equipment for specific flight rules, single-pilot IFR operations, altitude alerting, standby horizon, aeroplane lighting, flights over water, long-range flights, weather radar, icing conditions equipment, the Machmeter, Ground Proximity Warning System (GPWS), Terrain Awareness Warning System (TAWS), ACAS, and finally communications equipment including the Audio Selector Panel (ASP). Let’s begin with the first major heading: Basic Requirements. This section sets the minimum equipment that must be fitted to an aeroplane for it to be operated commercially. We start with Internal Doors and Curtains. The regulation here is about crew compartment security and passenger safety. Any door or curtain separating the flight crew from the passenger cabin must be capable of being opened by either crew member from their seated position. That means the pilot or co-pilot can reach and operate the latch without leaving their seat. Additionally, if there’s a locking mechanism, it must be possible to unlock it from outside the compartment — for example, by cabin crew in an emergency. The key point is that the door or curtain must not be able to be inadvertently locked in a way that traps the crew inside. Next, First Aid Kits. Every aeroplane must carry at least one first aid kit. The number and contents are specified by the operator’s national authority, but the kit must be readily accessible to the crew. On larger aeroplanes, you’ll often find multiple kits distributed through the cabin. The regulation also requires that the kit be inspected regularly to ensure it’s complete and within its expiry date. Then we have First Aid Oxygen. This is separate from the crew and passenger oxygen systems used for pressurisation emergencies. First aid oxygen is intended for use by passengers who may feel unwell or suffer from hypoxia after a depressurisation event, even after the main oxygen masks have deployed. The system typically consists of portable oxygen bottles with masks, stored in locations where cabin crew can quickly access them. The number of units and the oxygen quantity are determined by the number of passenger seats and the maximum flight duration. Moving on to Break-in Markings. These are markings on the exterior of the fuselage that indicate where emergency services can cut into the aeroplane to reach the interior. They are usually a series of coloured lines or crosses, often yellow or red, at specific locations near emergency exits and overwing areas. The markings tell rescue personnel exactly where it’s safe to cut without hitting fuel lines, hydraulic pipes, or electrical cables. Next, Means of Emergency Evacuation. This covers all the equipment designed to get passengers and crew out of the aeroplane quickly in an emergency. That includes emergency exits, escape slides, slide rafts, and any other devices like ropes or ladders. The regulation requires that the means of evacuation be capable of being deployed and ready for use within a specified time, and that all exits be clearly marked both internally and externally. Now we come to a critical recording system: Cockpit Voice Recorders (CVRs). The CVR is a device that continuously records all sounds in the cockpit — crew conversations, radio transmissions, and ambient noises like alarms or engine sounds. Its purpose is to provide investigators with a complete audio record of the last moments before an accident or incident. The CVR must be capable of retaining at least the last two hours of recording, though newer regulations may require longer. It’s housed in a crash-survivable container, usually bright orange or red for visibility, and fitted with an underwater locator beacon (ULB) that activates on contact with water. The next subsection, CVRs – Operation, Construction and Installation, goes into more detail. The CVR is typically installed in the tail section of the aeroplane, as that area is statistically most likely to survive a crash. It records on multiple channels — usually four — capturing the pilot’s headset, co-pilot’s headset, the cockpit area microphone, and a fourth channel for additional audio sources like the public address system or a third crew member’s position. The recorder operates automatically whenever the aeroplane’s electrical system is powered, and it overwrites the oldest data continuously. In the event of an accident, the recorder is designed to withstand high impact forces, fire, and deep-sea pressure. Following that, we have Flight Data Recorders (FDRs). While the CVR records audio, the FDR records parameters — things like altitude, airspeed, heading, vertical acceleration, engine power, control positions, and many more. Modern FDRs can record hundreds of parameters for at least 25 hours. Like the CVR, it’s housed in a crash-survivable container with an underwater locator beacon, and it’s also installed in the tail. The FDR receives data from various sensors and systems around the aeroplane, and it stores that data in a digital format that can be downloaded and analysed after a flight. The Summary sections for both CVRs and FDRs will consolidate the key points — but for now, understand that these two recorders together form the ‘black box’ system, though they are actually bright orange. They are the primary tools for accident investigation. Next, Equipment for Compliance with Flight Rules. This section lists the instruments and equipment that must be carried depending on the type of flight — Visual Flight Rules (VFR) or Instrument Flight Rules (IFR), day or night, and over different types of terrain. For example, IFR flights require additional navigation and communication equipment, while night flights require position lights and anti-collision lights. Then we have Single-pilot IFR Operations. When a single pilot operates an aeroplane under IFR, there are special equipment requirements to reduce workload and provide redundancy. This typically includes an autopilot, a headset with a microphone that switches automatically, and a means of selecting and monitoring the correct radio frequency without the pilot having to look down for extended periods. Altitude Alerting System is next. This is a system that warns the flight crew when the aeroplane is approaching or deviating from a preselected altitude. It’s mandatory for turbine-powered aeroplanes with a maximum take-off mass over a certain threshold. The system typically provides an aural and visual alert, such as a chime and a flashing light, when the aeroplane is within a few hundred feet of the selected altitude, and again if it deviates from that altitude. Standby Horizon refers to a backup attitude indicator, independent of the primary flight display and the main attitude heading reference system. It’s powered by a separate electrical source, often a dedicated battery, so that if all other instruments fail, the pilot still has a reliable artificial horizon to maintain aircraft attitude. Aeroplane Lighting covers all external and internal lights. Externally, you have navigation lights (red on left, green on right, white on tail), anti-collision lights (red or white flashing beacons), landing lights, taxi lights, and strobe lights. Internally, you have cockpit lighting, cabin lighting, and emergency lighting that automatically activates if the main electrical system fails. Flights over Water require additional equipment like life jackets for each occupant, life rafts with sufficient capacity for all on board, and emergency locator transmitters (ELTs). The specific requirements depend on the distance from land and the type of operation. Long Range Flights — typically over 6 to 8 hours — require additional equipment such as a second set of flight crew rest facilities, extended oxygen supplies, and additional communication and navigation equipment to ensure reliability over long distances. Weather Radar is essential for detecting and avoiding hazardous weather, particularly thunderstorms and areas of heavy precipitation. The radar antenna is mounted in the nose of the aeroplane and scans ahead, displaying returns on a screen in the cockpit. The pilot uses this to deviate around weather rather than flying through it. Equipment for Operations in Icing Conditions includes ice detection systems, anti-icing and de-icing systems for the wings, tail, engine inlets, and probes like pitot tubes and static ports. The aeroplane must be certified for flight in known icing conditions, and the equipment must be functional before entering such conditions. Machmeter is an instrument that displays the ratio of the aeroplane’s true airspeed to the speed of sound — that’s the Mach number. It’s critical for high-speed jet aircraft because exceeding the maximum operating Mach number (Mmo) can lead to control issues or structural damage due to shock waves. Ground Proximity Warning System (GPWS) is a system that warns the flight crew if the aeroplane is in immediate danger of colliding with terrain. It uses radio altimeter data to detect excessive closure rate with the ground, and it provides aural warnings like ‘Pull up’ or ‘Terrain, terrain’. Terrain Awareness Warning System (TAWS) is an enhanced version of GPWS. It uses a digital terrain database to provide forward-looking terrain avoidance warnings, not just downward-looking. TAWS can predict a potential collision with terrain ahead of the aircraft, giving the crew more time to react. ACAS stands for Airborne Collision Avoidance System. It works with the aeroplane’s transponder to detect other aircraft equipped with transponders, and it issues traffic advisories (TAs) and resolution advisories (RAs) to avoid mid-air collisions. The system tells the pilot whether to climb or descend to avoid the threat. Communications Equipment covers the radios used for air traffic control communications — VHF and HF, depending on the route. It also includes the intercom system for crew communication. Finally, Internal Communications and the Audio Selector Panel (ASP). The ASP is the central control unit that allows the pilot to select which radio to transmit on and which audio sources to listen to — for example, both VHF radios, the intercom, and navigation receivers. It’s essentially the audio routing hub in the cockpit. That’s the full scope of Chapter 6. We’ll now go through each section in detail, starting with Basic Requirements and Internal Doors and Curtains. Let’s begin.