Aerodromes - Physical Characteristics — Page 381, Lesson 515

I want to walk you through the physical characteristics of aerodromes, starting with what conditions get reported on the aerodrome and then moving into the runways themselves. First, let's look at the list of things that must be reported to pilots. These are the conditions that affect the safety of operations on the ground. We have construction or maintenance work; rough or broken surfaces on a runway, a taxiway or an apron; snow, slush or ice on a runway, a taxiway or an apron; water on a runway, a taxiway or an apron; snow banks or drifts adjacent to a runway, a taxiway or an apron; anti-icing or de-icing liquid chemicals on a runway or a taxiway; other temporary hazards, including parked aircraft; failure or irregular operation of part or all of the aerodrome visual aids; and failure of the normal or secondary power supply. Now, there's an important note here about frozen water. The three defined states of frozen water on a runway are snow, slush and ice. That's a precise definition you need to remember — those are the only three states recognised for reporting purposes. Let me explain why each of these matters. Construction or maintenance work means there could be obstacles, machinery or uneven surfaces where you don't expect them. Rough or broken surfaces affect your braking and the smoothness of your roll. Snow, slush and ice all change the friction characteristics of the runway dramatically. Water on the surface can cause aquaplaning. Snow banks or drifts adjacent to the runway can restrict the usable width or create a hazard if you deviate. Anti-icing or de-icing liquid chemicals are slippery and can affect braking performance. Other temporary hazards, including parked aircraft, are self-explanatory but critical — you need to know where an aircraft is sitting. Failure or irregular operation of part or all of the aerodrome visual aids means your lighting or markings may not be reliable. And failure of the normal or secondary power supply means the aerodrome may lose its electrical systems, which affects lighting and other equipment. Now let's move to runways themselves. This is paragraph 19.28, the general description. Runways are the parts of the manoeuvring area used for take-off and landing of aircraft. That's the definition — the manoeuvring area is the part of the aerodrome used for taxiing, take-off and landing, and the runway is specifically the part used for take-off and landing. Except in remote areas, runways will always be prepared and usually paved, with concrete and tarmac being the typical surfaces. A runway should be straight and not have excessive slopes. That's a design requirement — you want a straight, relatively level surface for safe operations. Here's an interesting point. It is usual to be able to use the concrete strip in either direction, so one concrete strip will provide two runways. That means the same physical strip, when used in one direction, is one runway, and when used in the opposite direction, it's a different runway with a different designator. In all cases, runways require markings painted on the surface. These markings give the pilot indications about the use of the runway and also assist the pilot to land the aircraft. So the markings are not just decorative — they convey operational information and help with the landing task. Now, a practical point for you as a future airline pilot. It is true to say that no two runways are identical. Part of the learning curve for a pilot new to an airline is to become familiar with the aerodromes and the runways used during the operation. So you will need to study the specific characteristics of each aerodrome you operate into. Finally, there's the matter of control. At a controlled aerodrome, the runway belongs to the aerodrome controller. The pilot will be given permission to enter, backtrack, cross, take off from and land on a specified runway. The air traffic control officer, the ATCO, will always specify the runway, and the pilot always reads back the runway designator in RTF communications — that's radio telephony. So for example, the ATCO might say something like "G-AG..." — and the excerpt cuts off there, but the principle is clear: the controller names the runway, and you, the pilot, must read back that designator to confirm you've understood correctly. That readback is a critical safety loop. It ensures both parties agree on which runway is in use before any movement happens. So remember: the runway designator is always specified by the ATCO and always read back by the pilot. Let me summarise the key points. The reported conditions cover surface state, contaminants, hazards and equipment failures. The three frozen water states are snow, slush and ice. Runways are paved, straight, with minimal slope, and one strip gives two runways depending on direction. Markings are mandatory and serve both informational and landing-assistance purposes. And at a controlled aerodrome, the runway belongs to the controller, with the designator always specified and always read back.