There are two FMGC (Flight Management Guidance Computers) on board. Each FMGC computes its own aircraft position (called the “FM position”). To grasp the method of position calculation in the A320, it’s crucial to first comprehend three key terms individually. Once these concepts are clear, connecting them becomes much simpler. In this article, we aim…
While VA (Design Maneuvering Speed) is a familiar concept, there’s another airspeed that often takes a backseat but holds immense significance in turbulent skies: VB (Turbulence Penetration Speed). By definition VA represents the maximum speed at which the aircraft can be safely subjected to full and abrupt control movements without exceeding its structural limits. Learning…
Flap Setting for Take-off Flaps are used during takeoff to increase the lift coefficient (CL) of the wings, allowing the aircraft to achieve the necessary lift in available take-off distance with maximum weight/payload. Take-off distance depends on unstick speed and rate of acceleration to that speed. The unstick speed (Vr) is the speed at which…
Issue When altering the Vapp entry or adjusting altitude constraints, the Flight Plan (F-PLN) profile undergoes a re-computation. If the Required Time of Arrival (RTA) function had been utilized prior to these modifications, the MCDU and PFD may unexpectedly present inaccurate speed targets. In addition, this scenario could occur if the flight crew has initially…
Issue On the Airbus A320, the “CHECK WEIGHT” message appears on MCDU when there’s a significant disagreement between the gross weight computed by FMGC and the gross weight computed by FAC. This could indicate a potential discrepancy in the aircraft’s weight calculations, which is crucial for safe flight operations. The threshold for triggering this message is…
In normal law speed scale displays VLS, V Alpha prot and V Alpha max speed. In alternate and direct law speed scale is same. It displays VLS and Vsw only. VLS Speed: VLS is the lowest selectable speed for the autopilot and autothrust. It’s represented by the top of an amber strip along the airspeed…
Appendix 1 of ICAO Annex 11 outlines the guidelines for naming ATS routes, also known as Airways. This article delineates the structure for formulating designators for these vital air navigation routes. ATS route designator can be subdivided in to 3 parts: Basic Designator Prefix (if required) Suffix (if required) – Number of characters required to…
The placement of taxiway edge lights and taxiway centerline lights is crucial for providing clear guidance to pilots while taxiing on the ground. Spacing between taxiway edge lights and taxiway centerline lights can vary depending on factors such as: the curvature of the taxiway, the speed of aircraft expected to use the taxiway, and the…
Estimated Position Uncertainty is a measure of the accuracy or uncertainty associated with the estimated position of an aircraft. For an Airbus A320, EPU typically refers to the uncertainty in the aircraft’s calculated position. This uncertainty can be influenced by various factors including the accuracy of the navigation sensors, environmental conditions, and the quality of…
“GPS PRIMARY” is displayed when Flight Management Guidance System (FMGS) prioritizes GPS as the primary navigation source. Article background: FM uses following positions to navigate in decreasing order of priority: IRS-GPS (GPIRS position) – this is the condition when GPS Primary is displayed on MCDU IRS-DME/DME (Mix IRS and Radio position) IRS-VOR/DME (Mix IRS and…