As we have read during this module, there are many environmental factors that affect an aircraft’s performance. For this activity, you will research and identify one environmental factor that affects aircraft performance. In your blog, explain the impact of the environmental factor on performance, then identify and support a mitigation strategy that can be used to address your selected environmental factor. The goal is to engage in a collaborative and constructive debate that promotes critical thought and reflection.
Your initial posts and responses to your classmates need to be thoughtful, thorough, and comprehensive. This means your initial post needs to be about a paragraph and thoroughly explain your answer. Additionally, include a properly formatted in-text citation and reference to support your position. After you create your blog, you will be expected to engage in dialogue with at least one of your classmates. Your responses to your classmates’ blog entries need to be more than “I agree/disagree.” You need to elaborate and explain why you agree or disagree, and you may even want to ask additional questions.
There are plenty of environmental factors that may affect an aircraft’s performance. It’s safe to say we have no control over these factors, so instead, we have created new ways to mitigate the risks derived from them. One of these environmental factors is outside air temperature, or OAT, especially when flying at high altitudes since it can cause icing to form on the aircraft’s surface. Of course, there are other factors involved, such as humidity, cloud density, and composition, etc., but ultimately you can’t have ice form unless the temperature is right.
A standard temperature lapse rate is when the temperature decreases at the rate of approximately 3.5 °F or 2 °C per thousand feet up to 36,000 feet, which is approximately –65 °F or –55 °C (FAA, 2016, p. 4-3). At those temperatures, Ice could easily form on leading edges, flight surfaces, and even on engine components. Ice formation on the leading edges of wings can reshape the wing.
Depending on the shape it takes, ice on the wing can cause an increase in drag, which the pilot detects as a loss in airspeed or an increase in the power required to maintain the same airspeed (FAA, 2015, p.19). Furthermore, Ice formation on flight surfaces, such as ailerons, can restrict the movement of such, making the aircraft difficult to control. Lastly, if icing is bad enough, it could accumulate inside turbine engines, which could cause engine upset, engine damage from ice shedding, power loss, or engine shutdown (FAA, 2015, p.14)
How do we deal with icing? Well, nowadays aircraft come equipped with anti-icing and de-icing systems in order to prevent the formation of ice, or, if ice does form, be able to remove it at once. Anti-icing comes in the form of heating systems, whereas deicing is a bit more interesting. De-icing consists of rubber tubes attached to critical aircraft surfaces, such as the leading edges of wings.
These tubes are collapsed during normal operations, but when the system is activated, a timer-operated valve selectively inflates either all or half of the tubes intermittently to crack the ice and then allow the airflow over the wings to blow off the broken ice (FAA, 2015, p.19). Put in simple, these tubes smack the wings from the inside with such a force that it shatters ice on the outside. If you have ever heard the de-ice actuators go off, you know how loud, powerful, and scary they are. Ice does not stand a chance against them!
FAA. (2015, October 8). AC 91–74b pilot guide: Flight in icing conditions. Federal Aviation Administration. https://www.faa.gov/documentlibrary/media/advisory_circular/ac_91-74b.pdf
FAA. (2016). Principles of flight. In Pilot’s Handbook of Aeronautical Knowledge (2016th ed., pp. 4–2-4–10). Aviation Supplies & Academics, Inc. https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/phak/media/06_phak_ch4.pdf