The Effects of Weather on Aircraft Part 2 of 2 Video Delta Flight 191 Aug 2, 1985 Causes and Effects https://www.youtube.com/watch?v=BWtlCirzRjs Microburst Is a violent downdraft Takes place in space of less than one mile horizontally and within 1,000 feet vertically Lasts about 15 minutes, and can create wind speeds greater than 115 mph Effects of a Microburst Plane experiences a quick series of events Increased headwinds => increased relative wind, more lift Downdrafts => Sudden loss of altitude Wind rapidly shears to tailwind => decreased relative wind, loss of lift Impact with ground or aircraft pushed dangerously close to the ground Detecting Microbursts Difficult because they crop up in relatively small areas Often associated with convective precipitation in cumulonimbus formations Weather resulting from vertical exchange of heat and moisture Airports have installed low-level wind shear alert system NASA, FAA and others developed sensor that reads speed and direction of invisible particles of water vapor and dust in the wind Most airliners today equipped with these systems Activity 2: Effects of a Microburst Examine Answer the illustration the questions and explain what is occurring with the aircraft and the weather Activity 3 Video Delta Flight 191 Aug 2, 1985 Causes and Effects https://www.youtube.com/watch?v=BWtlCirzRjs Sandstorms https://www.youtube.com/watch?v=ersxqFwDkWA Sandstorms Strong, dry winds generally take place over arid—hot and dry—lands Reduce visibility, clog aircraft engines and instruments, and make it difficult to breathe Can damage aircraft and other machinery Operation Eagle Claw Runs Into Sandstorms November 4, 1979 – Iran Hostage Crisis 52 American diplomats and citizens held captive 444 days April 24, 1980, President Carter approves 2-day rescue mission dubbed Operation Eagle Claw Eight RH-53D helicopters took off from USS Nimitz and USS Coral Sea Helicopters would meet up with several C-130 refueling planes at area designated “Desert One” The aircraft ran into two major sandstorms Operation Eagle Claw (cont) Prior to the sandstorms, one helicopter aborted due to damaged rotor blade (RH-53D left in the desert) The remaining helicopters had to spread out to avoid running into one another during the sandstorms A second RH-53D aborted in the second sandstorm and returned home A third RH-53D had hydraulic problems but made it to the refueling location Col Beckwith recommended aborting the mission since they were essentially down to 5 operational helicopters As the helicopters repositioned themselves to refuel, one ran into a C-130 and crashed, killing 8 U.S. servicemen How Wake Turbulence Affects Air Flight Aircraft generate wake turbulence while in flight Disturbance caused by a pair of vortices trailing from an aircraft’s wingtips Dangerous to other aircraft that get too close Can damage aircraft parts and equipment Intensity Depends on weight, speed, and wing shape of vortex-producing aircraft Greatest when generating aircraft is heavy, slow, and clean Strong vortices created during takeoff, climb, and landing when angle of attack is highest Vortices typically last about 3 minutes Vortex Behavior Trailing vortices behave in predictable ways Helps pilots avoid wake turbulence Vortices move outward, upward, and around the wingtips Vortices generally maintain a distance of a little less than a wingspan apart Avoiding Wake Turbulence Avoid flying through another aircraft’s flight path The pilot should climb above the other aircraft’s climb path until clear of its wake => rotate before previous aircraft When landing behind a departing aircraft, land before the departing aircraft’s rotating point Wake Turbulence Rules General Rules: Avoid flying through another aircraft’s flight path Avoid flying below or behind another aircraft Maintain at least 1,000 feet of difference in altitude between aircraft on similar flight paths During Takeoff: Pilot should rotate aircraft (lift nose wheel off the runway) before reaching point on runway at which plane ahead rotated Wake Turbulence Rules During Landing: Approach runway above the previous aircraft’s path when landing behind it Touch down after the point at which other aircraft did When landing behind departing aircraft, land before the departing aircraft’s rotating point Next…. Done – the effects of weather on aircraft Next – Chapter 2 Test Last - Human Flight Physiology