1. The Effects of Weather on Aircraft Part 2 of 2

2. Video Delta Flight 191 Aug 2, 1985 Causes and Effects https://www.youtube.com/watch?v=BWtlCirzRjs

3. 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

4. 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

5. 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

6. Activity 2: Effects of a Microburst  Examine the illustration  Answer the questions and explain what is occurring with the aircraft and the weather

7. Activity 3 Video Delta Flight 191 Aug 2, 1985 Causes and Effects https://www.youtube.com/watch?v=BWtlCirzRjs https://www.youtube.com/watch?v=BWtlCirzRjs

8. Sandstorms https://www.youtube.com/watch?v=ersxqFwDkWA

9. 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

10. 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

11. 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

12. 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

13. 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

14. 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

15. 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

16. 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

17. 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

18. Next….  Done – the effects of weather on aircraft  Next – Chapter 2 Test  Last - Human Flight Physiology