The Effects of Weather on Aircraft Part 2 of 2

1. The Effects of Weather on AircraftPart 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

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 ClawRuns 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 TurbulenceAffects 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