2. Aviation Safety

3. Acknowledgement of sources: Aviation Safety January 2004 The Internet

4. Aviation Safety can be looked at from two points of view: can be looked at from two points of view: 1 accident and incident statistics2 flying techniques that reduce their causes

5. Re 2 flying techniques that reduce their causes For this presentation we’ll concentrate on damage to the nose gear due to improper landing technique and maintenance

6. We may see this on the ramp

7. The aftermath of abuse: A flat nose strut and a puddle of hydraulic fluid

8. Or this

9. After landing the trim tab is still set for cruise

10. Here is something that could fool any pilot

11. In flight the nose strut is fully extended, thus upon landing the nose wheel is much closer to the runway than the pilot may think

12. Not quite our airplane type, but you get point the point

13. This also means that a low strut should not be casually given a shot of high-pressure N 2 Instead, it should be adjusted to the manufacturer’s specification

14. Let’s take a look at the construction of the nose gear

17. What can cause damage is that due to a hard touchdown or fast derotation, the ‘O’ ring, that seals the strut, rolls up and becomes twisted; and a leak results A dirty or corroded strut will aggravate that

18. Fast derotation may also be caused by aggressive braking Therefore when simulating a short-field landing also simulate the hard braking

19. A non-steerable, free-castering nose gear is especially vulnerable to not holding the nose off upon landing

20. Pretty flimsy

21. By comparison the nose gear on an airliner may look indestructible

22. But keep in mind the weight difference

23. Perhaps it would be a good idea to just beef up the nose gear a little on our type of airplanes

25. That would make for easy towing too

26. A quick look at Shimmy Here it is shown looking down on the nose wheel

29. This phenomenon is more violent if there is more rotational energy, which equals: Note that it is proportional to the square of the touchdown speed

30. What else should we be paying attention to ?

31. The effect of touchdown speed on the angle of attack

32. The “big” boys aren’t immume to this either, as is shown in the next few slides

33. That is not just a little paint blister

34. Not quite as bad as the next one though

35. Or the next one

37. However, here the cause is not landing too flat, but excessive derotation after the mains have touched down The problem was serious enough that Boeing produced a crew training video

38. The lesson for us is that we should relax the backpressure on the yoke gently

39. One more Slide (that has nothing to do with this topic)

41. That’s all folks !