Aviation Safety

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Aviation Safety
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Acknowledgement of sources
Aviation Safety
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Aviation Safety
can be looked at from two points of view
1 accident and incident statistics
2 flying techniques that reduce their causes
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Re 2 flying techniques that reduce their causes
For this presentation well concentrate on damage
to the nose gear due to improper landing
technique and maintenance
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We may see this on the ramp
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The aftermath of abuse A flat nose strut and a
puddle of hydraulic fluid
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Or this
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After landing the trim tab is still set for cruise
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Here is something that could fool any pilot
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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
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Not quite our airplane type, but you get the point
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This also means that a low strut should not be
casually given a shot of high-pressure
N2 Instead, it should be adjusted to the
manufacturers specification
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Lets take a look at the construction of the nose
gear
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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
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Fast derotation may also be caused by aggressive
braking Therefore when simulating a short-field
landing also simulate the hard braking
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A non-steerable, free-castering nose gear is
especially vulnerable to not holding the nose
off upon landing
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Pretty flimsy
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By comparison the nose gear on an airliner may
look indestructible
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But keep in mind the weight difference
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Perhaps it would be a good idea to just beef up
the nose gear a little on our type of airplanes
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That would make for easy towing too
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A quick look at Shimmy Here it is shown looking
down on the nose wheel
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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
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What else should we be paying attention to ?
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The effect of touchdown speed on the angle of
attack
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The big boys arent immume to this either, as
is shown in the next few slides
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That is not just a little paint blister
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Not quite as bad as the next one though
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Or the next one
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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
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The lesson for us is that we should relax the
backpressure on the yoke gently
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One more Slide
(that has nothing to do with this topic)
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Thats all folks !
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