rates generated by full or nearly full forward control column
application before nosegear touchdown. Flight crews need to
be aware of the potential for significant structural damage
from hard nosegear contact and know which actions to take
to prevent such incidents.
Hard nosegear landings
can produce heavy loads on the nosegear and its support structure.
The resulting high stresses in the forward fuselage upper crown
and between the flight deck and wing front spar can cause the fuselage
structure to buckle. Appropriate actions by the flight crew can
help prevent such incidents. Understanding which actions are appropriate
requires a discussion of the following:
of hard nosegear landings.
control during landing and derotation.
INCIDENTS OF HARD NOSEGEAR LANDINGS
Recent incidents of hard
nosegear touchdown share two characteristics. First, a relatively
normal main gear touchdown is followed by full or nearly full forward
control column application, which results in overderotation and
hard nosegear contact. Second, the resulting airplane damage is
significant and requires lengthy and expensive repairs. (The location
and type of damage depend on the particular model of airplane.)
incidents of structural damage incurred from hard nosegear contact
with the runway are described below.
An airplane was on approach
to a relatively short runway in gusty conditions. The airplane experienced
a normal main gear touchdown, but the full forward column movement
applied by the flight crew caused very hard nosegear contact with
the runway. Resulting damage included displaced nosegear, bent axles,
and a buckled and cracked fuselage structure (fig.
1). In addition, the cockpit door, forward lavatory doors, and
forward passenger doors were jammed closed.
An airplane returned
to the departure airport following an in-flight engine shutdown.
The airplane landed firmly on the main gear. Recordings by the digital
flight data recorder ended abruptly because of damage from the nosegear
contact; however, the last data point showed that considerable forward
control column movement had been applied. The nosegear was rotated
aft and to the left of its normal position, resulting in damage
to the lower fuselage and nosegear wheel well area (fig.
An airplane landing in
strong crosswinds and turbulent conditions touched down on the main
gear firmly, but not abnormally for the conditions. The airplane
bounced, full forward column movement was applied, and the nosegear
contacted the runway very hard, causing the nosegear to fail and
rotate upward in the aft direction. The nosegear wheel assembly
penetrated the electronics bay and caused considerable damage (fig.