NOTE: Braking or a combination of braking and NWS inputs may result in PIO. If PIO about the runway
centerline occurs, discontinue braking and use low gain NWS to accomplish a straight track down the
runway. Once a straight track is accomplished, resume normal braking. Slight pumping of the brakes
prior to normal brake application may preclude PIO.
NOTE: It has been determined through testing that the T-45 has an unstable critical speed for ground
handling above 57 knots. Although the aircraft is shown stable at touchdown speeds, the aircraft rapidly
loses directional stability as it slows. Below 40 knots stability increases.
CAUTION: Improper braking and NWS technique may result in exaggerated PIO. The sensitive
directional control characteristics of the T-45 during landing rollout will require the SNA to make
frequent, coordinated brake/NWS inputs to safely perform full stop landings. Not using these
techniques or excessive or exaggerated NWS inputs may result in the airplane departing the
runway at high speeds.
NIGHT LANDING AT A FIELD WITHOUT A FRESNEL LENS
Night landings at a field with no Fresnel lens are usually preceded by an instrument approach, so review
the circle-to-land procedures as outlined in the Instrument FTI, pp. 110-111. Many civilian fields provide
visual glideslope indicators in the form of the Visual Approach Slope Indicator (VASI) or the Precision
Approach Path Indicator (PAPI).
VASIVASI is a system of lights that provides visual descent guidance to the runway installed on either or
both sides of the approach end of the runway. At night, these lights can be seen from as far as 20 miles or
more. VASI provides safe obstruction clearance within plus or minus 10 degrees of the extended runway
centerline up to 4 miles from the runway threshold. VASI systems consist of two light units or bars, near
and far, with some having three bars, near, middle, and far. VASI operates on the principle of color
differentiation between red and white. Each light unit projects a beam of light having a white segment in
the upper part of the beam and a red segment in the lower part. A two-bar VASI provides a visual glide-
path normally set at 3 degrees. A three-bar VASI provides two glidepaths, the lower using the near and
middle bars set at 3 degrees, with the middle and far bars providing a glidepath normally 1/4 degree higher
used for high cockpit aircraft to provide sufficient threshold crossing height. The light units are arranged
so the pilot will see the combination of lights shown in Figure 23A.
PAPIPAPI uses light units arranged in a single row of two or four light units installed on the left side of
the approach end of the runway. Pilots may see this system from 20 miles at night. Glidepath indications
are shown in Figure 23A.
When transitioning from instruments to the runway environment, note the VSI required to stay on the VASI
or PAPI glidepath. Maintain on-speed and make corrections from above or below the indicated glidepath
in the same manner as flying with the Fresnel lens, noting that once on glidepath, it is much wider and VSI
must be kept in your scan all the way to touchdown.
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