Aero Chapter 06 (ADV & IUT) and 07 (TS), Performance
T-45 Aerodynamics Student Workbook
TAKEOFF DISTANCE CHART
The takeoff distance chart contains a table that shows main wheel lift-off speed for various gross weights.
Lift-off occurs when the lift generated by air moving over the wings exceeds the weight of the aircraft.
To obtain the takeoff distance under three circumstances, one will first obtain a no-wind solution and, if
appropriate, a wind solution, and finally the distance required from the commencement of takeoff roll to
clear a 50-ft obstacle. One might find a 50-ft obstacle at the end of a short runway while showing a static
display at a small New England airport. Note the wind correction can be for head or tail wind. Most likely
you will find your solution in the middle of this chart and not use the 50-ft calculation.
LINE CHECK SPEED
Line check speed is the speed to which the aircraft should accelerate in a given distance during takeoff.
The pilot uses the known distance to an object such as the arresting gear or a runway distance remaining
marker to compute the speed. On takeoff, if the aircraft does not achieve the calculated speed by the
selected obstacle, the pilot should abort and have the aircraft checked.
Use the Velocity During Takeoff Ground Run chart to calculate the line check speed. Enter the chart with
the distance from the commencement of takeoff roll to the selected object.
VELOCITY DURING TAKEOFF GROUND RUN
This chart is used to determine the ground velocity during the takeoff at any distance down the runway.
The line check speed is determined for the distance from commencement of takeoff roll to the object. Dry
runway charts are the only charts included as T-45 acceleration is essentially the same under dry and wet
conditions.
MAXIMUM ABORT SPEED
This chart calculates the maximum speed to which an aircraft can accelerate on takeoff roll and
commence an abort that will permit the aircraft to stop on the remaining runway without using the overrun
or the arresting gear. Wet and dry charts are presented because the aircraft’s stopping distance is much
greater on a wet runway.
COMPRESSIBILITY CORRECTION TO CALIBRATED AIRSPEED
This chart indicates that subsonic air is compressible at higher speeds. One can gain airspeed over that
computed in the charts by using this table to increase CAS and TAS. At the extreme limits of the T-45’s
envelope, 550 KCAS and 40,000 ft, the compressibility correction would be 75 KCAS. Under most
circumstances, it will be less than half of that.
CLIMB SPEED SCHEDULE
This matrix is used to determine climb speed for various drag indexes and altitudes. This schedule is a
simplified normal climb speed schedule. It is independent of weight and is expressed in indicated
airspeed or Mach number.
TIME, FUEL, AND DISTANCE TO CLIMB
These three charts are used to determine the time, fuel, or distance to climb to a selected altitude. Climb
is at maximum-rated thrust at the climb speed schedule in NATOPS (see previous paragraph). These
charts account for kinetic energy corrections due to rate of climb.
BINGO
Bingo charts are in your NATOPS manual and pocket checklist. Learn to use the pocket checklist, as it
will be with you when your signal is “bingo.” Bingo is a fuel state that will permit you to fly to a divert field
and land with a fuel reserve, 300 pounds in the case of the T-45. Bingo is sometimes used to mean, “Go
to your divert field,” which could occur for many reasons, i.e., the carrier deck will not be ready within your
fuel remaining, the ship needs to move to another operating area, etc.
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