Aero Chapter 06 (ADV & IUT) and 07 (TS), Performance

T-45 Aerodynamics Student Workbook

The divert/bingo concept could apply to operations at any shore-based airport, especially the vulnerable

ones with a single runway. A crosswind out of limits, arrestment, or accident could dictate a divert. To

conserve fuel for an unknown eventuality, use the bingo chart and fly the recommended profile. What if

you should have to hold at your divert field while a plane is removed from the runway? Is there a second

divert field nearby? The chart shows the fuel, time, and speed to proceed at sea level.

To use the bingo chart, enter with the distance to divert field and appropriate drag index. In succeeding

columns, read fuel required, climb speeds, optimum range cruise, and maximum range descent.

The “FUEL REQD” and “DESCEND DISTANCE” columns have figures for NO HEADWIND and 100-KT

HEADWIND. Compute the headwind component in the WIND COMPONENT chart of NATOPS or the

PCL. Using the calculated headwind component, interpolate between the zero and 100-knot wind values

and between the entry mileage and the chart values, if necessary. Compute the descent point by

interpolation, realizing that the descent point will be closer to the bingo field if the headwind is stronger.

The bingo charts consider the 300 pounds required as a fuel reserve. Remember that reserve fuel is

yours to burn if circumstances warrant. It will be on your fuel gauge but only should be used in an

emergency. Anticipate that a runway might be closed suddenly and for a long period.

This chart calculates the approach speed that a given gross weight will produce when flying a steady

17 units angle of attack. You must calculate the gross weight by knowing the zero fuel weight of the

particular bureau number aircraft that you are flying. Add the weight of external stores and the fuel on the

gauge. Enter the table with this total weight and go up to the appropriate flap configuration line and left to

the airspeed that will result at 17 units AOA.

The weight-to-speed ratio is a constant. Each additional 200 pounds of fuel increases approach speed by

1 knot. Conversely, 200 pounds less fuel reduces the speed by 1 knot.

Each increment of flaps less than full flaps adds 19 kts to the approach speed. Calculations like these

will be used to verify that the angle of attack at 17 units is providing the correct airspeed. If uncertain, fly

the higher of the AOA or airspeed.

These charts provide landing ground roll distance for various flap configurations, gross weights, and

runway conditions––dry, wet or icy. Variables of temperature and pressure altitude are also taken into

consideration. The data is for a normal 17-unit AOA approach and landing using moderate braking

coefficients.

Using altitude commencing pullout, dive angle, and CAS or Mach, compute the altitude lost in a pullout

from a dive. Subtract the altitude lost during pullout from the altitude the pullout is initiated to find the

altitude remaining after pullout.

The T-45 operating envelope is a graphic representation of the airspeed and altitude limits. In addition,

portions of the envelope impose additional restrictions on throttle movement and position.

The symmetrical and unsymmetrical maneuvering limits are shown on this graph. The graph depicts the

T-45 load limits under various gross weight, altitude, and airspeed conditions. Unsymmetrical maneuvers

are rolling maneuvers at other than 1-g flight.

(7-99) Original

Page 61

Integrated Publishing, Inc. |