In the second part of this module’s assignment we will revisit our takeoff condi

Question

In the second part of this module’s assignment we will revisit our takeoff conditions from module 1. This time, we will take a closer look into the speeds involved. Let’s assume the given 150 kts lift-off speed was the indicated value in the cockpit, i.e. the Indicated Airspeed [KIAS].

G. Find the Calibrated Lift-Off Speed [KCAS] using the chart below, which is a typical example of an aircraft position error correction chart. (Consider that the gear would obviously still be in the down position at lift-off).

H. Find the Equivalent Lift-Off Speed [KEAS] using your Calibrated Airspeed from G above and the Pressure Altitude for your selected airfield (from A). (Compressibility Correction Chart, see “Flight Theory and Aerodynamics”, Fig. 2.6).

Comment on your findings in H. Why was/wasn’t the Compressibility Effect in your case negligible?

I. Find the True Lift-Off Speed [KTAS] (use the Density Ratio found in D).

J. Calculate the Dynamic Pressure ‘q’ [lb/ft2], based on the TAS above. (Dynamic Pressure definition and formula can be reviewed in “Flight Theory and Aerodynamics” page 22; make sure to use a formula consistent with a Lift-Off Speed in kts).

Explanation / Answer

According to the given problem,

G) From the above figure,

154 KCAS

H) From the above figure ,

EAS 154-4= 150 KEAS

Comment: Due to the fact the aircraft is at low relative speed and low altitude. Compressibility effect comes into play at higher speeds (near mach) and altitudes. Negligible.

I) True Lift-Off Speed,

150(1.0565)= 154.18 KTAS

J) Dynamic Pressure,

154.18 2 /295= 80.58 lb/ft2

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects