QUIZ 4 WORKSHEET
NAME_____________________________
SECTION_______
WRITE ALL ANSWERS ON THE FRONT OF THE WORKSHEET PAGES IN THE SPACES PROVIDED
1. What causes DI? What causes DP? Be precise in your answer: explain when DP and DI are high and low in
SS SL flight as airspeed variews. Refer to the formula for dynamic air pressure when discussing DP.
2. List the six constraints on, or properties of, the TR/DT curve.
3. What is the significance of the low point on an airplane’s TR/DT curve? What does this point tell us about
power-off gliding in the airplane?
4. Given the TR curve for an airplane at a given gross weight, density altitude, and configuration, one can
construct the corresponding PR curve for the same airplane at the same weight, altitude, and configuration by
transforming points on the TR curve to corresponding points on the PR curve. Suppose (200 KTAS, 1400 #) is
a point on an airplane’s TR curve. Calculate the corresponding point on its PR curve.
5. Given the PR curve for an airplane at a given gross weight, density altitude, and configuration, one can
construct the corresponding TR curve for the same airplane at the same weight, altitude, and configuration by
transforming points on the PR curve to corresponding points on the TR curve. Suppose (150 KTAS, 600 HP)
is a point on an airplane’s PR curve. Calculate the corresponding point on its TR curve.
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6. When interpreting a jet airplane’s TR and PR curves, we assume FF  TR. For a jet (thrust producer),
explain the significance of the airspeed corresponding to the low point on its TR.
7. For a jet, explain the significance of airspeed corresponding to the point where a line drawn from the
origin tangent to its TR curve intersects the curve.
8. For a jet, explain the significance of the airspeed corresponding tothe point where a line drawn from the
origin tangent to its PR curve intersects the curve.
9. When interpreting a normally aspirated reciprocating engine-powered prop-driven airplane’s TR and PR
curves, we assume FF  PR. For a prop (power producer), explain the significance of the airspeed
corresponding to the low point on its PR curve.
10. For a prop, explain the significance of the airspeed corresponding to thepoint where a line drawn from the
origin tangent to it PR curve intersects the curve.
11. For a prop, explain the significance of the airspeed corresponding to the low point on its TR curve.
12. True/False
The tangent point on an airplane’s TR curve corresponds to the low point on its PR curve.
13. True/False
The tangent point on an airplane’s PR curve corresponds to the low point on its TR curve.
14. True/False From a jet’s TR curve, one can find both VBE and VBR.
15. True/False From a prop’s TR curve, one can find both VBE and VBR.
16. True/False For a jet airplane, there is more information about range and endurance airspeeds available
from its PR curve than from its TR curve.
17. True/False When weight increases from W1 to W2, a TR curve moves up by a factor of (W2/W1) and to
the right by a factor of W2/W1. Because the curve moves up more than it moves right, the slope of the tangent
line to the curve drawn from the origin steepens, indicating that range for a thrust producer (jet) has
decreased even though VBR has gone up.
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18. True/False When weight increases from W1 to W2, a PR curve moves up by a factor of (W2/W1)1.5 and to
the right by a factor of (W2/W1). Because the curve moves up more than it moves right, the slope of the
tangent line to the curve drawn from the origin steepens, indicating that range for a power producer (prop)
has decreased even though VBR has gone up.
19. Suppose a corporate jet cruises at SL at 250 KEAS/KTAS using 2,500# of thrust. Now consider the same
jet at the same gross weight cruising at FL400 at 250 KEAS using the same 2,500# of TR.
a) Explain why TR doesn’t change at the higher altitude. Write the drag equation and refer to itwhen you
answer.
b) Does no-wind range go up at FL400? Explain your answer in some detail. Remember that range depends
on TAS, not EAS.
20. True/False When density altitude increases from 1 to 2 ( decreases, because air density is inversely
proportional to density altitude) , a TR curve moves right by a factor of (1/2) without moving up. As a
result, the slope of the tangent line to the curve drawn from the origin becomes shallower, indicating that
range for a thrust producer has increased. Moreover, the increased range is due solely to an increase in TAS
for the same EAS and TR.
21. True/False When density altitude increases from 1 to 2, a PR curve moves up by a factor of (1/2)1.5
and to the right by a factor of (1/2)1.5. As a result, the slope of the tangent line to the curve drawn from the
origin remains unchanged. This fact implies that range for a power producer is maximum at SL, since it takes
fuel to climb and after the climb, PR and fuel flow at VBR have not changed.
22. A line from the origin drawn tangent to a TR curve has slope (TR/V)MIN. Explain why the point where this
line touches the curve corresponds to VBR for a jet. To answer this question, you must provide a definition of
best range in terms of TR and V (TAS) and also explain the relationship between TR and FF for a jet.
23. The slope of a line from the origin drawn tangent to a P R curve is (PR/V)MIN. Explain why the point where
this line touches the curve corresponds to VBR for a prop. To answer this question, you must provide a
definition of best range in terms of PR and V (TAS) and also explain the relationship between P R and FF for a
prop.
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24. Explain why this figure should be in your study sheet for Exam 2.
Gross Weight Change
W1 to W2
TR
V2 = V1 (W2 / W1)
Curve (TR)2 = (TR)1 (W2 / W1)
PR
V2 = V1 (W2 / W1)
Curve (PR)2 = (PR)1 (W2 / W1)1.5
Density Altitude Change
1 to 2
V2 = V1 (1 / 2)
(TR)2 = (TR)1
V2 = V1 (1 / 2)
(PR)2 = (PR)1 (1 / 2)
Change W1 to W2 & 1 to 2
V2 = V1 (W2 / W1) (1 / 2)
(TR)2 = (TR)1 (W2 / W1)
V2 = V1 (W2 / W1) (1 / 2)
(PR)2 = (PR)1 (W2 / W1)1.5 (1 / 2)
25. Prop 15,000# gross; VBR = 150 KTAS @ SL; PR = 350 HP. At 18,000# gross, find V BR, PR, and TR. Also
find TR for 15,000# gross and 18,000# gross.
26. Jet transport requires 25,000# thrust at VBR = 250 KTAS at SL in SA. At FL300, find VBR (KTAS &
KEAS) and TR. Explain why the airplane gets better range at FL300 than at SL.
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27. Light A/C. Thrust = 700#; weight = 2200#; VBR = 75 KTAS SL. At 10,000 feet and 2100#, find VBR in
KTAS and KEAS. Also find PR for the original and the final situation.
28. Suppose weight increases by 20%. How much is the corresponding percentage change in Vs? Show work.
29. Suppose density altitude changes such that air density increases by 25%. What is the corresponding
percentage change in VBR TAS change? Is the change an increase or a decrease? Show calculations.
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