Questions and Answers of Elasticity Theory Applications

The thrust available from a jet engine at 35 000 ft altitude compared to that at sea level isa. less.b. more.c. the same.
Fuel flow for a jet at 100% rpm at altitude compared to that at sea level isa. less.b. more.c. the same.
A pilot is flying an airplane at the speed for best range under nowind conditions. A tailwind is encountered. To get best range now, the pilot musta. speed up by an amount less than the wind speed.b.
To obtain maximum range, a jet airplane must be flown ata. a speed less than that for (L/D)max.b. a speed equal to that for (L/D)max.c. a speed greater than that for (L/D)max.
Maximum rate of climb for a jet airplane occurs ata. a speed less than that for (L/D)max.b. a speed equal to that for (L/D)max.c. a speed greater than that for (L/D)max.
Maximum climb angle for a jet aircraft occurs ata. a speed less than that for (L/D)max.b. a speed equal to that for (L/D)max.c. a speed greater than that for (L/D)max.
If the weight of a jet airplane is increased, thena. parasite drag increases more than induced drag.b. induced drag decreases more than parasite drag.c. both parasite and induced drag increase by the
If the weight of a jet airplane is reduced as fuel is burned, the Tr curvea. moves down and to the right.b. moves up and to the right.c. moves down and to the left.d. moves up and to the left.
If a jet airplane is in the gear‐down configuration,a. the increase in parasite drag is more than that of the induced drag.b. the increase in induced drag is more than that of the parasite drag.c.
If it is impossible to raise the landing gear of a jet airplane, to obtain best range, the airspeed must be _____ from that for the clean configuration.a. increasedb. decreasedc. not changed
From Figure 6.33, the glide ratio (L/D)max for the airplane in the full flaps and gear‐down configuration isa. 12.05.b. 5.4.c. 5.0d. 4.2.
The minimum drag for a jet airplane does not vary with altitude.a. Trueb. False
Figure 6.34 shows an increase in specific range with altitude becausea. Tr decreases while fuel flow decreases.b. Tr remains the same while fuel flow decreases.c. Tr remains the same while Ta
A jet airplane is flying to obtain maximum specific range. As fuel is burned the pilot musta. reduce throttle but maintain the same airspeed.b. maintain throttle setting and let the plane
A lightly loaded airplane will be able to glide farther but at a lower airspeed than when it is heavily loaded.a. Trueb. False
Which of the following words should never be used in the discussion of jet aircraft?a. Power.b. Horsepower.c. Power curve.d. All of the above.
A single engine turbojet aircraft is flying at 296 kts. TAS at sea level. The mass flow rate through the engine is 10 slugs/s. The exit velocity from the engine is 800 fps. Finda. The thrust of the
A jet airplane has thrust available as shown in Figure 6.17 and specific fuel consumption as shown in Figure 6.14. Find the fuel flow at sea level (military rpm and M = 0.70).
Using Figure 6.16, find the fuel flow for the airplane in Problem 22 at the tropopause.
A jet airplane has the Ta−Tr curves shown in Figure 6.17. The airplane data are gross weight = 10 000 lb, standard sea level day, rpm at 100% unless noted, and clean configuration. Find:a. Vmax at
Using Figure 6.30, find the velocity for best range for the airplane at 12 000 and 8 000 lb.
Using Figure 6.30, calculate the specific range for the airplane at both weights if it is flying at the best‐range airspeed.
Using Figure 6.30, calculate the specific range of the airplane if the throttle is not retarded from the 12000 lb best‐range position, the airspeed is allowed to increase as fuel is burned, and
Using Figure 6.34, calculate the specific range for this airplane if it is flying at best‐range airspeed at sea level and at 20 000 ft altitude.
In the formula HP = TVk/325a. power required is in horsepower units.b. power required is in ft‐lb/sec.
Power isa. (Force × Velocity)/Time.b. Work/Time.c. (Force × Distance)/Time.d. Both (b) and (c).
Power required to overcome induced drag variesa. inversely with V2.b. inversely with V3.c. inversely with V.d. directly with V.
Power required to overcome parasite drag variesa. directly with V2.b. directly with V3.c. directly with V.d. inversely with V2.
Maximum rate of climb for a propeller airplane occursa. at (L/D)max.b. at Pr(min).c. at CL(max).d. at (Pa − Pr)max.
The lowest point on the Pr curve is (L/D)max.a. Trueb. False
Propeller aircraft are more efficient than jet aircraft becausea. they do not go so fast.b. they process more air and do not accelerate it as much.c. they use gasoline instead of jet fuel.d. V1 is
Turboprop aircraft are classified as power producers becausea. nearly all of the engine output goes to the propeller.b. the engine is a turbine engine.c. the fuel flow is proportional to the power
Propeller aircraft use VX to climba. when a climb is needed for maximum height to minimum horizontal distance.b. when a large excess of power is available.c. when flying at (L/D)max.d. when a climb
Propeller aircraft get the highest angle of climb at (L/D)max.a. Trueb. False
A lightly loaded propeller airplane will be able to glide ________when it is heavily loaded.a. farther thanb. less far thanc. the same distance as
To obtain maximum glide distance, a heavily loaded airplane must be flown at a higher airspeed than if it is lightly loaded.a. Trueb. False
In order to maximize range on a propeller‐driven airplane at high altitude, true airspeed should be ________.a. decreasedb. increasedc. not changed
In Figure 7.29, the specific range for a propeller airplane isa. less at altitude than at sea level.b. more at altitude than at sea level.c. the same at altitude as at sea level.
The pilot of a propeller airplane is flying at the speed for best range under no‐wind conditions. A head wind is encountered. To obtain best range, the pilot now musta. speed up by the amount of
As a propeller airplane burns up fuel, to fly for maximum range, the airspeed musta. remain the same.b. be allowed to speed up.c. be slowed down.
The turboprop aircraft has its lowest specific fuel consumption at about 25 000 ft altitude becausea. the turbine engine wants to fly at high altitudes.b. the propeller has higher efficiency at lower
The power‐required curves for an increase in altitude show that thea. Pr remains the same as altitude increases.b. Pr increases by the same amount as the velocity.c. Pr increases but the velocity
A propeller aircraft in the dirty condition shows that the Pr moves up and to the left over the clean configuration. This is becausea. the increase in the induced Pr is more at low speed.b. the
The increase in the Pr curves for a weight increase is greater at low speeds than at high speeds because the increase ina. induced Pr is greatest.b. parasite Pr is greatest.c. profile Pr is greatest.
Pa − Pr curves for a propeller airplane are shown in Figure 7.23.Finda. Vmax at full power.b. Climb angle at Vs.c. Climb angle at (L/D)max.d. Rate of climb at Vs.e. Rate of climb at 150 kts.f.
In Chapter 5, Problem 20, you calculated the drag for a 10 000‐lb turbojet airplane for sea‐level standard day conditions. The values that you found are repeated below. Calculate the values for
Using Figure 7.26, find the velocity for the best range for the airplane at 30 000 lb and 20 000 lb gross weight (GW).
Using Figure 7.26, calculate the specific range for the airplane at both weights if it is flying at the best range airspeed.
Using Figure 7.26, calculate the specific range for the 20 000‐lb airplane if the throttle is not retarded and the airspeed is allowed to increase as weight is reduced. Compare your answer to that
Using Figure 7.29, calculate the specific range for this airplane if it is flying at best range airspeed at mean sea level (MSL) and also at 20 000 ft altitude.
A 20 000‐lb propeller airplane at sea‐level standard day has the following data. Calculate its Pr and plot the curve on the graph paper. V Drag Pr 150 2074 182.7 1923 200 1954 300 2948 400 4809
The airplane in Problem 27 now has its GW increased to 30 000 lb.Calculate the new values and plot the curve on the graph paper.Data from in problem 27A 20 000‐lb propeller airplane at sea‐level
Calculate new values for the 20 000‐lb airplane in Problem 27, but now flying at 20 000 ft density altitude. Plot the values and draw the curve on the graph paper.Data from in problem 27A 20
V1 should always be at or above VR:a. Trueb. False
Takeoff distance is a function ofa. takeoff velocity.b. acceleration.c. Both (a) and (b).
Takeoff distance isa. directly proportional to the acceleration.b. inversely proportional to the velocity squared.c. inversely proportional to the acceleration.d. directly proportional to the
After completing a short‐field takeoff, the following IAS should be maintained to maintain obstacle clearance:a. VXb. VYc. VLEd. VR
The speed at which the aircraft first departs the runway:a. VRb. VLOc. VLEd. VLOF
A 10% increase in takeoff weight produces roughly a 10% increase in kinetic energy, while a 10% increase in speed results in a ____%increase in kinetic energy.a. 10b. 21c. 15d. 25
The maximum speed in the takeoff at which the pilot must take the first action (e.g. apply brakes, reduce thrust, deploy speed brakes)to stop the airplane within the accelerate‐stop distance:a.
As weight increases, the takeoff distance increases becausea. there is less thrust and thus less acceleration.b. there is more mass and thus less acceleration.c. the takeoff velocity is higher.d.
As weight (W2) increases, the takeoff distance increasesa. directly as the square of W2/W1.b. directly as W2/W1.c. inversely as the square of W2/W1.d. inversely as W2/W1.
For jet aircraft, takeoff distance at altitude is greater than at sea level becausea. the thrust available is less.b. the EAS for takeoff is greater.c. the TAS for takeoff is higher.d. Both (a) and
Which of the aircraft below will pay the greatest penalty in highaltitude takeoff distance?a. One with a turbocharged reciprocating engine.b. One with a turbine engine.c. One with an
Takeoff acceleration through the air mass is not reduced by a headwind.a. Trueb. False
Takeoff with a tailwind requires that the takeoff groundspeed be _____ by the amount of the tailwind.a. increasedb. decreasedc. not affected
If the net accelerating force (FN) on an aircraft traveling down a runway is 5000 lb, what is the rolling friction (F) given the following information: Thrust = 7000 lb, Drag = 1560 lba. 2000 lbb.
Using Figure 8.1, calculate the takeoff ground roll given the following information:Temperature = 10 °C Pressure altitude = 8000 ft Weight = 2400 lb Tailwind component = 5 kts.a. 2400 ftb. 900 ftc.
Calculate the airplane’s no‐wind takeoff distance from a brakes locked position given the following information:Liftoff speed = 110 kts.Sea level, standard day Takeoff constant acceleration = 10
The takeoff distance for a turbojet airplane, at sea level on a standard day, is 3500 ft when at a weight of 9000 lb. If the airplane weighs 1000 lb less during the subsequent takeoff, assuming all
The takeoff distance for a turbojet airplane, at sea level on a standard day, is 2800 ft when at a weight of 6000 lb. If the same airplane departs an airport with a density ratio of 0.8881, assuming
Calculate the airplane’s acceleration.Aircraft data :Thrust available during takeoff = 3000 lb Turbojet engines Average drag = 400 lb Average rolling friction = 100 lb Gross weight = 10 000 lb
What should the airspeed be at the 1000‐ft runway marker?Aircraft data :Thrust available during takeoff = 3000 lb Turbojet engines Average drag = 400 lb Average rolling friction = 100 lb Gross
Calculate the no‐wind takeoff distance.Aircraft data :Thrust available during takeoff = 3000 lb Turbojet engines Average drag = 400 lb Average rolling friction = 100 lb Gross weight = 10 000 lb
If the weight is increased to 15 000 lb, calculate the no‐wind takeoff distance.Aircraft data :Thrust available during takeoff = 3000 lb Turbojet engines Average drag = 400 lb Average rolling
Calculate the takeoff distance for the 10 000 lb airplane if there is a 12‐kts. headwind.Aircraft data :Thrust available during takeoff = 3000 lb Turbojet engines Average drag = 400 lb Average
Calculate the no‐wind takeoff distance for the 10 000 lb airplane operating from an airfield where the density ratio is 0.8.Aircraft data :Thrust available during takeoff = 3000 lb Turbojet engines
An airplane is in trimmed flight and its velocity is constant.a. It has no unbalanced forces acting on it.b. It has no unbalanced moments acting on it.c. It is in a state of equilibrium.d. All of the
An airplane is in a constant velocity engine out glide. Its altitude is decreasing. It is not in a state of equilibrium.a. Trueb. False
At (L/D)max an airplane willa. be at minimum glide angle.b. be achieving maximum glide distance.c. have a glide ratio equal to the numerical value of (L/D)max.d. All of the above.
The power‐off stalling speed or minimum steady flight speed at which the aircraft is controllable in the landing configuration:a. VS0b. VREFc. VS1d. VLOF
The speed at which the aircraft is controllable in a specified configuration, published by the manufacturer:a. VS0b. VREFc. VS1d. VS2
When landing in an airplane equipped with tricycle‐gear while experiencing a right crosswind, with proper crosswind control technique applied, the first wheel to make contact with the runway should
When conducting a short‐field approach, a stabilized approach is not recommended in order to clear the required obstacle and/or to stop in the shortened runway available.a. Trueb. False
Once on the ground, the recommended braking technique for a short‐field and a soft/rough‐field landing are the same.a. Trueb. False
A steep, low‐power approach is more dangerous for heavy airplanes than light airplanes becausea. recovery from a high rate of descent involves a great increase in power (or thrust).b. the aircraft
A low‐angle, high‐power (or thrust) approacha. may be used for propeller aircraft if a short‐field landing is required.b. is dangerous for propeller aircraft if an engine fails.c. should be
Aerodynamic drag is more effective than wheel braking during the first part of a landing.a. Trueb. False
As a general rule, when the nose of a tricycle landing gear airplane can no longer be held off the runway, it is time to start applying wheel brakes.a. Trueb. False
In applying wheel brakes, it is not a good idea to apply full brake pressure because:a. you might cause a blow‐out.b. you get lower coefficients of friction when wheel slippage exceeds about 15%.c.
In general, if maximum wheel braking of a tricycle landing gear airplane is desired, the pilot should keep the stick full aft even after the nose is on the runway.a. Trueb. False
Headwinds and tailwinds affect the landing distance by the same amount as they affect the takeoff distance.a. Trueb. False
Using Figure 9.1, calculate the landing ground roll given the following information:Temperature = 10 °C Pressure altitude = 8000 ft Weight = 2400 lb Tailwind component = 5 kts.a. 1500 ftb. 1375 ftc.
Using Figure 9.1, calculate the landing distance over a 50 ft obstacle given the following information:Temperature = 20 °F Pressure altitude = 4000 ft Weight = 2600 lb Headwind component = 5 kts.a.
If your tire pressure is 140 psi, calculate the approximate speed in knots where total dynamic hydroplaning may occur.a. 106 kts.b. 110 kts.c. 12 kts.d. 68 kts.
Calculate the deceleration of an aircraft during landing rollout given the following conditions:Ta (average) = 575 lb Average drag = 1300 lb Average braking/rolling friction = 4200 lb Aircraft weight
Calculate your landing distance if your initial approach speed at touchdown is 140 kts. and your average acceleration during landing rollout is −19.6 fps.a. 1428 ftb. 500 ftc. 549 ftd. 1639 ft
Calculate the deceleration.Aircraft data:Landing speed = 100 kts.Gross weight = 8000 lb Average retarding force = 2000 lb (brakes + thrust reversers if applicable)Sea level standard conditions.
Calculate the no‐wind stopping distance.Aircraft data:Landing speed = 100 kts.Gross weight = 8000 lb Average retarding force = 2000 lb (brakes + thrust reversers if applicable)Sea level standard
If the weight is increased to 13 000 lb, calculate the no‐wind stopping distance. Assume the same landing speed (100 kts.).Aircraft data:Landing speed = 100 kts.Gross weight = 8000 lb Average

Showing 100 - 200 of 709