Fuselage Design and Layout Questions and Answers

Answer: C

Correct answer: 3.26 m

Add the seats and the aisle:

\[ 6 \times 0.46 + 0.50 = 2.76 + 0.50 = 3.26\ \mathrm{m} \]

This is the clear internal width required; the structure, insulation and trim add perhaps 0.2 m to the external diameter. The calculation is why narrow-body fuselages cluster around 3.7 m externally - six abreast with a single aisle is what that diameter buys, and the next step up needs two aisles.

Answer: D

Correct answer: 3.06 m plus clearance

Two containers side by side need twice the width of one:

\[ 2 \times 1.53 = 3.06\ \mathrm{m} \]

with clearance for handling and the restraint system on top of that. The figure is a hard requirement rather than a preference: a hold a few centimetres narrower carries one container abreast instead of two and loses half its capacity, which is why container dimensions drive the cross-section of a freighter.

Answer: A

Multiplying, \( 180 \times 100 = 18\,000 \) kg. The hundred kilogramme figure is the standard planning allowance covering the passenger, their cabin baggage and a share of hold baggage, and it is what payload-range figures are quoted against.

Answer: B

Correct answer: 31 rows

Divide the cabin length by the new pitch and take the whole number:

\[ \frac{24.3}{0.76} = 31.97 \rightarrow 31\ \text{rows} \]

At 0.81 m the same cabin gave 30 rows, so the reduction buys one row - six seats at six abreast. The gain is modest because the arithmetic is a ratio: a 6 per cent pitch reduction buys about 3 per cent more rows once the result is rounded down.

Answer: C

The first is correct and is why transports are essentially round. The second is the reverse: an ellipse must carry part of the pressure in bending, which uses the material far less efficiently and makes the shell heavier rather than lighter.

Answer: D

Correct answer: Statement I is correct but Statement II is incorrect

The first statement is true: upsweep raises the rear fuselage so the aircraft can rotate further before the tail strikes, without the weight and complexity of a longer undercarriage.

The second is false. Upsweep is bought at a drag cost, since the asymmetric closure of the afterbody generates a pair of vortices and can provoke separation. It is used as much as the rotation requirement demands and no more, which is why freighters with rear ramps pay a measurable drag penalty for theirs.

Answer: A

Both are correct and they reinforce one another. Repeatable frames, panels and tooling make the barrel cheap to build, and the same parallel section is what makes a family stretch possible without redesigning the shell.

Answer: B

Correct answer: Statement I is correct but Statement II is incorrect

The first statement is true: a low wing puts the carry-through box below the cabin floor, so the passenger cabin is unobstructed.

The second reverses the comparison. A high wing gives the lower cargo floor, because the fuselage can sit close to the ground with the gear short or fuselage-mounted - which is exactly why tactical freighters are high-winged and load vehicles up a rear ramp. The low wing wins on the cabin and loses on floor height.

Answer: C

The first is standard practice. The second is inverted: holding the cabin lower means a greater difference from the outside pressure, which is why composite fuselages, tolerating a higher differential, can offer a more comfortable cabin altitude.

Answer: D

Both are correct and the second follows from the first. Certification bands the exit provision by seat count, so a stretch that crosses a threshold incurs a door, its structure and its surround, which is a substantial cost.