A&P Aircraft Weight & Balance 1 — Questions and Answers
Question 1: What is the datum in aircraft weight and balance?
- The aircraft's center of gravity location
- An imaginary vertical plane from which horizontal distances are measured (Correct answer)
- The point where all aircraft weight is concentrated
- The manufacturer's recommended CG location
Correct answer: An imaginary vertical plane from which horizontal distances are measured
The datum is an imaginary vertical reference plane chosen by the manufacturer from which all horizontal arm distances are measured to calculate moments.
Question 2: What term describes the product of a weight multiplied by its arm?
- Station
- Moment (Correct answer)
- Datum
- Balance point
Correct answer: Moment
Moment is the product of weight (in pounds) multiplied by the arm (distance from the datum in inches), expressed in pound-inches.
Question 3: Which document provides the approved CG range and weight limits for a specific certificated aircraft?
- AC 43.13
- Type Certificate Data Sheet (TCDS) (Correct answer)
- FAR Part 91
- Airworthiness Directive
Correct answer: Type Certificate Data Sheet (TCDS)
The Type Certificate Data Sheet (TCDS), issued by the FAA, specifies the datum location, approved CG range, and maximum weight limits for each certificated aircraft model.
Question 4: What is included in the standard empty weight of an aircraft?
- Airframe, engines, unusable fuel, and undrainable oil only
- Airframe, engines, all permanently installed equipment, unusable fuel, and undrainable oil (Correct answer)
- Airframe and engines only, with no fluids
- Airframe, engines, full usable fuel, and crew
Correct answer: Airframe, engines, all permanently installed equipment, unusable fuel, and undrainable oil
Standard empty weight includes the airframe, engines, all permanently installed equipment, unusable fuel, and undrainable oil, but excludes usable fuel and payload.
Question 5: How is useful load defined?
- The weight of passengers and baggage only
- The difference between maximum certificated gross weight and empty weight (Correct answer)
- The maximum allowable payload excluding fuel
- The weight of usable fuel and oil only
Correct answer: The difference between maximum certificated gross weight and empty weight
Useful load is the difference between the maximum certificated gross weight and the empty weight, and includes crew, passengers, cargo, and usable fuel.
Question 6: An aircraft has a total moment of 150,000 lb-in and a total weight of 3,000 lbs. What is the CG location?
- 45 inches from the datum
- 50 inches from the datum (Correct answer)
- 55 inches from the datum
- 60 inches from the datum
Correct answer: 50 inches from the datum
CG = Total Moment ÷ Total Weight = 150,000 ÷ 3,000 = 50 inches aft of the datum.
Question 7: What condition results when an aircraft's CG is located ahead of the forward CG limit?
- The aircraft becomes tail-heavy and pitches up
- The aircraft requires more down elevator to maintain level flight
- The aircraft may be difficult to rotate and requires excessive back pressure on the controls (Correct answer)
- The aircraft becomes more laterally unstable
Correct answer: The aircraft may be difficult to rotate and requires excessive back pressure on the controls
A CG forward of the forward limit creates a nose-heavy condition that makes rotation difficult and may require back-stick forces exceeding control authority.
A&P Aircraft Weight & Balance 1
What is the datum in aircraft weight and balance?