Brunei DCA CPL(A) Mass & Balance Exam flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Basic empty mass

Mass of aircraft with crew, unusable fuel, full oil, and fixed equipment, excluding usable fuel and payload.

Dry operating mass

Basic empty mass plus operational items such as crew, catering, and potable water, excluding usable fuel and traffic load.

Zero fuel mass

Dry operating mass plus traffic load, with no usable fuel included; used to check MZFM limit.

Take-off mass

Zero fuel mass plus take-off fuel; must not exceed MTOM and must satisfy performance limits.

Moment calculation

Moment equals mass multiplied by balance arm; sum moments and masses to determine centre of gravity position.

MTOM definition

Maximum certified mass for commencing take-off run; structural and performance limited.

MLM definition

Maximum certified mass at touchdown; may be lower than MTOM and limited by brake energy and approach performance.

MZFM definition

Maximum mass without usable fuel; protects wing bending and fuselage structure; must not be exceeded even if MTOM is respected.

MRW definition

Maximum ramp mass equals MTOM plus taxi fuel allowance; also called maximum taxi mass.

Regulated take-off mass

Lowest of MTOM, performance-limited take-off mass, and field-length-limited mass; determines actual take-off mass limit.

Centre of gravity

Point where aircraft mass is considered concentrated; expressed as distance from datum or percentage of MAC.

%MAC formula

Percentage MAC equals (CG distance from datum minus LEMAC) divided by MAC, multiplied by 100.

Forward CG limit

Ensures sufficient elevator authority for rotation and flare; also increases stall speed and cruise drag.

Aft CG limit

Ensures static and dynamic stability; too far aft reduces stick force and may cause pitch-up at stall.

CG shift formula

CG shift equals (mass added multiplied by distance from original CG) divided by new total mass.

Datum definition

Arbitrary vertical reference plane from which all balance arms are measured; often near the nose.

Balance arm

Horizontal distance from datum to an item's centre of gravity; positive aft of datum, negative forward.

Index unit

Scaled moment value (moment divided by a constant) used to simplify load sheet calculations and CG determination.

Load sheet purpose

Document showing DOM, traffic load, fuel, TOM, LM, ZFM, and CG position; must be signed before flight.

Trim sheet

Chart or table used to determine CG position from total mass and total moment/index; must fall within envelope.

Last-minute change

Change to load after load sheet signed; must be recorded and signed, and may require new load sheet if threshold exceeded.

Standard passenger mass

84 kg adult male, 76 kg female, 35 kg child, 0 kg infant; use actual masses if known.

Fuel density

Jet fuel approximately 0.78–0.80 kg/L; AVGAS 0.72 kg/L; use actual density from refueller when available.

Fuel burn CG effect

Fuel burn changes CG as tank contents change; wing fuel burn generally moves CG aft initially.

Cargo floor limits

Maximum load per compartment and per unit area must not be exceeded; check both mass and volume limits.

Landing mass excess

If landing mass exceeds MLM, burn or jettison fuel equal to LM minus MLM before landing.

Mass effect on stall speed

Stall speed increases with square root of mass; higher mass also increases take-off and landing distances.

Forward CG performance effect

Increases elevator deflection and trim drag, reducing cruise speed and range; also increases stall speed.

Aft CG performance effect

Reduces trim drag and can increase range, but reduces static stability and may cause pitch-up at stall.

Load sheet retention

Load sheet must be retained for period specified by operator (often 3 months) and made available to authority on request.

PIC responsibility

Pilot-in-command must ensure mass and CG within limits before flight; load sheet and trim sheet are part of documentation.

Regulatory compliance

Brunei DCA ANR Part 121/135 or equivalent; operator's manual and MEL must be complied with for mass and balance.