Mass and balance Flashcards
Basic empty mass
Includes airframe, engine , fixed equipment, unusable fuel, full oil and other items necessary for all flights.
Empty mass
Uses undrainable oil instead of full oil
ZFM (Zero fuel mass)
The gross mass of the plane including pilot, payload and ballast but excluding usable fuel
GM
Gross mass, the total mass at a particular time. It is the basic mass plus pilot, payload, passengers, ballast plus fuel.
MTOM
Maximum take off mass (structual)
tom
take of mass
MLM
maximum landing mass (structural)
LM
landing mass
Maximum ramp mass
Maximum gross mass permitted prior to taxiing. It may exceed the MTOM becuase fuel is burnt in the taxi
In short runways, high obstacles, high density altitude, high pressure altitude: (regarding MTOM)
The performance-limited take-off mass can be less than MTOM
Performance limited landing mass
Short runways, high density, wind or slope, may limit the landing mass to be less than MLM
A regulated mass
the lower of maximum structural mass and performance limited mass
RTOM
Regulated take off mass
An overweight plane will have:
- stalling speed
- takeoff speed
- climb performance
- landing speed
- braking
- manourverability
- takeoff run
- fuel consumption
- range
- landing distance
Higher stall speed, higher take off speed
Less climb perforamnce
Higher landing speed
Braking requires more force
Less manourverability
Higher take off run
Higher fuel consumption
Less range
Higher landing distance
1kg to lb
2.2lb
Avgas 100LL has a mass of
0.75kg
Oil has a mass of
0.90 - 0.96
PLTOM
Performance limited take off mass
PLM
Performoance limited landing mass
The turning moment of a force depends on two things:
The size of the force * moment arm
Datum
A reference point which everything is measured from (the arm length)
The position of the datum affects / not affects the balance?
Does not affect
Index units regarding mass and balance can be:
Pounds and inches, or kg and millimeters
Whats the moment of a 200kg force acting 300mm from the datum.
200 * 300 = 60,000 kg.mm
60,000 kg.mm to index units
60 index units
How much is 1 IU ? (index unit)
1000 kg.mm
Why is there more pitch stability (regarding the tailplane) with more forward CG
The arm is longer
How to calculate CG point?
Adding all masses together, adding all MOMENTS together. We can then calculate the arm which is the CG position from the datum
