Max Structual Weights Flashcards
Define ZFW
Dry operating weight+ PAX/cargo/baggage
Where DOW is operational empty weight + operator items
Define LW
Weight at landing with reserves.
LW= ZFW + reserves
Define TOW
Weight at T/O at departure AD.
TOW= LW + trip fuel or TOW= ZFW + trip fuel + reserves
Define ramp weight
Ramp weight= T/O fuel + taxi + ZFW
Where T/O fuel is fuel at BR
What impact speeds are max TOW/LW determined at?
MTOW -360 ft/min
MLW -600ft/min
Just remember this…
Actual LW = TOW- trip fuel < MLW
Actual TOW < MLW + trip fuel
Why do we have MZFW?
Bending moments apply between the fuselage and wings in flight. As fuel weighs the wings down, this bending moment is not as great with full wing tanks, however is greatest when no fuel in tanks. Therefore the ZFW needs to be limited to prevent over stress from the bending.
Define MTW
Max taxi weight, is required due to potential stress on shock absorbers and bending of landing gear in turns.
What is the minimum structural weight?
Lowest weight set by applicant at which structural loading conditions are met, usually set by considering gusts and turbulence.
What is an environmental envelope?
Range of ambient temperature and pressure altitude limits for which a/c performance is established and meets certification requirements.
How long is TOGA thrust certified to operate for? What about MCT & CL?
What limitation causes these?
TOGA is max thrust, certified for max time of 5 min (all engines) or 10 min (n-1).
Max continuous thrust has unlimited use and must be set in case of engine failure when TOGA not available after 10 min.
Climb thrust has unlimited use to reach cruise.
Is limited by EGT
How does temperature and pressure altitude affect the amount of thrust produced?
At a given pressure altitude, below the flat rating temp (Tref), temperature has no effect on engine thrust. Above Tref, engine thrust is limited by EGT so max thrust produced decreases.
At a set temperature, an increase in pressure altitude will decrease T/O thrust.
