Weight Definitions and Environmental Envelope

Question 1

What is MEW

Answer 1

Manufacturers Empty Weight

Question 2

What is OEW

Answer 2

Operational Empty Weight

Question 3

What is DOW

Answer 3

Dry Operating Weight AKA “ready for service weight”

Question 4

What is ZFW

Answer 4

Zero Fuel Weight

Question 5

What is LW

Answer 5

Landing Weight

Question 6

What is TOW

Answer 6

Takeoff Weight

Question 7

What is Ramp Weight?

Answer 7

TOW + Taxi Fuel

Question 8

What is MTOW?

Answer 8

Maximum Structural Takeoff Weight

- Landing impact no greater than 360 ft./min

Question 9

What is MLW?

Answer 9

Maximum Structural Landing Weight

- Landing impact no greater than 600 ft./min

Question 10

What is MZFW? how is it determined?

Answer 10

Maximum Structural Zero Fuel Weight

- determined by the maximum stress at the inboard section of the wing when no fuel is in the wing tanks)

Question 11

What is the environmental envelope?

Answer 11

• Pressure and Temperature range at which the aircraft is allowed to operate

Question 12

What is the main cause of engine limitations?

Answer 12

• The exhaust gas temperature (EGT)

Question 13

What are the thrust limitations?

Answer 13

• TOGA thrust for 5 mins, 10 if engine failure

- MCT for 10 mins max

Question 14

How does flat rated thrust change with altitude?

Answer 14

• As pressure altitude increases, flat rated thrust decreases
• flat rated thrust is constant up to Tref.