737-400 Specifications & Systems

737-400 Specifications & Systems

Dimensions and Weight Specifications

  • Length: 119' 7"

  • Height: 36' 3"

  • Wingspan: 94' 9"

  • Operating Empty Weight: 77,100 Lbs.

  • Maximum Zero Fuel Weight: 113,000 Lbs.

  • Maximum Landing Weight: 121,000 Lbs.

  • Maximum Takeoff Weight: 143,500 Lbs.

  • Maximum Taxi Weight: 144,000 Lbs.

Engine Specifications

  • Engines: GE-Snecma CFM56-3B2

  • Thrust: 22,000 Lbs. Sea Level Static Thrust

Seating Capacity

  • 1st Class: 8 passengers

  • Economy Class: 138 passengers

Regulatory and Operational Specifications

  • Certified in Transport Category: FAR Pt 25 & Pt 36

  • Approved Operations: VFR, IFR, Icing - Not Severe Icing

  • Flight Crew: 2 Pilots, 3 Attendants

  • Tailwind Component: 10 Knots

  • Approved Runway Slope: ± 2%

  • Maximum Operating Altitude: 37,000 ft. Pressure Altitude

  • Maximum Takeoff & Landing Altitude: 8,400 ft. Pressure Altitude

  • Maximum Flight Operating Latitudes: 73° N to 60° S

  • Maximum Differential Pressure: 8.65 PSI

  • Maximum Cabin Differential Pressure for Takeoff & Landing: 0.125 PSI

Auxiliary Power Unit (APU) Specifications

  • Maximum Operating Altitude for APU: 25,000 ft.

Fuel System Specifications

  • Maximum Fuel Capacity:

    • Main Tanks (Wings): 10,643 Lbs. each

    • Center Tank: 16,422 Lbs.

  • Lateral Fuel Imbalance: Must be scheduled to be Zero

  • Random Fuel Imbalance: Must NOT exceed 1,000 Lbs. for Taxi, Takeoff, Flight, Landing

  • Main Tanks 1 & 2: Must be full if Center Tank contains 1,000 Lbs. or more

  • Fuel Description:

    • 3 Tanks: 2 Main Tanks at 10,643 Lbs. Each, 1 Center Tank at 16,422 Lbs.

    • 8 Fuel Pumps: 2 Electric Pumps in each tank and 1 gear-driven pump on each engine

    • Crossfeed valve allows feeding both engines from either Wing Tank

    • Must use Center Tank first

    • Scavenger Pump in Center Tank pumps last 1,000 Lbs. of fuel into #1 Wing Tank

    • APU is fed from #1 Wing Tank

    • Fuel Temperature Gauge in #1 Wing Tank

    • Fueling & De-fueling valves on #2 Wing Tank

Landing Gear Specifications

  • Nose Wheel Control:

    • Rudder controlled over 60 Knots

    • Steering Wheel controlled under 60 Knots

  • Maximum for Taxiing: Anti-skid system prevents tire lock-up, skidding, and longer stopping distances.

  • Anti-skid System Description:

    • Wheel speed sensors detect rotation speed

    • Computer system modulates braking, temperature-sensitive

    • Thermal plug sensor requires brakes to be cool enough to operate

Fire Protection Systems

  • Fire bottle specifications:

    • 3 Main Fire Bottles: Freon charged

    • 2 for Main Engines (Located in Landing Gear Well) can feed either Engine

    • 1 By APU

  • Fire Detection: 4 pairs of detectors (2 loops, 4 detectors each) for each Engine, 1 in the Wheel well, 1 by APU

Hydraulic Systems Specifications

  • Overview: 3 systems at 3,000 PSI

    • A System: Gear driven pump with electric A/C motor backup

    • B System: Same as A system - Operates Auto-Slats, Flaps & Leading edge devices

  • Functionality:

    • A & B Systems operate: Rudder, Ailerons, Elevator, Landing Gear

  • Standby System Function: Operates Rudder, Thrust Reversers, Flaps, Auto-Slats, Leading Edge Devices

  • Power Transfer Unit (PTU): Powered by System A to pressurize System B and to operate Flaps, Auto-Slats, Leading Edge Devices.

Electrical Systems Specifications

  • Generators: 3 Generators

    • Each generator drives (transmission) on each Engine attached to shear shaft, 115 volts A/C @ 400 Hz constant

    • APU: Direct driven Generator running at one speed also 115 volts A/C @ 400 Hz

  • Generator Buses:

    • Bus #1: #1 Engine Generator

    • Bus #2: #2 Engine Generator

    • Cross-feed to transfer buses, 2 main 115 volt A/C Buses (Fuel Pumps)

  • Transformer/Rectifiers: 3 units convert 115 v A/C to 28 v D/C to 2 D/C Buses

  • Battery Systems:

    • Battery to Battery Charger and Hot Battery Bus to Battery Bus to Inverter (28 v D/C to 115 v A/C) for emergency use to operate some fuel pumps, hydraulics, etc.

Air Conditioning System Overview

  • Hot Air Source: Hot air from 5th and 9th stages of each Engine and/or the APU

  • Air Condensation Mechanism:

    • Hot Air goes to 2 A/C packs for conditioning

    • Left Pack feeds Cockpit and Mix Manifold, Right Pack feeds Mix Manifold Only (Main Cabin Forward and Aft)

    • Trim Air system regulates temperature by adjusting hot air into each cabin mix line

Cabin Pressure Management

  • Outflow Valves & Relief Valves: Regulate cabin pressure at 8.65 PSI

  • Pressure Relief Valve Function: Releases excess cabin pressure if main & forward outflow valves are inoperative (backup power supply)

  • Negative Pressure Relief Valve: Allows pressure input into aircraft below 8,000 ft.

Emergency Equipment Specifications

  • Emergency items Include:

    • Megaphone

    • First Aid Kit

    • Crash Axe

    • CO2 Extinguisher

    • Water Extinguisher

    • Dry Chemical Extinguisher

    • BCF Extinguisher

    • Smoke Hood

    • Life Vests

    • Flashlights

  • Fire Extinguisher Types:

    • Class A: Combustible Materials

    • Class B: Flammable Liquids

    • Class C: Live Electrical

Weight Restrictions & Performance Metrics

  • Takeoff Weight Criteria: Determined by runway length, temperature, altitude, tire speed limits, brake energy limits, obstacle clearance, en route clearance, and operating requirements.

  • Climb Rate Calculation: 3° = 48' per nautical mile

  • Landing Weight Determination: Based on maximum landing weight and climb rate charts.