The accessory compartments are aircraft structures in the forward fuselage that contain electrical and avionics components and equipment. These include the electrical, electronic equipment and main battery structure.

The avionics compartment is in the nose fuselage, below the flight compartment floor. Access is through the floor. The avionics compartment contains mounting racks and mounting trays that contain avionics units and components. The avionics compartment is between FS280.00 and FS557.00 below WL79.50 for Global Express/XRS and is between FS280.00+32.00 and FS557.00 below WL79.50 for Global 5000.

The avionics compartment has the components that follow:

• Cabin Pressure Controllers
• Air Conditioning System Controllers
• Secondary-Power Distribution Assemblies
• Slat/Flap Control Unit (SFCU)
• Flight Control Units
• Heater/Brake-Temperature Monitoring Units (HBMU)
• Brake Control Unit
• Steering Control Unit
• Auto Shut-off Unit
• Fuselage-Strobe Anticollision Light Power Supplies
• Inertial Reference Units (IRU)
• Global-Navigation Satellite Sensor Units (GNSSU) (Post SB 700-34-005 on Global Express/XRS)
• Bleed Management Controllers
• Engine Vibration-Monitoring Unit (EVMU)
• Cabin Telecommunication Unit (CTU)

Additionally on Global Express/XRS, the avionics compartment has the components that follow:

• VHF Communications Units
• Satellite Data Link Unit (Post SB 700-23-001)
• Radio Frequency Unit (Post SB 700-23-001)
• Air Radio-Telecommunication Unit (ARTU) (Post SB 700-23-003)
• Duplexer (Post SB 700-23-003)
• SELCAL Decoder
• Airborne Data-Link Unit (Post SB 700-23-005)
• Junction Box JB3
• Junction Box JB4
• Junction Box JB5
• Junction Box JB6
• Fuel Computer
• Integrated Avionics Computers (IAC)
• IAC Configuration Modules
• Data Acquisition Units (DAU)
• Landing-Gear Electronic Control-Unit (LG ECU)
• Failure Indicator Box
• Ground-Proximity Warning System (GPWS) Computer
• Traffic/Collision Avoidance System (TCAS) Receiver/Transmitter
• VHF Navigation Units

Global 5000


Global 5000


Global Express/XRS


Global Express/XRS

The avionics rack located on the right hand side aft of the cockpit bulkhead contains trays for the installation of avionic units and components.

The avionic rack has been divided into two vertical sections. The fwd section contains LH components from under floor, and the aft section contains RH components from under floor. The LRUs installed in the avionic rack have been installed as per their previous side location under floor to maintain left and right side segregation.

The layout of the LRUs within the avionics rack is such that redundant system units are not placed in close proximity to each other. Adequate space between units is provided to allow for maintenance accessibility, modifications and troubleshooting. The complete rack structure is attached to the top support intercostals, utilizing slotted holes to avoid fuselage pressurization loads. This top support is used to react fore/aft loads.

Attachment at approximately stringer no. 13 is designed to carry inboard/outboard loads and the bottom base is bolted to the machined floor panel and to the underlying reinforced floor support structure.

The rack is not attached to the FS280 cockpit bulkhead directly and does not affect the existing jump seat support structure.

The avionics rack has the components that follow:

• Data Acquisition Units (DAU)
• Junction Box JB3
• Junction Box JB4
• Junction Box JB5
• Junction Box JB6
• Head-up-Display (HUD) Computer
• VHF Communication Unit 1
• VHF Communication Unit 2
• VHF Navigation Unit 1
• VHF Navigation Unit 2
• Landing Gear Electronic Control Unit (LGECU)
• Fuel Computer
• Datalink
• SELCAL
• Integrated Avionics Computers (IAC) 1, 2, 3
• Traffic Collision Avoidance System (TCAS)
• VHF Strap Boards
• Enhanced Ground Proximity Warning System (EGPWS)
• IAC Configuration Modules
• Iridium Transceiver
• Iridium Filter
• Satellite data unit

This compartment is in the forward part of the nose fuselage in front of the instruments. Access is through a door on the nose of the aircraft. The forward equipment compartment contains racks and trays for the installation of electrical units and components and a mounting rack that contains the avionics battery. The equipment compartment is between FS169.00 and FS202.75 above WL79.50 for Global Express/XRS and is between FS169.00+32.00 and FS202.75+32.00 above WL79.50 for Global 5000.

The forward equipment compartment has the components that follow:

• Avionics Battery
• Avionics Battery Charger
• Four Transformer Rectifier Units (TRU)