Method and apparatus for auxiliary power unit installation
An aircraft is disclosed, including a fuselage having a compartment configured to house refueling apparatus. An auxiliary power unit is mounted in the compartment.
1 . A method of installing an Auxiliary Power Unit (APU) in an aircraft, wherein the aircraft includes a refueling hose reel housed in a Hose Drum Unit (HDU), the method comprising:
retrofitting a HDU compartment in a fuselage to house the APU, wherein the retrofitting step comprises:
removing the refueling hose reel from the HDU compartment; and
mounting the APU in the HDU compartment.
2 . The method of claim 1 , wherein the mounting step includes extending an exhaust duct of the APU through a hose trough of the HDU compartment.
3 . The method of claim 1 , wherein the mounting step includes altering an exterior access door of the HDU compartment to include an air inlet.
4 . The method of claim 1 , wherein the mounting step includes connecting a fuel supply of the aircraft to an engine of the APU through a fuel pipe of the HDU compartment.
5 . The method of claim 1 , wherein the mounting step includes electrically connecting the APU to an electrical system of the aircraft through an existing electrical connection point of the HDU compartment.
6 . The method of claim 1 , wherein the mounting step includes suspending the APU from an upper wall of the HDU compartment with one or more APU mounts.
7 . The method of claim 1 , wherein the mounting step includes pneumatically or hydraulically connecting the APU to a pneumatic or hydraulic system of the aircraft through an existing access point of the HDU compartment.
8 . A method of retrofitting an aircraft, comprising:
removing a refueling apparatus from an un-pressurized internal compartment disposed in a pressurized fuselage of the aircraft, wherein the refueling apparatus comprises a refueling hose reel, and
mounting an Auxiliary Power Unit (APU) in the un-pressurized internal compartment.
9 . The method of claim 8 , wherein the un-pressurized internal compartment is a refueling Hose Drum Unit (HDU) compartment.
10 . The method of claim 8 , wherein the aircraft includes a tail-mounted APU prior to the mounting step.
11 . The method of claim 8 , wherein the mounting step is performed without structural alterations to the compartment or the fuselage.
12 . The method of claim 8 , wherein the mounting step includes extending an exhaust duct of the APU through a hose trough of the un-pressurized internal compartment.
13 . The method of claim 8 , wherein the internal compartment is defined between a plurality of reinforced wall sections and a skin of the fuselage.
14 . The method of claim 13 , wherein the mounting step includes suspending the APU from an upper one of the plurality of reinforced wall sections.
15 . The method of claim 8 , wherein the fuselage has a tail cone and the un-pressurized internal compartment is disposed forward of the tail cone.
16 . The method of claim 8 , wherein the mounting step includes altering an exterior access door of the HDU compartment to include an air inlet.
17 . The method of claim 8 , wherein the mounting step includes pneumatically or hydraulically connecting the APU to a pneumatic or hydraulic system of the aircraft.
18 . The method of claim 17 , The method of claim 8 , wherein the mounting step includes pneumatically or hydraulically connecting the APU to a pneumatic or hydraulic system of the aircraft through an existing access point of the HDU compartment.
19 . A method of retrofitting a tanker aircraft, comprising:
removing a refueling Hose Drum Unit (HDU) from a HDU compartment in a fuselage of the tanker aircraft;
mounting an Auxiliary Power Unit (APU) in the HDU compartment, the mounting step including:
suspending the APU from an upper wall section of the HDU compartment,
extending an exhaust duct of the APU through a hose trough of the HDU compartment, and
altering an exterior access door of the HDU compartment to include an air inlet.
20 . The method of claim 19 , wherein the mounting step further includes connecting a fuel supply of the aircraft to an engine of the APU through a fuel pipe of the HDU compartment, and connecting the APU to an electrical system of the aircraft through an existing electrical connection point of the HDU compartment.