# US 2014/0360206 A1 · Aircraft powerplant

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2014/0360206 A1
- Document ID: US20140360206A1
- Status: Published application
- Kind: A1
- Application number: 14/228,854
- Filed: 2014-03-28
- Published: 2014-12-11
- Earliest claimed: 2013-04-24
- Assignees: ROLLS-ROYCE plc
- Applicants: Rolls-Royce PLC
- Inventors: Stephen John BRADBROOK
- Web page: https://patentgrep.com/patent/US20140360206A1

## CPC

- B64D 35/04: characterised by the transmission driving a plurality of propellers or rotors
- B64D 27/14: within, or attached to, fuselages
- B64D 31/18: for hybrid-electric power plants
- B64D 33/00: Arrangement in aircraft of power plant parts or auxiliaries not otherwise provided for
- B64D 35/00: Transmitting power from power plants to propellers or rotors; Arrangements of transmissions
- B64D 35/023: of series-parallel type
- B64D 35/024: of series type
- B64U 50/30: Supply or distribution of electrical power
- F02C 7/20: Mounting or supporting of plant; Accommodating heat expansion or creep
- F02C 7/32: Arrangement, mounting, or driving, of auxiliaries
- B64D 27/026: {comprising different types of power plants, e.g. combination of a piston engine and a gas-turbine (Hybrid electric aircraft B64D27/33)}
- B64D 27/402: {comprising box like supporting frames, e.g. pylons or arrangements for embracing the power plant}
- B64D 31/16: for electric power plants
- Y10T 29/49229: Prime mover or fluid pump making
- B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- B64U: UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
- F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

An aircraft propulsion power plant for use in an aircraft includes one or more core engines housed in an airframe of the aircraft, one or more secondary propulsion units, each of the one or more secondary propulsion units being removably attached to the airframe, and one or more power transmission means, each of the one or more power transmission means being configured to transmit mechanical power from the or each core engine to a corresponding one of the or each secondary propulsion unit when the or each secondary propulsion unit is attached to the airframe.

## Claims

### Claim 1

An aircraft propulsion power plant for use in an aircraft comprising:
one or more core engines housed in an airframe of the aircraft;
one or more secondary propulsion units, each of the one or more secondary propulsion units being removably attached to the airframe; and
one or more power transmission means, each of the one or more power transmission means being configured to transmit mechanical power from the or each core engine to a corresponding one of the or each secondary propulsion unit when the or each secondary propulsion unit is attached to the airframe.

### Claim 2 (depends on 1)

The power plant as claimed in claim 1, wherein the or each core engine comprises a turbofan engine and the turbofan engine comprises a low pressure spool.

### Claim 3 (depends on 2)

The power plant as claimed in claim 2, wherein the or each power transmission means is configured to transmit mechanical power from the low pressure spool of the or each core engine to a corresponding one of the or each secondary propulsion unit.

### Claim 4 (depends on 1)

The power plant as claimed in claim 1, wherein the or each secondary propulsion unit comprises a propeller.

### Claim 5 (depends on 6)

The power plant as claimed in claim 6, wherein the propeller is a variable pitch propeller.

### Claim 6 (depends on 1)

The power plant as claimed in claim 1, wherein the or each secondary propulsion unit comprises a ducted fan.

### Claim 7 (depends on 6)

The power plant as claimed in claim 6, wherein the fan is a variable pitch fan.

### Claim 8 (depends on 1)

The power plant as claimed in claim 1, wherein the or each power transmission means comprises an electrical generator attached to the or each core engine, an electrical power transmission means and an electric motor mounted within each of the one or more secondary propulsion units, and
the or each electrical generator being adapted to generate an electrical current during operation of the or each core engine, and the or each electrical power transmission means being adapted to transmit the electrical current to the or each corresponding electric motor.

### Claim 9 (depends on 8)

The power plant as claimed in claim 8, wherein the or each electrical generator is driven from the low pressure spool of the turbofan engine.

### Claim 10 (depends on 1)

The power plant as claimed in claim 1, wherein the or each power transmission means comprises a driveshaft being in coupling engagement at a first end thereof with the or each core engine and at a second end thereof with the or each corresponding secondary propulsion unit.

### Claim 11 (depends on 10)

The power plant as claimed in claim 10, the or each driveshaft comprising:
a first portion accommodated within the airframe of the aircraft; and
a second portion accommodated within the or each corresponding secondary propulsion unit;
wherein each first portion is removably coupled to each respective second portion.

### Claim 12 (depends on 2)

The power plant as claimed in claim 2, wherein the turbofan engine comprises a variable area exhaust nozzle.

### Claim 13 (depends on 2)

The power plant as claimed in claim 2, wherein the turbofan engine comprises a removably attached exhaust nozzle.

### Claim 14 (depends on 1)

The power plant as claimed in claim 1, further comprising an engine control unit adapted to control the operation of the or each core engine by actively altering one or more engine control parameters in dependence on whether the or each secondary propulsion unit is attached to the airframe.

### Claim 15 (depends on 14)

The power plant as claimed in claim 14, wherein the engine control parameters comprise one or more parameters selected from the group comprising:
fuel flow rate;
compressor air bleed volume;
exhaust nozzle area
variable stator geometry; and
variable vane geometry.

### Claim 16 (depends on 1)

The power plant as claimed in claim 1, further comprising a convoluted air inlet duct being in fluid communication with an inlet face of the core engine such that there is no direct line of sight through the duct.

### Claim 17 (depends on 1)

The power plant as claimed in claim 1, wherein each of the one or more secondary propulsion units comprises a pylon connecting the respective secondary propulsion unit to the airframe, a respective one of the one or more power transmission means being located within the corresponding pylon.

### Claim 18 (depends on 1)

A method of configuring an aircraft comprising the steps of:
a. providing an airframe having a power plant as claimed in claim 1;
b. attaching to the airframe a first lifting surface if the or each secondary propulsion unit is attached to the airframe; and
c. alternatively, attaching to the airframe a second lifting surface if the or each secondary propulsion unit is not attached to the airframe.

### Claim 19 (depends on 18)

The method as claimed in claim 18, wherein the first lifting surface comprises a pair of high aspect ratio wings.

### Claim 20 (depends on 18)

The method as claimed in claim 18, wherein the first lifting surface comprises a pair of low aspect ratio wings.

### Claim 21 (depends on 18)

The method as claimed in claim 18, the aircraft comprising an engine control unit, wherein step b comprises the additional step of:
b1. providing the engine control unit with a first set of pre-determined control parameters;
and step c comprises the additional step of:
c1. providing the engine control unit with a second set of pre-determined control parameters.