1

Electronic Standby Instruments System

OASIS: Introduction

The OASIS is designed to serve as the secondary source of cockpit instrumentation and provides the following functions:

• Attitude• Indicated Airspeed• Barometric Corrected Altitude• Slip/Skid• Heading (Optional, requires a magnetometer)

2

OASIS: LRU’s/Modular Design

DU-1(Display Unit)

DU-2(Display Unit)

Optional

MSU(Magnetic Sensing

Unit) Optional

ASU(Aerosonic

Sensor Unit)

The OASIS modular designed allows installation flexibility by separating the display from the ASU

enhancing installation flexibility in congested cockpits

3

OASIS: Standard System and Options

Standard system includes:• ASU, 1ea.• DU, 1ea.

Enhanced system options:• Second DU• DU with NVS• ASU with internal standby battery• MSU for heading reference

4

5

OASIS: System Block Diagram

AHRS

Aerosonic Sensor Unit

ASU

Attitude, Heading, Airspeed, Altitude Data

AHRS

POWERGROUND

Display UnitDU-2

(Optional)

CO-PILOT

Display Unit DU-1

PILOT

Power

MagneticSensing Unit

(Optional)

Power

PowerAHRS Data

HeadingData

Air Data Air Data

6

OASIS: Display Features

Barometric Setting

Slip-Turn Indicator

Altimeter Tape

Magnified Altitude Window

Menu Select Keys

Heading Window

(optional)

Battery Status

Airspeed Tape

Magnified Airspeed Window

7

OASIS: Part 27/29 Airspeed Window

Red

Yellow

Green VNE Power OFF

VNE power ON

VCAUTION

Min Airspeed Max Airspeed Color

0 VCAUTION Green

VCAUTION VNE Power ON Yellow

VNE Power ON Max Airspeed Value

Red

VNE Power OFF Red Cross-Hatched Line

8

OASIS: Display Unit

Features:• 4 inch diagonal screen• 3 inch ATI opening• Chassis depth: 1.35 inches• Bezel: 4 inches x 3 inches• Weight: .75 lbs• NVS compatible (Option)

The DU is installed on the instrument panel adjacent to the primary display or instruments and provides a secondary graphical display of all of critical, primary functions necessary for the continued safe flight and landing of an aircraft during a loss of primary instruments. The DU provides user interface for data entry and settings through a bezel keypad. The DU is directly connected to, and obtains power and sensor data from the remote mounted ASU.

9

OASIS: Display Unit

10

OASIS: Aerosonic Sensor UnitThe ASU is a separate remote mounted LRU that provides power and sensor data to the DU. It’s connected to aircraft power and the pitot/static pneumatic lines. The ASU contains sensors required for the computation of Indicated Airspeed, Barometric Corrected Altitude, Attitude, Slip/Skid. Heading is available with the installation of an Aerosonic Remote Magnetometer. Power to the remote magnetometer is provided by the ASU. In addition the ASU has an optional internal battery that allows the OASIS to operate for a minimum of 1 hour without aircraft power.

Features:• Dimensions: 3 x 3 x 6.25 inches• Weight: 2 lbs• Power: 28 Vdc nominal, 14 watts max (2 displays, 1 ASU)• Internal standby battery (Option)

11

OASIS: Aerosonic Sensor Unit

12

OASIS: Specification/Certification

Operating Specification• Altitude: -1,500 to +55,000 ft.• Airspeed: 20 to 450 kts• Max roll/pitch rate: 200 deg/sec• Operating temperature

• DU: -20º to +55º C• ASU: -40º to +70º C

• Baro setting: 28.00 to 30.99 mb• Reliability: 10,000 hrs MTBF

Certification• Software: DO178B level B• Environmental: DO 160F (Helicopter and Fixed Wing)• FAA /EASA TSO

• TSO-C2d: Airspeed Instruments• TSO-C4c: Bank and Pitch Instruments• TSO-C6e: Direction Instrument, Magnetic• TSO-C10b: Altimeter, Pressure Actuated, Sensitive Type• TSO-C113: Airborne Multipurpose Electronic Displays• TSO-C3e: Turn and Slip Instruments• TSO-C46a Maximum Allowable Airspeed Indicators• TSO-C179 Rechargeable Lithium Cells and Lithium Batteries