Page 39 D633W101-BEJ Sep 05/2002
ADIRS -ADIRU AIR DATA FUNCTION -1
Calculate Corrected AOA
The calculate corrected AOA function calculates the left and right corrected AOA. The calculate corrected AOA function receives these additional signals:
*
Mach from the calculate mach and airspeed logic
*
True airspeed (TAS) from the calculate true airspeed logic.
The corrected AOA goes to the AOA redundancy management logic.
AOA Redundancy Management
The AOA redundancy management logic uses a modified mid-value selection. The modified mid-value selection chooses the mid-value of these three AOA values:
*
Left corrected AOA
*
Right corrected AOA
*
Calculated AOA.
The AOA redundancy management logic receives inputs from the inertial and air data systems to calculate the calculated AOA.
Static Pressure
Static pressure comes from the left, center, and right static air data modules (ADMs). The static source error correction (SSEC) function uses mach and corrected AOA plus flap position to compensate for errors in measurement of static pressure. The static pressure goes to the static ADM redundancy management logic.
The static ADM redundancy management logic uses mid-value selection to choose one of the static pressures from the SSEC logic. The static ADM redundancy management logic uses body accelerations from the ADIRU inertial reference section to adjust fault detection thresholds.
EFFECTIVITY BEJ ALL 34-20-00
Page 40
D633W101-BEJ Sep 05/2002
777 AIRCRAFT MAINTENANCE MANUAL
ADIRS -ADIRU AIR DATA FUNCTION -1
EFFECTIVITY BEJ ALL 34-20-00
Page 41
D633W101-BEJ Jan 05/2002
777 AIRCRAFT MAINTENANCE MANUAL
THIS PAGE IS INTENTIONALLY LEFT BLANK
34-20-00
Page 42 D633W101-BEJ Jan 05/2002
ADIRS -ADIRU AIR DATA FUNCTION -2
Total Air Temperature (TAT)
The TAT correction function receives TAT and calculated mach and computed air speed (CAS). Mach and CAS correct the TAT.
Static Air Temperature (SAT)
The calculate static air temperature function receives TAT, mach and CAS inputs. The SAT signal goes to the output memory buffer.
True Air Speed (TAS)
The calculate TAS function uses static air temperature CAS to calculate TAS. The corrected TAS is invalid when the CAS is less than 30 knots.
Corrected Angle of Attack (AOA)
The corrected AOA, from the AOA redundancy management logic is invalid when the CAS is less than 30 knots.
Mach and Computed Air Speed (CAS)
The calculate mach and CAS function uses impact pressure to calculate mach and CAS. The corrected mach and CAS are invalid when the CAS is less than 30 knots.
EFFECTIVITY BEJ ALL
Impact Pressure
The calculate impact pressure function receives static pressure inputs from the static ADM redundancy management logic. The calculate impact pressure function also receives pitot pressure from the pitot ADM redundancy management. The impact pressure signal goes to the output memory buffer.
Altitude and Altitude Rate.
The calculate altitude and altitude rate function gets signals from the static and pitot ADM redundancy management logic. Altitude and altitude rate goes to the output memory buffer.
Pitot Pressure and Static Pressure
Pitot and static pressure come directly from the pitot and static ADM redundancy management logic. These pressures go to the output memory buffer.
Single Channel Operation
If the ADIRU and SAARU air data parameters from the redundancy management logic are invalid, the flight deck displays show single channel air data from the ADIRU and SAARU. Single channel air data parameters bypass the redundancy management logic that the flight displays show during normal operation. Air data from the left pitot ADM and left static ADM goes to the ADIRU single channel operation
function. This function calculates these single channel
quantities:
34-20-00
Page 43 D633W101-BEJ Jan 05/2002
ADIRS -ADIRU AIR DATA FUNCTION -2
*
Mach
*
Airspeed
*
Static pressure
*
Barometric altitude
*
Total pressure.
EFFECTIVITY BEJ ALL 34-20-00
Page 44
D633W101-BEJ Sep 05/2002
777 AIRCRAFT MAINTENANCE MANUAL
ADIRS -ADIRU AIR DATA FUNCTION -2
EFFECTIVITY BEJ ALL 34-20-00
Page 45
D633W101-BEJ Jan 05/2002
ADIRS -ADIRU AIR DATA FUNCTION -3
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：777 AMM 飞机维护手册 导航 Navigation 1(10)
