I have another question sir, I understand that the ADIRU system which replaced the IRS system consists of lasers as opposed to gyroscopes, so what does this do for the alignment time?   Is it instantaneous or does it still require alignment of about 10 mins?

 

Kind regards.

ADIRU is just a bit broader name for IRS and associated stuff. Still the same principle - IRSes used laser gyros since 75/67s and 737s classics. Also still require alignment, but alignment might work a bit different in 777 compared with 737; also I am willing to bet that time-to-align is customizable, as it was in NGX.

Yes. Although I don't know how high it goes. Maybe 1000?

 

Valid entries in the Honeywell FMS are 0 to 9999.

 

We on average use a cruise CI of 180. Always changing though due to delays etc.

I have another question sir, I understand that the ADIRU system which replaced the IRS system consists of lasers as opposed to gyroscopes, so what does this do for the alignment time?

 

Laser gyros have been used for decades.

 

ADIRU stands for Air Data Inertial Reference Unit. Basically, all your IRS and air data inputs (static temperature, pitot tube pressure, static pressure, alpha vane, etc.) feed into a computer which then outputs to flight control computers, flight instrumentation, FMC, etc.