Very good point. Last last four of our 200s also has an ISIS.

Greetings
I think that ISIS was added to increase dispatchability :E

ISIS does not increase dispachability on the md-11, rather the opposite as the stby horizon used to be deferable and you can not defer the aux IRU any more as it gets it's heading info from it.

It is still standby instrumentation with all eggs in one basket, can't get the logic here. But hey it is more shiny glass to stare at during long flights.

Flight Standards Information System (FSIMS)

Greetings,
The situation was specific to the B777:}, and was quite unic, one ADIRU was feeding the stand-by so if that ADIRU unit was inop they no standby:eek:, this was on the early B777, so Airline added an ISIS which has its own Gyro. :ok:
Now this situation doesnot exist any more Boeing changed the architecture.:E

ISIS stands for inertial standby instrument system or some such? Just following this discussion interested as i only fly the puny twin (737) which only has two ADIRUS to begin with and an added ISFD which provides third set of attitude data but receives heading information from the left IRS, the third attitude source however is mandatory for CAT IIIb operation.

Greetings
the I stands for Integrated because it integrates 3 in one Airspeed Attitude a Altitude
Integrated Standby Instrument System made by Thales Avionics... :}

A Tad adrift here sir, the SAARU sends data the the Stby Attitude Indicator, not the ADIRU. Your point however is valid, although I can not recall any in flight SAARU failures, but system integrity is certainly increased with the ISIS

@Kijangnim, found a press release from Thales stating that they supply the same ISFD for the boeing 737, 757, 767, 777, 744 and now 787. Seems its just different acronyms for the same thing, on the 737 it means Integrated Standby Flight Display, displays a mini PFD with attitude, altitude, airspeed and approach (ILS and backcourse) information.

Anyway, thanks for the information :)

Denti
in fact Thales did a very good job with this product it is Pin programed plug and fly..:ok: so there is NO dedicated model for a specific airplane

Apologies to bring up an old thread.

In continuation to the ORIGINAL question asked, being in the same situation that I am, after getting airborne and prior to the NAT ENTRY,
If there is a GPS failure indicated, I Have 2 FMC and the 'ADIRU UNIT',

The questions are

"Do I have 2 LRNS as FMC L and FMC R NOW To Enter NAT ?"

" is it ok to have both FMC have the same input from ADIRS and Continue? "

Any info on above subject matter will be of great help :)