Originally Posted by
itsnotthatbloodyhard
Sorry, this is not true. The A330/A340 FCOM has procedures for Unreliable Speed Indication, IAS Disagree, and All ADR Off - and NOWHERE does it make any mention of groundspeed. Nor does the FCTM.
Ah! OK, Body. Point taken if so. Another posting here from an Airbus guy spoke of "reviewing IRS GS data" as part of the procedure. I will have to try and find it. Any other Airbus people out there confirm of deny?
All I can say is that next time we have an AF 447, and we will, lack of that excellent GS data in your toolbox will be a terrible shame!.
It happened to me yesterday on my boat actually. Sailing along in fog with no visibility at 6knots indicated boat speed. . Boatspeed went to zero instantly - weed I guess = bird strike on plane? Blocked pitot due ice? No way of verfirying by visual reference due to fog.
But, GPS reading 6 knots still so I knew we hadn't really stopped and knew which of the two was telling the truth.
And the engine was still at 2000 revs and, there was no current at the time, aka wind to us pilots!
Now if I had not looked at GS I would. have had a reasonable idea that we were still doing 6 knots since the steady state conditions still existed, and the engine was still going at 2000 revs. But the GS confirmed it and was quite nice to have.
The rest of the trip back was done on GS only. And because I knew the tidal steams - up to 3 knots (half my boat speed at times so equivalent to 300 its wind in a jet) I knew my boat speed too. All the time very accurately.
But I digress as usual because I learned to fly when Pontius was a pilot and pilots were real men. No ladies then. Back to my therapist now.
ps I did fly 737-800 sim. until a year or so ago as a TRE examiner so not utterly senile or out of date.
And I can still an inverted circuit in a 737 sim - taught to me by a Red Bull ace of my acquaintance !
Happy flying
Y