Nige,
I had no intention of patronising people and if that is how it came across then I apologise. However, your sources are correct and incorrect. There was an aspiration to freeze the MRA4 design late last year (PA X) and any changes defined as delta PA X to be frozen, as you say, in December. However, this has not stopped the changes. The current roll control circuit has yet to be fully defined to alleviate current handling quality issues and will probably not be until the end of the year.
To state that the AAR system is the same as MR2 is too simplistic. Yes the probe is retained but the rest of the AAR SOVs, fuel system, pumps etc which intrinsically control the fuel flow and distribution (USMS computers control valve sequencing) are so far removed from MR2 as to not even try to compare them. It is how the system copes to fuel flow fluctuations and what it does with the fuel that merits investigation and therefore to compare MR2 and MRA4 AAR systems as one is flawed.
'The AAR system will not be qualified on delivery. It has to be available ready to use at short notice.' - The AAR will not be qualified, period. Not only because the system will not be tested, but because the aircraft engines will not be cleared for wake penetration behind large aircraft. It will have no evidence to support RTS, therefore will not be cleared.
Flight deck armour has always been an aspiration but there is no funding. MR2 armour was fitted under a UOR in short order and this does not preclude the same happening for MRA4 following ISD (2010). It is easier to get funding in the current climate for a UOR post ISD than to contract BAe to change the specification.
My reference to project timeline extensions was poor, what I am trying to point out is how long will people want to wait for these modifications (the list could be endless) whilst the MR2 is forced to still fly as there is still an operational requirement to fulfil, that is all.
Last edited by MOA; 7th November 2007 at 22:24.