2. Recalibrating the Cost Index
Curves representating specific range variation versus Mach Number being quite flat, the original computation software of the cost index in the FMS led to the following :
- cost index 0 or MRC corresponds to slower than anticipated cruise speed ;
- the new MRC-calculation process increases the Mach Number, thus resulting in a recalibrated Cost Index ;
- when calculated for low Cost Index (see Figure 44 for CI=70), original software led to speeds that could be lower than the real Specific Range optimum ;
- a new software was defined as from April 1996, in order to achieve a result close to the real SR optimum.

In the meantime, airlines were provided with Cost Index corrective charts that were to be furnished in the form of a temporary revision of the FCOM .
Altogether, improvements are staggered as follows :
.  
The modified definition of MRC and hence of LRC (1% off) was to be introduced in the IFP with subsequent distribution to the airlines.

.  
Customers were provided with a modified table of the Cost Index, converting the old value to a new one, thereby allowing the use of higher Mach Numbers ; Figures 42 and 43 represent these correction charts for, respectively, A340-311 and -211 (CFM56-5C2) and A340-313 (E) (CFM56-5C4).

Pending Load 7, the corrections of Figures 42 and 43 are necessary. Thereafter they will be obsolete and use will then be made of the Table 3, in Section 3 of this brochure.

A340-313/CFM56-5C4 High Cross Weight

.  The next version of the FMGEC, Load 7, will be modified so as to integrate the above modifications; the default value of the cost index will be modified accordingly, shifted from 0 to a value corresponding to a more representative cruise speed ; Figure 44 illustrates the improvement.
Example : 210t 37 000 ft CI-70kg/min

3. Transforming cost index brackets
Using Figures 42 and 43, Table 3 transforms into Tables 4 and 5 for, respectively, A340-311 (and -211), (CFM56-5C2 and C4) and A340-313(E) (CFM56-5C4).
These tables provide typical industry values covering the low to the high cost brackets for both fuel- and time-related costs.
Following integration of the above-mentioned modifications, Tables 4 and 5 will become obsolete. Use will then be made of Table 3, now also still valid for the A330.

APPENDIX 4

A340-200 AND -300 CLIMB IAS PRESELECTION PROCEDURES FOR LOAD 6
PENDING LOAD 7 RELEASE

The following are the recommended procedures pending the release of FMS Load 7, after which corrected climb speeds will be fully integrated.
1. Aircraft is not in climb phase
.  
The preselected CLIMB IAS may be entered on the MCDU PERF-CLIMB page on the PRESEL field. It is displayed in large font.
　
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