The fog extends to the CAA at times :
However, on a number of occasions, there has been some discrepancy between BAA‟s published figures and the CAA‟s interpretation of the data. In most cases, it has been possible to explain the differences, following extra work from NATS and BAA, but this reconciliation is not always apparent from the data which BAA is routinely publishing. (Section 7.9)
and suggest that the Cambridge boffins look closely :
A key step in the data validation process for the final report will be ensuring that the two principal sources of data used in measuring use of the trial freedoms (i.e. the Noise and Track-Keeping System and NATS operations logs) are reconciled accurately and consistently so as to provide a robust and reliable picture of the flights that have benefited from the application of the operational freedoms. We would recommend that Cambridge University look specifically at this aspect of data generation as part of their validation role.