In 2011 CE Delft carried out a study for the Collectif d’élus Doutant de la pertinence de l’aéroport de Notre-Dame-des-Landes (CéDpa) which showed that the results of the social cost benefit analysis (SCBA) presented in the Enquête Publique (notably Pièce F) were flawed. Because the study on which Pièce F was based was unavailable, CE Delft was unable to analyse the causes of the flaws. CéDpa has since obtained a number of documents that might explain some of the apparent shortcomings in Pièce F and asked CE Delft to analyse them to establish whether or not this is the case. This report presents the results of that analysis.