Load a PDF in StageWebView - iOS

I am trying to create an iOS app that loads my companies product catalogue into a webview stage. I cannot figure out after a lot of google how to access this local file, although external files load fine. I'm trying to use the "file:" command. I'm doing this in flash builder.

<![CDATA[

                              import flash.display.MovieClip;

                              import flash.media.StageWebView;

                              import flash.geom.Rectangle;

                              var webView:StageWebView = new StageWebView();

                              var yOffset = 47

                              {

                                             public function FestoKP() {

                                                       webView.stage = this.stage;

       webView.viewPort = new Rectangle( 0, yOffset, stage.stageWidth, stage.stageHeight - yOffset);

       webView.loadURL( "file:///asset/Festo_KP_Catalogue.pdf" );

                                                       closeBtn.visible = true

       }

       public function Close() {

       webView.stage = null;

       closeBtn.visible = false;

       }

                              }