just wondering how can I get P charts for Echo on excel? I have got them in performance's supplement but wanted to try them on excel.

I don't know of anyone who has put the equations into Excel but I have no doubt that some of the present Industry engineering consultants will have done so. I used to run them on an ancient Texas Instruments programmable calculator in the 70s. That calculator is floating around somewhere at home and, possibly, even still works. At the time it was a great little machine .. TI-59 if my memory serves me correctly.

The charts are to the old DCA P-chart format style which went into the Civil Mk whatever flight manuals in vogue at that time so are, almost certainly, based on a couple of old DCA tech pubs which provided a series of quite simple equations for deriving P-chart data. This approach was the basis for all the old P-chart style charts in vogue during the 70s and into the 80s. John Fincher updated the analyses to cover light turboprops but the earlier, simpler equations continued to be used for pistons.

I have copies of the documents tucked away in the archives but not readily available until such time as I get unpacked into some new office accommodation. You would be welcome to a scan copy at that time if you wish to run a model in Excel.

In the meantime, you could look up any of the standard engineering analyses for takeoff and landing .. the equations are all much in the way of similar for simple analyses. Just be a matter of using some data read off from the Echo charts to set a few constants and away you go.