 So, basically if we just recall now we started by estimation of the mission fuel fraction for that we were looking at the two segments of cruise and loiter and for these segments we use the Brighay equations. For the Brighay equations we needed L by D max and SFC for that we looked at some empirical and approximate procedures and now the total fuel fraction is going to be estimated as the 1 minus the mission fuel fraction plus a reserve fuel factor. This reserve fuel fraction is normally specified by the regulatory authorities or sometimes also decided by the airline themselves from their own experience and from their own policies from the point of view of safety. Typically airlines assume 6 percent or 10 percent so airlines normally carry around 6 to 10 percent extra fuel to take care of the contingencies, okay. So, summing up now we revisit this particular formula in this formula W crew and W payload they were estimated based on the requirements given by the customer for W payload and requirements specified by the airworthiness agencies or the operating procedure or operating norms of the airline. Empty weight fraction was obtained using the AW0 power C formulation based on the type of the aircraft WF bar was obtained by calculating the mission segment profile for each mission. Many of them were assumed by historical data but two of them for loiter and for crews were obtained using the Brighay equations. So, therefore if I replace the WE bar formula by the formula used by us and if I replace the W fuel bar formula by this formula that we just obtained earlier you get a large formula which allows you to calculate. Now, X by W0 has been obtained by a multiplication of the various mission fuel fractions. Reserve fuel factor is a number which is assumed by the airline A and C are the constants which depend upon the aircraft type. So, now we come up with a slight problem we basically have an iterative equation because what we want W0 also appears on the RHS because the empty weight fraction of the aircraft depends on the W0 and as you noticed C exponent is negative. So, heavier aircraft tend to have a lower empty weight fraction. So, we end up with an implicit equation. So, what we need to do now is we need to. So, this number and this number will be available to you as a fixed number RFF is an assumed constant W for W0 is what has been estimated all you need to do now is follow an iterative procedure. So, you assume some starting value of W0 typically we assume it 4 times as the payload because payload is typically 25 percent of the total aircraft weight. So, it is good to assume 4 times the payload as a starting value of W0. First thing you do is estimate the empty weight fraction using the formula A W0 power C into KVS where KVS is equal to 1 for most aircraft because we do not reach variables we transport aircraft in general. Then you estimate the segment weight fuel fractions for some segments like warm up taxi out, climb descent and approach and taxi in we use historical data for the cruise and loiter segments we use the Brighay range and endurance formulae and using that we estimate the fuel fraction for the entire mission and then you just include a reserve fuel factor and get the WF bar which is the WF by W0 and then you calculate by iterating and you iterate till convergence. So, this is the procedure which is used for initial sizing thanks a lot for your attention and if you have any questions we will use our channel of communication to sort out your queries. Thank you.