ESDU 77001 gives a method that is intended for use in estimating installed take-off thrust during initial design and can be used in conjunction with ESDU 76034 or with other "bare-engine" thrust data. Total pressure loss data are given for three classes of intake, namely, pod or pitot types with well rounded lips, intakes with well rounded lips and long and/or curved ducts leading to the engine, and sharp-lipped intakes. It is assumed that the flow is unchoked at take-off. The Mach number range of the data is 0 to 0.5. Values of thrust loss per unit intake total pressure loss are given for engines having two types of engine control and unreheated specific thrusts in the range 25 s to 90 s (corresponding to bypass ratios up to about 10). Data are applicable to unreheated or reheated turbo-jet or turbo-fan engines.