Tool · Mission profiles and weight fractions

Mission Profile Builder

Assemble a mission from segments, as sizing does: start from a typical profile or a blank one, set each segment's altitude, speed, distance or time, and see the profile drawn, its time and distance added up, and its weight fractions multiplied into the mission fuel fraction. Use it to check the examples of Lessons 5 and 6, and for your own design.

Build a mission

Start from

Figure T.1 The mission as altitude against time or distance, colored by segment type: climb green, cruise blue, loiter amber, combat orange, descent and ground segments gray. Numbers mark the end of each segment, where the aircraft weighs \(W_i\).

    Segment by segment

    Distance, time and weight fraction of each segment. \(W_i/W_0\) is the weight at the end of the segment as a fraction of the takeoff weight.
    \(i\)SegmentDistance (km)Time (min)Altitude at end (km)\(W_i/W_{i-1}\)\(W_i/W_0\)

    How it is calculated

    Segment models for initial sizing (historical fractions from Raymer, Table 3.2)
    SegmentTime and distanceWeight fraction \(W_i/W_{i-1}\)
    Warmup and takeoffTime as entered; no distanceHistorical: 0.970
    Climb\(t = \Delta h/\overline{RC}\), \(d = \overline{V}t\)Historical: 0.985
    Cruise\(t = R/V\) at the current altitudeBreguet: \(\exp[-RC/(V\,L/D)]\)
    LoiterTime as entered; distance not counted toward the rangeEndurance: \(\exp[-EC/(L/D)]\)
    CombatTime as entered; no distance countedAs entered; for example \(1 - C(\TW)t\) at full thrust
    Descent\(d = \Delta h/\tan\gamma_d\), \(t = d/\overline{V}\)As entered (often taken as 1, counting descent fuel with the landing)
    Landing and taxiTime as entered; no distanceHistorical: 0.995

    The mission fraction is the product \(W_x/W_0 = \prod W_i/W_{i-1}\), and the fuel fraction with the 6% allowance for reserve and trapped fuel is \(\Wf/\Wo = 1.06(1 - W_x/W_0)\). If the profile already contains explicit reserve segments (a diversion, a hold), the allowance double-counts part of the reserve: switch it off to see the difference. The tool does not model weight dropped in flight (weapons released, cargo air-dropped); Module 3 shows how. Your mission is saved in this browser, so it is still here when you come back.

    See Lesson 5 for the profiles and the timeline, and Lesson 6 for reserves and the endurance equation.