Flight planning in the future collaborative environment

New flight planning procedures being developed by ICAO allow an operator to obtain feedback on planned flights. This can be used during planning to obtain an improved estimate of a flight´s expected cost and variance. This estimate allows a more optimal flight to be selected. An approach for estimating the effect of constraints with uncertain impact is presented and applied to the example of miles-in-trail. Operating characteristics of feedback on miles-in-trail is derived from sixteen months of data and applied in an example Monte Carlo simulation. Blending feedback with historical constraints is proposed to account for feedback missed alerting. An example indicates that blending can improve the forecast, and that the magnitude of predicted impacts can be sufficient for some flights to switch routing.