What does the red schedule mean ?
I have all the timings correct and with the right logic , what does that mean ?
I have a picture attached .
It means the timing is incorrect and/or you do not have the required slots.
what do you mean by not having required slots?
Slots at the departure airport and arrival airport.
Click the right button on your screenshot to see the schedule, find the flights that are marked red, then edit those flights. All chechmarks need to be green in order for the flight to be ok.
what do you mean by not having required slots?
In the real world, the world's busiest airports are usually said to be 'slot controlled'. This reflects the regulations of various governments (usually copied from the FAA) that require a certain amount of distance between aircraft, and a certain amount of time between each takeoff or landing on a given runway. (The space requirement to help prevent collisions, the time requirement is to let the air settle after being disrupted by a large object passing through it.) These departure or landing 'slots' reflect the mathematical relationship between the necessary space and time requirements.
London-Heathrow airport is slot controlled because the runway capacity has been calculated to be [url=https://www.caa.co.uk/docs/5/ergdocs/baajan03/acl2baajan03.pdf]1357 departures or landings[/url] per day. The AirlineSim version of LHR uses a similar calculation, and goes further by splitting those slots into a 5-minute time period. Where the real world version dictates that an available slot pair (as you need one slot for your arrival, and one more for your departure later) must go to a specific area (i.e. to/from Moscow, or to/from Canada), our slots don't have the same restrictions and can be used to anywhere.
In the game, the biggest airports are usually already full. After all, who doesn't want to provide service to LHR, JFK, LAX, SYD, HKG, etc. It can be difficult to find an available slot, and if you can get a pair, they may not work well with your existing schedules.