Work in progress
The map below shows three classes of aircraft waiting to take off at EHAM Amsterdam.
- Top left on 36L is a 737 Airliner (helijah)
- heavy aircraft for international 10 hr flight
- takeoff speed is 140 knots into headwind
- Bottom left on 06 is a Beechcraft twin prop (trennor)
- nimble small regional aircraft for 1 hour flight
- takeoff speed is 90 knots into a slight side wind
- Bottom right on 36R is Citation Bravo twin jet (ac001)
- small jet for euro hopping on 3 hour flight
- takeoff speed is 120 knots
- Each pilot has calculated the speed required to actually take off based on aircraft performance, runway length, weight, air pressure and many, many other factors some featured more below.
- Each pilot has shortened the runway by a "safety margin" (yellow lines) that has been deducted from the runway length, a "gut feel" for headwind, alignment in fog, etc.
- The red dot indicates the point that the aircraft is at enough speed it can safely take off with ONLY one engine.
- The green dot is the point where the aircraft has to take off as there is not enough runway left to stop.
- The purple dot is the hypothetical point where the aircraft would safely stop and well within runway limits.
- This aircraft is heavy with passengers, cargo and fuel and needs some momentum, and therefore requires more stopping distance.
- The aircraft is just within the "margins" of runway/takeoff parameters.
- The throttle would be set to TOGA ie max.
- This aircraft is light and requires little runway to take off at a slow takeoff speed
- Throttle not full on as there is a lot of runway
- The aircraft could have entered the taxiway halfway down the runway, and still conducted the takeoff on a shorter runway.
- The lighter jet aircraft is taking advantage of the runway length.
- The plan is accelerate slower and take off further down the runway with a Flex Temp takeoff, saving fuel, engine wear and less noise.
Below are some notes on the 'real world' scenario, some of the problems and techniques to get familiar and is biased towards jet aircraft and airliners.
- First the aircraft is aligned to the runway and positioned. Parking brakes on.. this is an effort.. then pre-take off checklists
- Clearance = ATC has said clear for take off
- The engines are fired up to 10% with the brakes ON. this will give time to warm up the engine and pumps, air bubbles.
- The 25% period, where the jets are fired up more. Its not full on yet to avoid blowouts caused by air bubbles with in jet..
- There is stabilized flow thought the engines and the aircraft is accelerating down the line...
- v1 is achieved.. meaning we can take off.
- v2 the point of having to take off is reached.. We can stop now. Before this point is a "rejected takeoff"