4 Stages of Takeoff (Stage 1?)

[wangus]

I recall stage one ENDS at 35' screen height, V2 and gear up. Where does it officially start??? Lift off or commencement of takeoff run at zero knots?

[RunSick]

From Airbus "Getting to Grips with Aircraft Performance"

4.1.2. Takeoff Segments and Climb Requirements

(Figure C16)
Shows first segment starting at 35feet screen hight with speed V2 and second segment starting at gear retracted, also V2

but then also:

(Table C4)

First Segment
starts: Vlof reached
speed: Vlof

Second Segment
strats: Gear fully retracted
speed: V2

So I´m not sure exactly whre it starts but that´s what the book says. If anyone could explain? :confused:

The start of the takeoff run (brake release) is only considered for the takeoff distance, not part of the Takeoff segments.

Also, the takeoff is broken down into 3 PHASES:
Ground acceleration (from Brake release to start of rotation)
Rotation (From start of rotation until airborne)
Airborne acceleration (after liftoff)

[TonyDavis]

I have always understood that the 1st Sement starts at Vlof and ends at gear up, 35 feet and V2.

I stand to be corrected.

[D-ENIM]

First Segment

Reference Zero (35ft) to gear fully retracted.

Reference Zero: 35 feet below the end of the TODR.

[wangus]

Thanks people,
Have read several "references" which all have their own DIFFERENT take...... The most repeated one seems to be from reference height / 35' until V2, gear up, as D-ENIM. Debatable??
Thank you for inputs.

[212man]

I suggest you take a browse through this: http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%2025-7B%20Chg%201.pdf

Page 68 has the diagram you need...