Does the following shed some light?
CORRECTIONS PRODUCED ON THE RTOW CHART
Applicable to: All
For example: Refer to PER-TOF-TOC-10-30 EXAMPLE OF TAKEOFF CHART
A description of this correction is given on Refer to PER-TOF-TOC-10-20 DESCRIPTION OF THE
CORRECTIONS ON TAKEOFF CHART. The list of corrections is not exhaustive, however the most
commonly used corrections are wet runway, QNH, air conditioning and/or anti ice. A maximum of
three corrections can be produced on one chart.
To apply the corrections, proceed as follows:
1. Enter the chart with given OAT and wind to determine the maximum takeoff weight before
correction.
2. Apply the first correction:
If OAT is less than or equal to TVMC (line 3), apply W correction from line 1 and V1/ VR/ V2
corrections from line 2.
Else, (for OAT greater than TVMC), apply W correction from line 3 and V1/ VR/ V2 corrections
from line 4.
3. To combine a second (and third, as applicable) correction:
If OAT is less than or equal to TVMC (line 3), apply W correction from line 1 and V1/VR/ V2
corrections from line 2.
Check that the resulting speeds are higher than the minimum speeds displayed on the RTOW
chart and that V2 is higher than the VMU limited speed (Refer to PER-TOF-TOD-25-10 SPEEDS
LIMITED BY VMC).
If OAT is higher than TVMC (line 3) or if the above speed check is not fulfilled, apply W correction
from line 3 and V1/ VR/ V2 corrections from line 4. No speed check is required.
Note: ‐ QNH correction is given for ±10 hPa . It is allowed to extrapolate linearly for greater QNH
deviation.
‐ When using a takeoff chart with failure cases, it is not allowed to combine two failure
cases.
‐ Corrections from the chart must be applied from top to bottom, i.e. in the RTOW on Refer
to PER-TOF-TOC-10-30 EXAMPLE OF TAKEOFF CHART, apply the wet correction first.
‐ If asterisk or dotted lines appear in the correction boxes, refer to more conservative
corrections provided in the FCOM.
‐ No speed check is required for the first correction. However, if the first influence
correction follows a conversative FCOM correction, a speed check is required.