RTOW Charts Interpolation

[SU-GCM]

Hello,
I am looking for reference from EU OPS that you can interpolate for Wind / Weight on RTOW Charts

For example, If your RTOW Charts on A320 for Conf 1+F shows only for the wind -10 0 +10 and if the wind is calm , according to Airbus you have to use 5 Wind but if your chart don't have +5 / -5 would it still be legal to interpolate ?

Thanks in advance !

[john_tullamarine]

As a general observation, the end user doesn't know the physical layout of the chart.

Specifically, where discontinuities exist and the extent of non-linearities.

While one can get around some of these problems by crossplotting that is beyond the line pilot's approach to the question during operations.

Therefore, unless the operations manual provides specific guidance regarding interpolation techniques, it is better to take the published conservative data point and accept whatever penalty is associated.

Re the specific question, and acknowledging nil specific background with Airbus, why ever would one use other than the nil wind line if the wind is calm ? There might be some rationale in L&V conditions.

[HazelNuts39]

SU-GCM,

If there is any reason that would make interpolation invalid, the chart should say so.

[FoxForce44]

Check the FCOM, pages PER-TOF-TOC and you're gonna see that interpolations are pretty commom, specially using speeds and temperatures. I remember in CBT an explain about data interpolation, but I cannot assure you where (probably on performance CBT).

[vilas]

SU-GCM
Can you quote the Airbus document that says you have to use 5kt wind for calm? Because in type rating course documents and performance CD it is not mentioned. Also seems bit odd that if you have to use 5 knot wind then why there is no column for that and why the charts provide zero wind column when it is useless.

[SU-GCM]

Thank You FoxForce44

TAKEOFF DATA - NET TAKEOFF FLIGHT PATH
PER - TOF - TOD 50 P 1/8
HOW TO PROCEED

2. READ THE ASSOCIATED WEIGHT CORRECTION . INTERPOLATE IF NECESSARY . THE SECOND SEGMENT GRADIENT IS GIVEN FOR INFORMATION ONLY

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