Some of this confusion may result from “reader error”... in missing the difference between IAS and TIAS. Some (most) of the charts and data rely upon TIAS... while the specific text of the recommended technique for avoiding obstacles uses IAS.
(Reece, are you certain your Section V is accurately quoted in your previous post...?? Or did you inadvertently copy the earlier text and use the latter number of 67..?? My Section V does not make that exact quote you posted.... and it switches to TIAS.)
While there may be slight differences between various year-models (where we’ve measured with the micrometer) .... the practical recommendations (where we marked it with the grease-pencil) .... and the specific data becomes muddy (because we cut it with the hatchet.)
In an effort to make some sense of it, from yet another Owner’s Manual (172C) which is essentially the Same Airplane (same engine and prop, same pitot system, same essential performance numbers) comes an “Airspeed Correction Table” which offers the “correction” to be applied so we can convert the data in the performance charts which use TIAS.... into the actual INDICATED airspeed IAS we actually use while operating the airplane.
And, BTW, the Production-Standard of the airplane was the McCauley DM7653 prop and is to which all the data pertains.)
(What’s the difference between IAS and TIAS?
IAS is what we see on the instrument. TIAS accounts for
installation error,** and Calibration error,.)
Here’s the chart (and notice that 62 IAS matches 67 TIAS.... the IAS and the TIAS do not merge until entering into the 90-100 mph ranges, largely because the pitot-tube is more aligned with relative-wind ):
**Later airplanes like the 172 switched instrument mfr’s, and pitot tube mfr’s/design and do not apply to our 170s. This chart is from the 172C which is the identical wing, engine, propeller, instrument, installation, pitot-tube, and performance charts as the 170B.)