Mach only uses the TAT probe, not pitot. ...... Say again all after the first word
Ditto to
John_Tullamarine's wise words.
Whether it be old 'steam driven' equipment, or modern high fallutin' electronic ADCs, Mach Number is derived by comparing the degree of compression of the Total Pressure on the aircraft against the Static Pressure.
And where does the Total Pressure come from?............The Pitot Tube of Course
And where does the Static Pressure come from?...........The Static Port of course
And where does the TAT probe come into measuring Mach Number?.......It
DOESN'T
No Pitot and no Static, no Mach Number
From the 'raw' Total Pressure gauged in the Pitot Tube, we can obtain -
.1.
CAS/RAS after removing position error,
.2.
EAS after removing compressibility error,
.3.
Mach after comparing CAS with Static Pressure.
The only time that TAT/SAT comes into play with the manometry of the aircraft is by comparing to Mach Number to obtain
TAS, and as one of several temperature components in correcting Indicated Altitude to
TRUE Altitude. Not forgetting that Mach Number (or TAS) and TAT (or RAT) can be used to calculate SAT, but that's not a manometry issue, which is what this thread is all about.
Regards,
Old Smokey (With apologies to
J_T for chipping in, I couldn't help myself, as usual)