On 08 Oct 2003 05:26:31 GMT, (B2431) wrote:

From: Jim Thomas
Date: 10/7/2003 8:22 PM Central Daylight Time
Message-id: . net

Actually, flight-test nose booms pick up both Pitot (dynamic) and static
pressure. I'll bet the one on the X-1 did, too.

Jim Thomas

I bet the X-1 had a pitot-static tube witch detects pitot and static pressure.
In fact he said "pitot tube" which only detects pitot pressure. There really is
a difference between a pitot and a pitot-static tube. Then tarver came along
and said a pitot tube "produces" pressure. Neither a pitot tube nor a pitot
static tube produces pressure, they simply sense them.

First, during the period of the X-1, and for many years thereafter,
the common practice was for the pitot tube to provide dynamic pressure
(the ram effect of air created by the forward velocity of the
aircraft) and a static port on the fuselage surface to provide the
static source (undisturbed air around the aircraft). Static ports were
usually paired with one on each side of the fuselage to correct for
sideslip errors. They were round areas, always free of paint with 13
pinholes--we used to ask student pilots how many holes in a static
port.

Since high speed jets often create an artificial pressure around
themselves within the boundary layer, it became the modern practice to
incorporate static port holes in a pitot boom, clear of the turbulence
of the boundary layer. The boom might be on the nose (F-104, F-105D),
on the wing (F-100, F-105B), or on the vertical fin (F-4C, F-4D). As
an experimental aircraft, the X-1 probably incorporated static
measurement from the pitot boom as well as side ports. Some good photo
exam will probably disclose the fact on that.

Second, the pitot tube does not "produce" pressure. It measures it.
I'll give John credit for a typo on that.

Third, the much earlier assertions that pitot tubes were somehow
relevant only to jet engine powered aircraft is absurd. Conventional
(i.e. piston-driven) aircraft has just as much of a requirement for
measurement of pitot pressure. And, even sailplanes, with no engine at
all, use a pitot tube for airspeed indication.

Poor Henri, he probably never would have believed what his invention
has wrought on Usenet.