T33357
(UPPER LEFT)
(LOWER LEFT)
Pitot-Static System Simplified Schematic
Figure 2 (Sheet 1)

EFFECTIVITY ALL

7XA Page 6
34-11-00
Aug 25/87

Pitot-Static System Simplified Schematic
Figure 2 (Sheet 2)

EFFECTIVITY ALL

703 Page 7
34-11-00
 Apr 25/86
PITOT STATIC DRAIN ASSEMBLY DESIGNATION

T33385

XA

________ ____TYPE LOCATION
DRAIN NO. ________
STATIC LEFT SIDE LOWER LOBE BODY SECTION 41 STATIC RIGHT SIDE LOWER LOBE BODY SECTION 41
and

PITOT LEFT SIDE FWD STATION 400 BULKHEAD BODY SECTION 41 thru
STATIC LEFT SIDE FWD STATION 400 BULKHEAD BODY SECTION 41 and
PITOT RIGHT SIDE FWD STATION 400 BULKHEAD BODY SECTION 41 and
STATIC RIGHT SIDE FWD STATION 400 BULKHEAD BODY SECTION 41 STATIC RIGHT SIDE OF MAIN EQUIPMENT CENTER BODY SECTION 41 PITOT RIGHT SIDE OF MAIN EQUIPMENT CENTER BODY SECTION 41
thru

PITOT LEFT SIDE OF MAIN EQUIPMENT CENTER BODY SECTION 41 thru
and

STATIC LEFT SIDE OF MAIN EQUIPMENT CENTER BODY SECTION 41 STATIC RIGHT SIDE AFT OF FORWARD CARGO DOOR BODY SECTION 42 PITOT RIGHT SIDE AFT OF FORWARD CARGO DOOR BODY SECTION 42
and

STATIC LEFT SIDE AFT CARGO AREA FWD STA 2160 BHD BODY SECTION 46 and
PITOT LEFT SIDE AFT CARGO AREA FWD STA 2160 BHD BODY SECTION 46 and
STATIC RIGHT SIDE LOWER LOBE AFT OF CANTED BHD BODY SECTION 41 and
STATIC LEFT SIDE LOWER LOBE AFT OF CANTED BHD BODY SECTION 41 and
STATIC LEFT SIDE LOWER LOBE AFT OF CANTED BHD BODY SECTION 41 and
STATIC RIGHT SIDE LOWER LOBE AFT OF CANTED BHD BODY SECTION 41
PITOT LINE
STATIC LINE
DRAIN FITTING FREIGHTERS

APLS WITH FAIL-OP A/P-F/D OR PROVISIONS APLS WITH CF6 SERIES ENGINES
AZ 201,202,209-211; IB 405
LH 082-099; LH 051-064; AF 151-192,

LH 001-003; AF 101-103; LESS APLS 193-199; AZ 231 WITH SB 27-2343, AND
INCORP SB 27-2027
AZ 281-299; SN 351-399; IB 415-499;

AF 101-114; AZ ALL; SN ALL; IB 405MD ALL; GN ALL; AT ALL; VM ALL; PLUS (AEB AF21-157)
APLS INCORP SB 27-2179 OR SB 27-2297
AZ 212-299

INSTALLED IN AFT EQUIPMENT CENTER OR IN SECTION 48
ALL FREIGHTERS EXCEPT LH 082; AF 151-154 INSTALLED ON AIRPLANES WITH
AF 161-169,198,199; IB 409-499; MD 502-599;SUPPLEMENTARY FUEL TANKS
GN 602-699; AT 702-749; VM 752-799; LH 001-003; AF 101-104; AZ 201,202
PLUS APLS INCORP SB 21-2176
LH 001-050; LH 060-070; AF 101-150,

LH 011-099; AF 152-199; IB 415-499; 191,192; AZ 231 WITHOUT SB 27-2343, AND
PLUS APLS INCORP SB 77-2060 AZ 201-230, 232-280; SN 301-350; IB 401-414; GN 601, LESS APLS INCORP SB 27-2179 OR SB 27-2297

APLS WITH FAIL-OP A/P-F/D
Pitot-Static System Simplified Schematic
Figure 2 (Sheet 3)

EFFECTIVITY ALL

7XA Page 8
34-11-00
Apr 25/94
 (1)  The pitot-static system consists of four independent pitot-static subsystems and one alternate static pressure source available to two of the four subsystems through source selector valves. The theory of operation for each of the subsystems is similar. The inputs and distribution are discussed in the following paragraphs.
 (a)  Pitot Pressure Sensing
 1)  For each of the four pitot systems, a pitot-static probe is located on the outside of the airplane. In this position, dynamic or ram pressure created by the forward motion of the airplane pressurizes the entire pitot portion of each subsystem.
 2)  A drain hole located in the bottom of the probe head 2.25 inches aft of the tip exits to the atmosphere to drain any moisture that may be collected.
 (b)  
Static Pressure Sensing

 1)  Static pressure ports are located on the top and bottom of the pitot-static probe head, approximately 4.5 inches aft of the tip. The forward set of ports (one on top and two on the bottom) open into static line S1 and the aft set (one on top and two on the bottom) open into static line S2 The surface of the probe in the area of the static ports is designed to provide an accurate sensing of ambient air pressure as independent as possible of airspeed. To further assure accurate ambient pressure sensing, static pressure inputs are equalized by cross-connecting each set of static ports to a set of static ports on the opposite side of the airplane through a common manifold. (See figure 2.) Note that static ports from upper probes connect to static ports on lower probes. This tends to reduce any error caused by a localized pressure anomaly.

 (c)  
Captain's Pitot-Static System (Fig. 2)

 1)  The static pressure portion of the captain's pitot-static system is pressurized from a set of static pressure ports on the auxiliary 2 (lower right) pitot-static probe cross-connected with a pair of static pressure ports on the captain's pitot-static probe (upper left).
　
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