PITOT STATIC PROBE - CLEANING/PAINTING
1. Cleaning
A. Internal
(1)
To remove foreign materials lodged in the pitot opening, static ports or drain hole, disconnect the pitot static probe pressure lines and blow compressed dry air through the line and out the ports. Maximum air pressure to be used is 60 psi.
(2)
If the forced air method fails to remove the foreign material, remove the pitot static probe from the airplane (Ref 34-11-11, Pitot Static Probe - R/I). Soak or flush the unit with clean water, drain it and repeat (1).
CAUTION: DO NOT USE FLUIDS THAT CONTAIN SODIUM CHLORIDE OR SULFUR COMPOUNDS TO CLEAN THE PROBE. SODIUM CHLORIDE AND SULFUR CAN CAUSE PREMATURE FAILURE OF THE PROBE.
(3)
If the forced air and soaking methods do not clean the drain hole because of its small size, cleaning may be accomplished by manually inserting first a 0.025 drill rod and then a
0.029 drill rod into the drain hole.
CAUTION: CARE MUST BE TAKEN SO THAT THE DRAIN HOLE IS NOT ENLARGED DURING THE CLEANING PROCESS (DRAIN HOLE DIAMETER IS 0.031 +0.001 INCH).
B. External
(1) To remove foreign material from external surfaces, wash them with clean water and dry them with a soft cloth.
CAUTION: DO NOT PROBE INTO THE STATIC PORTS WITH ANY OBJECT. DO NOT EXPOSE PITOT-STATIC TUBES TO SOLVENTS, LUBRICATING OIL AND/OR GREASE. DO NOT SCOUR OR BUFF THE MACHINED CONTOUR SURFACE.
2. Painting
A. The pitot static probe should not be painted. The data from the pitot static probe can be affected if you paint the probe.
501
Feb 20/93 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 34-11-11 Page 701
ALTERNATE PRESSURE PORT - REMOVAL/INSTALLATION
1. Equipment and Materials
A. High Temperature Fillet Sealant - BMS 5-18A, Type II - PR-810 (or equivalent)
2. Remove Static Pressure Port (Fig. 401)
A. Remove forward cargo compartment lining to gain access to static pressure ports (Ref Chapter 25, Equipment and Furnishings).
B. Disconnect static hose from elbow. Cap static hose to prevent entry of foreign material.
C. Loosen jamnut and remove elbow and O-ring from static pressure port.
D. Remove lockwire and clean away sealant from around static pressure port.
E. Remove static pressure port retaining nut and washer.
F. Remove static pressure port from exterior of airplane.
3. Install Static Pressure Port
A. Clean away any remaining sealant and prepare area for application of new sealant.
B. Insert static pressure port in mounting hole. Adjust until face of port is as flush with airplane skin as possible and hold in place.
C. Install static pressure port retaining nut and washer. Tighten retaining nut to torque value of 250 to 400 inch-pounds. Lockwire nut using double-twist method.
D. Check port is flush with the skin within +0.003/-0.000 inch after installation. If necessary, shave external surfaces of static pressure port until it is flush with airplane skin within tolerance. After shaving is complete, ensure surface finish on face of static port is 63 RMS maximum. Ensure no burrs or materials are in static pressure port and all inlet holes are free from obstructions or deformation.
E. After installation, the skin surface, for a distance of 3 inches forward and aft of the port centerline, should be flush within 0.010 inch maximum measured as the clearance between the skin and the edge of a 6-inch straightedge placed horizontally against the skin. All rivets within a 3-inch radius of the port center should be flush with the skin within 0.003 inch maximum.
500
Oct 20/91 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 34-11-21 Page 401
H28368
Alternate Static Port Installation 501
34-11-21Page 402 Figure 401 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. Nov 15/67
F. Alodize static pressure port with Alodine 1000 (Ref Protective Finishes in Chapter 51, Structures - General).
G. Apply sealant to static pressure port as shown in Fig. 401, Detail A (Ref 51-30-0, Seals and Sealing).
H. Install elbow and O-ring in static pressure port. Tighten jamnut.
I. Remove cap from end of static hose and check for any foreign material inside hose, clean if necessary.
J. Connect static hose and fitting to elbow. Tighten to torque value of 100 to 125 inch-pounds.
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