Regulation_TO_1-1-691_para_3.5.3.3.pdf

f. Rinse by deicing as in step a. Heated deicing/anti-icing fluid mixtures will speed up the rinsing process.

3.5.3 Clear Water Rinsing of Aircraft.

• Do not rinse aircraft with a solid stream of wa-ter. Use a soft, spray pattern to avoid damaging fragile sections or causing water intrusion. Wa-ter must not be directed at pitot tubes, static ports, vents, etc. Critical areas shall be ad-equately protected with ground plugs, covers, etc.

• Clear water rinsing shall not be accomplished outside when the temperature is at 40° F (4° C) or below. Spraying flight control areas outside with water when the temperature is below freezing can result in ice that could impair flight controls.

• Application of water in wheel wells, flap wells, flight control wells, etc., may necessitate the relubrication of some components/areas. Ensure that these areas are adequately drained and check the system specific aircraft maintenance manuals to determine lubrication requirements.

NOTE

• Clear water rinsing does not satisfy aircraft washing requirements.

• Only water meeting the requirements in Para-graph 3.1.1, step g shall be used for clear water rinse operations.

3.5.3.1 Requirements. As directed by the requirements

in Paragraph 3.2.3, aircraft shall be clear water rinsed to remove salt contamination from aircraft surfaces caused by operations near salt water. Most salt deposits are readily dis-solved and/or dislodged and flushed away by rinsing. Rins-ing can be done in a taxi-through facility or by direct manual spraying.

3.5.3.2 Taxi-Through Rinsing. Deluge rinse facilities

(bird baths) are automatic installations located in a taxiway area for use by aircraft after flight through salt air. These installations provide multiple jet sprays of fresh water to cover the entire aircraft exterior surface to rinse off salt and water soluble contaminants. Such facilities should be used as frequently as possible per the requirements in Paragraph 3.2.3.

3.5.3.3 Manual Application. Fresh water can be applied

from a hand held hose or piece of spraying equipment. The force or pressure used to apply the water is not as critical as the amount of water. Satisfactory results are achieved with an amount of water that will create a full flowing action over the surface. This requires a minimum of eight gallons per minute (GPM) of water at a nozzle pressure of 25 PSI mini-mum to 175 PSI maximum.

3.5.3.4 Rinsing Procedures. Clear water rinsing shall be

accomplished as follows:

a. Direct water at an angle of 15° to 30° from the surface.

Ensure that sufficient water flow is achieved on all sur-faces.

b. Begin rinsing on lower surfaces and work upward starting with the lower wing surfaces, then the lower fuselage, and the lower horizontal stabilizer surfaces.

Then rinse from the top down, starting with the upper and lower surfaces of the horizontal stabilizer on T-tail aircraft, the vertical stabilizer surfaces, then the upper fuselage, upper wing surfaces, and upper horizontal stabilizer surfaces. (Refer to Figure 3-7).

3.5.4 Post Cleaning Procedures.

Do not use synthetic wiping cloths with flammable solvents as these solvents can dissolve them.

3.5.4.1 Post Cleaning Task Sequence. Strict compli-

ance with the following post cleaning procedures is essential and they shall be done in the following order.

a. Remove covers and masking from all static vents, pitot static tubes, air ducts, heater ducts, etc.

b. Remove tape from all other openings sealed with mask-ing tape.

c. Remove all tape adhesive residues with TT-N-95 ali-phatic naphtha or TT-I-735 isopropyl alcohol.

d. Ensure all drain holes are open by inserting a probe, such as a pipe cleaner.

e. Ensure that all areas that accumulate water have been drained and/or otherwise dried. Whenever this is a re-curring problem, specialized procedures shall be de-veloped and implemented to remove entrapped water and other fluids to prevent their accumulation.

TO 1-1-691

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