Par 9-30 Page 9-432 TABLE 9-3. Aircraft hose specifications.
SINGLE WIRE BRAID FABRIC COVERED MIL.
PART NO.
TUBE SIZE O.D.
HOSE SIZE I.D.
HOSE SIZE O.D.
RECOMM.
OPER.
PRESS.
MIN.
BURST PRESS.
MAX.
PROOF PRESS.
MIN BEND RADIUS
MIL-H-8794- 3-L MIL-H-8794- 4-L MIL-H-8794- 5-L MIL-H-8794- 6-L MIL-H-8794- 8-L MIL-H-8794-10-L MIL-H-8794-12-L MIL-H-8794-16-L MIL-H-8794-20-L MIL-H-8794-24-L MIL-H-8794-32-L MIL-H-8794-40-L MIL-H-8794-48-L 3/16 1/4 5/16 38 1/2 5/8 3/4 1 1 1/4 1 1/2 2 2 1/2 3 1/8 3/16 1/4 5/16 13/32 1/2 5/8 7/8 1 1/8 1 3/8 1 13/16 2 3/8 3 .45 .52 .58 .67 .77 .92
1.08
1.23
1.50
1.75
2.22
2.88
3.56 3,000 3,000 3,000 2,000 2,000 1,750 1,750 800 600 500 350 200 200 12,000 12,000 10,000 9,000 8,000 7,000 6,000 3,200 2,500 2,000 1,400 1,000 800 6,000 6,000 5,000 4,500 4,000 3,500 3,000 1,600 1,250 1,000 700 300 300
3.00
3.00
3.38
4.00
4.63
5.50
6.50
7.38
9.00
11.00
13.25
24.00
33.00
Construction: Seamless synthetic rubber inner tube reinforced with one fiber braid, one braid of high tensile steel wire and covered with an oil resistant rubber impregnated fiber braid.
Identification: Hose is identified by specification number, size number, quarter year and year, hose manufacturer’s identification.
Uses: Hose is approved for use in aircraft hydraulic, pneumatic, coolant, fuel and oil systems.
Operating Temperatures:
Sizes-3 through 12: Minus 65 °F. to plus 250 °F.
Sizes - 16 through 48: Minus 40 °F. to plus 275 °F.
Note: Maximum temperatures and pressures should not be used simultaneously.
MULTIPLE WIRE BRAID RUBBER COVERED
MIL PAR NO.
TUBE SIZE O.D.
HOSE SIZE I.D.
HOSE SIZE O.D.
RECOMM.
OPER.
PRESS.
MIN.
BURST PRESS.
MIN.
PROOF PRESS.
MIN.
BEND RADIUS
MIL-H-8788- 4-L MIL-H-8788- 5-L MIL-H-8788- 6-L MIL-H-8788- 8-L MIL-H-8788-10-L MIL-H-8788-12-L MIL-H-8788-16-L 1/4 5/16 3/8 1/2 5/8 3/4 1 7/32 9/32 11/32 7/16 9/16 11/16 7/8
0.63
0.70
0.77
0.86
1.03
1.22
1.50 3,000 3,000 3,000 3,000 3,000 3,000 3,000 16,000 14,000 14,000 14,000 12,000 12,000 10,000 8,000 7,000 7,000 7,000 6,000 6,000 5,000
3.00
3.38
5.00
5.75
6.50
7.75
9.63
Hose Construction: Seamless synthetic rubber inner tube reinforced with one fabric braid, two or more steel wire braids, and covered with a synthetic rubber cover (for gas applications request perforated cover).
Identification: Hose is identified by specification number, size number, quarter year and year, hose manufacturer’s identification.
Uses: High pressure hydraulic, pneumatic, coolant, fuel and oil.
Operating Temperatures:
Minus 65 °F. to plus 200 °F.
Par 9-30 Page 9-433
RIGHT WAY WRONG WAY
Do not bend or twist the hose as illustrated.
Allow enough slack in the hose line to provide for changes in length when pressure is applied. The hose will change in length from + 2% to – 4%.
Metal end fittings cannot be considered as part of the flexible portion of the assembly.
The use of elbows and adapters will ensure easier installation and in many installations will remove the strain from the hose line and greatly increase service life.
At all times keep the minimum bend radii of the hose as large as possible to avoid tube collapsing.
FIGURE 9-9. Proper hose installations.
INSIDE BEND RADII V.S. OPERATING PRESSURE MIL-H-8794 HOSE WITH NO FLEXING 10 BEND RADIUS INCHES 20
- 16 5 4 200 400 600 800 1000 1500 2000 2500 3000 OPERATING PRESSURE - POUNDS/SQ. IN. (-3 TO -24 INCLUSIVE) MINIMUM BEND RADII FOR . - 40, AND 48 AT ALL PRESSURES ARE AS FOLLOWS: -32 13.25" MIL-H-8788 HOSE WITH - 40 24" NO FLEXING -48 33" DASH HO. BEND RADII
3.000 BEND FACTOR 3.375
5.000
5.750 10 6.500 20 40 60 80 100 120 140 160 180 12 7.750 16 9.625
TOTAL FLEXING RANGE OF INSTALLED HOSE (DEGREES) MINIMUM BEND RADIUS OF HOSE UNDER FLEXING CONDITIONS = "N" × NO FLEXING BEND RADIUS OF EITHER MIL-H-8794 OR MIL-H-8788 HOSE EXAMPLE: FOR MIL-H-8794 HOSE ONCE OF STIMUM BEND US AND MAN INS (MEASURED AT INSIDE OF BEND).
MINIMUM BEND RADII MEASURED AT INSIDE OF BEND DIMENSIONS IN INCHES.
FIGURE 9-10. Minimum bend radii.
Par 9-30 Page 9-434
Par 9-30 Page 9-435 (and 9-26) TABLE 9-4. Ball diameters for testing hose restrictions or kinking.
HOSE SIZE -4 -5 -6 -8 -10 -12 -16 -20
BALL SIZE 5/64 9/64 13/64 9/32 3/8 1/2 47/64 61/64
FIGURE 9-11. Suggested handling of preformed hose.
9-31.9-36. [RESERVED.]
Par 9-37 Page 9-436
SECTION 3. EMERGENCY EQUIPMENT
LIFE RAFTS. Inflatable life rafts are subject to general deterioration due to aging. Experience has indicated that such equipment may be in need of replacement at the end of 5 years due to porosity of the rubber-coated material. Wear of such equipment is accelerated when stowed on board aircraft because of vibration which causes chafing of the rubberized fabric. This ultimately results in localized leakage. Leakage is also likely to occur where the fabric is folded because sharp corners are formed. When these corners are in contact with the carrying cases or with adjacent parts of the rubberized fabric, they tend to wear through due to vibration (Ref: TSO-C70a).
When accomplishing maintenance, repair, and inspection of unpacked rafts, personnel should not step on any part of the raft or flotation tubes while wearing shoes. Rafts should not be thrown or dropped, since damage to the raft or accessories may result. Particular care should be exercised at all times to prevent snagging, cutting, and contact with gasoline, acids, oils, and grease. High standards of performance for proper maintenance, inspection, and repair cannot be overemphasized, since the lives of passengers could be involved.
Inspection and inflation tests, when applicable, will be accomplished during storage and after installation in an aircraft in accordance w ith the manufacturer’s specifications and/or FAA-approved procedures.
Accessory items will be installed during these inspections. A raft knife will be attached by a 24-inch nylon lanyard to the mooring eye located above the CO2 cylinder case to enable rapid cutting of the mooring line.
LIFE RAFT INSPECTIONS. Inspection of life rafts should be performed in accordance with the manufacturer’s specifications. General inspection procedures to be performed on most life rafts are as follows.
CAUTION: Areas where life rafts are inspected or tested must be smooth, free of splinters, sharp projections, and oil stains.
Floors with abrasive characteristics, such as concrete or rough wood, will be covered with untreated tarpaulins or heavy clean paper.
Inspect life rafts for cuts, tears, or other damage to the rubberized material. If the raft is found to be in good condition, remove the CO 2 bottle(s) and inflate the raft with air to a pressure of 2 psi. The air should be introduced at the fitting nor mally connected to the CO 2 bottle(s). After at least 1 hour, to allow for the air within the raft to adjust itself to the ambient temperature, check pressure and adjust, if necessary, to 2 psi and allow the raft to stand for 24 hours. If, after 24 hours, the pressure is less than 1 psi, examine the raft for leakage by using soapy wate r. In order to eliminate pressure variations due to temperature differences at the time the initial and final reading are taken, test the raft in a room where the temperature is fairly constant. If the pressure drop is satisfactory, the raft should be considered as being in an airworthy condition and returned to service after being fitted with correctly charged CO 2 bottles as determined by weighing them.
Rafts more than 5 years old are likely to be unairworthy due to deterioration. It is suggested that serviceable rafts be marked to indicate the date of inspection and that soapstone be used when folding them preparatory to insertion into the carrying case. Take care to see that all of the raft’s required equipment is on board and properly stowed. If the raft lanyard, used to prevent the raft from floating away from the airplane, is in need of
Par 9-37 Page 9-437 replacement, use a lanyard not less than 20 feet long and having a breaking strength of about 75 pounds.
It is recommended that the aforementioned procedure be repeated every 18 months using the CO 2 bottle(s) for inflation. If a single bottle is used for inflating both compartments, it should be noted whether the inflation is proceeding equally to both compartments.
Occasionally, the formati on of “carbon-dioxide snow” may occur in one passage of the distribution manifold and divert a larger volume of gas to one compartment, which may burst if the mattress valve is not open to relieve the pressure. If the pressure is satisfactory, return the raft to serv ice in accordance with the procedure outlined.
Inspect the CO 2 cylinder for evidence of crossthreading or stripping.
Inspect the CO 2 bottle inflation valve cable rigging as follows.
Remove the screws that attach the cover plate to the valve and remove the cover plate.
Inspect the firing line cable ball swage for engagement in the correct recess for either “Upward Pull” or “Downward Pull.” The cable will be wrapped around the sheave approximately 270 degrees.
Reposition the cable ball swage as required.
(See figure 9-12.)
Replace the cover plate. The green dot on the sheave should be visible through the window in the cover plate, indicating a charged cylinder.
Check the CO 2 cylinder release cable and housing for condition and security.
Make sure the safety deflector is removed from the cylinder outlet before connecting the cylinder to the raft. (See figure 9-12.)
Stencil the life raft’s inspection date on the raft.
SURVIVAL KIT INSPECTION.
Survival Kit Contents . Each raft accommodating passengers or crew members should contain, as a minimum, the following:
Hand Pump (if required) Desalting Kit, First-Aid Kit Mirror/Reflector Emergency Rations Tarpaulins Fishing Kit Raft Knife Compass Protective Ointment (Sunburn) Oars Emergency Water Containers Repair Kits Signal Flares Carrying Case Locator Beacon and Battery Lines and Anchor Police Whistle Flashlight Space Blankets (if required) Light-sticks Solar Still Kit Survival Manual Duct Tape Plastic Trash Bags Accessory Containers
- Bailing Bucket
- Sponge Dye Marker Shark Chaser
Par 9-39 Page 9-438
FIGURE 9-12. Inflation valve.
Exposure Suits. Quick-donning exposure suits should be provided in sufficient quantity to accommodate the passengers and crew on extended over-water missions whenever any of the following conditions exist.
The water temperature is 59 ºF or below, or
The Outside Air Temperature (OAT) is 32 ºF or below.
Physical Inspection. Make a physical inspection of the life raft’s accessories and/or contents, in accordance with manufacturer’s specificati ons, to ascertain that all items required are in a serviceable condition.
Pumps and Hoses.
Check the air pump for condition and security.
Check the air pump hose and hose fittings for ease of attachment to the pump and mattress valves.
Operate the pump to ensure that it delivers air.
Close the outlet and check the seal of the piston.
Blow into the outlet to determine if the pump check valve will seal.
Desalting Kit.
Check the desalting kit expiration date, if applicable.
Replace the severely dented or punctured cans.
NOTE: Type MK-2 desalter kits have an indefinite shelf and service life and do not have to be age-controlled.
First-Aid Kit. Inspect each kit prior to flight to ensure that the seal is intact; the kits have not been tampered with or opened; and check the date when the kit contents should be inspected (120-day interval), and containing the following:
Par 9-49 Page 9-439 1 Case First-Aid Kit, empty;
1 Bottle Benzalkonium Chloride Zinc;
Tinted, 1:1000 2cc 1 Package Sodium Chloride;
(Sodium Bicarbonate Mix) 4.5 gm;
1 Bandage each, Gauze, & Compress (2 inches x 6 yd);
2 Dressings, First-Aid, 4 inches x 7 inches;
1 Package Bandages; Absorbent & Adhesive, 3/4-inch x 3 inches;
3 Bottles, Snap-On Cap, Plastic Tablet and Capsule, Round, (issued empty; to be used as needed by user);
1 Tube Lipstick, Anti-Chap; and 1 bottle Water Purification Tablets, Iodine 8 mg (50).
If the seal is found to be broken, or there is evidence of tampering, the kit should be opened and inspected to ensure that all components are included and undamaged.
After such inspection, the kit should be resealed.
To reseal the kit, use a wire and lead seal according to the manufacturer’s specifications. Pass the wire through grommets or opposite flaps, bend the wire back and force each end through the middle of the lacing cord on each side of the square knot. Pass the ends of the wire through the holes in the lead seal, draw the wire taut, and compress the seal.
Mirror/Reflector. Check the reflector for defective reflection surface and the reflector lanyard for defective conditions and security of attachment.
Emergency Rations. Check the food ration cans for obvious damage, severe dents, and an expiration date. Replace items when severely damaged, dented, or when the date is expired. Ensure that the opening key is attached.
Tarpaulins. Spread out and check for tears, mildew, corroded grommets, and general condition.
Fishing Kit. Check for damaged container or for tampering. Replace if damaged or incomplete.
Raft Knife. Check for corrosion and ease of opening and security of the knife lanyard to the raft.
Compass. Check for proper operation and condition.
Protective Ointment (Sunburn).
Check the sunburn ointment containers for cracks or crushed condition.
Install the ointment in a 6 inch mailing tube and tape the ends to prevent crushing. Stow it where it will be subjected to the least amount of pressure in the kit.
Oars.
Check for serviceability.
Wrap the oars separately in craft paper and seal with tape.
Stencil inspected in letters not less than 1/2-inch high on each package.
Emergency Water Containers. Check for open seams, holes, etc. Replace defective containers.
Repair Kit. Check for proper wrapping and missing items. Four plugs are wrapped in a single container. This container and the pliers are wrapped in waterproof paper and sealed
Par 9-49 Page 9-440 with waterproof tape. The package is stenciled repair plugs and pliers with letters not less than 1/2-inch high.
Par 9-39 Page 9-441 Signal Flares. Check the flares for obvious damage and suspended lot numbers.
Replace if lot number is over-age or obvious damage exists.
Carrying Case. Check for snags, abrasions, and defective snaps. Repair or replace as necessary.
Locator Beacon and Battery.
Check for corrosion and obvious damage per the manufacturer’s manual.
Assemble as an operating unit. Perform an operational test, prepare the beacon for water activation by pulling out the battery switch plug from the end of the transmitter section, and package as instructed on the container.
Lines and Anchor. Check all lines and sea anchors for conditions and security.
Police Whistle. Inspect and test.
Flashlight. Test the flashlight switch for operation; remove old batteries and inspect the case for corrosion and condition; and install new batteries and test momentarily for operation.
Space Blankets. Check space blankets (if required) for rips, tears, and obvious damage.
Light-sticks. Inspect light-sticks for condition and check expiration date.
Solar Still Kit. Check the solar still kit for condition.
Survival Manual. Inspect the survival manual for condition and completeness.
Par 9-39 Page 9-442 Duct Tape. Check the duct tape for deterioration.
Plastic Trash Bags. Assure that three (each) plastic trash bags are serviceable.
Accessory Containers.
Check the containers for condition and security.
Repack the accessories, secure, and record the inspection data on data cards. Record the Inspection date.
Dye Marker. Check for dents and overall condition.
Shark Chaser. Check for dents and overall condition.
After Inspection. Replace accessories in the container, close, and tie securely with tying tapes. Draw a 25-pound breaking strength cord tightly around the center and one approximately 5 inches from each end of the container, tie with square knots, and seal with a lead seal.
Folding Life Rafts . Fold the life rafts per the manufacturer’s folding diagram using soapstone and secure the raft in its contai ner. Check the container for obvious damage.
SPECIAL INSPECTIONS. Life rafts in storage or in service shall be unpacked and thoroughly inspected for mildew whenever weather or other conditions warrant. The extent of a special inspection will be determined by the inspector or maintenance chief following a review of the circumstances or conditions to which the life rafts have been subjected. The inspector or maintenance chief may direct a complete overall inspection and inflation test
Par 9-39 Page 9-443 of the life rafts, regardless of the last date of inspection, if it is considered that another inspection is warranted.
INSPECTION RECORD. The date the inspection was completed will be stenciled on the flotation tube at the left of the cylinder. The size of lettering will not be less than 1/4-inch or greater than 1/2-inch in height. Previous inspection dates will not be removed or obliterated, but will be arranged in columnar form with the latest date at the top. After the inspection is completed, fill out the raft’s inspection record in accordance with part 43 section 43.9, and attach the parts tag to the survival equipment. The date on the tag will reflect the same date as stenciled on the flotation tube and will be used to determine the next due date of inspection and test.
RAFT REPAIRS.
Repairs. The service life for flotation equipment will be determined by condition rather than age. Equipment passing tests and inspections may remain in service indefinitely since the inflation tests and material inspections will identify and condemn equipment having more than minor installation defects. However, the service life for life rafts operating under normal usage and environmental conditions is anticipated by the manufacturers to be 8 to 10 years, and it is appropriate to base life raft’s parts replacement programs upon this estimate. It is not considered advisable or economical to perform major repairs on life rafts.
Life Rafts. Life rafts with any of the following conditions should be condemned rather than repaired:
Life rafts over 3-1/2 years of age and requiring major repair or more than two minor repairs.
A rip or tear across an air retaining seam.
Rafts on which oil, grease, or any other foreign substance has caused a deterioration of the rubberized fabric.
Rafts on which a heavy mildew condition has caused deterioration of the rubberized fabric.
Rafts on which porous flotation tubes allow diffusion of air. A porous area is located by a soap test on the inflated raft. Higher diffusion is indicated by the excessive loss of pressure after a soap test has failed to locate a specific area of injury on the raft.
Rafts requiring internal repair or opening of air retaining seams for repair.
Rafts with an excessive number of injuries that would not, in the judgment of competent inspectors, justify repair.
Patches. Holes or abrasions which are 2 inches or less, in diameter (in air retaining chambers) will be repaired by the application of an out side patch. Holes exceeding 2 inches in length or diameter, will require an inside patch as well as an outside patch. Inside and outside patches should be round or rectangular and manufactured of fabric (specification MIL-C-6819).
Cement should conform to Class 1 of specification MIL-C-5539. Patch as follows:
Outside patches.
With a rubber solvent thoroughly clean the area to be patched.
From the material referenced, fabricate a patch as shown in figure 9-13.