(1) Appendix
1, "Federal Aviation Administration Standard for Liferafts," of this TSO
specifies certain test methods that are contained in Federal Test Method
Standard No. 191A unless otherwise noted. Federal Test Method Standard
No. 191A may be examined at the FAA Headquarters in the Office of Airworthiness,
Aircraft Engineering Division (AWS-110), and at all Aircraft Certification
Offices, and may be obtained (or purchased) from the General Services
Administration, Business Service Center, Region 3, 7th and D Streets,
S.W., Washington, D.C. 20407.
(2) Federal Aviation
Regulations Part 21, Subpart O and Advisory Circular 20-110, Index of
Aviation Technical Standard Orders may be reviewed at the FAA Headquarters
in the Office of Airworthiness, Aircraft Engineering Division (AWS-110),
and at all regional Aircraft Certification Offices.
{sig} J. A. Pontecorvo
Acting Director of Airworthiness
TSO-C70a - 4/ 13/84
Appendix 1
APPENDIX 1. FEDERAL
AVIATION ADMINISTRATION STANDARD FOR LIFERAFTS
1. Purpose.
This standard provides the minimum performance standards for liferafts.
2. SCOPE.
This standard covers the following types of liferafts:
TYPE I - For use
in any category aircraft.
TYPE II - For use
in nontransport category aircraft.
3. Materials
and Workmanship.
3.1 Nonmetallic
Materials.
3.1.1
The finished device must be clean and free from any defects that might
affect its function.
3.1.2 Coated
fabrics and other items, such as webbing, subject to deterioration
must have been manufactured not more than 18 months prior to the date
of delivery of the finished product.
3.1.3 The materials
must not support fungus growth.
3.1.4 Coated
fabrics - General. Coated fabrics, including seams, subject to
deterioration used in the manufacture of the devices must possess
at least 90 percent of their original physical properties after these
fabrics have been subjected to the accelerated ageing test specified
in paragraph 6.1 of this standard. Material used in the construction
of flotation chambers and decks must be capable of withstanding the
detrimental effects of exposure to fuels, oils and hydraulic fluids.
3.1.4.1
Strength. Coated fabrics used for these applications must conform
to the following minimum strengths after ageing:
Tensile Strength
(Grab Test)
Warp 190 pounds/inch
Fill 190 pounds/inch
Tear Strength
Trapezoid Test: 13 x 13 pounds/inch (minimum); or
Tongue Test: 13 x 13 pounds/inch (minimum)
3.1.4.2 Adhesion.
In addition to the requirements of 3.1.4.1, coated fabrics must
meet the following minimum strengths after ageing:
Ply Adhesion
-
5 pounds/inch width at 70 +/- 2 degrees F at a pull rate of 2.0
to 2.5 inches/minute
Coat Adhesion
-
5 pounds/inch width at 70 +/- 2 degrees F at 2.0 to 2.5 inches/minute
3.1.4.3 Permeability.
For coated fabrics used in the manufacture of inflation chambers,
the maximum permeability to helium (Permeability Test Method) may
not exceed 10 liters per square meter in 24 hours at 77 degrees
F, or its equivalent using hydrogen. The permeameter must be calibrated
for the gas used. In lieu of this permeability test, an alternate
test may be used provided the alternate test has been approved as
an equivalent to this permeability test by the manager of the FAA
office to which this TSO data is to be submitted, as required in
Paragraph (c), Data Requirements.
3.1.5 Seam
Strength and Adhesives. Cemented or heat sealable seams used in
the manufacture of the device must meet the following minimum strength
requirements:
Shear Strength
(Seam Shear Test Method) -
175 pounds/inch width at 75 degrees F
40 pounds/inch width at 140 degrees F
Peel Strength
(Peel Test Method) -
5 pounds/inch width at 70 degrees F
3.1.6 Seam
Tape. If tape is used for seam reinforcement or abrasion protection
of seams or both, the tape must have a minimum breaking strength (Grab
Test Method) of 40 pounds/inch width in both the warp and fill directions.
When applied to the seam area, the adhesion strength characteristics
must meet the seam strength requirements in paragraph 3.1.5.
3.1.7 Canopy.
Fabrics used for this purpose must be waterproof and resistant to
sun penetration, must not affect the potability of collected water,
and must meet the following minimum requirements in the applicable
tests prescribed in paragraph 6.1 of this standard, except that in
lieu of meeting the tensile strength requirements, a fabricated canopy
may be demonstrated to withstand 35-knot winds and 52-knot gusts:
Tensile Strength
(Grab Test)
Warp 75 pounds/inch
Fill 75 pounds/inch
Tear Strength
Trapezoid Test: 4 x 4 pounds/inch; or
Tongue Test: 4 x 4 pounds/inch
Coat Adhesion
of Coated Fabrics
3.5 pounds/inch width at 70 +/- 2 degrees F at a separation rate of
2.0 to 2.5 inches/minute
3.1.8 Flammability.
The device (including carrying case or stowage container) must be
constructed of materials which meet FAR 25.853 (14 CFR 25.853) in
effect on May 1, 1972, as follows: Type I rafts must meet 25.853
(b) and Type II rafts must meet 25.853 (b-3).
3.2 Metallic
Parts. All metallic parts must be made of corrosion-resistant material
or must be suitably protected against corrosion.
3.3 Protection.
All inflation chambers and load carrying fabrics must be protected in
such a manner that nonfabric parts do not cause chafing or abrasion
of the material in either the packed or the inflated condition.
4. Design and
Construction.
4.1 Capacity.
The rated and overload capacities of a liferaft must be based on not
less than the following usable sitting areas on the deck of the liferaft:
Rated Capacity -
3.6 feet2 per person
Overload Capacity
- 2.4 feet2 per person
4.1.1 Capacity
- Alternate Rating Methods. In lieu of the rated capacity as determined
by paragraph 4.1 of this standard, one of the following methods may
be used:
4.1.1.1 The
rated capacity of a Type I or Type II liferaft may be determined
by the number of occupant seating spaces which can be accommodated
within the occupiable area exclusive of the perimeter structure
(such as buoyancy tubes) without overlapping of the occupant seating
spaces and with the occupant seating spaces located to provide each
occupant with a back support of not less than 8 inches high. The
occupant seating space may not be less than the following size:
4.1.1.2 The
rated capacity of a Type I or Type II liferaft may be determined
on the basis of a controlled pool or fresh water demonstration which
includes conditions prescribed under Paragraph 6.2.3 of this standard
and the following:
4.1.1.2.1
The sitting area on the liferaft deck may not be less than 3 square
feet per person.
4.1.1.2.2
The liferaft must have a back support for each occupant of not
less than 14.7 inches wide and 8 inches high.
4.1.1.2.3
At least 30 percent but no more than 50 percent of the participants
must be female.
4.1.1.2.4
Except as provided below, all participants must select their sitting
space without placement assistance. Instructions, either identified
on the raft or announced prior to the demonstration, may be used
informing that each participant should have a back support. A
raft commander, acting in the capacity of a crewmember, may direct
occupant seating to the extent necessary to achieve reasonable
weight distribution within the raft.
4.1.1.2.5
All participants must not have practiced, rehearsed, or have had
the demonstration procedures described to them within the past
6 months.
4.2 Buoyancy.
An average occupant weight of not less than 170 pounds must be used
in all applicable calculations and tests specified herein. In tests,
ballast in the form of sand bags or equivalent may be used to achieve
the 170 pound average, provided the appropriate weight distribution
within the raft is maintained.
4.2.1
Type I Liferaft. Buoyancy must be provided by two independent
buoyancy tubes each of which, including the raft floor, must be capable
of supporting the rated and overload capacities in fresh water if
the other tube is deflated. The liferaft loaded to its rated capacity
must have a freeboard of at least 12 inches with both buoyancy tubes
at minimum operating pressure. The liferaft loaded to its rated capacity
with the critical tube deflated and the remaining tube at minimum
operating pressure must have a freeboard of at least 6 inches. The
liferaft loaded to its overload capacity with the critical tube deflated
must have a measurable freeboard.
4.2.2
Type II Liferaft. When single tube construction is used to
provide the buoyancy, internal bulkheads must divide the flotation
tube into at least two separate chambers such that the liferaft will
be capable of supporting the rated number of occupants out of fresh
water in the event that one chamber is deflated. The complete liferaft
loaded to its rated capacity must have a freeboard of at least 6 inches.
4.3 Inflation.
The inflation system must be arranged so that failure of one inflatable
chamber or manifold will not result in loss of gas from the other chambers.
The inflation equipment must be located so as not to interfere with
boarding operations. Components of the inflation system must meet Department
of Transportation Specification 3AA (49 CFR 178.37) or Specification
3HT (49 CFR 178.44) in effect May 30, 1976, as applicable, or an equivalent
approved by the manager of the FAA office to which this TSO data is
to be submitted, as required in paragraph (c), Data Requirements. The
inflation system must be constructed to minimize leakage due to back
pressure after inflation. If an air aspirator system is used, the system
must be constructed either to prevent the ingestion of foreign objects
or to prevent failure or malfunction as a result of ingestion of small
foreign objects. For Type I liferafts, there must be an independent
inflation source for each primary flotation tube, except that there
may be a single inflation source for all flotation tubes if data substantiating
the reliability of the single inflation source is approved by the manager
of the FAA office to which this TSO data is to be submitted, as required
in Paragraph (c), Data Requirements.
4.4 Liferaft
Canopy. A canopy must be packed with or attached to the raft. The
erected canopy must be capable of withstanding 35-knot winds and 52-knot
gust in open water. The canopy must provide adequate headroom and must
have provision for openings 180 degrees apart. Means must be provided
to make the openings weathertight. If the canopy is not integral with
the raft, it must be capable of being erected by occupants following
conspicuously posted, simple instructions. It must be capable of being
erected by one occupant of an otherwise empty raft and by occupants
of a raft filled to rated capacity. For a reversible raft, attachment
provisions must be installed to permit the canopy to be installed on
either side of the raft.
4.5 Capsize
Resistance - There must be water pockets or other means to provide
capsize resistance for an empty or lightly loaded liferaft.
4.6 Boarding
Aids. For Type I liferafts, boarding aids must be provided at two
opposing positions on the raft. One boarding aid is sufficient for a
Type II liferaft. Boarding aids must permit unassisted entry from the
water into the unoccupied raft and must not at any time impair either
the rigidity or the inflation characteristics of the raft. Puncturing
of inflatable boarding aids must not affect the buoyancy of the raft
buoyancy chambers. Boarding handles and/or stirrups used in conduction
with the boarding aids must withstand a pull of 500 pounds.
4.7 Righting
Aid(s). Means must be provided to right a nonreversible liferaft
if it inflates in an inverted position. The means provided for righting
must be such that they may be used by one person in the water.
4.8 Lifeline.
A nonrotting lifeline of contrasting color and at least 3/8-inch diameter
or 3/4-inch width must encircle the liferaft on the outside periphery
so that it can be easily grasped by persons in the water. The lifeline
and its attachment must be capable of withstanding a minimum load of
500 pounds and must not interfere with the liferaft inflation.
4.9 Grasp Line.
A grasp line, meeting the size and strength requirements for the lifeline,
must be provided with sufficient slack for use by liferaft occupants
to steady themselves when seated an the liferaft deck with their backs
to the main flotation tube(s).
4.10 Color.
The color of the liferaft's surfaces, including the canopy surface,
visible from the air must be an International Orange-Yellow or an equivalent
high visibility color.
4.11 Placards.
Suitable placarding must be provided in contrasting colors in waterproof
paint which is not detrimental to the fabric, that denotes use and location
of the inflation systems, raft equipment, boarding aids, and righting
aids. For reversible rafts, placement of the placarding
must take into account
usage of either side of the raft. The letters used for such placarding
must be at least 2 inches high except that details and miscellaneous
instructions my be of smaller lettering. Applicable placarding must
take into account persons boarding or righting the raft from the water.
4.12 Lights.
One or more survivor locator lights must be provided that are approved
under TSO-C85. The lights must be automatically activated upon raft
inflation in the water, and visible from any direction by persons in
the water.
4.13 Raft Sea
Performance. The raft must meet the seaworthiness requirements in
6.2.3.2 and must be capable with its equipment of withstanding a saltwater
marine environment for a period of at least 15 days.
5.Liferaft Equipment.
All lines must be suitably stowed and secured to prevent entanglement
during launching/inflation of a liferaft.
5.1 Mooring
Line. A nonrotting mooring line at least 20 feet in length must
be attached at one end to one end of the raft, with the remainder of
the line held flaked to the carrying case (See 5.2). The mooring line
must be capable of keeping the raft, loaded to maximum rated capacity,
attached to a floating aircraft, and not endanger the raft or cause
the raft to spill occupants if the aircraft sinks. The line may be equipped
with a mechanical release linkage. The breaking strength of the line
must be at least 500 pounds, or 40 times the rated capacity of the raft,
whichever is greater, but need not exceed 1,000 pounds.
5.2 Liferaft
Launching Equipment. A parachute ripcord grip and retaining pocket
must form the primary inflation control. The ripcord grip or the attached
static mooring line must be provided with means for attachment to the
aircraft. If the ripcord grip is designed to attach to the aircraft,
its strength may not be less than that of the static mooring line. The
position of the ripcord grip must be standardized. When facing the release
end of the carrying case, the center line of the ripcord grip retaining
pocket must lie at 45 degrees in the right upper quadrant of the end
section. The outermost extremity of the ripcord grip may not extend
beyond the outer margin of the carrying case. The line attached to the
ripcord grip must serve both to retain the liferaft and to actuate the
gas release(s). The tension required to withdraw the static mooring
line and to actuate the gas release mechanism(s) must be between 20
and 30 pounds. The strength of the gas release mechanism(s), its fittings,
and its attachments may not be less than 100 pounds.
5.3 Sea Anchor.
A sea anchor, or anchors, or other equivalent means must be provided
to maintain the raft, with rated capacity and canopy installed, on a
substantially constant heading relative to the wind and have the ability
to reduce the drift to 2 knots in 17 to 27 knot winds.
Unless analysis
and/or test data substantiating the adequacy of a lower breaking strength
is approved by the manager of the FAA office to which this TSO data
is to be submitted as required in paragraph (c), Data Requirements,
the line securing a sea anchor to the raft must have a breaking strength
of 500 pounds or 40 pounds tines the rated capacity of the raft, whichever
is greater. The attachment of the line to the raft must be capable of
withstanding a load of 1.5 times the line rated strength without damaging
the raft. The line must be at least 25 feet in length and must be protected
to prevent it from being cut inadvertently by raft occupants.
5.4 Heaving-Trailing
Line. At least one floating heaving-trailing line not less than
75 feet in length for Type I rafts and not less than 35 feet in length
for Type II rafts, and at least 250 pounds strength, must be located
on the main flotation tube near the sea anchor attachment. The attach
point of the line must withstand a pull of not less than 1.5 times the
line rated strength without damage to the raft. A heaving-trailing line
must be accessible in any inflated position of a reversible liferaft.
5.5 Emergency-Inflation.
Means readily accessible to occupants of the raft, and having a displacement
of at least 32 cubic inches per full stroke, must be provided to manually
inflate and maintain chambers at minimum operating pressure. Manual
inflation valves, with a nonreturn opening adequate for the size and
capacity of the inflation means, must be located to permit inflation
of all chambers. The location must take into consideration occupancy
of each side of reversible raft. The inflation means and valves must
have provisions to prevent inadvertent removal and loss when either
stowed or in use.
5.6 Accessory
Case Tiedowns. Provisions must be made for tiedowns to hold any
accessory case. Each accessory case tiedown must withstand a pull of
250 pounds.
5.7 Carrying
Case. A carrying case which meets the flammability requirements
of this standard and which properly fits the packed liferaft must be
provided. Carrying case materials must be of a highly visible color,
be fungus proof, and be resistant to aircraft fuels and other fluids.
The carrying case must provide chafe protection to the liferaft. The
carrying case must be provided with easily distinguishable handles so
that it may be carried by one person, carried by two persons in tandem,
or dragged by either end; none of these carrying operations must tend
to pull the carrying case open. Each handle mist be easily grasped and
its strength must be at least four tines the total weight of the liferaft
and case. Conventional zippers may not be employed for closure. Location
of and instructions for use of the inflation handle must be clearly
identified and marked on the carrying case surface.
5.8 Knife.
A hook type knife secured by a retaining line must be sheathed and attached
to the liferaft adjacent to the point of mooring line attachment.
6. Tests.
6.1 Material
Tests. The material tests required in paragraph 3 of this standard
must be determined in accordance with the following test methods or
approved equivalent methods:
Test Method
| Test Required |
Federal Test Method
Standard No. 191A
dated July 20, 1978 |
Notes |
| Accelerated Age |
Method 5850 |
Per Note (1) |
| Tensile Strength (Grab Test) |
Method 5100 |
|
| Tear Strength (Trapezoid Test) |
Method 5136(4) |
|
| Tear Strength (Tongue Test) |
Method 5134 |
(Alternate to Trapezoid
Test. See 3.1.4.1) |
| Ply Adhesion |
Method 5960 |
|
| Coat Adhesion |
Method 5970 |
|
| Permeability |
Method 5460(4) |
|
|
| Seam Shear Strength |
|
Per Note (2) |
| Seam Peel Strength |
Method 5960 |
Per Note (3) |
NOTES:
(1) Samples for
the accelerated ageing test must be exposed to a temperature of 158
+/- 5 degrees Fahrenheit for not less than 168 hours. After exposure,
the samples must be allowed to cool to 70 +/- 2 degrees Fahrenheit
for neither less than 16 hours nor more than 96 hours before determining
their physical properties in accordance with paragraph 3.1 of this
standard.
(2) Each sample
shall consist of two strips 2 inches maximum width by 5 inches maximum
length bonded together with an overlap of 3/4 inch maximum. The free
ends must be placed in the testing machine described in Method 5100
and separated at a rate of 12 +/- 0.5 inches per minute. The average
value of two samples must be reported. Samples may be multilayered
as required to provide adequate strength to ensure against premature
material failure.
(3) Separation
rate must be 2.0 to 2.5 inches per minute.
(4) Federal Test
Method Standard No. 191 in effect December 31, 1968.
6.2 Liferaft
Tests.
6.2.1 Pressure
Retention. Under static conditions and when inflated and stabilized
at the nominal operating pressure, the pressure in each inflatable chamber
must not fall below the minimum operating pressure in less than 24 hours.
The minimum operating pressure is the pressure required to meet the
minimum design buoyancy requirements of paragraph 4.2 of this standard.
6.2.2 Overpressure
Tests.
6.2.2.1 The
device must be shown by test to withstand a pressure at least 1.5
times the maximum operating pressure for at least 5 minutes without
sustaining damage.
6.2.2.2 At
least one specimen of the inflatable device model must be shown
by test to withstand a pressure at least 2 times the maximum operating
pressure without failure. Devices so tested must be clearly identified.
6.2.3 Functional
Tests. Each liferaft model must pass the following tests:
6.2.3.1 Water
tests. In either a controlled pool or fresh water, the liferaft
capacity and buoyancy must be demonstrated as follows:
6.2.3.1.1
Both rated and overload capacities established in accordance with
the requirements of paragraph 4.1 of this standard must be demonstrated
with inflation tubes at minimum operating pressure and with the
critical buoyancy chambers deflated. The resultant freeboard in
each case must meet the requirements of paragraph 4.2 of this
standard.
6.2.3.1.2
Persons used in the demonstration must have an average weight
of not less than 170 pounds. Ballast in the form of sand bags
or equivalent may be used to achieve proper loading provided the
appropriate weight distribution within the slide/raft is maintained.
6.2.3.1.3
Persons used in the demonstration must wear life preservers with
at least one chamber inflated.
6.2.3.1.4
The required liferaft equipment, including one emergency locator
transmitter or a weight simulating a transmitter, must be aboard
the liferaft.
6.2.3.1.5
It must be demonstrated that the liferaft is self-righting, or
can be righted by one person in water, or while inverted can be
boarded and provide flotation for the normal rated capacity.
6.2.3.1.6
It must be demonstrated that the boarding aids are adequate for
the purpose intended and that it is possible for an adult wearing
an inflated life preserver to board the liferaft unassisted.
6.2.3.2 Sea
Trials. The liferaft must be demonstrated by tests or analysis,
or a combination of both, to be seaworthy in an open sea condition
of 17 to 27-knot winds and waves of 6 to 10 feet. In tests, ballast
in the form of sand bags or equivalent way be used to achieve proper
loading provided the appropriate weight distribution within the
raft is maintained. If analysis is used, the analysis must be approved
by the manager of the FAA office to which the TSO data is to be
submitted as required in paragraph (c), Data Requirements. For this
seaworthiness demonstration, the following apply:
6.2.3.2.1
The liferaft must be deployed to simulate deployment from an aircraft
under the most adverse wind direction and wave condition. If the
liferaft is an aspirated inflated type, it must be demonstrated
that water ingested during inflation will not cause the raft to
fail to meet the requirement for buoyancy under rated capacity
in 4.2.
6.2.3.2.2
All required equipment must be aboard and the proper functioning
of each item of equipment must be demonstrated.
6.2.3.2.3
The canopy must be erected for a sufficient time to assess its
resistance to tearing and the protection it affords. The method
of erection must be shown to be accomplished by one occupant of
an otherwise empty liferaft and by occupants of a liferaft filled
to rated capacity.
6.2.3.2.4
The stability of the liferaft must be demonstrated when occupied
at normal rated capacity and at 50 percent rated capacity.
6.2.3.3 Liferaft
Drop Test. A complete liferaft package must be dropped or thrown
from a height of 5 feet onto a hard surface floor after which it
must be inflated and meet the pressure retention requirements of
paragraph 6.2.1 of this standard.
6.2.3.4 Portability
Test. If the liferaft is to be manually deployed, it must be
demonstrated that the complete liferaft package can be moved from
a typical stowage installation by no more than two persons and then
deployed at another suitable exit.
6.2.3.5 Carrying
Case. It must be demonstrated at least 10 times that the carrying
case will open satisfactorily and cause no delay in the deployment
and inflation of the liferaft.
6.2.3.6 Gas
Cylinder Releases. It must be demonstrated that pulling the
ripcord grip from any position will actuate the primary gas release(s).
6.2.5 Temperature
Exposure and Inflation. The manufacturer shall determine the minimum
temperature at which the complete liferaft assembly with its inflation
bottles, will be "rounded out"' (i.e., attain its design shape and
approximate dimensions) so that the liferaft will be able to receive
and to support the first occupant within one minute after the start
of inflation. Thereafter, the rate of inflation must progress in such
a manner and rate as to ensure a serviceable and rigid liferaft for
boarding by the remainder of the occupants. Similarly, a maximum environmental
temperature to which the liferaft assembly may be exposed and still
remain in a seaworthy condition upon inflation must be determined.
The temperature limitations must be submitted to the FAA and liferaft
purchaser in accordance with the data requirements of this TSO.
6.2.5.1 Test
Procedure. The packed liferaft assembly with its inflation bottles
installed must be exposed to each of the above temperatures for
not less than 24 hours and must be inflated within 5 minutes after
removal from such temperatures. The liferaft must be allowed to
return to a temperature of approximately 70 +/- 5 degrees Fahrenheit
before being deflated, repacked, and subjected to a second exposure.
After the above tests have been completed, the liferaft must be
able to pass tests required by paragraphs 6.2.1 and 6.2.2 of this
standard.
