Civil Aviation Administration
Statens Luftfartsvæsen
AIS HQ / Luftfartsinformationstjenesten, Ellebjergvej 50, DK-2450 København SV, Danmark
TEL: +45 36 18 60 00, FAX: +45 36 18 60 22, E-mail: ais@slv.dk, Internet: www.slv.dk
AIC B
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15 / 04
18 MAR
AIC B-15/04 SPECIAL AIRWORTHINESS INFORMATION BULLETIN (SAIB).
a.
Utilsigtet udløsning af sædebælter på sæder monteret med ”D-ring”. (No. NM-04-37 Dec. 22.2003).
b.
Montering og vedligeholdelse af komponenter for udstødssystemer (No. CE-04-22 Dec. 17-2003).
SLV har valgt at udsende 2 SAIB’er fra FAA vedrørende manglende kontrol og utilstrækkelig vedligeholdelse.
Det anbefales at gennemlæse disse SAIB’er og eventuelt tage nødvendig aktion.
TL
1
SPECIAL
AIRWORTHINESS
INFORMATION
BULLETIN
Aircraft Certification Service
Washington, DC
U.S. Department
of Transportation
Federal Aviation
Administration
No. NM-04-37
December 22, 2003
We post SAIBs on the internet at www.airweb.faa.gov
This is information only. Recommendations aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin alerts you, owners and operators of airplanes with
passenger seats equipped with “D-ring” type seat belt attachment fittings (see figure 1), that
these
fittings have the potential of inadvertently releasing the seat belts attached to them
. The
“D-ring” type of seat belt attachment fitting is a type that has been commonly used by most seat
manufacturers. These fittings may be installed on, but not limited to the following aircraft:
Aerospatiale (S.N.I.A.)
ATR42
ATR72
SN-601 "Corvette"
Airbus Industries
A300
A310
A318
A319
A320
A321
A330
A340
BAE Systems Limited
ATP
BAe 146
Jetstream 4100 Series
Boeing
707
717
727
737
747
757
767
777
2
Bombardier Aerospace Inc.
BD-100-1A10 (Challenger)
Bombardier Inc.
BD-700-1A10 (Global Express)
CL-600-1A11 (CL-600 series)
CL-600-2C10 (CRJ 700 series)
CL-600-2D24 (CRJ 900 series)
DHC-3
DHC-4
DHC-6
DHC-7
British Aerospace Airbus Limited
BAC 1-11
Cessna Aircraft Company
500
550
S550
560
560XL
750
Dassault-Aviation
Fan Jet Falcon
Mystere-Falcon 20
Mystere-Falcon 200
Mystere-Falcon 50
Mystere-Falcon 900
Falcon 900EX
Falcon 2000
Falcon 2000EX
Embraer
EMB-120
EMB-135
EMB-145
Fairchild Dornier GmbH
328-100
328-300
Fokker Services
F27
F.28
Gulfstream Aerospace Corporation
G-IV
GV
GV-SP
Gulfstream Aerospace LP (Israel Aircraft Industries, Ltd.)
Astra
Galaxy
Israel Aircraft Industries, Ltd.
1121
Learjet
24
25
31
35
45
55
60
Lockheed Martin Corporation
L-1011
3
McDonnell Douglas
DC-8
DC-9
DC-10
MD-11
Raytheon
BAe.125
BH.125
DH.125
HS.125
Saab Aircraft AB
SAAB 2000
SAAB 340
Short Brothers PLC
SD3-30
SD3-60
Background
The FAA has received reports indicating that during two accidents involving transport category
airplanes, several passengers’ seat belts had released from the seat attachments (i.e., the seat belts
remained buckled but had become unhooked at their attachment fittings to the seat). The absence of
damage to the hook end of the seat belts and the “D-ring” type seat belt attachment fittings suggests
that in each case, the fitting aligned with the opening in the hook end of the seat belt, and the seat belt
became detached from the “D-ring” type seat belt attachment fittings. Detachment of a seat belt from
the “D-ring” type seat belt attachment fittings could result in injury to the seat occupant during an
accident, turbulence, or a hard landing.
During our investigation, we discovered one repeatable method of demonstrating the seat belt
detachment. When the hook end of the seat belt is near the seat belt fastener that attaches the fitting
to the seat, the seat belt hook end can become aligned such that the hook end is contacting two points
on the “D-ring” fitting. In this configuration, the spring keeper on the hook end of the seat belt is in
alignment with the upper portion of the “D-ring” type attachment fitting (figure 2). Detachment
occurs when an out-of-plane load is applied to the hook end of the seat belt by the seat belt webbing.
As the seat belt attempts to align the hook end of the seat belt with the load, the spring keeper is
depressed and the seat belt becomes detached from the fitting.
4
Figure 1
Figure 2
“D-ring” type
attachment fitting
“D-ring” type
attachment fitting
fastener
Spring keeper on the seat belt
hook end is depressed by the seat
belt attachment fitting
Hook end of the seat
belt is contacting
two points on the
attachment fitting
5
Recommendation
The FAA recommends that you inspect your passenger seat (seat) belts.
If the seats have the “D-
ring” type of seat belt attachment fitting, we highly recommend that you replace the fitting with
an improved design fitting.
The seat belts on the passenger seats are replaced periodically because
of wear in service. We recommend that you replace the “D-ring” type of seat belt attachment fittings
as soon as possible but no later than when you replace the passenger seat belts.
For seats that have Technical Standard Order (TSO) approval, the operator should contact the seat
manufacturer of the seats for service information. For seats that aren’t TSO approved, the operator
should contact the airplane manufacturer for service information.
For Further Information Contact
Jayson Claar, Aerospace Engineer, FAA Transport Airplane Directorate, Standards Staff,
Airframe/Cabin Safety Branch, 1601 Lind Ave. SW, Renton, Washington 98055; phone: (425) 227-
2194; fax: (425) 227-1149
.
1
SPECIAL
AIRWORTHINESS
INFORMATION
BULLETIN
Aircraft Certification Service
Washington, DC
U.S. Department
of Transportation
Federal Aviation
Administration
No. CE-04-22
December 17, 2003
www.faa.gov - Search "SAIBs"
This is information only. Recommendations aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin (SAIB) advises you, owners and operators of
reciprocating engine powered airplanes
and anyone else who may deal with
exhaust system
components
, of the importance and need to properly inspect and maintain the components. You can
apply our recommendations to any reciprocating engine powered airplane’s exhaust system
components.
Background
Review of accident/incident reports reveal that there have been numerous fatalities and injuries to
pilots and passengers as a result of exhaust system component failures. We have identified the
probable causes for these accidents and incidents as:
•
Carbon Monoxide (CO) poisoning
•
Partial or complete loss of engine power
•
Fire
•
A combination of the above
We received a Safety Recommendation concerning a muffler internal failure of a cone on a Cessna
207 airplane. The cone blocked the exhaust gas outlet flow resulting in engine power loss on take-
off. This muffler configuration is common or similar to many other general aviation airplane
mufflers.
We want to emphasize the safety hazards and potential dangers of inadequate and infrequent
inspections and of a lack of a routine preventative maintenance on exhaust system components
between interval inspections.
You should regard any exhaust system component failure as a
severe hazard
. Many light airplane cabins are warmed by air that has been circulated around the
engine exhaust pipes or a bellows by a shroud or a muffler with an exhaust gas to air heat exchanger
(heat exchanger) under a shroud that is in line with the exhaust pipe(s). Many of the most common
exhaust system component failures are muffler or exhaust gas to air heat exchanger related.
Some of
these failures are:
2
•
Muffler or heat exchanger leakage, which permits exhaust gas to escape and directly enter the
cabin or enter through the cabin heat system.
•
Muffler or heat exchanger, heat transfer pins or knobs. These can be found under the shroud
on heat exchangers or mufflers that function as both a heat exchanger and muffler. Pin or
knob failure can lead to leakage of the exhaust gas directly into the cabin or through the cabin
heat system.
•
Muffler or heat exchanger, loose or internal failure of baffles, cones or diffusers can partially
or completely block the exhaust gas outlet flow, which can lead to partial or full engine power
loss. This condition may occur intermittently if internal components are loose within the
muffler and move around during subsequent flights
Recommendations
Inspections and Checks
All inspections, checks, and processes should be in accordance with the manufacturers
recommendations.
We highly recommend thorough pre-flight and repetitive inspection of the exhaust system
components because failures can occur in a relatively short time. All airplane owners and operators
should acquaint themselves with the configuration, pieces and parts that make up the exhaust system
on their airplane. This will assist in any pre-flight or inspection to identify areas that are not normal
or that may have changed since last review.
You should do daily inspections, if your airplane is flown often. This consists of a visual inspection
of the complete exhaust system installation. Simple tools such as a flashlight, mirror, awl or pick,
and length of small diameter wooden dowel rod or solid core wire may assist in this process. This
inspection should consist of checking the exposed exhaust system components and vicinity.
Typical areas to check and potential problems are:
1. All external surfaces for signs of leakage.
•
Leakage presents as a flat gray, gray-white or light gray powdering, or a sooty
appearance. Signs of deterioration include warping, deformation, thinning, collapse,
dents, cracking, tears, separation, scaling, weld separation, discoloration, corrosion,
metal pitting or burn-thru. Muffler or heat exchanger housing corrosion can often be
determined before the corrosion breaks thru the most outer surface by examining the
area of the muffler at either end where the end plate (which adapts the connection for
the inlet or the outlet) is inserted into the muffler shell. If corrosion is advancing in
this area, a swelling often occurs that can be seen as a raised area off the normal
surface line of the muffler surface at either end. Any protrusion in the exhaust gas
flow such as dents can result in localized hot spots which can lead to burning, bulging,
or rupture at those locations.
2. All external joints, flex-joints, slip-joints, clamps, couplings for misalignment, warpage,
broken, loose or missing fasteners, clamps, gaskets or seals and abnormal wear.
•
Signs of leakage such as flat gray, gray-white or light gray powdering, or a sooty
appearance.
3
3. All interior areas for blockage, restrictions, dents or protrusions into the exhaust flow path.
•
Using a flashlight, look in the interior of the tailpipe for loose or displaced baffles,
cones or diffusers in the mufflers. On airplanes that have a bend in the tail pipe, it
may be advantageous to remove the tailpipe at least at annual inspection for interior
inspection of the muffler. Look for the accumulation of deposits from
coking/carbonization, which can form, grow and create an ember or localized hot spot
or component mal-function or failure. Signs of erosion or abnormal wear can be
found where directional changes are made in the exhaust gas flow.
4. Muffler, heat exchanger, bellows or shrouds, heat transfer pins or knobs, baffles, cones or
diffusers or support rods.
5. Stack or riser to flange interface for cracks in welds or weld heat affected area, blown out or
missing gaskets.
6. All welds and area adjacent to the weld for cracks or weld separation.
7. Tailpipes, for erosion, thinning, bulging or burn through.
8. Contoured, shaped or bend areas, turns and interfaces (wyes) for erosion, thinning, bulging
or burn through.
9. Fluid or moisture traps, for scaling, corrosion, or cracks.
10. Bracing, supports and support attach lugs on other structures for security and self locking or
safetied hardware, and signs of overheat or burning.
11. Surrounding structures for discoloration, heat damage, or burning.
•
Impingement heating or torching of the surrounding structure can occur in any area
where exhaust system components exist or are breached, and may lead to failure or
fire conditions. Torching is of particular concern on turbocharged engines, which
operate at higher exhaust gas temperatures and pressures.
12. Usage of non-high temperature materials, or non-self-locking or unsafetied hardware.
The exhaust system components should be inspected thoroughly at any inspection interval, noting at
least those areas above. The above inspections may be more practically implemented at intervals
such as at an engine oil change. The exhaust system can also be pressure tested on the aircraft with
reasonable results that will usually show leaks.
A vacuum cleaner with the hose attached to the blowing side of the vacuum (with a filter installed)
can be attached to the aircraft tailpipe and sealed securely. The vacuum will pressurize the system
sufficiently for a soap solution to be brushed or applied from a spray bottle to the surface and
contours of the exhaust system and will show breaches (leakage) in the system from cracks and
corrosion. If the particular aircraft service manual does not specify such a test at the aircraft annual
inspection, it is highly recommended that this be accomplished. This test is also recommended
anytime exhaust system components are removed or replaced.
4
It may be advantageous to remove the exhaust system components to a certain extent to enhance
inspections and checks. Total removal may also be required if there is a need for a pressurized leak
test in a water tank. We also recommend that exhaust systems be completely inspected when the
major work or overhaul of the aircraft engine is accomplished. Airplanes that do not operate more or
less on a continual basis or those located in humid climates are also more likely to have a higher rate
of exhaust system component deterioration. Always use new gaskets or seals when replacing or
reinstalled the exhaust system components.
Allow the system to attain normal operating temperature prior to checking the exhaust system after
shut down for leaks. Re-align the exhaust system components if necessary after run-up to preclude
preloading the components. Re-torque all fasteners, taking care to not preload any of the
components. If hardware cannot be re-torqued to proper settings, the hardware should be replaced as
it may have stretched or deformed over time. Safety everything as required.
Repairs and Overhaul
Cessna recommends that you replace any exhaust system component that fails maintenance manual
inspection procedures or that you find defective. Generally, it is recommended you replace exhaust
system components that are burned, cracked, warped, or so worn that leakage occurs. Weld repairs to
exhaust system components are complicated by the constant deterioration of the base materials,
proper identification of the base materials, the generally thin base materials, changes in the base
materials composition and grain structure, and the contaminants and deposits that exist on any
component after a short period of time.
We strongly encourage consulting with an FAA approved Repair Station that has experience and a
demonstrated expertise in exhaust system inspection and repair prior to attempting the repair of any
exhaust system component. We also recommend a pressure test after any repair to a welded
component of the exhaust system.
For Further Information Contact
Jeff Janusz, Senior Aerospace Engineer, FAA Wichita Aircraft Certification Office, 1801 Airport Rd,
Rm 100, Wichita, Kansas, 67209; phone (316) 946-4148
.
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