Title: Safety of Flight Message Review Class
1Safety Of Flight Message Review
References AR 95-1, AR 385-16, DA PAM
738-751, AMCOM
SOF/ASAM/GEN-ASAM Messages Unclassified
2Purpose
To review Safety of Flight Messages pertinent
to the CH-47 helicopter from FY 91 to the
present, and to discuss some pre-flight related
issues.
3Overview
Origins Definitions History Review Pre-Flight
4Overview
This material is testable
5Origins
Someone out there finds a serious fault with
the aircraft. Sources include the manufacturer
and the users (Pilots, FE, CE, Maintenance).
They tell AMCOM.
6Origins
Safety of Flight Headquarters, Department of
the Army (HQDA), Office Chief of Staff of the
Army (OCSA) is the approval authority for
Army-wide grounding and un-grounding of an entire
MDS.
7Origins
IAW AR 95-1, a SOF message and/or an ASAM is
developed, prepared, and electronically sent by
AMCOM to all users of Army aircraft and
recipients of Foreign Military Sales (FMS).
8Origins
Aviation Safety Action Message The Commander,
AMCOM, approves the release of an ASAM.
9Origins
If applicable, a SOF message or an ASAM would
be followed up by a printed Technical Bulletin
(TB).
10Origins
The Technical Bulletin would be used for
describing issues such as An inspection
procedure Detailing corrective
actions Installation of equipment (MWO)
11Definition
A Safety of Flight Message (SOF) is an
Emergency, Operational, or Technical message
issued by AMCOM to restrict the use of an
aircraft because an UNSAFE condition may exist.
12Definition
A SOF message is further defined as pertaining
to any defect or hazardous condition, actual or
potential, that can cause personal injury, death,
or damage to aircraft, components or repair parts
where a medium to high risk safety condition
exists (AR 385-16).
13Definition
There are three types of SOF Messages
Emergency Operational Technical
14Definition
SOF Emergency Message A SOF Emergency message
grounds affected aircraft and calls for changing
the status symbol to a RED X.
15Definition
SOF Emergency Message Is an immediate
grounding, because a hazardous condition exists
that has the potential to cause a catastrophic
accident.
16Definition
SOF Emergency Message Are for grounding only,
and will be followed up by an Operational or
Technical SOF message.
17Example
SOF Emergency Message The Forward or Aft
Transmission is suspected of having an internal
mechanical defect.
18Example
SOF Emergency Message SUBJECT -
SAFETY-OF-FLIGHT MESSAGE, EMERGENCY, RCS
CSGLD-1860(R1), IMMEDIATE GROUNDING OF ALL H-47
SERIES AIRCRAFT (CH-47-99-02).
19Definition
SOF Operational Message A SOF Operational
message may ground affected aircraft for
operational reasons, other than emergency, to
correct unsafe conditions pertaining to aircraft
or aviation associated equipment.
20Definition
SOF Operational Message Reasons May
include Flight Procedures Operating
Limitations Operational Policy
21Example
SOF Operational Message The APU has a
potentially catastrophic defect associated with
the turbine wheel.
22Example
SOF Operational Message SUBJECT - SAFETY OF
FLIGHT MESSAGE, OPERATIONAL, RCS CSGLD- 1860(R1),
CH-47D, MH-47D, AND MH-47E AIRCRAFT, OPERATIONAL
RESTRICTIONS AND REVISION TO HISTORICAL RECORDS
FOR T-62T-2B AUXILIARY POWER UNIT (APU),
CH-47-00-01 (TB 1-2835-205-20-4).
23Definition
SOF Technical Message A SOF Technical
message may be issued to cause grounding of
aircraft, but allow them to fly with specific
limitations.
24Definition
SOF Technical Message Operation of the aircraft
is allowed with specific limitations and for a
certain amount of calendar time, flying hours,
component hours, or rounds fired.
25Definition
SOF Technical Message The aircraft status
symbol is normally a Circled Red X, but can be a
Red Dash.
26Example
SOF Technical Message The Synchronizing Shafts
may be improperly installed.
27Example
SOF Technical Message SUBJECT - SAFETY OF
FLIGHT MESSAGE, TECHNICAL, RCS CSGLD-1860(R1),
CH/MH-47D/E, ONE TIME INSPECTION OF SYNC SHAFT
MOUNTING BRACKETS FOR PROPER CLEARANCE TO SYNC
SHAFT, CH-47-99-01 (TB 1-1520-240-20-111).
28Definition
Aviation Safety Action Message A lower priority
message than a SOF.
29Definition
Aviation Safety Action Message (ASAM) Defined
as a message which conveys maintenance, technical
or general interest information where a low to
medium risk safety condition exists (AR 385-16).
30Example
Aviation Safety Action Message Cracks were
found extending from the lightening holes in the
vertical web area of the rotor head center hub.
31Example
Aviation Safety Action Message SUBJECT -
AVIATION SAFETY ACTION MESSAGE, MAINTENANCE
MANDATORY, RCS CSGLD-1860(R1), ALL H-47 SERIES
AIRCRAFT, FORWARD AND AFT ROTOR HUB LIGHTENING
HOLE INSPECTIONS, CH-47-01-ASAM-03 (TB
1-1520-240-20-131).
32Definition
General Aviation Safety Action Message (GEN-ASAM)
Similar to the aircraft specific ASAM in its
development, but contains information that
generally pertains to all aircraft MDS.
33Example
General Aviation Safety Action Message The
Commander, AMCOM, wishes to provide field units
with updated Night Vision Goggle information.
34Example
General Aviation Safety Action Message SUBJECT
- AVIATION SAFETY ACTION MESSAGE, MAINTENANCE
MANDATORY, RCS CSGLD-1860(R1), ALL U.S. ARMY
AIRCRAFT, UPDATED INFORMATION ON NIGHT VISION
GOGGLES, GEN-00-ASAM-01.
35Bored ?
Doesnt concern me, its a maintenance
problem. I dont worry about it, the Technical
Inspectors catch everything.
36FYI
CH-47-00-ASAM-02 requires a recurring
inspection to be performed during each scheduled
daily inspection, preflight inspection, and
post-flight inspection of the Horizontal Hinge
Pin Shouldered Bolt, P/N 114R2201-1.
37History
September 11th
38Historical Case
74-22292 A CH-47C assigned to the 295th Assault
Support Helicopter Company (ASHC) -Cyclones,
crashed while on a Para-drop mission during an
airshow.
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47Results
Subsequent accident investigation revealed
failure of the Forward Transmission Input Pinion
Capsule.
48Why?
Walnut Grit and the cleaning process.
49Lessons to be Re-Learned
Decisions made by the individual to do or not
do a specific task can and will have a tremendous
affect on hundreds or even thousands of lives.
50Break
51Review
Safety of Flight Messages
52CH-47-91-01
Subject One time inspection and removal of
Combining Transmissions and Engine Transmissions
containing suspect input pinions and gears.
53CH-47-91-01
Summary A CH-47D helicopter experienced a Class
A accident. While inflight at high gross
weight and low altitude the crew noted a No. 2
engine transmission hot light and smoke swirling
around the engine.
54CH-47-91-01
Purpose Directed a records check of all engine
and combining transmissions to identify those
transmissions containing suspect gears and to
remove those suspect transmissions from service.
55CH-47-91-02
Subject Update to CH-47-91-01 to identify
serviceable Engine and Combining Transmissions.
56CH-47-91-02
Summary An update to CH-47-91-01 to identify
serviceable Combiner Transmissions and Engine
Transmissions .
57CH-47-91-02
Purpose To inform units that transmissions
listed in Para 9C, of the Safety of Flight, with
DG, DGC, or DGS at the end of the gear serial
number are considered serviceable even though the
gear has a P" (Papa) prefix.
58CH-47-93-01
Subject Immediate grounding of CH-47 and MH-47
series aircraft.
59CH-47-93-01
Summary During the investigation of a CH-47
accident in Alaska, the probable cause was
isolated to the suspected material failure of a
screw in the Upper Boost Actuator Control Valve.
60CH-47-93-01
Purpose To immediately ground all CH-47 and
MH-47 aircraft until the problem could be
identified and a solution found.
6189-00173, 10 October 1992, near Fort Richardson,
Alaska.
6289-00173, after the move to Fort Richardson,
Alaska.
63CH-47-93-02
Subject Un-grounding of U.S. Army CH-47D,
MH-47D, and MH-47E aircraft.
64CH-47-93-02
Summary CH-47-93-01 grounded all U.S. Army
CH-47D, MH-47D and MH-47E aircraft due to the
material failure of a screw in the Upper Boost
Actuator Control Valve due to Hydrogen
Embrittlement.
65CH-47-93-02
Purpose To provide un-grounding instructions
for CH-47D, MH-47D and MH-47E aircraft.
66CH-47-93-02
67CH-47-93-03
Subject One time records check of Engine
Transmissions, P/N 145D6300-(Series), to identify
unserviceable transmissions.
68CH-47-93-03
Summary A CH-47D helicopter experienced an
Engine Transmission failure resulting in a Class
C accident while at a steady state hover.
Teardown analysis of the components revealed that
an Engine Transmission Spiral Bevel Gear failed
from fatigue originating from a defect.
69CH-47-93-03
Purpose To direct a records check of all Engine
Transmissions to identify unserviceable
transmissions prior to next mission day.
70CH-47-94-01
Subject Immediate grounding of H-47 aircraft
assigned only to the 160th SOAR.
71CH-47-94-01
Summary An inspection revealed that the
electrical connector for the fuel pump inside the
HM-020-800 tank could have a faulty connector and
could cause the pumps to fail.
72CH-47-94-01
Purpose To ground the 160th aircraft until the
cause could be pinpointed and a solution found.
73CH-47-94-02
Subject Rescission of Safety of Flight Message
CH-47-94-01 that grounded H-47 aircraft only
assigned to the 160th SOAR.
74CH-47-94-02
Summary A review of the inspection procedures
regarding the electrical connector for the fuel
pump inside the HM-020-800 has revealed an error
in the inspection process used.
75CH-47-94-02
Purpose To rescind the previous Safety of
Flight Message CH-47-94-01.
76CH-47-95-01
Subject One time visual inspection of Upper
Boost Actuator serial numbers to ensure proper
screws are installed.
77CH-47-95-01
Summary A 1992 accident in Alaska was caused by
a screw in the Upper Boost Actuator Control Valve
failing from Hydrogen Embrittlement. The failed
screw restricted the travel of the Pilot Valve in
the Actuator resulting in reduced controllability
of the aircraft.
78CH-47-95-01
Purpose To direct a one time visual inspection
of serial numbers on all Upper Boost Actuators.
Actuators without the letter A behind the
serial number are required to be replaced prior
to the next flight.
79CH-47-95-01
80CH-47-95-02
Subject One time visual inspection and torque
check of Lower Drive Link to Swashplate retaining
hardware.
81CH-47-95-02
Summary A CH-47D from Fort Hood crashed.
Initial results indicate the Lower Drive Link to
Swashplate retaining bolt failed in fatigue.
82CH-47-95-02
Purpose To direct a one time visual inspection
of the Lower Drive Link to Swashplate retaining
hardware for proper installation and perform a
torque check of bolts P/N 114RS352-2 prior to
next engine run up.
83CH-47-95-02
84CH-47-97-01
Subject One time visual inspection of Forward
Transmission Mounting (Barrel) Nuts, P/N
NAS577B20A.
85CH-47-97-01
Summary A previous SOF Messages issued in April
1990 required the inspection and / or replacement
of NAS577B20A Barrel Nuts to purge the supply
system of nuts manufactured by Hartford Aircraft
Products, Inc.
86CH-47-97-01
Purpose To require another one time visual
inspection of Forward Transmission NAS 577B20A
Mounting (Barrel) Nuts prior to next flight and
removal of nuts manufactured by Hartford Aircraft
Products, Inc.
87CH-47-97-01
88CH-47-98-01
Subject One time inspection of Aft Upper Boost
Actuators to Stationary Swashplate retaining
hardware.
89CH-47-98-01
Summary Two reports were received documenting
that the wrong bolt was installed between the Aft
Upper Boost Actuators and the Aft Stationary
Swashplate.
90CH-47-98-01
Purpose To require a one time verification of
hardware installation of the Aft Upper Boost
Actuators to Stationary Swashplate for proper
attachment.
91CH-47-98-01
92CH-47-98-02
Subject Flight restrictions for aircraft with
MWO 1-1520-240-50-67, Non-Metallic Spline
Adapters for Combining Transmission Cooling Fan
Drive Shaft, applied.
93CH-47-98-02
Summary Three Combining Transmission Cooling
Fan Drive Shafts sheared. All three of these
shafts were the new Combining Transmission
Cooling Fan Shafts which were installed as part
of MWO 1-1520-240-50-67.
94CH-47-98-02
Purpose To implement flight restrictions,
additional pre-flight inspection procedures, and
a recurring inspection every four flight hours.
95CH-47-99-01
Subject One time inspection of Sync Shaft
mounting brackets for proper clearance to Sync
Shaft .
96CH-47-99-01
Summary A Quality Deficiency Report (QDR) was
received concerning unacceptable clearance
between the Sync Shaft assembly and the Mounting
Bracket, commonly referred to as the Lord Mount
mounting bracket.
97CH-47-99-01
Purpose To perform a one time inspection of all
Sync Shaft Mounting Brackets to ensure proper
clearance from the rotating Sync Shafts and
surrounding structure.
98CH-47-99-01
99CH-47-99-02
Subject Immediate grounding of all H-47 series
aircraft.
100CH-47-99-02
Summary A cracked Second Stage Planetary Gear
was discovered during overhaul.
101CH-47-99-02
Purpose As a prudent measure of safety, the
Army grounded its fleet of H-47 helicopters
until a full records search and inspections could
be conducted to determine the extent of the
discrepant parts.
102CH-47-99-03
Subject Inspection of H-47 aircraft Forward and
Aft Transmissions Gear/Bearing assemblies.
103CH-47-99-03
Summary Five cracked Second Stage Planetary
Gears/Bearing assemblies were found. The cracks
were not detected by the required non-destructive
testing procedure at time of manufacture.
104CH-47-99-03
Purpose To identify transmissions which have
had all gear/bearing assemblies inspected and
have been re-identified by an MG" serial number
prefix.
105CH-47-99-04
Subject Inspection of H-47 aircraft for Forward
and Aft transmission Gear/Bearing assemblies
identified by serial number prefix VB.
106CH-47-99-04
Summary One discrepant Second Stage Planetary
Transmission Gear/Bearing assembly identifiable
to a VB" serial number prefix was found. Four
discrepant Second Stage Planetary Transmission
Gear/Bearing assemblies identifiable to a
GG" serial number prefix were found.
107CH-47-99-04
Purpose To direct the inspection all Forward
and Aft Transmission records for specific part
number/serial number combinations.
108CH-47-99-05
Subject Replacement of suspect Forward and Aft
Transmission assemblies with ones that have been
inspected and cleared for operation.
109CH-47-99-05
Summary Safety of flight messages 99-02, 99-03
99-04, grounded all H-47 aircraft.
110CH-47-99-05
Purpose To provide implementation instructions
for Safety of Message 99-03.
111CH-47-99-05
112CH-47-99-05
113CH-47-99-05
114CH-47-99-05
115CH-47-00-01
Subject Operational restrictions and revision
to historical records for the T-62T-2B Auxiliary
Power Unit.
116CH-47-00-01
Summary In 1995 there was an incident where an
APU compressor wheel burst during start-up.
117CH-47-00-01
Purpose To impose a retirement life on certain
APU compressor wheels.
118CH-47-00-01
119CH-47-00-02
Subject Revision to SOF CH-47-00-01,
Operational Restrictions and revision to
historical records for the T-62T-2B Auxiliary
Power Unit.
120CH-47-00-02
Summary SOF Message CH-47-00-01 contained
incorrect funding and reimbursement instructions.
121CH-47-00-02
Purpose The purpose of this message was to
correct the paragraph 10D reimbursement
instructions and to make minor changes to
paragraphs 9A, 9B and 12C of SOF Message 00-01.
122CH-47-00-03
Subject Increase of operating limitations for
Forward and Aft Transmission Gear/Bearing
assemblies identified by serial number prefix
VB.
123CH-47-00-03
Summary SOF Messages 99-02, 99-03, 99-04, and
99-05 grounded all H-47 aircraft, provided
inspection requirements, and released some
aircraft for restricted flight.
124CH-47-00-03
Purpose To increase to 100 percent dual engine
torque, the 80 percent dual engine torque
limitation imposed by SOF Message 99-04 on
aircraft with both transmissions that have VB"
serial numbered gear/bearing assemblies installed.
125CH-47-00-04
Subject One time inspection of Engine
Transmission records for suspect gears and
replacement of suspect transmissions.
126CH-47-00-04
Summary During a Boeing overhaul of
international CH-47 Engine Transmissions, three
instances of cracked gears have been found.
These cracks have been found in the bevel gear
shaft and spiral gear shaft.
127CH-47-00-04
Purpose To identify and remove from service
high risk engine transmissions.
128CH-47-00-04
129CH-47-00-04
130CH-47-00-05
Subject One time inspection of Pitch Housings.
131CH-47-00-05
Summary Quality Deficiency Reports reported new
Pitch Housings were received from supply that had
surface gouges and nicks.
132CH-47-00-05
Purpose To direct an inspection of all Pitch
Housings which were obtained from Tura Machine
Company and to remove from service any with a
defect that exceeds safe limits.
133CH-47-00-05
134CH-47-00-06
Subject APU Containment Device.
135CH-47-00-06
Summary SOF 00-01 was issued in October 1999.
The message directed the establishment of a
retirement life based on starts and operational
restrictions for aircraft with an APU that had
reached a specified start-count.
136CH-47-00-06
Purpose To authorize aircraft having an
improved APU, or an APU having the containment
device, to operate without operational
restrictions of SOF 00-01.
137CH-47-00-06
138CH-47-00-07
Subject Combining Transmission Cooling Fan
Drive Shaft inspections.
139CH-47-00-07
Summary An MH-47E aircraft experienced a
failure of the Combining Transmission Cooling Fan
Drive Shaft (P/N 145D5319-5).
140CH-47-00-07
Purpose Remove from service those Cooling Fan
Shafts and Combining Transmissions found
unserviceable.
141CH-47-00-07
142CH-47-01-01
Subject One time inspection of Aft Rotor Head
assemblies and Engine Cross Shaft Adapter
assemblies.
143CH-47-01-01
Summary Two Deficiency Reports were received
which indicated that a CH-47D unit was issued
MH-47E closed loop items through the normal
supply system.
144CH-47-01-01
Purpose To account for and verify the correct
Rotor Hub and Engine Cross Shaft Adapter
assemblies are installed on the appropriate
airframe.
145CH-47-01-01
146CH-47-01-02
Subject Inspection of Droop Stops.
147CH-47-01-02
Summary While conducting an accident
investigation, incorrectly installed Droop Stops
were discovered.
148CH-47-01-02
Purpose To perform a one time inspection for
proper installation of Droop Stops.
149CH-47-01-02
150CH-47-01-02
151CH-47-01-02
152CH-47-01-02
153CH-47-01-03
Subject Un-grounding requirements for aircraft
with incorrectly installed Droop Stops.
154CH-47-01-03
Summary While conducting an accident
investigation, incorrectly installed Droop Stops
were discovered. Safety of Flight Message
CH-47-01-02 was issued calling for a one time
inspection on Forward and Aft Droop Stops for
proper installation.
155CH-47-01-03
Purpose To identify an additional Droop Stop
configuration and provide instructions to
un-ground aircraft that have had incorrectly
installed Droop Stops.
156CH-47-01-03
WARNING Numerous cases of improper stenciling
of the Droop Stops have been identified.
157CH-47-01-03
158CH-47-01-03
159CH-47-01-03
160CH-47-01-03
161Break
162Pre-Flight Items
163Pre-Flight Items
IAW SOF CH-47-93-02 and 95-01 The letter A
stamped on the data plate attached to the Upper
Dual Boost Actuators.
164Pre-Flight Items
165Pre-Flight Items
166Pre-Flight Items
167Pre-Flight Items
168Pre-Flight Items
169Pre-Flight Items
IAW SOF CH-47-97-01 Ensure that no Forward
Transmission Barrel Nuts manufactured by Hartford
Aircraft Products, Inc. are installed on the
helicopter.
170Pre-Flight Items
171Pre-Flight Items
IAW SOF CH-47-99-01 Check the clearance on the
Sync Shaft to the Lord Mount mounting brackets.
172Pre-Flight Items
173Pre-Flight Items
IAW SOF CH-47-00-01 Check the Dash number of
the installed APU and ensure you adhere to the
restrictions imposed by the SOF.
174Pre-Flight Items
IAW SOF CH-47-00-03 Check the aircraft logbook
for the dual engine torque restriction of 100
percent.
175Pre-Flight Items
IAW CH-47-00-ASAM-02 A recurring inspection is
to be performed on the Horizontal Hinge Pin
Shouldered Bolts during each scheduled daily
inspection, pre-flight inspection, and
post-flight inspection.
176Pre-Flight Items
177Pre-Flight Items
IAW SOF CH-47-01-03 Check the Droop Stops to
ensure they are correctly installed.
178Pre-Flight Items
179Pre-Flight Items
180Pre-Flight Items
181Pre-Flight Items
182Pre-Flight Items
183Pre-Flight Items
184Summary
Origins Definitions History Review Pre-Flight
185Conclusion
Fly like youre going to Court