Allison Circular Letters

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Allison Circular Letters

ALLIS-CIR MANUALS AND RESOURCES AVAILABLE WITH MEMBERSHIP (103 documents)

Torque - External Nuts and Screws
Torque - External Nuts and Screws
30-Mar-1945
Circular Letter No. 193 Supplement
Scintilla Ignition Coils from Bulletin #111
Scintilla Ignition Coils from Bulletin #111
11-Jan-1944
Circular Letter No. 128
Inspection on Air Maze Oil Filter, #53073, Prior to Change F on -99 Engines
Inspection on Air Maze Oil Filter, #53073, Prior to Change F on -99 Engines
19-June-1944
Circular Letter No. 163
Fuel Selector Valve Malfunctioning P-63A
Fuel Selector Valve Malfunctioning P-63A
3-May-1944
Circular Letter No. 153A
PT-13E9 Carburetors - Matching with Discharge Nozzles
PT-13E9 Carburetors - Matching with Discharge Nozzles
28-June-1944
Circular Letter No. 171A
Compression Check Method
Compression Check Method
25-Aug-1944
Circular Letter No. 189
Cross Over Baffle -93 Engine
Cross Over Baffle -93 Engine
28-June-1944
Circular Letter No. 179
Briggs Clarifier Operation
Briggs Clarifier Operation
26-July-1944
Circular Letter No. 185
Jet -  Supercharger Vent Air Metering - Part #53998
Jet - Supercharger Vent Air Metering - Part #53998
8-July-1944
Circular Letter No. 181
Chafed or Frayed Ignition Switch Wires Conducive to Backfiring
Chafed or Frayed Ignition Switch Wires Conducive to Backfiring
9-May-1944
Circular Letter No. 165
Rivets, Part AN-435-5-6, Holding the Reduction Gear Pinion Plug 37097 in the Pinion
Rivets, Part AN-435-5-6, Holding the Reduction Gear Pinion Plug 37097 in the Pinion
18-Jan-1944
Circular Letter No. 131
Coolant System
Coolant System
13-Jan-1944
Circular Letter No. 129
Removal of Manifold Pressure Regulator for P-38
Removal of Manifold Pressure Regulator for P-38
30-Nov-1943
Circular Letter No. 119
Nozzle - Reduction Gear Pinion Oiler - Part No. 40962
Nozzle - Reduction Gear Pinion Oiler - Part No. 40962
19-May-1944
Circular Letter No. 172
Curtiss Propeller Surging
Curtiss Propeller Surging
3-Nov-1943
Circular Letter No. 117
E-11 Operation
E-11 Operation
11-Mar-1944
Circular Letter No. 145
Information on the V-1710-99 (F26R)
Information on the V-1710-99 (F26R)
15-Oct-1943
Circular Letter No. 105A
Air Scoop Hot Air Shutter on P-40N
Air Scoop Hot Air Shutter on P-40N
19-Feb-1944
Circular Letter No. 139
Replacing High Tension Cables in Distributor Caps
Replacing High Tension Cables in Distributor Caps
19-Feb-1944
Circular Letter No. 140
Refinishing of Aircraft Engines at Overhaul
Refinishing of Aircraft Engines at Overhaul
20-Mar-1944
Circular Letter No. 124-A
Manifold Pressure Gauge Line P-38J
Manifold Pressure Gauge Line P-38J
18-May-1944
Circular Letter No. 169
Outboard Reduction Gear Rear Case Change to Accommodate Larger Mouting Studs
Outboard Reduction Gear Rear Case Change to Accommodate Larger Mouting Studs
19-May-1944
Circular Letter No. 173
Oil Dilution
Oil Dilution
7-Oct-1943
Circular Letter No. 109
Manifold Pressure Regulator Brace Part #42690
Manifold Pressure Regulator Brace Part #42690
27-Jan-1944
Circular Letter No. 130A
Elimination of Coolant Jacket Bleed Holes
Elimination of Coolant Jacket Bleed Holes
19-Feb-1944
Circular Letter No. 138
Modification of PT-13E9 Carburetor Setting of Dry Installation
Modification of PT-13E9 Carburetor Setting of Dry Installation
28-June-1944
Circular Letter No. 171A Supplement
Cuno or Air Maze Oil Filter Gasket #35398
Cuno or Air Maze Oil Filter Gasket #35398
27-April-1944
Circular Letter No. 157
Handling of Engine Parts in Process of Overhaul
Handling of Engine Parts in Process of Overhaul
25-July-1944
Circular Letter No. 184
Periodic Oiling of all SC and PC Control Linkage
Periodic Oiling of all SC and PC Control Linkage
1-May-1944
Circular Letter No. 160
Supercharger Control and Regulator Inter Connecting Link #43078
Supercharger Control and Regulator Inter Connecting Link #43078
20-April-1944
Circular Letter 156
Materials Going Through Air Scoops into Engines
Materials Going Through Air Scoops into Engines
20-Oct-1943
Circular Letter No. 114
Check for Sheared Front Scavenge Pump Drive
Check for Sheared Front Scavenge Pump Drive
31-Oct-1944
Circular Letter No. 161A
Coolant Expansion Line Tee on P-38's
Coolant Expansion Line Tee on P-38's
13-April-1944
Circular Letter No. 152
Matching Carburetors on Engines being Installed in P-38
Matching Carburetors on Engines being Installed in P-38
4-Dec-1943
Circular Letter No. 122
Steel Wool on Cuno and Magnetic Plug
Steel Wool on Cuno and Magnetic Plug
22-Feb-1944
Circular Letter No. 141
Information on the V-3420-23 (-B10) Model Engine
Information on the V-3420-23 (-B10) Model Engine
2-June-1944
Circular Letter No. 176
Rework of Engine Crankcase Breather Vents
Rework of Engine Crankcase Breather Vents
11-Mar-1944
Circular Letter No. 144
Matching of Propeller Governor Arm Serrations - P-40
Matching of Propeller Governor Arm Serrations - P-40
31-Dec-1943
Circular Letter No. 126
Reported Effect of Uninhibited Ethylene Glycol on Coolant Pump Seals
Reported Effect of Uninhibited Ethylene Glycol on Coolant Pump Seals
17-March-1945
Circular Letter No. 166
Oil Pump Failures in Reduction Gear Assemblies
Oil Pump Failures in Reduction Gear Assemblies
28-Sept-1943
Circular Letter No. 102
Carburetor Idle Spring Adjustment Screws
Carburetor Idle Spring Adjustment Screws
1-Nov-1943
Circular Letter No. 116
Cross Over Baffle -93 Engine
Cross Over Baffle -93 Engine
6-July-1944
Circular Letter No. 179 Supplement
Ignition Switch, A.C. Type A-9
Ignition Switch, A.C. Type A-9
13-April-1944
Circular Letter No. 154
Check for Sheared Front Scavenge Pump Drive
Check for Sheared Front Scavenge Pump Drive
5-May-1944
Circular Letter No. 161
Use of Modifier Unit on Automatic Engine Control Part 43801
Use of Modifier Unit on Automatic Engine Control Part 43801
12-Feb-1944
Circular Letter 135
Piston Ring Gap Clearances
Piston Ring Gap Clearances
11-Jan-1944
Circular Letter No. 99
Correct Oil Pressure Relief Valve Body
Correct Oil Pressure Relief Valve Body
13-Oct-1943
Circular Letter No. 111
Oil Change
Oil Change
11-April-1944
Circular Letter No. 151
F Reduction Gear 3/4" Square Shank Pipe Threaded Plugs
F Reduction Gear 3/4" Square Shank Pipe Threaded Plugs
11-Jan-1944
Circular Letter No. 118A
Air Filter Control Valve for P-38H Location Wheel Well
Air Filter Control Valve for P-38H Location Wheel Well
2-Dect-1943
Circular Letter No. 120
Cuno or Air Maze Oil Filter Gasket #35398
Cuno or Air Maze Oil Filter Gasket #35398
25-July-1944
Circular Letter No. 157
Carburetor Air Temperature and Mean Effective Pressure Charts
Carburetor Air Temperature and Mean Effective Pressure Charts
30-Aug-1944
Circular Letter No. 190
Low Oil Pressure in Overhauled Engines on Test Stands
Low Oil Pressure in Overhauled Engines on Test Stands
14-Sept-1944
Circular Letter No. 196
Induction Pipe Tie Strap
Induction Pipe Tie Strap
7-Oct-1943
Circular Letter No. 113A
Reduction Gear Pinion Plug
Reduction Gear Pinion Plug
23-Mar-1945
Circular Letter No. 131
Bolts, Engine and Center Bearing Mount - Torque Recommendations - P-39
Bolts, Engine and Center Bearing Mount - Torque Recommendations - P-39
17-Feb-1944
Circular Letter No. 136
Carburetor Throttle Rod Binding Caused by use of Large Washer
Carburetor Throttle Rod Binding Caused by use of Large Washer
29-May-1944
Circular Letter No. 175
Numbering of Engines by Overhaul Depots
Numbering of Engines by Overhaul Depots
10-April-1944
Circular Letter No. 149
Advanced Information Caution
Advanced Information Caution
27-June-1944
Circular Letter No. 178
Aerated Accelerating Pump and Water in Fuel System on P-63 Aircraft
Aerated Accelerating Pump and Water in Fuel System on P-63 Aircraft
13-Sept-1944
Circular Letter No. 195
Checking Coolant Expansion Tank Relief Valve
Checking Coolant Expansion Tank Relief Valve
27-April-1944
Circular Letter No. 158
C-15 Accessory Housing Vent Connections
C-15 Accessory Housing Vent Connections
9-May-1944
Circular Letter No. 164
Coolant System Pressure Relief Valve Information
Coolant System Pressure Relief Valve Information
25-July-1944
Circular Letter No. 177 Supplement
Adjusting Automatic Engine Control Assembly - 43801
Adjusting Automatic Engine Control Assembly - 43801
13-Oct-1943
Circular Letter No. 112
Spray Nozzle Gaskets
Spray Nozzle Gaskets
19-May-1944
Circular Letter No. 174
Installation of NaMBT Inhibited AN-E-2, Ethylene Glycol in Installations Previously Operated with AN-E-2 Glycol
Installation of NaMBT Inhibited AN-E-2, Ethylene Glycol in Installations Previously Operated with AN-E-2 Glycol
9-May-1944
Circular Letter No. 166
Reports of Engine Cutting Out and Backfire in P-40N - Low Throttle Glides
Reports of Engine Cutting Out and Backfire in P-40N - Low Throttle Glides
21-Feb-1944
Circular Letter No. 133A
AAF List of Supply Requirements for the Alternate Installations of Allison Engines
AAF List of Supply Requirements for the Alternate Installations of Allison Engines
27-July-1944
Circular Letter No. 127A
Supplement, P-40 Vibration Check Tips
Supplement, P-40 Vibration Check Tips
12-Oct-1943
Circular Letter No. 110
Cracking of Melmac Distributor Heads Part 10-27751
Cracking of Melmac Distributor Heads Part 10-27751
3-Feb-1944
Circular Letter No. 132
E-11 Operation
E-11 Operation
10-Nov-1944
Circular Letter No. 145
Air Maze Oil Filter Inspection - Aluminum Foil
Air Maze Oil Filter Inspection - Aluminum Foil
10-April-1944
Circular Letter No. 148
Failure of Cuno Oil Strainer - Part 35398
Failure of Cuno Oil Strainer - Part 35398
20-Mar-1944
Circular Letter No. 146
Carburetor Air Screens
Carburetor Air Screens
25-Aug-1944
Circular Letter No. 188
Auxiliary Stage Supercharger Mounting Bosses
Auxiliary Stage Supercharger Mounting Bosses
19-Sept-1944
Circular Letter No. 197
Supercharger Inlet Cover Gasket #36852 Rework
Supercharger Inlet Cover Gasket #36852 Rework
17-April-1944
Circular Letter No. 155
Coolant System Pressure Relief Valve Information
Coolant System Pressure Relief Valve Information
6-June-1944
Circular Letter No. 177
Spring - Oil Pressure Relief Valve - Part #54464
Spring - Oil Pressure Relief Valve - Part #54464
19-May-1944
Circular Letter No. 170
Part #42206 BH Scroll, Auxiliary Supercharger
Part #42206 BH Scroll, Auxiliary Supercharger
16-May-1944
Circular Letter No. 167
Nailing Spark Plugs Leads
Nailing Spark Plugs Leads
11-Feb-1944
Circular Letter No. 134
Preparing Magnetos for Service
Preparing Magnetos for Service
19-Mar-1944
Circular Letter No. 125B
Air Passage Hole in Supercharger Inlet Cover
Air Passage Hole in Supercharger Inlet Cover
12-Sept-1944
Circular Letter No. 194
Inspection of Air Maze Oil Filter, #53073, Prior to Change F
Inspection of Air Maze Oil Filter, #53073, Prior to Change F
5-May-1944
Circular Letter No. 163
Fires in P-38 Aircraft
Fires in P-38 Aircraft
6-July-1944
Circular Letter No. 180
Torque - External Nuts and Screws
Torque - External Nuts and Screws
Circular Letter No. 193
Starter Jaw Engagement
Starter Jaw Engagement
11-April-1944
Circular Letter No. 150
P-63 Installation Fire Hazard
P-63 Installation Fire Hazard
5-Sept-1944
Circular Letter No. 192
Coolant System Filling Instructions as Recommended by Allison
Coolant System Filling Instructions as Recommended by Allison
23-Feb-1944
Circular Letter No. 142
Installation of Oil Return Elbows on Model E and F Engines
Installation of Oil Return Elbows on Model E and F Engines
22-Mar-1944
Circular Letter No. 147
Excessive Smoking - Right Bank - Exhaust Stacks 1, 2 & 3
Excessive Smoking - Right Bank - Exhaust Stacks 1, 2 & 3
2-Oct-1943
Circular Letter No. 106
Y Drain Oil Leak
Y Drain Oil Leak
2-Dec-1943
Circular Letter No. 121
Supercharger Drive Gear Train 9.6 to 1 Ratio
Supercharger Drive Gear Train 9.6 to 1 Ratio
14-Sept-1944
Circular Letter No. 191
Carburetor Idle Spring
Carburetor Idle Spring
17-July-1944
Circular Letter No. 168
Distributor Shaft Bearing Gage, #43545-B
Distributor Shaft Bearing Gage, #43545-B
3-May-1944
Circular Letter No. 162
Jacobson Test Stands
Jacobson Test Stands
2-Aug-1944
Circular Letter No. 187
Spark Plugs
Spark Plugs
17-Dec-1943
Circular Letter No. 123
Synchronized Quadrant Schedule for P-39 and P-63
Synchronized Quadrant Schedule for P-39 and P-63
19-Feb-1944
Circular Letter No. 137
Spark Plug Operation
Spark Plug Operation
2-Mar-1944
Circular Letter No. 143
Operation and Maintenance on V-3420-23, B-10
Operation and Maintenance on V-3420-23, B-10
19-Aug-1944
Circular Letter No. 183A
Bleeding Vapor Mechanical Accelerating Pumps
Bleeding Vapor Mechanical Accelerating Pumps
29-April-1944
Circular Letter No. 159
Quality Improvements Affecting Vibration Characteristics of the P-39
Quality Improvements Affecting Vibration Characteristics of the P-39
26-Oct-1943
Circular Letter No. 115
Water Injection Pump Switch
Water Injection Pump Switch
2-Aug-1944
Circular Letter No. 186
E-11 Operation
E-11 Operation
10-Nov-1944
Circular Letter No. 145