Service Letter ME| Name | Revision | Lang | Subject | Date |
|---|
| ME69-16 | | en | WING TIP TANK PUMP INSTALLATION | 08/14/1969 |
| ME70-26 | | en | IMPROVED CONTACTS FOR 400 SERIES NAV/COM | 07/15/1970 |
| ME70-43 | | en | ALTERNATE AIR INTAKE DEFLECTOR BAFFLE INSTALLATION | 12/23/1970 |
| ME71-17 | | en | WING STROBE LIGHT FLASHTUBE INSTALLATION | 06/28/1971 |
| ME71-20 | | en | IMPROVED OSCILLATOR CAVITY (400 and 800 Transponder) | 08/20/1971 |
| ME72-19 | | en | WING FLAP ACTUATORMODIFICATION | 10/06/1972 |
| ME73-1 | | en | FLAP ACTUATOR ASSEMBLY - REPLACEMENT OF COMPONENTS | 01/12/1973 |
| ME73-11 | 1 | en | PROPELLER ATTACHMENT IMPROVEMENT | 08/17/1973 |
| ME74-13 | | en | VOLTAGE REGULATOR MODIFICATION | 08/09/1974 |
| ME75-6 | | en | | 02/28/1975 |
| ME75-11 | | en | TURBOCHARGER OIL INLET ADAPTER AND FITTING IMPROVEMENT | 05/02/1975 |
| ME75-21 | | en | IMPROVED AFT SLIP JOINT SEALS | 08/29/1975 |
| ME76-15 | | en | TROUBLESHOOTING FOR ENGINE ROUGHNESS | 09/13/1976 |
| ME76-17 | | en | | 08/16/1976 |
| ME76-21 | #1 | en | AILERON PULLEY BRACKET INSPECTION | 11/08/1976 |
| ME77-8 | | en | | 03/28/1977 |
| ME77-12 | | en | NOSE WHEEL WELL MODIFICATION | 05/02/1977 |
| ME77-16 | | en | PILOTS OPERATING HANDBOOK CHANGES FOR 1976 and 1977 Model 421C and 1977 Model 404 | 06/13/1977 |
| ME77-29 | | en | POWER APPROACH PLACARD AND OWNERS MANUAL REVISION | 10/24/1977 |
| ME77-32 | | en | STROBE LIGHT FLASHER CHOKE ASSEMBLY REPLACEMENT | 12/23/1977 |
| ME78-6 | | en | RUBBER FUEL TANK PRORATA ADJUSTMENT | 03/13/1978 |
| ME78-29 | 1 | en | IN-LINE AUXILIARY FUEL PUMP | 11/13/1978 |
| ME78-47 | 1 | en | IMPROVED FUEL CAPS MODEL 336 AND 337 | 02/12/1979 |
| ME78-47 | 2 | en | VENTED FUEL CAPS | 09/28/1979 |
