# SDR DLM88960220

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 28, 1996
- Submitted: March 26, 2000
- Operation: Air carrier
- Aircraft: N996DL
- Make and model: Doug MD-88
- Registry model: [Doug MD-88](https://openairdocs.org/model/mcdonnell-douglas-md-88) (OpenAirDocs)
- Aircraft serial: 53363
- System (JASC): [2210 · Autopilot System](https://openairdocs.org/jasc/2210)
- Part: Switch
- Part number: 26ET59T
- Condition: Failed
- Location: Auto Flt Contl
- Component: 4034242972
- Stage of operation: AP
- Nature of condition: F, J
- Precautionary procedure: L
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/DLM88960220

## Discrepancy

ON FINAL APPROACH A/P WOULD NOT DISCONNECT WITH THE YOKE DISCONNECT SWITCHES OR THE ON/OFF SWITCH ON THE AUTO FLIGHT CONTROL PANEL.  IT WAS NECESSARY TO PULL C/BS TO DISCONNECT A/P.  REPLACED MODE CONTROL PANEL OPERATION NORMAL.  ANALYSIS REVEALED THAT THE FGCP FAILURE WAS CAUSED BY A DEFECTIVE AUTOPILOT ENGAGE TOGGLE SWITCH.  MICROSWITCH, DIVISION OF HONEYWELL INC  HAS IDENTIFIED AN INFERIOR SWITCH MANUFACTURING PROCESS FOR SWITCHES PROCUCED FROM MAR 1991 TO MAY 1993.  DELTA ISSUED A SPECIAL INSPECTION TO FIND AND REMOVE FROM SERVICE ALL SUSPECT UNITS.

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