# NTSB DEN74AD009: Boeing 737, N7381F, Rapid City, SD, August 22, 1973

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Closed
- Date: August 22, 1973
- Place: Rapid City, SD · RAPID CITY, SD
- Location: 44.0805° N, 103.2310° W: Placed by OpenAirDocs: center of Rapid City, SD, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=44.0805&lon=-103.2310&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious, 45 uninjured
- Status: Completed, report November 21, 1973
- Report: Brief approved by the director
- NTSB case key (mKey): 189823
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN74AD009
- Page: https://openairdocs.org/ntsb/DEN74AD009

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
1-0025  73/8/22  NR.RAPID CITY,S DAK   BOEING 737          CR-  0  1  5  SCHED DOM PASSG SRV       ATP,FLIGHT INSTR., AGE
        TIME - 0555                    N7381F              PX-  0  0 40                            49, 20112 TOTAL HOURS,
                                       DAMAGE-NONE         OT-  0  0  0                            2050 IN TYPE, INSTRUMENT
                                                                                                   RATED.
        OPERATOR - FRONTIER AIRLINES,INC.
        DEPARTURE POINT             INTENDED DESTINATION         LAST ENROUTE STOP
          MINOT,N DAK                 TUCSON,ARIZ                  ALBUQUERQUE,N MEX
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           MISCELLANEOUS                                            IN FLIGHT: NORMAL CRUISE
        PROBABLE CAUSE(S)
           SYSTEMS - FLIGHT CONTROL SYSTEMS: FLIGHT CONTROL BOOST SYSTEM, ELECTRICAL
           MISCELLANEOUS ACTS,CONDITIONS - FLUCTUATING
           MISCELLANEOUS ACTS,CONDITIONS - INTERFERENCE WITH FLIGHT CONTROLS
        FACTOR(S)
           PILOT IN COMMAND - FAILED TO FOLLOW APPROVED PROCEDURES,DIRECTIVES,ETC.
        REMARKS- UNWANTED SUDDEN YAW DAMPER-INDUCED RUDDER INPUT,DUE DEFECTIVE COIL IN SYS.CTL MALF DRG PREV TKOF.
```

## Aircraft

- Registration: [N7381F](https://openairdocs.org/deregistered/N7381F-2013-05-07), registration cancelled 2013-05-07, S/N 20369, built 1970 (OpenAirDocs)
- Reported make and model: BOEING 737
- Registry model: [Boeing 737-2H4](https://openairdocs.org/model/boeing-737-2h4) (registry code 138448C) (OpenAirDocs)
- Registry engine: [Pratt & Whitney JT8D-9 series](https://openairdocs.org/engine/pratt-whitney-jt8d-9-series) (registry code 52048, turbo-jet) (OpenAirDocs)
- Category: Airplane
- Engines: turbo fan
- Damage: No damage

## Other investigations on N7381F (2)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB DCA83AA021](https://openairdocs.org/ntsb/DCA83AA021), Mar 23, 1983: Boeing 737-2H4 (N7381F), Casper, WY, minor damage
- [NTSB SEA74AS006](https://openairdocs.org/ntsb/SEA74AS006), Aug 16, 1973: Boeing 737 (N7381F), Missoula, MT, no damage

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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