# Accident 19961004030889A: Boeing 1072, Canby, OR, October 4, 1996

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: October 4, 1996
- Place: Canby, OR
- Damage: Destroyed
- Phase of flight: Normal Cruise
- Operating rules: General operating rules (Part 91)
- Operator: CHIL
- Location: 45.2108° N, 122.6605° W: From the FAA, an estimate near the named town, within about 3 miles
- Nearby events: https://openairdocs.org/map.md?lat=45.2108&lon=-122.6605&mi=10
- Aircraft: N196CH, registered now (https://openairdocs.org/aircraft/N196CH) (OpenAirDocs)
- Registry model: Vertol 107 (registry code 9420602, https://openairdocs.org/model/vertol-107) (OpenAirDocs)
- Registry engine: GE CT58 series (registry code 30011, https://openairdocs.org/engine/ge-ct58-series) (OpenAirDocs)
- Reported make and model: BOEING 1072
- People aboard: 3
- Fatal injuries: 3
- NTSB investigation: [NTSB SEA97FA001](https://openairdocs.org/ntsb/SEA97FA001) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19961004030889A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

(.4) THE BOEING MODEL BV-107-II DEPARTED ON A MAINTENANCE CHECK FLIGHT WITH 1.4 HRS TOTAL FLIGHT TIME AFTER CONVERSION FROM A MODEL HKP-4 PER FAA PROJECT #TDO639NY-R. ABOUT 37 MIN LATER, WITNESSES SAW THE ROTORCRAFT MOVING ERRATICALLY & TUMBLING OUT OF CONTROL. POSTCRASH EXAM OF THE ROTORCRAFT'S FLIGHT CONTROL SYSTEM REVEALED A DISCONNECT BETWEEN THE LOWER BEARING END OF THE AFT DIRECTIONAL AND LATERAL CONTROL PUSHROD & THE INBOARD CLEVIS OF THE FORWARD MIXING UNIT SECTION BELLCRANK. A BOLT, CONSISTENT WITH HARDWARE FOR THAT CONNECTION, WAS FOUND IN THE CONTROL CLOSET AREA. AN IMPROPER PART (COLLECTIVE BELLCRANK, PN 107C2606-8) WAS FOUND IN PLACE OF THE REQUIRED LATERAL BELLCRANK (PN 107C2606-9). CLEVIS WIDTH OF THE -8 PART WAS SLIGHTLY LARGER THAN THE -9 PART; THUS, THE CLEVIS BOLT WAS NOT LONG ENOUGH TO ALLOW A COTTER PIN TO BE PROPERLY INSTALLED THROUGH THE NUT & BOLT WITH THE REQUIRED WASHERS (2 THICK & 1 THIN) INSTALLED. TO COMPENSATE (ALLOW FOR INSTALLATION OF THE COTTER PIN), 2 THIN WASHERS WERE USED IN PLACE OF THE 2 THICK AND 1 THIN WASHERS. METALLURGICAL EXAM OF THE BOLT REVEALED EVIDENCE THAT A NUT HAD BEEN APPLIED TO THE THREADED END, BUT THERE WAS NO EVIDENCE THAT A COTTER PIN HAD BEEN INSERTED. NO PRE-ACCIDENT ENGINE MALFUNCTION OR CREW IMPAIRMENT WAS EVIDENT. THE NATIONAL TRANSPORTATION SAFETY BOARD DETERMINES THE PROBABLY CAUSE(S) OF THIS ACCIDENT AS FOLLOWS. FAILURE OF MAINTENANCE PERSONNEL TO INSTALL A COTTER PIN IN A CLEVIS BOLT IN THE FLIGHT CONTROL SYSTEM, WHICH RESULTED IN THE AFT DIRECTIONAL AND LATERAL CONTROL OUTPUT PUSHROD TO BECOME DISCONNECTED FROM A BELLCRANK IN THE FORWARD PORTION OF THE FIRST STAGE MIXING UNIT. A FACTOR RELATING TO THE ACCIDENT WAS THE USE OF AN IMPROPER BELLCRANK, WHICK WAS WIDER IN THE CLEVIS AREA.

## The NTSB's investigation of this event (1)

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 SEA97FA001](https://openairdocs.org/ntsb/SEA97FA001), Oct 4, 1996: Boeing Vertol BV-107 II (N196CH), Canby, OR, destroyed, 3 fatal. Probable cause: failure of maintenance personnel to install a cotter pin in a clevis bolt in the flight control system, which resulted in the aft directional and lateral control output pushrod to become disconnected…

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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