# NTSB DCA12CA042: Embraer EMB120, N1110J, Iliamna, AK, February 16, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: February 16, 2012, 13:08 local (17:08 UTC) - Place: Iliamna, AK - Coordinates: 59.755554, -154.927505 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=59.7556&lon=-154.9275&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-descent: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report March 30, 2020 - Report: Approved by Office Director - NTSB office: Major Investigations Division - NTSB case key (mKey): 82916 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DCA12CA042 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/82916/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=82916 - Page: https://openairdocs.org/ntsb/DCA12CA042 ## Probable cause the maintenance personnel's failure to install the cotter pins that secured castellated nuts on the left elevator vertical hinge bolts, which resulted in the left elevator partially detaching in flight. Contributing to the accident was the failure of maintenance personnel to document the non-routine maintenance procedure that was used to remove and reinstall the elevator during maintenance. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Maintenance personnel (probable cause); cases with it: [Embraer EMB-120FC, 1 case](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=3260204), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) - [Record-keeping: aircraft/maintenance logs](https://openairdocs.org/ntsb-findings/02062515): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Embraer EMB-120FC, 1 case](https://openairdocs.org/ntsb-findings/02062515/cases.md?model=3260204), [All aircraft, 21 cases](https://openairdocs.org/ntsb-findings/02062515/cases.md) - [Maintenance: repair](https://openairdocs.org/ntsb-findings/02062015): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Embraer EMB-120FC, 1 case](https://openairdocs.org/ntsb-findings/02062015/cases.md?model=3260204), [All aircraft, 99 cases](https://openairdocs.org/ntsb-findings/02062015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-descent: Inflight upset](https://openairdocs.org/ntsb-events/271); cases with it: [Embraer EMB-120FC, 1 case](https://openairdocs.org/ntsb-events/271/sequence.md?model=3260204), [All aircraft, 74 cases](https://openairdocs.org/ntsb-events/271/sequence.md) - [Enroute-descent: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) (defining event); cases with it: [Embraer EMB-120FC, 1 case](https://openairdocs.org/ntsb-events/333/sequence.md?model=3260204), [All aircraft, 410 cases](https://openairdocs.org/ntsb-events/333/sequence.md) ## Analysis On February 16, 2012, at about 1308 local time, Everts Air Cargo flight 1291, an Embraer EMB-120, N1110J, experienced an uncommanded pitch down while descending into Iliamna Airport (KILI), Iliamna, Alaska. There were no injuries to the 2 crewmembers onboard but the airplane sustained substantial damage. The flight was operating under 14 CFR Part 121 Supplemental as a cargo only flight from Anchorage, Alaska (KANC) to KILI. The Captain reported that the flight from KANC had been uneventful. The Captain reported that during the descent, while at about 250 knots airspeed with his hands on the controls and the autopilot engaged, the airplane pitched to about 20 degrees nose down. The captain reported he then disconnected the autopilot and adjusted the pitch trim while pulling back on the column to recover from the pitch excursion. The flight crew declared an emergency and slowed the airplane to about 200 knots. Approximately 5-10 miles from the airport, while in a slow left turn at 3000 feet msl altitude, the airplane pitched down a second time while the captain was hand flying. As he recovered from the pitch down, he was lined up for a 5 mile final approach for runway 35. The captain elected to make a high speed, flaps up landing and landed uneventfully on runway 35. Post-flight inspection revealed that the left elevator was bent at the mid span trim tab, had partially detached from the aircraft, and was missing two attachment bolts. A review of the airplane maintenance history showed that while in "A" check maintenance, a dent was noted in the left elevator and the elevator was removed. The maintenance team did not follow the EMB 120 maintenance manual procedure for removal of the left elevator. During the non-routine maintenance procedures used by the maintenance team, cotter pin safeties that were removed from castellated nuts on the 2 outboard vertical hinge bolts on the left elevator were not reinstalled. The removal of these two bolts is not part of the EMB 120 maintenance manual procedure for removal of the left elevator. The maintenance team did not document the non-routine procedure they used to remove and reinstall the left elevator. The Require Inspection Items (RII) inspector had inspected the elevator installation for the procedures in the manual and was not aware of the undocumented non-routine maintenance procedures used, and hence did not examine the nuts that did not have the required cotter pins, which were not to be removed as part of the approved procedure. The FAA found that the maintenance teams that removed and reinstalled the elevator were inexperienced in EMB 120 elevator removal and reinstallation procedures. ## Factual narrative On February 16, 2012, at about 1308 local time, Everts Air Cargo flight 1291, an Embraer EMB-120, N1110J, experienced an uncommanded pitch down while descending into Iliamna Airport (KILI), Iliamna, Alaska. There were no injuries to the 2 crewmembers onboard but the airplane sustained substantial damage. The flight was operating under 14 CFR Part 121 Supplemental as a cargo only flight from Anchorage, Alaska (KANC) to KILI. The Captain reported that the flight from KANC had been uneventful. The Captain reported that during the descent, while at about 250 knots airspeed with his hands on the controls and the autopilot engaged, the airplane pitched to about 20 degrees nose down. The captain reported he then disconnected the autopilot and adjusted the pitch trim while pulling back on the column to recover from the pitch excursion. The flight crew declared an emergency and slowed the airplane to about 200 knots. Approximately 5-10 miles from the airport, while in a slow left turn at 3000 feet msl altitude, the airplane pitched down a second time while the captain was hand flying. As he recovered from the pitch down, he was lined up for a 5 mile final approach for runway 35. The captain elected to make a high speed, flaps up landing and landed uneventfully on runway 35. Post-flight inspection revealed that the left elevator was bent at the mid span trim tab, had partially detached from the aircraft, and was missing two attachment bolts. A review of the airplane maintenance history showed that while in "A" check maintenance, a dent was noted in the left elevator and the elevator was removed. The maintenance team did not follow the EMB 120 maintenance manual procedure for removal of the left elevator. During the non-routine maintenance procedures used by the maintenance team, cotter pin safeties that were removed from castellated nuts on the 2 outboard vertical hinge bolts on the left elevator were not reinstalled. The removal of these two bolts is not part of the EMB 120 maintenance manual procedure for removal of the left elevator. The maintenance team did not document the non-routine procedure they used to remove and reinstall the left elevator. The Require Inspection Items (RII) inspector had inspected the elevator installation for the procedures in the manual and was not aware of the undocumented non-routine maintenance procedures used, and hence did not examine the nuts that did not have the required cotter pins, which were not to be removed as part of the approved procedure. The FAA found that the maintenance teams that removed and reinstalled the elevator were inexperienced in EMB 120 elevator removal and reinstallation procedures. ## Aircraft - Registration: [N1110J](https://openairdocs.org/deregistered/N1110J-2024-06-25), registration cancelled 2024-06-25, S/N 120.110, built 1988 (OpenAirDocs) - Reported make and model: Embraer EMB120 (FC) - Registry model: [Embraer EMB-120FC](https://openairdocs.org/model/embraer-emb-120fc) (registry code 3260204) (OpenAirDocs) - Registry engine: [Pratt & Whitney Canada PW118](https://openairdocs.org/engine/pratt-whitney-canada-pw118) (registry code 52116, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 120.110 - Year built: 1988 - Engines: Pratt & Whitney Canada PW118 turbo prop; Pratt & Whitney Canada PW118 turbo prop - Damage: Substantial damage - Flight: Part 121 - Operator: Arctic One Llc - Registered owner: Arctic One Llc - Airworthiness certificate: Standard, Transport - Departed: ANC, Anchorage, AK - Destination: ILI, Iliamna, AK - Flight plan: IFR - Airport: ILI, Iliamna, runway 36, 4,800 × 100 ft, asphalt ## Weather - Conditions: Visual (VMC), Day - Observed at: PAIL, 1 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20120216002539A](https://openairdocs.org/incident/20120216002539A), Feb 16, 2012: Embraer EMB-120FC, Iliamna, AK, Substantial damage. On February 16, 2012, everts flight 1291, an EMB-120, N1110J, on an IFR flight plan from anchorage, AK (anc) (panc) to Iliamna, AK (ili) (pail), experienced… ## Docket (1 files) The files NTSB released with the investigation on July 21, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=82916. 60 KB in all. - Flight crew irregularity report (item 1, PDF, 2 pages, 60 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9291252&FileExtension=pdf&FileName=Mulder021612-Rel.pdf 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. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.