# NTSB CEN11LA457: Beech B36TC, N93PP, Akron, CO, June 23, 2011

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: June 23, 2011, 09:15 local (15:15 UTC)
- Place: Akron, CO
- Coordinates: 40.175556, -103.221946 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.1756&lon=-103.2219&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Defining event: [Approach-VFR pattern final: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed, report November 3, 2011
- Report: Approved by Office Director
- NTSB office: Central Region
- Parties: FAA Flight Standards District Office
- NTSB case key (mKey): 81018
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN11LA457
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81018/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81018
- Page: https://openairdocs.org/ntsb/CEN11LA457

## Probable cause

The mixture control cable disconnected from the cable housing attach clamp, which resutlted in the pilot's inability to add power when needed.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Engine controls: mixture control](https://openairdocs.org/ntsb-findings/01057602): Aircraft › Aircraft power plant · Inoperative (probable cause); cases with it: [Beech B36TC, 1 case](https://openairdocs.org/ntsb-findings/01057602/cases.md?model=1151609), [All aircraft, 41 cases](https://openairdocs.org/ntsb-findings/01057602/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Approach-VFR pattern final: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Beech B36TC, 3 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=1151609), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md)
- [Approach-VFR pattern final: Controlled flight into terr/obj (CFIT)](https://openairdocs.org/ntsb-events/120); cases with it: [Beech B36TC, 4 cases](https://openairdocs.org/ntsb-events/120/sequence.md?model=1151609), [All aircraft, 1,074 cases](https://openairdocs.org/ntsb-events/120/sequence.md)

## Analysis

The pilot reduced power for landing because the approach was slightly high. When he added power to arrest the descent, the engine failed to respond. The airplane landed short of the runway. The impact drove the main landing gear through the right wing. Examination and functional testing of the engine revealed that the mixture control cable was disconnected from the cable housing attach clamp. The cable was reattached and the engine functioned normally with no anomalies noted.

## Factual narrative

On June 23, 2011, about 0915 mountain daylight time, a Beech B36TC, N93PP, impacted terrain short of the runway at Colorado Plains Regional Airport (AKO), Akron, Colorado. The pilot and passenger on board the airplane sustained minor injuries. The airplane was substantially damaged. The airplane was registered to and operated by Arizona Thunderbolts LLC, Phoenix, Arizona, under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as a personal flight. Visual meteorological conditions (VMC) prevailed at the time of the accident, and no flight plan had been filed. The flight originated at Yuma (2V6), Colorado, approximately 0900 and was en route to AKO. According to the pilot, he reduced power for landing because he was slightly high. When he added power to arrest the descent, the engine failed to respond. The airplane landed short of the runway. The impact drove the main landing gear through the right wing. During the first functional test, the engine was started using high boost prime. When low boost was selected, the engine quit. During a second examination, it was discovered that the mixture control cable was disconnected from the cable housing attach clamp. When the mixture control was moved inside the cockpit, the cable and housing moved together. The mixture control cable was reconnected and the engine was functionally tested again. The engine operated at all power settings, from idle to 2,800 rpm. Mixture adjustments were made with no anomalies noted.

## Aircraft

- Registration: [N93PP](https://openairdocs.org/deregistered/N93PP-2013-05-01), registration cancelled 2013-05-01, S/N EA-531 (OpenAirDocs)
- Reported make and model: BEECH B36TC
- Registry model: [Beech B36TC](https://openairdocs.org/model/beech-b36tc) (registry code 1151609) (OpenAirDocs)
- Category: Airplane
- Serial number: EA-531
- Airframe hours: 1730
- Engines: Continental TSIO-520-UB 300 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Arizona Thunderbolts LLC
- Registered owner: Arizona Thunderbolts LLC
- Airworthiness certificate: Standard, Utility
- Last inspection: Annual, March 14, 2011, 37 hours before
- Departed: 2V6, Yuma, CO
- Destination: Akron, CO
- Flight plan: Unknown
- Airport: AKO, Colorado Plains Regional, runway 11, 7,000 × 100 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 66; injuries: none; commercial, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review July 12, 2010; seat: left; flight hours: 5,390 total, 64 in this make and model, 3,267 as pilot in command, 9 in the last 90 days, 5 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 13 knots, gusting 20
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 72 °F, dew point 46 °F
- Altimeter: 30.04 inHg
- Observed at: KAKO

## 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 20110623013059A](https://openairdocs.org/incident/20110623013059A), Jun 23, 2011: Beech B36TC, Akron, CO, Substantial damage. On 6/23/2011 at 09:30 MDT, N93PP, a Beech bonanza airplane experienced engine problems while on approach to the Colorado plains airport (ako) and landed…

## Other investigations on N93PP (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 FTW03LA202](https://openairdocs.org/ntsb/FTW03LA202), Aug 16, 2003: Beech BE-36TC (N93PP), Temple, TX, substantial damage. Probable cause: The pilot's failure to attain adequate airspeed and his failure to abort the takeoff roll resulting in an overrun.

## Docket (8 files)

The files NTSB released with the investigation on October 4, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81018. 2.5 MB in all.

- NTSB Form 6120, Pilot-Operator Aircraft Accident Report (item 1, .PDF, 617 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353959&FileExtension=.PDF&FileName=NTSB%20Form%206120,%20Pilot-Operator%20Aircraft%20Accident%20Report-Redacted.PDF
- Pilot's Statement (item 2, .PDF, 155 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353973&FileExtension=.PDF&FileName=Pilot%27s%20Statement-Redacted.PDF
- Excerpt from the Beech B36TC Illustrated Parts Catalog. (item 3, .PDF, 940 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353977&FileExtension=.PDF&FileName=Excerpt%20from%20the%20Beech%20B36TC%20Illustrated%20Parts%20Catalog.-Master.PDF
- Parts Description. (item 4, .PDF, 177 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353978&FileExtension=.PDF&FileName=Parts%20Description.-Master.PDF
- Excerpt from the Beech B36TC Illustrated Parts Catalog, showing mixture control cable and clamp. (item 5, .PDF, 43 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353979&FileExtension=.PDF&FileName=Excerpt%20from%20the%20Beech%20B36TC%20Illustrated%20Parts%20Catalog,%20showing%20mixture%20control%20cable%20and%20clamp.-Master.PDF
- Photo 1. Engine compartment and firewall as viewed from left side of airplane. (item 6, .PDF, 240 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353974&FileExtension=.PDF&FileName=Photo%201.%20Engine%20compartment%20and%20firewall%20as%20viewed%20from%20left%20side%20of%20airplane.-Master.PDF
- Photo 2. Mixture control cable and clamp. (item 7, .PDF, 189 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353975&FileExtension=.PDF&FileName=Photo%202.%20Mixture%20control%20cable%20and%20clamp.-Master.PDF
- Photos 3 and 4. Another view. Note mixture control clamp does not appear to be crimped. (item 8, .PDF, 90 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353976&FileExtension=.PDF&FileName=Photos%203%20and%204.%20Another%20view.%20Note%20mixture%20control%20clamp%20does%20not%20appear%20to%20be%20crimped.-Master.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.

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