# NTSB CHI83IA054: Gates Lear Jet 35A, N1500E, Over Fargo, ND, December 10, 1982

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: December 10, 1982, 10:30 local (16:30 UTC)
- Place: Over Fargo, ND
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report December 10, 1983
- Report: Approved by Office Director
- NTSB case key (mKey): 72125
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI83IA054
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/72125/pdf
- Page: https://openairdocs.org/ntsb/CHI83IA054

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of engine power(total) - mech failure/malf, cruise - normal
  - turbine assembly,turbine wheel - disintegrated (cause)
  - inadequate quality control, manufacturer (cause)

## Analysis

WHILE LEVEL AT FL370 OVER FARGO, ND, THE CREW HEARD A LOUD BANG IN THE ENGINE AREA AND THE AIRCRAFT EXPERIENCED A SUDDEN LOSS OF CABIN PRESSURE. AT THE SAME TIME, THE CREW NOTICED THAT THEY HAD LOST POWER ON THE #2 ENGINE. AFTER SECURING THE ENGINE AND REGAINING CONTROL OF THE CABIN PRESSURIZATION, THE FLIGHT WAS CONTINUED TO MILWAUKEE, WI, WITHOUT FURTHER INCIDENT. EXAMINATION REVEALED TWO JAGGED HOLES IN THE ENGINE COWL AND ONE THROUGH THE AFT FUSELAGE. DETAILED EXAMINATION OF THE ENGINE REVEALED THAT IT HAD EXPERIENCED A SEGMENT SEPARATION OF THE 2ND STAGE LOW PRESSURE TURBINE DISC. THE CHUNK FAILURE WAS A RESULT OF IMPROPER MACHINING OF THE FORWARD SIDE WEB AREA OF THE DISC. THE PRESSURIZATION DROP OCCURRED WHEN SEPARATION DISC FRAGMENTS STRUCK AND DISABLED THE 3 WAY BLEED VALVE.

## Aircraft

- Registration: N1500E (not matched to a registry record)
- Reported make and model: GATES LEAR JET 35A
- Category: Airplane
- Serial number: 124
- Engines: AIRRESEARCH TFE-731-2-2B 3500 lbs thrust turbo fan
- Damage: Minor damage
- Flight: Executive/Corporate, Part 91
- Operator: Bucyrus Erie Company
- Registered owner: Bucyrus Erie Company
- Departed: JAMESTOWN, ND
- Destination: MILWAUKEE, WI
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 56; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; flight hours: 18,700 total, 2,500 in this make and model

## Weather

- Conditions: Visual (VMC), Day

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Incident 19821210070549I](https://openairdocs.org/incident/19821210070549I), Dec 10, 1982: Lear 35A, Fargo, ND, Minor damage. Lost left engine and cabin pressure. Turbine rotor disk separated. Debris severed bleed air valve and hit fuselage.

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.