Boeing 727-51 N463US

Summary

On 26 January 1985 at about 20:29 local time, a Boeing 727-51 registered N463US was involved in an incident near St. Paul, Minnesota, United States. 61 people were on board and nobody was injured. The aircraft was slightly damaged. No probable cause statement is available for this record.

Date

26 January 1985 at 20:29

Classification

Incident

Location

St. Paul, Minnesota, United States

Nearest airport

Minneapolis/St. Paul Arpt (MSP)

Coordinates

44.8796, -93.1996

Aircraft

Boeing 727-51

Registration

N463US

Category

Airplane

Engines

3

Operator

Not recorded

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Unknown → Dallas

Aircraft damage

Minor

Weather

IMC

Light

Day

NTSB number

CHI85IA097

Nobody was injured.

The NTSB has not published a probable cause for this record. No probable cause statement is present in the source data.

Nothing about the cause is stated here that is not in the source record.

Read the full NTSB narrative

SHORTLY AFTER TAKEOF, THE AIRCRAFT EXPERIENCED AN UNCONTAINED 7TH TO 8TH STAGE REMOVABLE SLEEVE COMPRESSOR SPACER FAILURE IN THE NUMBER 3 ENGINE. PIECES OF THE SPACER PASSED THROUGH THE NUMBER 2 ENGINES DUCT CAUSING COMPRESSOR STALLS IN THAT ENGINE. THE AIRCRAFT LANDED SUCESSFULLY 9 MINUTES AFTER TAKEOFF USING THE SINGLE GOOD ENGINE. METALLURGICAL ANALYSIS OF THE RECOVERED SPACER PIECES REVEALED THAT CADMIUM EMBRITTLEMENT HAD OCCURRED AROUND AT LEAST ONE TIEROD SLEEVE HOLE ON THE SPACER. THIS EMBRITTLEMENT OCCURRED BECAUSE THE SPACER WAS INCOMPLETELY PLATED WITH NICKLE DURING A SPACER MODIFICATION THAT TOOK PLACE IN 1975. THE INCOMPLETE NICKLE PLATING ALLOWED A SUBSEQUENT CADIUM LAYER TO COME IN CONTACT WITH THE STEEL SPACER, CAUSING THE EMBRITTLEMENT.

Quoted verbatim from the NTSB record.