Sikorsky S-58T N47B

Summary

On 18 July 1997 at about 21:15 local time, a Sikorsky S-58T registered N47B was involved in an accident near Page, Arizona, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

18 July 1997 at 21:15

Classification

Accident

Location

Page, Arizona, United States

Coordinates

36.6807, -111.4098

Aircraft

Sikorsky S-58T

Registration

N47B

Category

Helicopter

Engines

2

Operator

Not recorded

Operating rule

Part 133: Rotorcraft Ext. Load

Purpose of flight

Unknown

Phase of flight

Not recorded

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

LAX97LA247

Nobody was injured.

an engine failure resulting from the fracture of two power turbine blades, which had been previously subjected to a hot or hung start.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot was hovering with an external load, when he heard a loud noise and noticed a power loss. He turned and executed a precautionary landing with a hard touchdown. The main rotor blades flexed downward and impacted the tail boom. An inspection revealed that over half of the blades in the No. 2 power section were fractured. A metallurgical examination revealed that two consecutive blades showed evidence of solutioning and re-solidification; however, the fracture surfaces did not show similar evidence of heat distress. Discoloration was also found on the power turbine wheel at a point corresponding to the location of the two blades. The operator stated that the aircraft had flown about 138 hours since all the turbine blades were replaced. None of the pilots who had flown the aircraft since then reported experiencing any hung or hot starts.

Quoted verbatim from the NTSB record.