Serious incident Saab 340A N322PX, Tuesday 2 February 1988

You can contribute by submitting additional or updated information.

Date:	Tuesday 2 February 1988
Time:	12:58 LT
Type:	Saab 340A
Owner/operator:	Express Airlines
Registration:	N322PX
MSN:	340A-041
Total airframe hrs:	5387 hours
Engine model:	GE CT7-5A2
Fatalities:	Fatalities: 0 / Occupants: 23
Other fatalities:	0
Aircraft damage:	Minor
Category:	Serious incident
Location:	Fayetteville, AR - United States of America
Phase:	Landing
Nature:	Unknown
Departure airport:	Memphis International Airport, TN (MEM/KMEM)
Destination airport:	(KFYV)
Investigating agency:	NTSB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
THE CAPT RPRTD THAT DRG THE LNDG ROLL, THERE WAS A LOUD NOISE FROM THE LEFT ENG FOLLOWED BY HVY SMOKE & AN ENG FIRE WARNING BELL. HE STOPPED THE ACFT ON A TWY & ORDERED AN EVACUATION. THE FLT ATTENDANT HAD DIFFICULTY OPENING THE FLOOR-LEVEL EMERG EXIT. NO SLIDE OR ROPE WAS AVAILABLE FOR EXITING THE ACFT; 3 PSGRS RCVD MINOR INJURIES WHEN THEY DROPPED ABT 5-1/2 FT TO THE ICY TWY. AN EXAM REVEALED THE LEFT ENG POWER TURBINE (PT) HAD AN UNCONTAINED FAILURE. A TEARDOWN INSPN OF THE ENG REVEALED THAT A 'B' NUT ON THE STAGE 4 COMPRESSOR BLEED TUBE COUPLING HAD BECOME DISCONNECTED. THIS RESULTED IN A LOSS OF COOLING AIR TO THE PT ROTOR CAVITY & OVERHEATING OF THE STAGE 4 TURBING DISK. MEASUREMENT OF THE STAGE 3 & 4 DISKS SHOWED RADIAL (CREEP) GROWTH OF .006' & .150', RESPECTIVELY. THERE WAS EVIDENCE OF HVY BLADE TIP RUBS INTO THE STATOR TIP SHROUD BACKING MATERIAL (DRG APPLICATION OF REVERSE THRUST), THEN FAILURE OF THE STAGE 4 TURBINE BLADES & THE PT MODULE.

Probable Cause:

Accident investigation: