NTSB Identification: ATL86FA203.
The docket is stored on NTSB microfiche number 32274.
Nonscheduled 14 CFR
Accident occurred Monday, July 21, 1986 in CHAPEL HILL, NC
Aircraft: BELL 222UT, registration: N222DU
Injuries: 2 Minor,3 Uninjured.

NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

DRG AN EMERG MED SVC (EMS)/MED EVAC FLT, AN UNCONTAINED PWR TURBINE BURST OF THE #1 ENG OCCURRED. DEBRIS FM THE #1 ENG DISABLED THE #2 ENG & SEVERED THE TAIL ROTOR DRIVE SHAFT. THE #2 ENG FIRE LGT ILLUMINATED & THE PLT DISCHARGED THE #2 ENG FIRE EXTINGUISHER. DRG AN AUTOROTATIVE LNDG, THE PLT INCREASED COLLECTIVE TO CLR TREES, AND THE HELICOPTER ROLLED ON ITS SIDE AT TOUCHDOWN. THE PLT, 1 NURSE & THE PATIENT WERE UNHARMED, BUT 2 NURSES RCVD MINOR INJURIES. AN EXAM SHOWEDTHE #2 & #3 BRGS IN THE #1 ENG HAD OVERHEATED & FAILED DUE TO LACK OF LUBRICATION. OIL PASSAGES & JETS TO THE BRGS WERE FND CLOGGED WITH HVY CARBON DEPOSITS. THE ENG COMBUSTOR HOUSING WAS CHNGD APRX 13 FLT HRS BFR THE ACDNT DUE TO A CLOGGEDVENT STRUT; AFTER DRAINING OIL, THE OIL SYS WASN'T FLUSHED, BUT FLUSHING WASN'T REQD. EVIDENCE SHOWED LYC LTS 101-750C-1ENGS WERE SUSCEPTIBLE TO CARBON CLOGGING; THAT THE #2 SEALS TENDED TO ERODE & ALLOW EXCESSIVE HOT GASES INTO THE #2 & #3BRGS. AFTER THE ACDNT, THE FAA ISSUED AD 86-22-05, REQUIRING INCREASED INSPN & MAINT PROCEDURES TO PREVENT RECURRENCE.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

TURBINE ASSEMBLY,SEAL..WORN

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

ACFT/EQUIP,INADEQUATE AIRCRAFT COMPONENT..MANUFACTURER

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

FLUID,OIL..OVERTEMPERATURE

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

LUBRICATING SYSTEM..CONTAMINATION

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

LUBRICATING SYSTEM..BLOCKED(PARTIAL)

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

FLUID,OIL..STARVATION

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

TURBINE ASSEMBLY,SHAFT BEARING..OVERTEMPERATURE

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

TURBINE ASSEMBLY,SHAFT BEARING..FAILURE,TOTAL

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

TURBOSHAFT ENGINE,FREE(POWER) TURBINE..BURST


Contributing Factors

MAINTENANCE..INADEQUATE..COMPANY MAINTENANCE PERSONNEL


Contributing Factors

CONDITION(S)/STEP(S) NOT LISTED..MANUFACTURER







Contributing Factors

TERRAIN CONDITION..HIGH OBSTRUCTION(S)





Contributing Factors

TERRAIN CONDITION..ROUGH/UNEVEN

Index for Jul1986 | Index of months