PB96-910403
NTSB/AAR-96/03
NATIONAL TRANSPORTATION SAFETY BOARD
WASHINGTON, D.C. 20594

		AIRCRAFT ACCIDENT REPORT

	    UNCONTAINED ENGINE FAILURE/FIRE
              VALUJET AIRLINES FLIGHT 597
                DOUGLAS DC-9-32, N908VJ
                   ATLANTA, GEORGIA
                      JUNE 8,1995

[Page vi]

EXECUTIVE SUMMARY

On June 8, 1995, a Douglas DC-9-32, N908VJ, was being operated by
ValuJet Airlines as a scheduled, domestic passenger flight under the
provisions of Title 14 Code of Federal Regulations (CFR) Part 121.
Flight 597, destined for Miami, Florida, departed gate C25 at the
William B. Hartsfield Atlanta International Airport, Atlanta, Georgia,
at 1855, and was cleared for takeoff on runway 27R at 1908.  Five
crewmembers and 57 passengers were on board.

As flight 597 began its takeoff roll, a "loud bang" was heard by the
airplane occupants and air traffic control personnel. The right engine
fire warning light illuminated, the flightcrew of a following airplane
reported to the ValuJet crew that the right engine was on fire, and
the takeoff was rejected.  Shrapnel from the right engine penetrated
the fuselage and the right engine main fuel line, and a cabin fire
erupted.  The airplane was stopped on the runway, and the captain
ordered the evacuation of the airplane.

The flight attendant seated in the aft flight attendant jumpseat
received serious puncture wounds from shrapnel and thermal injuries.
Another flight attendant and five passengers received minor injuries.
The pilots, the third flight attendant, and 52 passengers were not
injured.  The airplane's fuselage was destroyed.

The National Transportation Safety Board determines that the probable
cause of this accident was the failure of Turk Hava Yollari
maintenance and inspection personnel to perform a proper inspection of
a 7th stage high compressor disk, thus allowing the detectable crack
to grow to a length at which the disk ruptured, under normal operating
conditions, propelling engine fragments into the fuselage; the
fragments severed the right engine main fuel line, which resulted in a
fire that rapidly engulfed the cabin area.  The lack of an adequate
recordkeeping system and the failure to use "process sheets" to
document the step-by-step overhaul/inspection procedures contributed
to the failure to detect the crack and, thus, to the accident.

The safety issues in this report include the clarity of operations
specifications for repair stations, recordkeeping requirements for
foreign repair stations, regulatory guidance concerning maintenance
documentation, intent of "serviceable tags," independently powered
public address systems on all transport-category airplanes, flight
attendant training programs and manuals, enforcement of occupant
restraint requirements, and cabin material/fire safety standards.

Safety recommendations concerning these issues were addressed to the
Federal Aviation Administration.


[Page 57]


3. CONCLUSIONS

3.1  Findings

1.  The flightcrew met the certification, training, and rest
requirements of the applicable Federal regulations before the
accident, and the flight attendants had completed Valujet' s
FAA-approved flight attendant training program in existence at the
time of the accident.

2.  The airplane was certificated and operated in accordance with
applicable Federal regulations.

3.  An uncontained failure of the right engine occurred at low
airplane and high engine rotational speed, during the initiation of
the takeoff roll.  As a result of the uncontained failure, engine
fragments penetrated the airplane's cabin, severing the right engine
main fuel line and causing the release of pressurized fuel inside the
cabin.  Sparks that most likely were generated by steel engine
fragments contacting steel galley components ignited a fire that
quickly spread through the airplane's cabin.

4.  The uncontained failure was caused by a fatigue crack in stress
redistribution hole "1" in the 7th stage high compressor disk of
engine SN 666966.  The fatigue crack length was consistent with a
critical crack length expected to produce separation of the disk under
normal operating conditions.

5.  Based on an analysis of fatigue striation measurements, a
detectable crack existed in SR hole "1" in the 7th stage high
compressor disk of engine SN 666966 when the disk was overhauled by
the THY repair station in 1991.

6.  The 7th stage high compressor disk of engine SN 666966 did not
receive a proper inspection in when the disk was overhauled at the THY
repair station in 1991.

7.  Had the THY repair station accomplished a proper inspection of the
7th stage high compressor disk of engine SN 666966, the crack would
probably have been detected, the part rejected, and consequently, the
accident might have been avoided.

8.  The THY repair station was not using "process sheets" at the time
of the 1991 overhaul and inspection of the 7th stage high compressor
disk of engine SN 666966; the use of such documents would have
increased the likelihood that the disk would have received a proper
inspection and that the crack would have been detected.

9.  Although the P&W JT8D engine manual could have presented more
precise information in terms of overhaul procedures and instructions,
this lack of clarity did not contribute to the failure of the disk.

10.  FAA guidance on what degree of detail is required in maintenance
records is insufficient and vague.


[Page 58]

11.  "Process sheets" or similar documentation of sufficient detail to
permit a complete determination of the work needed to be done and of
the work that has been done is necessary for a comprehensive
maintenance program to ensure the continued airworthiness of aircraft,
engines, and components.

12.  Foreign repair stations are not, but should be, subject to the
same FAA recordkeeping requirements as domestic repair stations.

13.  The industry practice of using serviceable tags without a clear
understanding of their purpose can result in the misinterpretation of
the intent of these tags.

14.  Although there were conflicting interpretations of THY's
authority to overhaul JT8D engines by the FAA and THY, the Repair
Station Operations Specifications in question can reasonably be read
to indicate that THY did have authority under Part 145 to overhaul
JT8D engines at the time engine SN 666966 was overhauled in 1991.

15.  The fourth item on the evacuation checklist was not completed by
the flightcrew because of smoke accumulation in the cockpit; as a
result, emergency lights were not available during a portion of the
evacuation.  Fortunately, the lack of emergency lights did not
preclude a successful evacuation.

16.  Although the pilot's delay in communicating the evacuation order
because of an electrical power loss did not adversely affect the
evacuation, the accident again highlights the need for an independent
power source for public address systems in transport-category
airplanes.

17.  Although deficiencies in ValuJet's flight attendant training
program, including emergency drills training, and the FAA's inadequate
oversight of this program did not affect occupant survivability in
this accident, they could have.

18.  Although Federal regulations require that all passengers more
than 24 months old be restrained during takeoff and landing, this
accident again demonstrates that this regulation is not always
enforced, as one child who was more than 24 months old was listed as a
lap child and was seen being held in an adult passenger's lap.

19.  Because one of the flight attendants had her own key for the
cockpit, she was able to quickly notify the flightcrew about the fire.
ValuJet procedures in effect at the time did not provide for prompt
flight attendant access to the cockpit.

20.  The aircraft involved in this accident did not meet current
regulatory requirements regarding flammability standards for materials
used in the interiors of transport-category airplane cabins nor was it
required to do so. However, this accident demonstrates the importance
of the current standards and the need for existing aircraft to be
brought up to these standards as quickly as possible.

[Page 59]

3.2  Probable Cause

The National Transportation Safety Board determines that the probable
cause of this accident was the failure of Turk Hava Yollari
maintenance and inspection personnel to perform a proper inspection of
a 7th stage high compressor disk, thus allowing the detectable crack
to grow to a length at which the disk ruptured, under normal operating
conditions, propelling engine fragments into the fuselage; the
fragments severed the right engine main fuel line, which resulted in a
fire that rapidly engulfed the cabin area.  The lack of an adequate
recordkeeping system and the failure to use "process sheets" to
document the step-by-step overhaul/inspection procedures contributed
to the failure to detect the crack and, thus, to the accident.


[Page 60]

4.  RECOMMENDATIONS

As a result of this accident investigation, the National
Transportation Safety Board recommends that the Federal Aviation
Administration:

Review the Air Agency Certificates and Repair Station Operations
Specifications of all repair stations and ensure that the language
used in the operations specifications clearly indicates the extent of
the repair stations' authority.  (Class II, Priority Action)(A-96-78)

Revise 14 CFR Part 145 to require Subpart C foreign repair stations to
adhere to the same recordkeeping requirements as domestic repair
stations.  (Class II, Priority Action)(A-96-79)

Revise the applicable regulations and provide specific guidance on the
documentation to be used and kept during inspections and overhauls,
including "process sheets" or similar detailed documentation for all
certificated repair stations.  (Class II, Priority Action)(A-96-80)

Require that "serviceable tags" be used to return engines and other
components to service, that they be in a prescribed format (perhaps in
the format of FAA Form 8130-3), and that when there is a change of
ownership, and certainly upon importation, the approval for return to
service attest to the overall airworthiness of the part and the tag
reflect that a complete and thorough review of records, including
"process sheets" of the last overhaul, has taken place.  In the
absence of such records, require an overhaul of the part when there is
a change in ownership.  (Class II, Priority Action) (A-96-81)

Require that all transport-category aircraft manufactured before
November 27, 1990, be retrofitted with a public address system capable
of operating on an independent power source.  (Class II, Priority
Action) (A-96-82)

Emphasize to principal operations inspectors the importance of
thoroughly reviewing flight attendant training programs before
approving them and flight attendant manuals before accepting them.
(Class II, Priority Action) (A-96-83)

Provide guidance on how to implement the requirement that occupants
who are more than 24 months old are restrained during takeoffs,
landings, and during turbulence.  (Class II, Priority Action)(A-96-84)

Require that each flight attendant have a cockpit key in his/her
possession at all times while on duty.  (Class II, Priority
Action)(A-96-85)

[Page 61]

Prohibit the use during any type of replacement, after 1997, of cabin
materials in all transport-category airplanes that do not comply with
the current fire safety standards contained in 14 CFR 25.853.  (Class
II, Priority Action) (A-96-86)

Amend 14 CFR Part 121 to prohibit, upon a transfer of the aircraft
from one certificate holder to another, or by January 1, 2001,
whichever occurs first, the operation of airplanes with cabin
materials that do not meet the requirements of 14 CFR Part 25.853.
(Class II, Priority Action) (A-96-87)

Issue an operations bulletin recommending that principal operations
inspectors advise their air carriers to disseminate Federal Aviation
Administration safety guidance on airline passenger attire to their
flight attendants.  (Class II, Priority Action) (A-96-88)

Require all aircraft currently required to be installed with a cockpit
voice recorder (CVR) to be retrofitted within 2 years with a CVR
installation designed such that an uninterrupted recording from the
boom or mask microphones and headphones for each flight crewmember's
position and from an area microphone can be made on dedicated channels
of the CVR.  A sidetone shall be produced only when the transmitter or
interphone is selected, and, in addition, all audio signals received
by hand-held microphones shall be recorded on the respective
crewmember's channel when keyed to the "ON" position.  (Class II,
Priority Action) (A-96-89)

BY THE NATIONAL TRANSPORTATION SAFETY BOARD

JAMES E. HALL
Chairman

ROBERT T. FRANCIS II
Vice Chairman

JOHN A. HAMMERSCHMIDT
Member

JOHN J. GOGLIA
Member

GEORGE W. BLACK
Member


August 30, 1996

Last modified: Tue Oct 22 12:34:24 1996