MIA98FA112

NTSB accident investigation · Boeing 727-212 · Fort Lauderdale, FL · March 31, 1998

Accident · Serious injuriesField investigationFinal report
Date
March 30, 1998, 21:14 local (Mar 31, 1998, 02:14 UTC)
Place
Fort Lauderdale, FL
Injuries
3 serious, 14 minor, 177 uninjured
Damage
Minor damage
Phase of flight
Takeoff
Aircraft
CFRYSBoeing 727-212
Weather
Visual (VMC) · Night/dark
Status
Completed · report November 17, 1999
Report
Approved by Office Director
Safety recommendations
Yes
Case key
38393

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The NTSB’s determination of the probable cause, and any contributing factors.

Failure of the No.2 engine low pressure compressor rear tierod. Also contributing to the accident was failure of the manufacturer to apply an antigallant treatment to the tierod's compressor disk lands during manufacture.

Analysis

On takeoff roll, between 90 and 100 knots, the No. 2 engine sustained an uncontained failure. The flight crew aborted the takeoff and when informed that smoke was emanating from No. 2 engine, the crew brought the airplane to a stop on a taxiway, and the pilot commanded a passenger emergency evacuation. Examination of the engine revealed that one of 12 low pressure compressor (LPC) rear tiebolts fractured at its 4th stage disk land and was separated into the plenum ahead of the LPC. The separated tierod impacted the other 11 tierods until they eventually fractured, causing catastrophic separation of the LPC assembly between the 3rd and 4th stage rotors. Metallurgical examination of the failed tierods revealed the first tierod failed due to fatigue and the other 11 due to stress. It was further revealed that an anti-gallant treatment to the tierods that are used to bolt the 3rd through 6th compressor disks together as a unit was not present. The treatment is applied to the lands of the tierods at manufacture as specified in Pratt & Whitney Service Bulletin No. 5407.

Factual narrative

The factual narrative1,225 words

History of flight

On March 30, 1998, about 2114 eastern standard time, a Boeing 727-212, Canadian registration C-FRYS, registered to and operated by Royal Aviation, Inc., as flight 311, a Title 14 CFR Part 129, nonscheduled international passenger flight, from Fort Lauderdale, Florida to Toronto, Canada, experienced a failure of No. 2 engine during takeoff roll at Fort Lauderdale-Hollywood International Airport. Visual meteorological conditions prevailed and an instrument flight plan was filed. The airline transport-rated pilot, first officer, flight engineer, 5 flight attendants, and 169 passengers, including 2 lap children, were not injured. Three passengers sustained serious injuries and 14 passengers sustained minor injuries during the emergency evacuation after takeoff was aborted. The flight was originating at the time of the accident.

The pilot stated that during takeoff roll from runway 9L, between 90 and 100 knots indicated airspeed, he felt a "thud" and observed an "engine fail" light and No. 2 engine fire warning . At about 110 knots, he aborted the takeoff, brought the airplane to a stop on a high-speed taxiway, and requested that the "engine fire on ground" and "aborted takeoff" check-lists be read and accomplished. When the tower advised that smoke was still emanating from the engine tailpipe, the pilot commanded that a passenger emergency evacuation be accomplished, and that the "emergency evacuation" checklist be read and accomplished. The four fuselage doors and slides were used, as well as the four overwing exits. The aft airstairs were not used. The pilot further stated that the flight attendant's safety brief, including emergency evacuation exits and escape routes had been given to the passengers, according to company procedures. The evacuation took about 3 minutes.

Fire rescue personnel stated that upon arrival at the aircraft they observed that some passengers had assembled on-wing at the wing-tips. They were directed back toward the wing root area by the first officer and fire rescue personnel on the ground, and that no one actually jumped from the wing tip area.

Personnel information

Information on the pilot, first officer, and flight engineer is included in this report under First Pilot, in supplement E, and in the attached Pilot/Operator Aircraft Accident Report.

Aircraft information

The aircraft, a Boeing 727-212, had been modified in accordance with Federal Aviation Administration Supplement Type Certificate SA 5938 NM. As part of the modification, the wing-tips had been modified to the winglet type. The trailing edge flaps were limited to 30 degrees from the original 40 degrees, by a blocking device installed on the cockpit flap quadrant. Examination of the aircraft after the accident showed the ground evacuation emergency checklist mounted on the cockpit yoke, and the Royal Airlines printed cockpit checklist called for "FLAPS-40", which was not possible. Examination of the aircraft also showed the passenger seatback pockets contained the Royal Airlines, Boeing 727-200 Safety Card, that depicts the escape route from each emergency escape exit. For additional information, see attached flight manual supplement for Boeing 727-200 series with STC SA 5938 installed under, Other Pertinent Forms and Reports. A copy of the seatback safety card is attached under, Other Pertinent Forms and Reports.

Meteorological information

Visual meteorological conditions prevailed at the time of the accident. For additional information, see Weather Information included in this report.

Flight recorders

The digital flight data recorder was removed from the airplane on April 1, 1998, and sent to the NTSB Vehicle Recorders Laboratory, Washington, D.C. The data extracted confirms the airplane's positioning to runway heading, the 3-engine spool-up to about 1.6 EPR, (engine pressure ratio, the primary thrust setting instrument) for 3 seconds, and the continuous increase of thrust to takeoff EPR of 2.1. The number 2 engine EPR sharply decreases to about 1.0 at an airspeed of 105 knots, followed immediately by the sharp decrease and slight increase of EPR's 1 and 3. (For additional information see the Flight Data Recorder/Specialist's Factual Report of Investigation.)

Wreckage and impact information

Postaccident inspection of the aircraft was conducted by NTSB and FAA personnel on April 1, 1998. The No.2 engine failure was uncontained just aft of the low pressure turbine, (LPT). The engine was cut completely in half just aft of the LPT. The fan exhaust duct was completely severed and the LPT case was completely separated from the remainder of the turbine exhaust case. The LPT containment shield was broken into several pieces. The LPT disks were intact but the blades were all fractured just above their root platforms, and most of them had been liberated. The two fan rotors and the 3rd stage compressor rotor could be rotated as a unit, but rotated independently of the remainder of the low pressure rotor assembly. The aft cowling halves had fire blistered paint and numerous shrapnel perforations just aft of the LPT's plane of rotation. Airframe and engine damage is included on page 3 and page 5 of the attached Powerplants Group Chairman's Factual Report.

Teardown inspection of the No. 2 engine by the Powerplants Group showed initial engine component failure was one or more of the 12 low pressure compressor, (LPC) rear tierods. One tierod had failed at its 4th stage compressor disk land and the 11 others failed adjacent to their threaded ends. (For additional information see the Powerplants Group Chairman's Factual Report.)

Medical information

A report from on-scene EMS personnel indicated that 17 passengers were treated at the scene and transported to three area medical centers for further evaluation. Injuries to those passengers included one small arm laceration, one hip trauma, one hypertensive reaction, and 11 with ankle trauma. The serious injuries were three fractured ankles sustained while sliding off the wing flap trailing edge to the ground.

Tests and research

The 12 LPC rear tierods, (PN 789550) and pieces of the failed low pressure turbine (LPT) containment shield were removed and shipped to the NTSB Materials Laboratory, Washington, D. C. It was revealed that an anti-gallant treatment to the tierods that are used to bolt the 3rd through 6th compressor disks together as a unit was not present. The treatment is applied to the lands of the tierods at manufacture as specified in Pratt & Whitney Service Bulletin No. 5407. One tierod was fractured transversely across the tierod's 4th stage compressor disk land. The entire fracture face on the tierod had surface corrosion, suggesting that the tierod had been broken for some time. The 11 remaining LPC rear tierods were fractured at their forward ends between the 3rd stage compressor disk lands and the tierod nut threads. These 11 fractures appeared to be overload caused. Pockmarks and bending damage suggest that after initial tierod fracture and liberation of its tierod end/nut, it tumbled around in the cavity at the front of the LPC and impacted the other tierod ends/nuts until they eventually fractured, causing the catastrophic compressor separation. Eleven equally spaced fan exit vanes showed imprints of the tierod ends/nuts on their leading edges, indicating that the 11 remaining tierods fractured nearly simultaneously at engine failure. For additional information see attached, NTSB Poweplants Group Chairman Factual Report and NTSB Materials Laboratory Factual Report.

Regarding the discrepancy between printed checklist response of "Flaps 40" for an emergency evacuation flap setting and having the maximum flap setting physically blocked at "Flaps 30", Royal Airlines flight operations personnel stated that the checklists simply had not been updated. Because of the flap extension limitation, the differenc

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of engine power(total) - mech failure/malfTakeoff - roll/run
1 engine - failure
Compressor assembly,wheel retention - fatigueCause
Aborted takeoff - performedPilot in command
Inadequate quality controlManufacturerCause
Miscellaneous/otherStanding - engine(s) not operating
Evacuation - initiatedPilot in command

Aircraft

Registration
CFRYS
Reported as
Boeing 727-212
Category
Airplane
Serial number
21349
Airframe hours
54,355
Engine
P&W JT8D-17A, 16,000 lbs thrust, turbo fan
Damage
Minor damage
Flight
Part 129
Registered owner
Royal Aviation, Inc
Airworthiness certificate
Standard, Transport
Last inspection
Continuous airworthiness · March 8, 1998 · 93 hours before
Departed
FLL
Destination
YYZ · Toronto
Flight plan
IFR
Airport
FLL · Ft. Lauderdale/Hollywood, runway 9L, 9,001 × 150 ft, asphalt

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
36
Certificate
Airline transport
Airplane ratings
Single-engine sea, Multi-engine sea, Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Seat
Left
Flight hours
7,900 total · 2,700 in this make and model · 3,500 as pilot in command · 270 in the last 90 days · 90 in the last 30 days · 4 in the last 24 hours

Weather

Conditions
Visual (VMC) · Night/dark
Wind
120° at 12 knots
Visibility
15 statute miles
Lowest ceiling
None
Temperature
82 °F, dew point 72 °F
Altimeter
30.00 inHg
Observed at
FLL, 1 nm away

Docket · 24

The files NTSB released with the investigation on April 16, 1999, on NTSB’s docket system: statements, records, photos and specialists’ reports. 17.1 MB in all.