# NTSB ANC89IA071: Boeing 747-121, N818FT, Anchorage, AK, May 17, 1989

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: May 17, 1989, 09:39 local (17:39 UTC)
- Place: Anchorage, AK
- Coordinates: 61.179718, -149.879074 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=61.1797&lon=-149.8791&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 6 uninjured
- Status: Completed, report September 17, 1992
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 5130
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC89IA071
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5130/pdf
- Page: https://openairdocs.org/ntsb/ANC89IA071

## Probable cause

FAILURE OF TIRES ON THE RIGHT INSIDE MAIN GEAR TRUCK.  A RELATED FACTOR WAS:  FAILURE OF OPERATOR/MANAGEMENT PERSONNEL TO FOLLOW PROPER LOADING PROCEDURES, WHICH RESULTED IN AN IMPROPER LATERAL WEIGHT AND BALANCE SITUATION.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Miscellaneous/other, takeoff - roll/run
  - procedures/directives - not followed, company/operator management (contributing factor)
  - landing gear,tire - failure,total (cause)
  - aircraft weight and balance - improper, company/operator management (contributing factor)

## Analysis

DRG THE TKOF ROLL, THE CREW FELT A VIBRATION BTN 135 KTS & LIFT-OFF. THEY LEFT THE GEAR EXTDD & WERE ADZD 2 TIRES HAD SEPD FM THE RGT INSIDE MAIN GEAR TRUCK, A 3RD TIRE BLEW OUT & THE 4TH APPEARED INTACT. THEY DUMPED FUEL & LNDD. AN EXAM REVEALED THE TIRES HAD FAILED, RESULTING IN SKIN DMG & BKN HYD LINE(S). CARGO HAD BEEN LOADED WITH MORE PALLETS ON THE RGT SIDE; SOME PALLETS WERE NOT MARKED TO INDC WT OR SHIPPING ID. A COMPUTER PRINT-OUT (SIGNED BY CAPT & STATION AGENT) SHOWED A LATERAL IMBALANCE OF 18,766 LBS. WITH THIS IMBALANCE, GROSS WT SHOULD NOT HAVE EXCEEDED 744,000 LBS; ACTUAL WT WAS 751,316 LBS. AFTER DEPG THE CARGO RAMP, ACFT WAS TAXIED 3 MI IN A STRAIGHT LINE, THEN 2 LEFT TURNS WERE MADE ONTO RWY 6R FOR TKOF. PREVIOUS LOADING CRITERIA PROVIDED 3% ALLOWANCE FOR RANDOM DISPOSABLE LOADS ON PALLETS. IN 1969, FAA ISSUED AN EXEMPTION FM FAR 25.471(B) TO ALLOW BOEING 747'S TO BE LOADED TO DESIGN LIMIT, PROVIDED INSTRNS WERE AVBL TO ASSURE A SYMMETRICAL LOADING. OF 239 KNOWN TIRE FAILURES, 71 INVOLVED THE FLYING TIGER LINE, AN ALL CARGO CARRIER.

## Aircraft

- Registration: N818FT (not matched to a registry record)
- Reported make and model: BOEING 747-121
- Category: Airplane
- Serial number: 20353
- Airframe hours: 47027
- Engines: P&W JT9D-7A 46150 lbs thrust turbo fan
- Damage: Minor damage
- Flight: Part 121
- Operator: Flying Tiger Line
- Registered owner: Flying Tiger Line
- Airworthiness certificate: Standard, Normal
- Last inspection: Continuous airworthiness, April 10, 1989, 352 hours before
- Departed: ANC, ANCHORAGE, AK
- Destination: RJAA, TOKYO,JAPAN, OF
- Flight plan: IFR
- Airport: ANC, Anchorage Intl, runway 6R, 10,897 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 43; airline transport, commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 14,690 total, 2,162 in this make and model, 2,883 as pilot in command, 205 in the last 90 days, 31 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 20° at 4 knots
- Visibility: 9 statute miles
- Lowest ceiling: 20,000 ft broken
- Temperature: 37 °F, dew point 21 °F
- Altimeter: 29.00 inHg

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Incident 19890517015039I](https://openairdocs.org/incident/19890517015039I), May 17, 1989: Boeing 747121, Anchorage, AK, Minor damage. Vibration on takeoff. Unable to retract gear due to hydraulic failure and blown tires. Returned. Landed safely.

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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