# NTSB SEA84IA033: Boeing B-727-90C, N766AS, Seattle, WA, January 5, 1984

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: January 5, 1984, 14:00 local (22:00 UTC)
- Place: Seattle, WA
- Coordinates: 47.479808, -122.289978 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.4798&lon=-122.2900&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 6 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 39834
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA84IA033
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/39834/pdf
- Page: https://openairdocs.org/ntsb/SEA84IA033

## Analysis

THE ACFT STRUCK THE APPROACH LIGHTS TO RWY 16R WHILE ON AN ILS APPROACH. ANALYSIS OF THE FDR READOUT SHOWED AN INCREASED DESCENT RATE FOLLOWING VISUAL SIGHTING OF THE RWY ENVIRONMENT.

## Sequence of events

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

- Undershoot, approach - faf/outer marker to threshold (ifr)
  - weather condition - low ceiling (contributing factor)
  - weather condition - fog (contributing factor)
  - weather condition - rain (contributing factor)
  - proper glidepath - not maintained, pilot in command (cause)
- In flight collision with object, approach - vfr pattern - downwind
  - object - approach light/navaid (contributing factor)

## Aircraft

- Registration: [N766AS](https://openairdocs.org/deregistered/N766AS-1989-01-18), registration cancelled 1989-01-18, S/N 19728 (OpenAirDocs)
- Reported make and model: BOEING B-727-90C
- Registry model: [Boeing 727-90C](https://openairdocs.org/model/boeing-727-90c) (registry code 1384030) (OpenAirDocs)
- Category: Airplane
- Serial number: 19728
- Airframe hours: 42425
- Engines: P&W JT8D-7 14000 lbs thrust turbo jet
- Damage: Minor damage
- Flight: Positioning, Part 91
- Registered owner: Alaska Airlines
- Airworthiness certificate: Standard, Transport
- Departed: PDX, PORTLAND, OR
- Flight plan: IFR
- Airport: SEA, Seattle-Tacoma, runway 16R, 9,425 × 150 ft, concrete

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 51; airline transport; airplane ratings: multi-engine sea, single-engine land, multi-engine land, single-engine sea; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 10,100 total

## Weather

- Conditions: Instrument (IMC), Day
- Wind: 10° at 3 knots
- Lowest ceiling: 200 ft overcast
- Temperature: 48 °F, dew point 46 °F
- Altimeter: 30.00 inHg
- Observed at: SEA

## 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 19840105025199I](https://openairdocs.org/incident/19840105025199I), Jan 5, 1984: Boeing 72790C, Seattle, WA, Minor damage. Struck runway approach light system while landing short of threshold. Damaged left wheel and tire and left flap.

## Other investigations on N766AS (1)

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

- [NTSB ANC87IA077](https://openairdocs.org/ntsb/ANC87IA077), Jun 9, 1987: Boeing 727-90C (N766AS), Anchorage, AK, incident, destroyed

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

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