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Accidents · NTSB SEA91LA086 · Final report

Grumman G-21A accident near Spokane, Washington, April 17, 1991

On April 17, 1991 at about 5:30 pm local time, a Grumman G-21A, registered N9750Z, was substantially damaged in an accident near Spokane, Washington (Spokane Intl airport). It was an instructional flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).

The NTSB's probable cause their words, unchanged

THE PILOT-IN-COMMAND DID NOT MAINTAIN DIRECTIONAL CONTROL OF THE AIRPLANE. FACTORS WERE: THE PIC'S INADEQUATE COMPENSATE FOR THE WIND, HIS LIMITED FLIGHT EXPEREINCE IN THIS TYPE OF AIRPLANE, AND THE CHECK AIRMAN'S POOR SUPERVISION.

Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.

What the record shows

Date
April 17, 1991 · about 5:30 pm local time · cases in 1991
Place
Spokane, Washington · Spokane Intl · cases near this airport · map
Type
Accident
Injuries
No one was hurt; 2 people were on board or involved.
Weather
visual conditions (good weather)
Aircraft
Grumman G-21A · all G-21As on the register
Registration
N9750Z · registry record · serial B-32
Damage
Substantial damage
Flight
Instructional flight · general aviation rules (Part 91)

The NTSB's narrative final · quoted from the NTSB record

THE PILOT IN-COMMAND DID NOT MAINTAIN DIRECTIONAL CONTROL OF THE AIRPLANE. FACTORS WERE THE PIC'S INADEQUATE COMPENSATION FOR THE WIND, HIS LIMITED FLIGHT EXPEREINCE IN THIS TYPE OF AIRPLANE, AND THE CHECK AIRMAN'S POOR SUPERVISION.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.

The factual record from the NTSB's investigation tables, in plain English

Pilot

  • Certificate: private
  • Ratings: multi-engine land; single-engine land; single-engine sea; instrument: airplane
  • Flight time: 645 hours in all; 6 in this make and model; 525 as pilot in command
  • Medical certificate: Class 3 (valid medical--w/ waivers/lim.)
  • Seat: unk

The aircraft

  • Last inspection: inspection type not recorded; 0 hours since
  • Maximum gross weight: 9,200 lb
  • Seats: 6
  • Landing gear: retractable
  • Engine: P&W R-985-AN14B (piston); 0 hours total

The flight

  • Flight plan: none
  • Runway 7, 8,199 ft by 150 ft
  • A second pilot was aboard

Weather at the time

  • Light: daylight
  • Wind: from 030° at 12 knots
  • Visibility: 30 statute miles
  • Sky: clear
  • Temperature: 0°F (-18°C), dew point 0°F (-18°C)

Injuries

FatalSeriousMinorNone
Crew2

Documents from the investigation the NTSB's docket: the evidence folder behind the report

The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.

Connections how this case links to the rest of the register

Aircraft
Place
Analytics

The whole map of how records connect · these connections as data: /graph/accident/SEA91LA086.json.

The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.

Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.