Grumman Acft Eng Cor-Schweizer G-164A accident near Harlan, Iowa, August 10, 2009
On August 10, 2009 at about 3:35 pm local time, a Grumman Acft Eng Cor-Schweizer G-164A, registered N4598, was substantially damaged in an accident during takeoff near Harlan, Iowa (Harlan Municipal Airport). It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's failure to perform accurate weight and balance calculations which resulted in exceeding the maximum takeoff weight and the airplane's climb capability.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 10, 2009 · about 3:35 pm local time
- Place
- Harlan, Iowa · Harlan Municipal Airport · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Grumman Acft Eng Cor-Schweizer G-164A · all G-164As on the register
- Registration
- N4598 · no longer on the register · serial 1068
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that the airplane would not climb out of ground effect during takeoff. The airplane settled into a corn field located off the end of the 3,100-foot-long asphalt runway. The left landing gear collapsed and the airplane nosed over resulting in substantial damage to the wings. The maximum certified gross weight of the airplane was 4,500 pounds with a basic empty weight of 3,093.8 pounds. The airplane was loaded with 80 gallons of fuel (480 pounds) and 170 gallons (1,419.5 pounds) of water/chemical mix. The pilot's weight was approximately 185 pounds. The airplane was approximately 678.3 pounds over the maximum gross weight at the time of the takeoff.
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
What happened, in order
- Loss of lift during takeoff defining event
- Collision with terrain or object (not controlled flight into terrain) during takeoff
- Landing gear collapse during post (impact)
- Nose over/nose down
The NTSB's findings
- cause Personnel issues › Task performance › Planning/preparation › Weight/balance calculations › Pilot
- cause Aircraft › Aircraft oper/perf/capability › Aircraft capability › Maximum weight › Capability exceeded
- Environmental issues › Physical environment › Terrain › Rough terrain › Contributed to outcome
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land
- Flight time: 345 hours in all; 39 in this make and model
- Last flight review: December 12, 2008
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: sngl
- Injury: no injuries
The aircraft
- Last inspection: inspection type not recorded
- Maximum gross weight: 4,500 lb
- Seats: 1
- Landing gear: fixed
- Engine: P&W R1340 SERIES (piston); 0 hours total
The flight
- Departed from: HNR Harlan IN at 3:35 pm
- Destination: HNR Harlan IN
- Flight plan: none
- Runway 33, 4,100 ft by 75 ft
Weather at the time
- Light: daylight
- Wind: from 300° at 8 knots
- Visibility: 10 statute miles
- Sky: a few clouds at 900 ft
- Temperature: 79°F (26°C), dew point 86°F (30°C)
- Altimeter: 30.05 inHg
- Observation at 3:52 pm from OMA, 30 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
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.
Other NTSB records under N4598 the same tail number, which may have belonged to a different aircraft at the time
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 never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.