Weatherly 620B accident near Downs, Kansas, April 20, 2005
On April 20, 2005 at about 11:15 pm local time, a Weatherly 620B, registered N9026F, was substantially damaged in an accident near Downs, Kansas. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The loss of engine power due to the failure of the number two cylinder which was the result of the maintenance facility's failure to detect the fatigue crack in the number two cylinder during the engine overhaul. A factor to the accident was the soft field.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 20, 2005 · about 11:15 pm local time
- Place
- Downs, Kansas · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Weatherly 620B
- Registration
- N9026F · no longer on the register · serial 1639
- 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 agricultural spray airplane sustained substantial damage during a forced landing to a farm field after a loss of engine power. The pilot reported that he was "pulling the airplane up into a right hand turn" at the end of a spray run when he heard a loud "bang" and the engine started to run "really rough." He executed a forced landing to a field. The landing gear broke off due to the soft field conditions. The engine was a 450 horsepower Pratt & Whitney R-985-14B engine. The engine was overhauled 43 hours prior to the accident. At overhaul, the engine had accumulated a total time of 7,027.1 hours. The engine logbook noted that AD 78-0807 was complied with. AD 78-0807 was effective May 2, 1978 for ultrasonic and visual inspections every 150 hours time in service to detect cracking and "to prevent cylinder head separation from the barrel." The logbook did not contain specific information on the previous histories of the installed cylinders. The inspection of the airplane revealed that the number 2 cylinder was broken at the third large cooling vent up from the bottom. The upper portion on the head assembly had separated from the sleeve. The National Transportation Safety Board's (NTSB) Materials Laboratory report noted that the fracture faces were covered by extensive and heavy combustion products and required extensive cleanings to reveal fracture details. Examinations of the fracture faces revealed features and topography indicative of a large area of fatigue progression. The fatigue area was on the aft side of the cylinder, biased toward the exhaust valve. Fracture face markings indicative of multiple fatigue initiation at the inner diameter threads along a wide arc of approximately 140 degrees. Progression was radial through the head with complete penetration over and arc of about 60 degrees centered in the fatigue region. The cylinder head was permanently marked with UT05, UT97, UT91, UT89, and UT89 stamped in the head near the intake port. The "UT" markings on the head are consistent with the markings required by AD 78-0807 and they denote five different ultrasonic inspections since 1989.
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: commercial pilot
- Ratings: single-engine land
- Flight time: 5,540 hours in all; 3,201 in this make and model; 53 in the last 90 days; 53 in the last 30 days; 5,465 as pilot in command
- Last flight review: March 1, 2004
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: ctr
- Injury: minor injuries
The aircraft
- Airframe total time: 2,319 hours
- Last inspection: annual inspection, March 1, 2005; 43 hours since
- Seats: 1
- Landing gear: fixed
- Engine: Pratt & Whitney R-985-14B (piston); 0 hours total
The flight
- Departed from: Private at 10:30 pm
- Flight plan: none
Weather at the time
- Wind: from 160° at 4 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 81°F (27°C), dew point 63°F (17°C)
- Altimeter: 29.73 inHg
- Observation at 11:53 pm from RSL, 40 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| 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.
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.