Beech E-90 accident near Des Moines, Iowa, February 15, 2011
On February 15, 2011 at about 3:30 pm local time, a Beech E-90, registered N51DN, was substantially damaged in an accident during enroute (climb to cruise) near Des Moines, Iowa. It was a flight test 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 improper installation of the right aileron by maintenance personnel.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 15, 2011 · about 3:30 pm local time
- Place
- Des Moines, Iowa · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Beech E-90 · all E-90s on the register
- Registration
- N51DN · registry record · serial LW-7
- Damage
- Substantial damage
- Flight
- Flight test · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The airplane had recently undergone maintenance, which included an inspection of the ailerons requiring removal, reinstallation, and a functional check. Prior to the test flight, the pilot performed a pre-flight inspection of the airplane and a flight control free and correct check with no anomalies noted. While executing a turn at flight level 180, the right aileron departed the airplane. The airplane landed without further incident. Examination of the airplane revealed the inboard and middle airframe aileron hinge brackets were attached to the aft spar, intact, and showed no visible damage. The outboard airframe aileron hinge bracket was pulled and separated from the aft spar. The aileron was not located. Based on the condition of the hinge brackets, the evidence indicated the aileron bolts were not properly engaged in the aileron nut plates which caused the bolts to fall out and the aileron to depart the airplane.
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
- Part(s) separation from AC during enroute (climb to cruise) defining event
The NTSB's findings
- cause Personnel issues › Task performance › Maintenance › Installation › Maintenance personnel
- cause Aircraft › Aircraft structures › Wing structure › Ailerons › Incorrect service/maintenance
Pilot
- Certificate: airline transport pilot, flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane
- Flight time: 15,449 hours in all; 329 in this make and model; 60 in the last 90 days; 49 in the last 30 days; 13,037 as pilot in command; 1,045 on instruments
- Last flight review: January 26, 2011
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 9,353 hours
- Last inspection: continuous airworthiness programme, February 14, 2011; 0 hours since
- Maximum gross weight: 10,100 lb
- Seats: 8
- Landing gear: retractable
- Engine 1: P&W Canada PT6A-27-28 (turboprop); 0 hours total
- Engine 2: U/A Canada PT6A-27-28 (turboprop); 0 hours total
- Operator: D-W Corporation
The flight
- Departed from: DSM Des Moines IA at 3:00 pm
- Destination: DSM Des Moines IA
- Flight plan: IFR
Weather at the time
- Light: daylight
- Wind: from 170° at 13 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 41°F (5°C), dew point 32°F (0°C)
- Altimeter: 30.03 inHg
- Observation at 2:50 pm from DSM, 45 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 2 |
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.