Piper PA-11 accident near Indianola, Iowa, August 5, 2016
On August 5, 2016 at about 4:13 pm local time, a 1947 Piper PA-11, registered N4707M, was destroyed in an accident during enroute (climb to cruise) near Indianola, Iowa (Laverty Field Airport). It was a personal flight under general aviation rules (Part 91). 2 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's inadequate preflight planning, which resulted in the airplane being operated above its maximum gross weight, degraded its climb performance, and led to an aerodynamic stall during the initial climb.
Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 5, 2016 · about 4:13 pm local time · cases in 2016
- Place
- Indianola, Iowa · Laverty Field Airport · cases near this airport · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-11, built 1947 · all PA-11s on the register
- Registration
- N4707M · no longer on the register · serial 11-216
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The commercial pilot was using a company airplane to accumulate flight time and experience. Two witnesses reported seeing the airplane climbing after takeoff and noted that the airplane was flying slowly and that it had a "hard time getting any lift." The airplane finally started to climb; however, the wings started rocking and the airplane subsequently descended into terrain. The witness statements were consistent with the prestall motions of the airplane. The pilot and passenger were employed as company ground personnel. According to company policy, the pilot was not allowed to fly with passengers, and the passenger was only allowed to fly with a company flight instructor. The pilot was not a flight instructor. Examination of the airplane revealed no mechanical anomalies that would have precluded normal operation. A postaccident estimation of the airplane's weight and balance showed that the airplane exceeded its maximum gross weight at the time of the takeoff. It is likely that the pilot's inadequate preflight planning led to the airplane being operated above its maximum gross weight and degraded its climb performance and led to an aerodynamic stall.
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
- Aircraft loading event during prior to flight
- Aerodynamic stall/spin during enroute (climb to cruise) defining event
- Loss of control in flight during enroute (climb to cruise)
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Angle of attack › Not attained/maintained
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Airspeed › Not attained/maintained
- cause Aircraft › Aircraft oper/perf/capability › Aircraft capability › CG/weight distribution › Capability exceeded
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Climb rate › Not attained/maintained
- cause Personnel issues › Task performance › Planning/preparation › Weight/balance calculations › Pilot
- Personnel issues › Action/decision › Info processing/decision › Decision making/judgment › Pilot
- Personnel issues › Task performance › Use of equip/info › Use of policy/procedure › Pilot
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land
- Flight time: 255 hours in all; 3 in this make and model
- Last flight review: April 29, 2016
- Medical certificate: Class 2
- Seat: frt
- Injury: fatal
Pilot-Rated Passenger
- Certificate: student
- Medical certificate: Class 3
- Seat: rear
- Injury: fatal
The aircraft
- Airframe total time: 6,231 hours
- Last inspection: annual inspection, October 1, 2015
- Maximum gross weight: 1,220 lb
- Seats: 2
- Landing gear: fixed
- Engine: Continental A-65-8 (piston); 3,548 hours total
- Fire on the ground
- Operator: Agri-Flite INC
The flight
- Departed from: IA41 Indianola IA at 3:45 pm
- Destination: IA41 Indianola IA
- Flight plan: none
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 020° at 7 knots
- Visibility: 10 statute miles
- Sky: broken clouds at 30,000 ft; a few clouds at 4,000 ft
- Temperature: 79°F (26°C), dew point 59°F (15°C)
- Altimeter: 30.04 inHg
- Observation at 3:54 pm from DSM, 9 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
5 documents, released by the NTSB on June 8, 2017. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 11 pages | View Download |
| 2 | Statement from Operator | PDF, 1 page | View Download |
| 3 | Record of Conversation - Operator | PDF, 2 pages | View Download |
| 4 | Police Report Witness Statement | PDF, 5 pages | View Download |
| 5 | Toxicological Report | PDF, 1 page | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Connections how this case links to the rest of the register
- N4707M: not on the register today · the record of its deregistration
- Piper PA-11 Cub Special 443 registered today · the model family and its accident history
- Piper 44,840 aircraft on the register
- Engine: Continental A-65-8 137 aircraft carry this series today · as the NTSB recorded it
- Laverty Field · nearest airport
- Accidents and incidents in Iowa 871 since 1982 · 131 in the last ten years
- Iowa 4,513 aircraft registered
The whole map of how records connect · these connections as data: /graph/accident/CEN16LA310.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.