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Accidents · NTSB CEN16LA310 · Final report

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).

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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 October 4, 2026. Docket and reports at the NTSB.

What the record shows

Date
August 5, 2016 · about 4:13 pm local time
Place
Indianola, Iowa · Laverty Field 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

  1. Aircraft loading event during prior to flight
  2. Aerodynamic stall/spin during enroute (climb to cruise) defining event
  3. Loss of control in flight during enroute (climb to cruise)
  4. 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

FatalSeriousMinorNone
Flight crew1
Passengers1

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.

About this page

Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number CEN16LA310.