FLIGHT FINDINGSAVIATION OCCURRENCE MAP
Back to map

WPR11FA228 · Bellanca 17-30A

18 May 2011 · Rock Springs, WY, United States

Bellanca 17-30A · Accident: structural icing en route

From Ralph Wenz Field (KPNA) to Northern Colorado Regional Airport (KFNL)

Report a problem

Event

NTSB case
WPR11FA228
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Accident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
API-reported fatalities
2 · all aircraft and ground
Ground fatalities
Unknown
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
General aviation
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Instrument Meteorological Cond

Bellanca 17-30A

Aircraft type
Bellanca 17
Category
Airplane
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N93577
Onboard fatalities
Unknown
Route
From Ralph Wenz Field (KPNA), Pinedale, WYTo Northern Colorado Regional Airport (KFNL), Fort Collins, CO
Aircraft age
Not recorded
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 91: General Aviation
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
En route · cruise
Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
Structural icing
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Substantial

Cause areas

  • Aircraft › Aircraft oper/perf/capability
  • Personnel issues › Action/decision

Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.

NTSB narrative

The pilot’s initial plan was to make the cross-country flight on the day before the flight actually took place. But, since the weather briefing he received forecast clouds, precipitation, and icing conditions along much of the route, the pilot elected not to attempt the flight but instead decided to wait until the next day. Although the weather briefer advised the pilot that the conditions he had described would still be present along the route of flight the next day, including areas of clouds, low ceilings, precipitation, icing conditions, snow, and thunderstorms, the pilot did not call back for an update briefing on the day of the flight, and he did not receive a weather briefing from either of the Direct User Access Terminal Service providers. It is possible that he may have accessed some raw weather data from a National Oceanographic and Atmospheric Administration website before departing for his planned destination. Overlaying the airplane’s radar track on weather radar imagery indicated that, about 30 minutes after departure, the pilot encountered the edge of the forecast weather conditions, entering an area of precipitation where supercooled liquid droplets had been forecast. This most likely resulted in a very rapid accumulation of ice on the airplane’s structure, including its wings and horizontal stabilizer. Soon thereafter, the airplane entered a steep uncontrolled descent, during which the outboard section of the right wing separated as it was stressed beyond the design limitations of the airplane. The airplane continued in a near vertical uncontrolled descent and impacted the terrain with a high amount of energy. Postaccident examination of the airframe, flight controls, and the engine did not find any evidence of a preexisting anomaly.

Probable cause

The pilot’s decision to continue flight into an area of known adverse weather, which resulted in an accumulation of structural ice that led to a loss of control and in-flight breakup. Also causal was the pilot’s inadequate preflight weather planning.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record WPR11FA228
Event ID
20110519X55356
Case number
WPR11FA228
Dataset
full-current
Source SHA-256
5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates. Values present in the bulk record are kept.
  • The date is the local date, which is the same as the UTC date the NTSB stores.
  • API snapshot SHA-256: 54d6981a744526d48a70d020f46a12e120dcc0dff08ef3b168ed76624821bcaa; retrieved 2026-09-13T21:24:34.728Z.