# NTSB CHI92DCD10: Curt Hoffstad Pitts S1-S, N90LB, Council Bluffs, IA, September 7, 1992

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Final report
- Date: September 7, 1992, 14:32 local (19:32 UTC)
- Place: Council Bluffs, IA
- Location: 41.2601° N, 95.7586° W: Placed by OpenAirDocs at COUNCIL BLUFFS MUNI (CBF), within about a mile (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=41.2601&lon=-95.7586&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report August 26, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 15214
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI92DCD10
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/15214/pdf
- Page: https://openairdocs.org/ntsb/CHI92DCD10

## Probable cause

THE FAILURE OF THE PILOT TO MAINTAIN AIRCRAFT CONTROL WHILE MANEUVERING DURING AEROBATIC FLIGHT.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of control - in flight, maneuvering
  - aerobatics - performed, pilot in command
  - aircraft control - not maintained, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - ground

## Analysis

THE PILOT OF THE ACCIDENT AIRPLANE WAS PERFORMING A LOW LEVEL AEROBATIC ROUTINE AT AN AIRSHOW.  WITNESSES OBSERVED THE AIRPLANE ENTER A FLAT SPIN FOLLOWING A VERTICAL CLIMB.  THE PILOT WAS ABLE TO STOP THE SPIN ROTATION BUT WAS UNABLE TO RETURN TO LEVEL FORWARD FLIGHT BEFORE COLLIDING WITH TERRAIN.

## Aircraft

- Registration: N90LB (not matched to a registry record)
- Reported make and model: CURT HOFFSTAD PITTS S1-S
- Category: Airplane, amateur-built
- Serial number: CH1977
- Airframe hours: 616
- Engines: LYCOMING IO-360 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Parmley Aviation
- Registered owner: Parmley Aviation
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, March 30, 1992, 12 hours before
- Departed: CBF
- Destination: CBF
- Airport: CBF, Council Bluffs Muni Airpt, runway 31, 4,100 × 75 ft, concrete

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 46; flight instructor, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: front; flight hours: 9,000 total, 400 in this make and model, 225 in the last 90 days, 75 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 320° at 12 knots
- Visibility: 20 statute miles
- Lowest ceiling: 2,900 ft
- Temperature: 75 °F, dew point 66 °F
- Altimeter: 29.00 inHg
- Observed at: OMA, 1 nm away

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19920907035229A](https://openairdocs.org/incident/19920907035229A), Sep 7, 1992: Amtrpt PITTSSPECS1, Council Bluffs, IA, Substantial damage. Entered unintentional flat spin after hammerhead stall. Slow engine response delayed recovery. Hit flat. Oily plugs

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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