# NTSB CEN21LA226: I.C.A.-Brasov IS-28B2, N41CR, Hampshire, IL, May 16, 2021

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Class 4 · Limited · Final report
- Date: May 16, 2021, 13:00 local (18:00 UTC)
- Place: Hampshire, IL
- Coordinates: 42.152653, -88.505268 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=42.1527&lon=-88.5053&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Defining event: [Initial climb: Miscellaneous/other](https://openairdocs.org/ntsb-events/900)
- Highest injury: Serious injuries
- Injuries: 1 serious, 1 minor
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 4 - Basic report with no Prelim publish
- NTSB office: Central Region
- Parties: FAA Greater Chicago FSDO
- NTSB case key (mKey): 103108
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA226
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103108/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103108
- Page: https://openairdocs.org/ntsb/CEN21LA226

## Probable cause

The flight instructor’s failure to maintain aircraft control resulting in the exceedance of the glider’s critical angle of attack following the breakage of the weak/safety link during a winch launch, which resulted in an aerodynamic stall and spin, and subsequent impact with trees and terrain.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Instructor/check pilot (probable cause); cases with it: [I.C.A.-Brasov IS-28B2, 3 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=4490102), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)
- [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Pilot; cases with it: [I.C.A.-Brasov IS-28B2, 1 case](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=4490102), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md)
- [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [I.C.A.-Brasov IS-28B2, 1 case](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=4490102), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md)
- [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [I.C.A.-Brasov IS-28B2, 2 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=4490102), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Initial climb: Glider tow event](https://openairdocs.org/ntsb-events/510); cases with it: [I.C.A.-Brasov IS-28B2, 2 cases](https://openairdocs.org/ntsb-events/510/sequence.md?model=4490102), [All aircraft, 45 cases](https://openairdocs.org/ntsb-events/510/sequence.md)
- [Initial climb: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) (defining event); cases with it: [I.C.A.-Brasov IS-28B2, 2 cases](https://openairdocs.org/ntsb-events/900/sequence.md?model=4490102), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md)
- [Initial climb: Simulated/training event](https://openairdocs.org/ntsb-events/600); cases with it: [I.C.A.-Brasov IS-28B2, 1 case](https://openairdocs.org/ntsb-events/600/sequence.md?model=4490102), [All aircraft, 173 cases](https://openairdocs.org/ntsb-events/600/sequence.md)
- [Emergency descent: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [I.C.A.-Brasov IS-28B2, 2 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=4490102), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md)
- [Emergency descent: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241); cases with it: [I.C.A.-Brasov IS-28B2, 1 case](https://openairdocs.org/ntsb-events/241/sequence.md?model=4490102), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md)
- [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [I.C.A.-Brasov IS-28B2, 2 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=4490102), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md)
- [Landing: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490); cases with it: [I.C.A.-Brasov IS-28B2, 3 cases](https://openairdocs.org/ntsb-events/490/sequence.md?model=4490102), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md)

## Analysis

The flight instructor of the instructional glider flight reported that during a winch launch with the student pilot, the glider accelerated to 70 kts exceeding the winch launch speed. As the flight instructor attempted to decrease the airspeed to the normal winch launch speed, the weak/safety link broke and the glider separated from the towing cable. The flight instructor attempted to maneuver the glider for a landing back to the runway; however, during the turn to enter the final approach, the glider’s critical angle of attack was exceeded, and the glider entered an aerodynamic stall/spin. The glider impacted trees and terrain coming to rest on a grass field. The glider sustained substantial damage to the fuselage and to both wings. The flight instructor reported that there were no preaccident mechanical failures or malfunctions with the glider that would have precluded normal operation. The flight instructor also reported that he should have maintained sufficient airspeed to prevent a “stall/spin” at a low altitude.

## Aircraft

- Registration: [N41CR](https://openairdocs.org/deregistered/N41CR-2023-10-21), registration cancelled 2023-10-21, S/N 71, built 1977 (OpenAirDocs)
- Reported make and model: I.C.A.-BRASOV (ROMANIA) IS-28B2
- Registry model: [I.C.A.-Brasov IS-28B2](https://openairdocs.org/model/i-c-a-brasov-is-28b2) (registry code 4490102) (OpenAirDocs)
- Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs)
- Category: Glider
- Serial number: 71
- Year built: 1977
- Airframe hours: 1553
- Engines: None None none
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Sky Soaring Inc, doing business as Sky Soaring Inc
- Registered owner: Sky Soaring Inc
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, March 20, 2021
- Departed: 55LL, Hampshire, IL
- Airport: 55LL, Sky Soaring, runway 09-27, 3,000 × 100 ft, grass/turf
- Equipment: None

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 65; injuries: minor; flight instructor, commercial; airplane ratings: single-engine sea; last flight review August 17, 2020; seat: rear; restraint: 4-point; flight hours: 762 total, 20 in this make and model, 527 as pilot in command, 28 in the last 90 days, 23 in the last 30 days
- Student pilot; age 59; injuries: serious; student; seat: front; restraint: 4-point

## Weather

- Conditions: Visual (VMC), Day
- Wind: 230° at 5 knots
- Visibility: 10 statute miles
- Temperature: 66 °F, dew point 54 °F
- Altimeter: 30.18 inHg
- Observed at: KDKB, 16 nm away
- METAR: KDKB 161755Z AUTO 23005KT 10SM SCT037 19/12 A3018 RMK AO2 T01930117 10194 20114

## 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 20210516009789A](https://openairdocs.org/incident/20210516009789A), May 16, 2021: I.C.A.-Brasov (Romania) IS-28B2, Hampshire, IL, Substantial damage. A glider winch launch was being conducted. Near the release point, the weak link failed. Reported altitude 600' AGL or above. While maneuvering for landing,…

## Docket (3 files)

The files NTSB released with the investigation on July 15, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103108. 6.9 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12430533&FileExtension=pdf&FileName=NTSB%206120_1%20Redacted-Rel.pdf
- Accident photographs (item 2, PDF, 5 pages, 3.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12430543&FileExtension=pdf&FileName=Photographs-Rel.pdf
- Additional documents (item 3, PDF, 12 pages, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12444211&FileExtension=pdf&FileName=Additional%20Documents%20Redacted-Rel.pdf

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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