# NTSB WPR11LA119: Czech Sportplanes Sro Dynamic, N595DY, Palm Springs, CA, January 9, 2011

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: January 9, 2011, 15:35 local (23:35 UTC)
- Place: Palm Springs, CA
- Coordinates: 33.829723, -116.506668 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.8297&lon=-116.5067&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Defining event: [Approach-VFR pattern final: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report November 17, 2011
- Report: Approved by Office Director
- NTSB office: Western Pacific Region
- Parties: Federal Aviation Administration FSDO
- NTSB case key (mKey): 78270
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR11LA119
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/78270/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=78270
- Page: https://openairdocs.org/ntsb/WPR11LA119

## Probable cause

Inadvertent opening of the airplane canopy during the landing approach in a downdraft, which resulted in a rapid descent and hard landing.

## Findings

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

- [Doors: passenger/crew doors](https://openairdocs.org/ntsb-findings/01035210): Aircraft › Aircraft structures · Malfunction (probable cause); cases with it: [Czech Sportplanes Sro DYNAMIC WT9, 1 case](https://openairdocs.org/ntsb-findings/01035210/cases.md?model=060007R), [All aircraft, 86 cases](https://openairdocs.org/ntsb-findings/01035210/cases.md)
- [Wind: downdraft](https://openairdocs.org/ntsb-findings/03034035): Environmental issues › Conditions/weather/phenomena · Effect on equipment; cases with it: [Czech Sportplanes Sro DYNAMIC WT9, 1 case](https://openairdocs.org/ntsb-findings/03034035/cases.md?model=060007R), [All aircraft, 178 cases](https://openairdocs.org/ntsb-findings/03034035/cases.md)

## Sequence of events

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

- [Approach-VFR pattern final: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Czech Sportplanes Sro DYNAMIC WT9, 1 case](https://openairdocs.org/ntsb-events/330/sequence.md?model=060007R), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md)
- [Landing: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Czech Sportplanes Sro DYNAMIC WT9, 1 case](https://openairdocs.org/ntsb-events/092/sequence.md?model=060007R), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md)

## Analysis

The pilot was landing the light sport airplane at the termination of a 2 1/2-hour-long flight. During final approach, the airplane encountered a strong downdraft and the canopy extended to the full up position. The pilot was unable to reach the canopy handle to close it, and the airplane landed hard, likely due to the drag created by the open canopy. The left horizontal stabilizer and left aileron were substantially damaged. Postaccident examination revealed that the canopy latch did not always fully engage in the cabin frame during the closing operation; the latching pin would sometimes extend about 5 millimeters short of the 15 millimeters of full travel. Thus, it is likely that the pilot's encounter with a strong downdraft could have caused the canopy to flex and open if the latch was not fully engaged. In 2008, the airplane's manufacturer issued a Mandatory Service Bulletin requiring a revision to the flight manual. The revision stated that, if the canopy locking pin is not securely latched during the pre-flight inspection, the canopy could open in flight. The revision included operational updates specifying procedures for securing an inadvertent canopy opening during various phases of flight. The procedures stated that provided the airplane is flown in a straight and level attitude, the canopy will only partially extend, and could be retracted and locked by hand. The procedures warned that, during uncoordinated flight, the canopy will extend to the full open position, acting as an airbrake and resulting in an excessive descent.

## Factual narrative

On January 9, 2011, about 1535 Pacific standard time, a Czech Sportplanes SRO, Dynamic WT9 light sport airplane, N595DY, landed hard at Palm Springs International Airport, Palm Springs, California. The student pilot was operating the airplane under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91. The pilot was not injured, and the airplane sustained substantial damage to the left horizontal stabilizer and left aileron. The cross-country personal flight departed Marana Regional Airport, Tucson, Arizona, about 1300. Visual meteorological conditions prevailed, and no flight plan had been filed. The pilot reported that during the final approach the airplane encountered a strong downdraft. As he attempted to recover control, the airplane's canopy opened, and extended to the full up position, such that he was unable to reach the handle to retract it. The airplane descended rapidly, and he applied full throttle in an effort to arrest the descent. As he approached the runway threshold he reduced engine power, the airplane descended rapidly, and landed hard. The airplane then departed the runway, coming to rest in the adjacent gravel verge. The composite airplane was equipped with a tip-up canopy, hinged at the forward cabin area, aft of the firewall. The canopy was locked in the down position by a single longitudinal spring-loaded latch pin, located in the center aft section of the canopy, above and behind the cabin seats. Lateral canopy support in the down position was provided by a set of two guide pins, which slide into slots in the aft cabin frame pillars. A set of gas struts were incorporated into the canopy frame to assist with raising the canopy. Examination of the airplane by the National Safety Board (NTSB) investigator-in-charge following the accident revealed that the latching pin, in the locked position, extended 15 millimeters beyond the canopy frame. During the examination, the latch was cycled in and out by hand, and it was found that the pin would intermittently extend 5 millimeters short of the full travel. The pilot stated that the latch was fully extended prior to departure. No damage was noted to the striker latch pin or guide pin striker plates. The airplane was not equipped with an audio or visual lock indicator. The airplane's manufacturer issued Mandatory Service Bulletin ZBTWT9 10A/2008 on October 23, 2008. The Service Bulletin addressed a series of operational updates, requiring a revision to the flight manual. The revision stated that the pin extends between 8 and 12 millimeters when locked, and if the pin is not securely latched during the pre-flight inspection, the canopy could open in flight. The revision included operational updates specifying procedures for securing an inadvertent canopy opening during various phases of flight. The procedures stated that provided the airplane is flown in a straight and level attitude, the canopy will only partially extend, and can be retracted and locked by hand. Theupdate included the following warning: "During side-slipping flights with partial cockpit canopy latching (incorrect turn – slipping turn, skidding turn, and side slipping for landing) due to asymmetrical flow over fuselage by the air flow, the cockpit canopy will be carved through the gap and subsequently will be full open by help of the gas struts. The cockpit canopy will become the braking shield, what will cause abnormal airplane descent due to increased total drag."

## Aircraft

- Registration: [N595DY](https://openairdocs.org/aircraft/N595DY), registered now, S/N DY 329/2009, built 2009 (OpenAirDocs)
- Reported make and model: CZECH SPORTPLANES SRO DYNAMIC (WT9)
- Registry model: [Czech Sportplanes Sro DYNAMIC WT9](https://openairdocs.org/model/czech-sportplanes-sro-dynamic-wt9) (registry code 060007R) (OpenAirDocs)
- Registry engine: [Rotax 912ULS series](https://openairdocs.org/engine/rotax-912uls-series) (registry code 55572, 4 cycle) (OpenAirDocs)
- Category: Airplane
- Serial number: DY 329/2009
- Airframe hours: 76
- Engines: Rotax 912ULS 100 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Special, Special light-sport (Special)
- Last inspection: Condition, October 9, 2010, 41 hours before
- Departed: AVQ, Marana, AZ
- Destination: Palm Springs, CA
- Airport: PSP, Palm Springs International, runway 31L, 10,001 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Student pilot; age 70; injuries: none; sport pilot, student; flight hours: 50 total, 50 in this make and model, 50 in the last 90 days, 15 in the last 30 days, 7 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 320° at 12 knots, gusting 17
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 63 °F, dew point 37 °F
- Altimeter: 29.84 inHg
- Observed at: PSP

## Docket (11 files)

The files NTSB released with the investigation on September 23, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=78270. 3.6 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 585 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40346745&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF
- Photo 1: Airplane Located On Gravel Area Adjacent To The Runway. (item 2, .PDF, 551 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353932&FileExtension=.PDF&FileName=Photo%201%3A%20Airplane%20Located%20On%20Gravel%20Area%20Adjacent%20To%20The%20Runway.-Master.PDF
- Photo 2: Damage To Left Horizontal Stabilizer (item 3, .PDF, 530 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353933&FileExtension=.PDF&FileName=Photo%202%3A%20Damage%20To%20Left%20Horizontal%20Stabilizer-Master.PDF
- Photo 3: Canopy Latch Handle In The Fully Locked Position (item 4, .PDF, 224 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353934&FileExtension=.PDF&FileName=Photo%203%3A%20Canopy%20Latch%20Handle%20In%20The%20Fully%20Locked%20Position-Master.PDF
- Photo 4: Canopy Latch Handle In The Partially Locked Position (item 5, .PDF, 258 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353935&FileExtension=.PDF&FileName=Photo%204%3A%20Canopy%20Latch%20Handle%20In%20The%20Partially%20Locked%20Position-Master.PDF
- Photo 5: Canopy Latch Handle In The Partially Locked Position (item 6, .PDF, 190 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353936&FileExtension=.PDF&FileName=Photo%205%3A%20Canopy%20Latch%20Handle%20In%20The%20Partially%20Locked%20Position-Master.PDF
- Photo 6: Canopy Latch Handle In The Fully Unlocked Position (item 7, .PDF, 294 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353937&FileExtension=.PDF&FileName=Photo%206%3A%20Canopy%20Latch%20Handle%20In%20The%20Fully%20Unlocked%20Position-Master.PDF
- Photo 7: Canopy Latch Pin In The Fully Locked Position (item 8, .PDF, 274 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353938&FileExtension=.PDF&FileName=Photo%207%3A%20Canopy%20Latch%20Pin%20In%20The%20Fully%20Locked%20Position-Master.PDF
- Photo 8: Latch Pin Striker Plate (item 9, .PDF, 286 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353939&FileExtension=.PDF&FileName=Photo%208%3A%20Latch%20Pin%20Striker%20Plate-Master.PDF
- Photo 9: Left Guidance Pin Striker Plate (item 10, .PDF, 321 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353940&FileExtension=.PDF&FileName=Photo%209%3A%20Left%20Guidance%20Pin%20Striker%20Plate-Master.PDF
- Mandatory Service Bulletin ZBTWT9 10A/2008 (item 11, .PDF, 105 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353931&FileExtension=.PDF&FileName=Mandatory%20Service%20Bulletin%20ZBTWT9%2010A%2F2008-Redacted.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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