# NTSB SEA07CA185: Hammer Thorp T-18, N3715, Everett, WA, June 26, 2007 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: June 26, 2007, 14:40 local (21:40 UTC) - Place: Everett, WA - Coordinates: 47.910278, -122.289443 - Nearby events: https://openairdocs.org/map.md?lat=47.9103&lon=-122.2894&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report October 31, 2007 - Report: Approved by Office Director - NTSB case key (mKey): 66084 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA07CA185 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/66084/pdf - Page: https://openairdocs.org/ntsb/SEA07CA185 ## Probable cause Excessive airspeed during a return for landing which resulted in an overrun. An unlatched canopy, a proper touchdown point not attained and rough terrain were factors. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Forced landing, emergency landing - window,canopy - unlatched (contributing factor) - Overrun, landing - airspeed - excessive, pilot in command (cause) - proper touchdown point - not attained, pilot in command (contributing factor) - On ground/water encounter with terrain/water, landing - roll - terrain condition - rough/uneven (contributing factor) - object - fence ## Analysis The pilot reported that the takeoff on runway 34L seemed normal until he raised the flaps. The pilot then heard a "big bang [that] shook the entire airplane" and he noticed that the canopy had come unlatched. Concerned that the canopy could possibly depart the aircraft and damage the tail, the pilot declared an emergency and circled left to land on runway 11. The pilot aligned the aircraft with the runway, but the airplane's airspeed was excessive for a normal touchdown point. When the pilot realized that he was "too fast", he pulled the throttle to idle and pulled the mixture out to stop the engine. The aircraft did not touchdown until it reached the numbers at the departure end of the runway. During the landing roll, the aircraft rolled across taxiway Golf, runway 16L-34R, and taxiway Foxtrot. The aircraft continued to roll off the taxiway surface, through the airport perimeter fence and onto a public street, where it encountered uneven terrain and nosed over, coming to rest upside down. ## Factual narrative The pilot reported that the takeoff on runway 34L seemed normal until he raised the flaps. The pilot then heard a "big bang [that] shook the entire airplane" and he noticed that the canopy had come unlatched. Concerned that the canopy could possibly depart the aircraft and damage the tail, the pilot declared an emergency and circled left to land on runway 11. The pilot aligned the aircraft with the runway, but the airplane's airspeed was excessive for a normal touchdown point. When the pilot realized that he was "too fast", he pulled the throttle to idle and pulled the mixture out to stop the engine. The aircraft did not touchdown until it reached the numbers at the departure end of the runway. During the landing roll, the aircraft rolled across taxiway Golf, runway 16L-34R, and taxiway Foxtrot. The aircraft continued to roll off the taxiway surface, through the airport perimeter fence and onto a public street, where it encountered uneven terrain and nosed over, coming to rest upside down. ## Aircraft - Registration: [N3715](https://openairdocs.org/deregistered/N3715-2012-01-11), registration cancelled 2012-01-11, S/N 66, built 1969 (OpenAirDocs) - Reported make and model: Hammer Thorp T-18 - Registry model: [Thorp T-18](https://openairdocs.org/model/thorp-t-18) (registry code 89510S7) (OpenAirDocs) - Registry engine: [Lycoming 0-290 series](https://openairdocs.org/engine/lycoming-0-290-series) (registry code 41506, 4 cycle) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 66 - Airframe hours: 251 - Engines: Lycoming O-320 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Robert Hammer - Registered owner: Robert Hammer - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, April 1, 2007 - Departed: PAE, Everett, WA - Destination: PAE, Everett, WA - Airport: PAE, Snohomish County Airport, runway 11, 4,500 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 71; injuries: minor; private; airplane ratings: single-engine land, single-engine sea; medical: class 3, with waivers/limitations; last flight review April 1, 2006; seat: left; flight hours: 1,567 total, 251 in this make and model, 1,567 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 350° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 70 °F ## 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 20070626009959A](https://openairdocs.org/incident/20070626009959A), Jun 26, 2007: Amtr T18, Everett, WA, Substantial damage. (-23) After take off from runway 34L at pae, aircraft reported an open canopy and declared an emergency. Aircraft attempted to land on runway 11 and bounced… ## Other investigations on N3715 (1) 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. - [NTSB SEA70D0023](https://openairdocs.org/ntsb/SEA70D0023), Jul 1, 1969: Thorp T-18 (N3715), Puyallup, WA, substantial damage 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. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.