What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
During a local instructional flight conducting traffic pattern operations at kpae, the instructor demonstrated a landing following a stabilized approach. The landing was firm but not considered hard, and touchdown occurred on the main landing gear with a normal landing attitude. During the subsequent touch-and-go, the nosewheel was lowered to the runway without any abnormal indications.
After liftoff during the next takeoff, a “clunk” sound was heard during rotation. The instructor did not observe any debris on the runway, and an initial visual assessment indicated no apparent damage to the main landing gear. While remaining in the traffic pattern, the instructor requested a low approach so personnel positioned near the taxiway could visually inspect the nose landing gear. During the low approach, ground observers advised air traffic control that the nosewheel appeared damaged and that the runway would likely need to be closed following landing.
The flight continued in the traffic pattern while the instructor evaluated available options and coordinated with ground personnel. A second low approach was conducted to further assess the condition of the nose landing gear and determine the potential effect on landing. The instructor elected to perform a landing on a separate runway using a soft-field technique and planned to secure the engine prior to nosewheel contact with the runway surface.
The approach and touchdown were conducted consistent with a soft-field landing technique. After touchdown on the main landing gear, the engine was secured and the propeller came to a stop while the nosewheel was held off the runway using aft elevator pressure. When the nosewheel eventually contacted the runway, the airplane initially maintained a normal landing attitude and decelerated gradually. As the airplane slowed further, the nose landing gear collapsed, and the airplane pitched forward, resulting in an abrupt stop. The propeller did not contact the runway and was not damaged.
Emergency response personnel arrived at the airplane following the landing. The occupants exited the airplane without injury.
Subsequent investigation identified several possible contributing factors related to the nose gear collapse, primarily involving the design and assembly of the nose spring assembly. Maintenance personnel reported that the assembly procedure makes it difficult to verify proper thread engagement and retaining washer positioning, creating the possibility that the upper bolt could gradually loosen during repeated landing cycles. New replacement urethane springs were also found to be slightly taller than earlier versions, complicating installation and increasing the risk of improper assembly. In addition, the design of the nose gear allows for compression of the assembly for impact absorption which can cause the retaining hardware to loosen.
As the FAA filed it
DURING A LOCAL INSTRUCTIONAL FLIGHT CONDUCTING TRAFFIC PATTERN OPERATIONS AT KPAE, THE INSTRUCTOR DEMONSTRATED A LANDING FOLLOWING A STABILIZED APPROACH. THE LANDING WAS FIRM BUT NOT CONSIDERED HARD, AND TOUCHDOWN OCCURRED ON THE MAIN LANDING GEAR WITH A NORMAL LANDING ATTITUDE. DURING THE SUBSEQUENT TOUCH-AND-GO, THE NOSEWHEEL WAS LOWERED TO THE RUNWAY WITHOUT ANY ABNORMAL INDICATIONS.
AFTER LIFTOFF DURING THE NEXT TAKEOFF, A “CLUNK” SOUND WAS HEARD DURING ROTATION. THE INSTRUCTOR DID NOT OBSERVE ANY DEBRIS ON THE RUNWAY, AND AN INITIAL VISUAL ASSESSMENT INDICATED NO APPARENT DAMAGE TO THE MAIN LANDING GEAR. WHILE REMAINING IN THE TRAFFIC PATTERN, THE INSTRUCTOR REQUESTED A LOW APPROACH SO PERSONNEL POSITIONED NEAR THE TAXIWAY COULD VISUALLY INSPECT THE NOSE LANDING GEAR. DURING THE LOW APPROACH, GROUND OBSERVERS ADVISED AIR TRAFFIC CONTROL THAT THE NOSEWHEEL APPEARED DAMAGED AND THAT THE RUNWAY WOULD LIKELY NEED TO BE CLOSED FOLLOWING LANDING.
THE FLIGHT CONTINUED IN THE TRAFFIC PATTERN WHILE THE INSTRUCTOR EVALUATED AVAILABLE OPTIONS AND COORDINATED WITH GROUND PERSONNEL. A SECOND LOW APPROACH WAS CONDUCTED TO FURTHER ASSESS THE CONDITION OF THE NOSE LANDING GEAR AND DETERMINE THE POTENTIAL EFFECT ON LANDING. THE INSTRUCTOR ELECTED TO PERFORM A LANDING ON A SEPARATE RUNWAY USING A SOFT-FIELD TECHNIQUE AND PLANNED TO SECURE THE ENGINE PRIOR TO NOSEWHEEL CONTACT WITH THE RUNWAY SURFACE.
THE APPROACH AND TOUCHDOWN WERE CONDUCTED CONSISTENT WITH A SOFT-FIELD LANDING TECHNIQUE. AFTER TOUCHDOWN ON THE MAIN LANDING GEAR, THE ENGINE WAS SECURED AND THE PROPELLER CAME TO A STOP WHILE THE NOSEWHEEL WAS HELD OFF THE RUNWAY USING AFT ELEVATOR PRESSURE. WHEN THE NOSEWHEEL EVENTUALLY CONTACTED THE RUNWAY, THE AIRPLANE INITIALLY MAINTAINED A NORMAL LANDING ATTITUDE AND DECELERATED GRADUALLY. AS THE AIRPLANE SLOWED FURTHER, THE NOSE LANDING GEAR COLLAPSED, AND THE AIRPLANE PITCHED FORWARD, RESULTING IN AN ABRUPT STOP. THE PROPELLER DID NOT CONTACT THE RUNWAY AND WAS NOT DAMAGED.
EMERGENCY RESPONSE PERSONNEL ARRIVED AT THE AIRPLANE FOLLOWING THE LANDING. THE OCCUPANTS EXITED THE AIRPLANE WITHOUT INJURY.
SUBSEQUENT INVESTIGATION IDENTIFIED SEVERAL POSSIBLE CONTRIBUTING FACTORS RELATED TO THE NOSE GEAR COLLAPSE, PRIMARILY INVOLVING THE DESIGN AND ASSEMBLY OF THE NOSE SPRING ASSEMBLY. MAINTENANCE PERSONNEL REPORTED THAT THE ASSEMBLY PROCEDURE MAKES IT DIFFICULT TO VERIFY PROPER THREAD ENGAGEMENT AND RETAINING WASHER POSITIONING, CREATING THE POSSIBILITY THAT THE UPPER BOLT COULD GRADUALLY LOOSEN DURING REPEATED LANDING CYCLES. NEW REPLACEMENT URETHANE SPRINGS WERE ALSO FOUND TO BE SLIGHTLY TALLER THAN EARLIER VERSIONS, COMPLICATING INSTALLATION AND INCREASING THE RISK OF IMPROPER ASSEMBLY. IN ADDITION, THE DESIGN OF THE NOSE GEAR ALLOWS FOR COMPRESSION OF THE ASSEMBLY FOR IMPACT ABSORPTION WHICH CAN CAUSE THE RETAINING HARDWARE TO LOOSEN.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.