PA-34 flight crew reported a nose wheel collapsed during taxi. The flight crew evacuated with no injuries.
Synopsis
PA-34 flight crew reported a nose wheel collapsed during taxi. The flight crew evacuated with no injuries.
Narrative
The objective of the flight is to instruct the commercial multi-engine add-on student in commercial maneuvers with a Piper Seneca I (PA-34-200). At XA:30 AM; the weight and balance of Aircraft X was checked. The pre-flight was completed around XA:50 AM and the pre-flight was checked thoroughly per the checklist. There was no sign of hydraulic leaks or any unusual circumstances with the landing gear and other aircraft parts. At XB:00 AM; the Seneca started and taxied to the run-up area near Runway XXR at ZZZ. At XB:10 AM; the aircraft took off from Runway XXR with the intention of two touch-and-goes followed by a west departure. The first lap; in the right pattern; consists of a single-engine traffic pattern where I cut the left engine on the downwind. The student performed the necessities to secure the inoperative engine throughout the simulated engine failure. The gear was extended when the aircraft abeam the touchdown point. My student and I verified that we received three green; no red; and one in the mirror. The student extended the flaps at his discretion. On final; I instructed him to perform the final check to verify that the mixture was rich; the propeller was fully forward; the gear was down visually; the fuel pumps were on; and the landing lights were on. The student performed a smooth landing with a simulated engine failure. The student retracted the flaps; opened the cowl flaps; and took off for another right traffic pattern. The second lap was instructed to be a short-field landing at the 1000 foot of the runway. During the abeam to the touchdown point; the flaps were set at 10-degree position and the gear selector switch was down. We always verified that we received three green; no red; and one in the mirror. The student turned the base leg and extended the flaps to 25 degrees. On the final; the student performed the final check and extended the flaps to 40 degrees. The second landing was at the point selected with a smooth landing.At XB:31 AM; we proceeded to the west of ZZZ to practice the commercial maneuvers. I informed my student to climb to 4500 feet for our maneuvers. Please be advised that most of the maneuvers; in commercial multi-engine land; consist of extending and retracting landing gears; except steep turns; VMC demonstrations; and accelerated stalls. Before our first maneuvers; I shut down the right engine for practicing one engine inoperative. During this situation; my students followed and verified each phase in the engine failure (feather procedures) checklist. Everything was within the limitation of the Airman Certification Standards. After we completed the checklist; we attempted to restart the engine and verified the checklist. Prior to our maneuvers; my student performed a pre-maneuver checklist. Our first maneuver was a slow flight followed by a power-on stall; power-off stalls; steep turn; VMC demonstration; accelerated stalls; and emergency descent. Everything went well as planned; so we decided to proceed to ZZZ with the intention of performing a single-engine approach maneuver.At XC:04 AM; we established a two-way radio communication with ZZZ Tower where they instructed us to join a straight-in for Runway XXR. A descent and approach checklist were performed. I instructed my student to load and activate the approach procedures (RNAV XXR LPV) where I vectored him to intercept the final approach course. At 4.6 NM from ZZZZZ (Final Approach Fix); I idled my student's right engine and he performed the memory items for the single-engine approach. The student maintained 1500 ft and the final approach course. When we were at the FAF; I instructed the student to reduce the throttle to 18 manifold pressure; flaps 10 degrees; and Gear selector in the down position. We both checked and verified that we received three green on the gear indicator; no red on the warning gear unsafe light; and one in the mirror. When we reached 1000 feet; I informed my student to perform a before-landing checklist or final check consisting of: verifying that the mixture was rich; the propeller was fully forward; the gear was down visually; the fuel pumps were on; and the landing lights were on. I instructed my student to go visual when we were at the decision altitude. Flaps 25 degrees were applied. Gear was verified and checked visually again on the short final.At XC:12 AM; my student landed the aircraft with a simulated single-engine approach which was smooth and soft at the 1000 feet marker. The main gear touched down first followed by the nose gear. All three landing gears touched the runway pavement. We counted three seconds and applied the brakes to stop the aircraft. Around four seconds after applying the brakes; the nose gear suddenly collapsed. The engine stopped and the aircraft skid for 50 feet on the runway. I performed the engine shutdown checklist and shut off all the fuel supplies. The propeller on both engines was dented; the nose scratched the runway pavement; and both engines were completely shut down. In addition; I did not feather; perform a complete shutdown of the engine; or land the aircraft myself beforehand because there was no sign of the nose gear malfunctions. All indications of the landing gear before the incident were verified precisely. I instructed my student to leave the aircraft and follow my lead when exited. We stood behind the aircraft and waited for the airport firefighter crew; as well as flight operations.In the aftermath of the incident; it was discovered that the nose gear collapsed due to a bent bolt that connects to the over-center joint and the assisted spring. The fatigue of the bent bolt; on the over-center joint side; caused the over-center joint to break loose. It caused the nose gear to collapse immediately after the four seconds of applying brakes. As mentioned above; the pre-flight was conducted thoroughly per the checklist but the plastic cover; under the nose gear; limits the view of the critical components. In addition; a week before the incident; the aircraft was in maintenance due to the gear indicator light not showing three greens and the gear was not down visually. I pulled the emergency gear extension; and the three green gear lights were shown with a visual from the nacelle mirror. The nose gear collapse on Aircraft X occurred on the third flight after the aircraft was released from maintenance.
Second reporter narrative
The objective of the flight is to practice towards my Multi Engine add-on and the commercial maneuvers; with a Piper Seneca I (PA-34-200). At XA:30 AM; the weight and balance of Aircraft X was checked. The pre-flight was completed around XA:50 AM and the pre-flight was checked thoroughly per the checklist. There was no sign of hydraulic leaks or any unusual circumstances with the Landing gear and other aircraft parts. At XB:00 AM; the Seneca started and taxied to the run-up area near Runway XXR at ZZZ. At XB:10 AM; the aircraft took off from Runway XXR with the intention of two touch-and-goes followed by a west departure. The first lap; in the right pattern; consists of a single-engine traffic pattern where the left engine was cut on the downwind. I performed the necessities to secure the inoperative engine throughout the simulated engine failure.The gear was extended when the aircraft abeam the touchdown point. My instructor and I verified that we received three green; no red; and one in the mirror. I extended the flaps at my discretion. On final; I performed the final check to verify that the mixture was rich; the propeller was fully forward; the gear was down visually; the fuel pumps were on; and the landing lights were on. I performed a smooth landing with a simulated engine failure. Retracted the flaps; opened the cowl flaps; and took off for another right traffic pattern. The second lap I was instructed to be a short-field landing at the 1000 foot of the runway. During the abeam to the touchdown point; the flaps were set at 10-degree position and the gear selector switch was down. We always verified that we received three green; no red; and one in the mirror. I turned the base leg and extended the flaps to 25 degrees. On the final; I performed the final checkand extended the flaps to 40 degrees. The second landing was at the point selected with a smooth landing.At XB:31 AM; we proceeded to the west of ZZZ to practice the commercial maneuvers. I was instructed to climb to 4500 feet for our maneuvers. Please be advised that most of the maneuvers; in commercial multi-engine land; consist of extending and retracting landing gears; except steep turns; VMC demonstrations; and accelerated stalls. Before our first maneuvers; my instructor shut down the right engine for practicing one engine inoperative. During this situation; my instructor followed and verified each phase in the engine failure (feather procedures) checklist. Everything was within the limitation of the Airman Certification Standards as he mentioned. After we completed the checklist; we attempted to restart the engine and verified the checklist. Prior to our maneuvers; I performed a pre-maneuver checklist. Our first maneuver was a slow flight followed by a power-on stall; power-off stalls; steep turn; VMC demonstration; accelerated stalls; and emergency descent. Everything went well as planned; so we decided to proceed to ZZZ with the intention of performing a single-engine approach maneuver.At XC:04 AM; we established a two-way radio communication with ZZZ Tower where they instructed us to join a straight-in for Runway XXR. A descent and approach checklist were performed. I was instructed to load and activate the approach procedures (RNAV XXR LPV) where he vectored me to intercept the final approach course. At 4.6 NM from ZZZZZ (Final Approach Fix); he idled my right engine and I performed the memory items for the single-engine approach. I maintained 1500 ft and the final approach course. When we were at the FAF; I was instructed to reduce the throttle to 18 manifold pressure; flaps 10 degrees; and Gear selector in the down position. We both checked and verified that we received three green on the gear indicator; no red on the warning gear unsafe light; and one in the mirror. When we reached 1000 ft; he informed me to perform a before-landing checklist or final check consisting of: verifying that the mixture was rich; the propeller was fully forward; the gear was down visually; the fuel pumps were on; and the landing lights were on. I was instructed to go visual when we were at the decision altitude. Flaps 25 degrees were applied. Gear was verified and checked visually again on the short final.At XC:12 AM; I landed the aircraft with a simulated single-engine approach which was smooth and soft at the 1000 feet marker. The main gear touched down first followed by the nose gear. All three landing gears touched the runway pavement. We counted three seconds and applied the brakes to stop the aircraft. Around four seconds after applying the brakes; the nose gear suddenly collapsed. The engine stopped and the aircraft skid for 50 feet on the runway. My instructor performed the engine shutdown checklist and shut off all the fuel supplies. The propeller on both engines was dented; the nose scratched the runway pavement; and both engines were completely shut down. In addition; all indications of the landing gear before the incident were verified precisely.Me and my instructor evacuated the aircraft and followed his lead when exited. We stood behind the aircraft and waited for the airport firefighter crew; as well as flight operations. My instructor informed the situation to the airport manager; and the FAA.In the aftermath of the incident; it was discovered that the nose gear collapsed due to a bent bolt that connects to the over-center joint and the assisted spring. The fatigue of the bent bolt; on the over-center joint side; caused the over-center joint to break loose. It caused the nose gear to collapse immediately after the four seconds of applying brakes.As mentioned above; the pre-flight was conducted thoroughly per the checklist but the plastic cover; under the nose gear; limits the view of the critical components. In addition; a week before the incident; the aircraft was in maintenance due to the gear indicator light not showing three greens and the gear was not down visually. My instructor pulled the emergency gear extension; and the three green gear lights were shown visually from the nacelle mirror. The nose gear collapse on Aircraft X occurred on the third flight after the aircraft was released from maintenance.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.