Investigator In Charge (IIC): Kemner, Heidi
The National Transportation Safety Board traveled to the scene of this accident.
Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; Farmingdale, New York
N46PD LLC
Location: East Hampton, New York
Accident Number: ERA23FA007
Date and Time: October 6, 2022, 12:29 Local
Registration: N46PD
Aircraft: SEAMAX AIRCRAFT M-22
Injuries: 1 Fatal
Flight Conducted Under: Part 91: General aviation - Personal
On October 6, 2022, at 1229 eastern daylight time, a Seamax Aircraft M-22 airplane, N46PD, was destroyed when it was involved in an accident near East Hampton, New York. The private pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
According to surveillance video, the pilot arrived at the airplane hangar at East Hampton Town Airport (JPX), East Hampton, New York, at 1159. At 1206, he pulled the airplane out of the hangar. Between 1206 and 1208 the pilot performed a preflight inspection, entered the airplane, shut the canopy, and started the engine at 1209. At 1214, the airplane began to taxi for departure.
Preliminary Automatic Dependent System – Broadcast (ADS-B) data indicated that the airplane departed runway 28, at 1219. Then, the airplane flew south over the water, east, and made a turn north. As the airplane was over Three Mile Harbor, ADS-B contact was lost. The airplane’s most recent flight before the accident flight occurred on September 30, 2022.
A witness reported that he heard the engine of an airplane flying over, which drew his attention. Then, he heard a loud “crack,” saw a wing separate from the airplane, and the airplane spiral down into the water.
The airplane came to rest in about 3-4 ft of water in the Three Mile Harbor. The right wing came to rest in a tree that was about 770 ft from the main wreckage.
Examination of the engine revealed that the engine was impact separated from the fuselage but remained attached to the engine mounts. There were no holes in the crankcase. All 4 cylinders remained attached to the engine. The carburetors were impact separated from the engine but remained attached through fuel lines. Both carburetor butterfly valves could be operated by hand. The spark plugs were removed and examined. All were light grey in color and exhibited minimal wear. The rocker box covers were removed and there were no anomalies noted with the rocker arms or valve springs.
Examination of the propeller revealed it remained attached to the engine. One propeller blade remained attached to the propeller hub. It exhibited chordwise scratching and leading-edge gouging. Another blade was separated from the propeller hub, was located in the vicinity of the main wreckage, and exhibited chordwise scratching. The third propeller blade was not recovered.
Examination of the airframe revealed that the fuselage was fragmented. Flight control continuity was confirmed from the flight control surfaces to the cabin through multiple breaks and overload failures. The right stabilator remained attached to the empennage and exhibited leading edge damage. The inboard section of the left stabilator remained attached to the empennage. The outboard section was impact separated and located in the vicinity of the main wreckage. The rudder remained attached to the vertical stabilizer and exhibited impact damage. The left wing was fragmented, but the left aileron, left flap, and left wing tip were located. The left wing strut was impact separated from the wing and the strut attach point bolt remained secure with the nut.
The entire right wing was separated from the main wreckage and located in a tree. The right aileron remained attached to the right wing. The right flap was separated from the right wing and located in the vicinity of the right wing. The right wing strut was separated from the right wing. The bolt attaching the right strut to the right wing remained attached to the right wing and was not fractured; however, the nut was not present. In addition, the bolt threads did not exhibit significant damage. The right and left wing strut assemblies were retained and sent to the NTSB Materials Laboratory for further examination.
Front view drawing of airplane. Red circle notes where bolt remained in place without a nut.
View of right wing strut attachment bolt as found.
Aircraft and Owner/Operator Information
Aircraft Make: SEAMAX AIRCRAFT
Registration: N46PD
Model/Series: M-22
Aircraft Category: Airplane
Amateur Built:
Operator: On file
Operating Certificate(s) Held: None
Operator Designator Code:
Meteorological Information and Flight Plan
Conditions at Accident Site: VMC
Condition of Light: Day
Observation Facility, Elevation: JPX,55 ft msl
Observation Time: 12:15 Local
Distance from Accident Site: 4.5 Nautical Miles
Temperature/Dew Point: 19°C /14°C
Lowest Cloud Condition: Clear
Wind Speed/Gusts, Direction: 6 knots / , 340°
Lowest Ceiling: None
Visibility: 10 miles
Altimeter Setting: 29.95 inches Hg
Type of Flight Plan Filed: None
Departure Point: East Hampton, NY (JPX)
Destination: East Hampton, NY
Wreckage and Impact Information
Crew Injuries: 1 Fatal
Aircraft Damage: Destroyed
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 1 Fatal
Latitude, Longitude: 41.0038,-72.1903 (est)
Those who may have information that might be relevant to the National Transportation Safety Board (NTSB) investigation may contact them by email witness@ntsb.gov, and any friends and family who want to contact investigators about the accident should email assistance@ntsb.gov. You can also call the NTSB Response Operations Center at 844-373-9922 or 202-314-6290.
Federal Aviation Administration / Flight Standards District Office; Farmingdale, New York
Aircraft crashed under unknown circumstances.
N46PD LLC
Date: 06-OCT-22
Time: 04:33:00Z
Regis#: N46PD
Aircraft Make: SEAMAX
Aircraft Model: M22
Event Type: ACCIDENT
Highest Injury: FATAL
Total Fatal: 1
Flight Crew: 1 Fatal
Pax: 0
Aircraft Missing: No
Damage: DESTROYED
Activity: PERSONAL
Flight Phase: MANEUVERING (MNV)
Operation: 91
City: EAST HAMPTON
State: NEW YORK
The SeaMax lawyers will have a heyday with this whether or not "aerobatic stunts" were performed in this aircraft.
ReplyDeleteIf there are no "deep pockets" in the US, and the fact that it is an Brazilian LSA, has folding wings, will probably keep lawyers at bay
Deletehow tragic it will be interesting to see who's at fault for that wing separation
ReplyDeleteAgreed, tragic indeed. Its very rare that you see an airplane failure not pilot induced. This being a brand new aircraft is also scary. Lets hope for a detailed preliminary report on this one!
DeleteIt's an aircraft with folding wings.
ReplyDeleteAn acquaintance died when a wing came off, but he was in a 1952 Piper Tri-Pacer. It had been sitting for a number of years and they were known to develop dangerous corrosion where it could not be seen. He was thinking about buying it and took it up for a quick check flight.......
ReplyDeleteAssuming you are talking about N3737A; that plane was out of Annual and had an outstanding AD for the exact issue that caused the separation. Not at all a surprise that it happened...
DeleteThere are no mulligans when you fly with a known structural issue. I'm guessing that poem wasn't the last thought he had when going down. Nothing poetic about falling out of the sky. RIP
DeleteHere is photo of the folding wing showing the interface:
ReplyDeletehttps://static.wixstatic.com/media/b0cfde_b50df6d664db4b24b29e6ca6d9ad7d5d~mv2_d_4032_3024_s_4_2.jpeg/v1/crop/x_0,y_0,w_4032,h_2492/IMG_1553.jpeg
That wing attachment doesn’t look very substantial. I had a KITFOX that had folding wings but attachments looked quit a bit stronger. RIP
DeleteThat looks scary and I'm fearless.
DeleteI wonder if a strut attachment broke.
ReplyDeleteLead advocate for local pilots at East Hampton. Wasn't there something going on at that field? Ominous possibilities...
ReplyDeleteMy TBF has folding wings, never had a problem and it's 75 years old.
ReplyDeleteSame exact design & parts as this?
DeleteJust don't reach for the flap handle and get the gear instead like the Crash Air Force did some years ago at KGEU.
Deletejust completed a 180 into a 10 minute flight @ 1,000 ft and seconds later ... https://globe.adsbexchange.com/?icao=a5988b&lat=41.000&lon=-72.188&zoom=13.9&showTrace=2022-10-06&trackLabels
ReplyDelete"had been complaining that it was having problems." from photo, sure appears a clean separation.
Certificate Issue Date 04/15/2022.
Without knowing any more, I'd be looking at the struts and strut attach points. There have been a number of tragic LSA crashes from mis-assembled or failed strut attachments.
ReplyDeleteWhen I was 16 in 1967 my dad bought me some lessons in a C150. I had not driven a car at that point. I really enjoyed the time spent in the air.
ReplyDeleteMany times over the past 55+ years I had thought if I were a pilot I would probably done something to rip a wing off one of them and am better being closer to the ground. Never exceed speed, that is just a recommendation surely. Max G surely just a number. That is my nature. For some reason even at a young age I realized my nature and never went on for flight training.
It is a true shame that others paid the price for such an incident.
There was a wing separation in a fatal crash in 21 (Italy) on the sea max. To say this “Rainer Groh, the writer behind the Aerospace Engineering Blog, was quoted as saying, “The only possible way for an airplane wing to snap off (in good weather) would be bad maintenance.” is irresponsible journalism. A simple search revealed the 21 crash the day Kent died. It’s a sea max problem. They redesigned the wing system in 21 (No surprise) again, simple research.
ReplyDeleteThe right strut that fell separately in the Italian crash presents a mystery. The top end disconnected from its connection to the wing at some point in the sequence but the bottom end tore the attachment out of the fuselage. If the top let go first, it is difficult to explain how the strut would then tear out the lower end bracket from the fuse while still in the air.
ReplyDeleteThe rotatable connection at the upper end of the wing strut allowing rotation of the wing to vertical during fold uses a fastener in tension, while the bottom of the strut uses a fastener of conventional shear tie arrangement.
In the preliminary report linked below of the Italy wing loss, photo 21 shows the tension fastener that let go at the upper strut connection. Note the thread condition and locknut insert material remnant. If not for the unexplained lower attach bracket tear out, this would seem to be the initiating event.
Photo 23 is the as-found lost strut, photo 25 is it's upper end, photo 24 is its bottom end with fuse bracket still connected. The manufacturer's website has a Foldable Wing Operation Manual. Section 2.7.1 shows "Upper wing strut end" connection.
Italy Preliminary Report:
https://ansv.it/wp-content/uploads/2021/03/Preliminary-Report-I-7608.pdf
(Wing redesign was for weight, changed some aluminum to carbon fiber.)
https://www.seamaxaircraft.com/post/when-it-can-t-get-any-better-seamax-m-22-receives-new-wings-welcome-to-the-carbon-fiber-world
Further review also reveals that tear-out of a lower strut attach bracket from the fuselage requires severing of the aluminum cross tube that carries the tension load inside the fuselage between the two lower strut brackets
ReplyDelete(The cross tube location is indicated by a horizontal blue line in Photo 6 of the Italy report, with Photo 7 showing the back side of the Photo 6 red arrow location. Both photos are oriented as top of frame = "up" in the example aircraft).
Tube remnants are visible within the lower attach bracket of Photo 13. The horizontal cross tube is running to the left and is severed at a thru bolt hole in the tube. Note that the Photo 13 view perspective is the underside, so you don't see the break of the related vertical tube's upper end, only the vertical tube's lower end is visible.
The maximum tension load that the horizontal cross tube can withstand without letting go at the noted through bolt hole can be calculated based on tube diameter, wall thickness, material specification and diameter of the through fastener hole.
If the design work was done correctly, the cross tube's tension withstand capability will be a multiple of the maximum expected value from two struts experiencing the maximum permissible flight maneuver wing loading.
Friends and relatives of N46PD's pilot should consider requesting the necessary info about the cross tube and having an accredited independent calculation performed if N46PD's lower strut attached brackets tore out similarly to the Italy accident.
Not a pilot but a Mech Engineer. The photo above, captioned: "View of right wing strut attachment bolt as found" seems very telling. The bolt does not appear to have suffered any structural damage, and the nut is missing. Seems as though this could be the point of failure which caused the wing to be separated from the plane.
ReplyDeleteAgreed. Wrote the earlier comment of "In the preliminary report linked below of the Italy wing loss, photo 21 shows the tension fastener that let go at the upper strut connection. Note the thread condition and locknut insert material remnant."
DeleteThe remnant of polymer insert material visible for both accidents suggests that the nut was pulled straight off in tension (although no sheared metal thread crescents from the nut internal diameter were left behind stuck to the male shank).
As an M.E., you know that a cross fastened joint in double shear such that no nut is carrying the strut working load is the superior design. Both the Italy accident and this accident may simply be threads yielding in the tension loaded nut, by lack of design margin or inferior vendor nut quality.
Shouldn't have happened a second time.
https://longisland.news12.com/hamptons-plane-crash-from-october-prompts-new-faa-safety-warning-for-pilots
ReplyDelete