This is preliminary information, subject to change, and may contain errors. Any errors in this writing will be corrected when the NTSB preliminary report is released.
https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=N696DB
- History of Flight:
On June 15, 2026, at about 1953 local time, a privately-registered Van's RV-3A, N696DB, was destroyed when it was involved in an accident near Lakeland, Florida. The pilot was fatally injured. The local personal flight originated from Bartow Airport (BOW/KBOW), Bartow, Florida, at 1930.
The aircraft was flying in a formation with a Van's RV-8, N881PH, that departed Lakeland (KLAL), Florida, at 1925.
According to Preliminary ADS-B data, both airplanes were cruising an altitude of 2,100 ft and proceeded north. Both airplanes were observed to make circling orbits near Polk City, Florida.
At about 1953:30, the airplanes were now headed west and were still cruising at 2,100 ft when the RV-3 suffered an apparent inflight breakup. The data shows that the RV-3 went from a 480 feet per minute (fpm) climb to a 9000 feet per minute (fpm) descent rate. Note that after this, the ADS-B exchange tracker jumped back in direction and repeated the final seconds of the initial track.
The pilot of the RV-8 reported to local police that he "saw a piece come off the low-wing aircraft just in time to watch the plane come apart and crash straight into the ground." Another news site reported that a wing came off, and not a piece.
The RV-8 initiated a descending left hand turn and proceeded to circle the area of the accident for about 30 minutes before returning to Lakeland. The wreckage was eventually located in a wooded area.
- Pilot Information:
Unknown.
- Airplane Information:
The accident aircraft, serial number 11083, was manufactured in 1996. It was a single-seat, single engine, low-wing, experimental, amateur built, kit airplane sold by Van’s Aircraft, Inc. The airplane is of all metal construction, has a conventional tail and is equipped with fixed conventional landing gear. The airplane is 19 feet long, has a wingspan of 19 feet, 11 inches, and a tail height of 5 feet. The accident airplane was powered by a four-cylinder Lycoming O-320 reciprocating engine driving a 2-blade constant speed propeller.
- Wreckage and Impact Information:
Unknown.
- Weather:
(1) METARs
METAR KZPH 152335Z AUTO 30008KT 10SM CLR 30/22 A3000 RMK A02 T02970223
METAR KZPH 160015Z AUTO 28007KT 10SM CLR 29/23 A3002 RMK A02 LTG DSNT E T02910227
METAR KGIF 152253Z AUTO 24007KT 210V280 10SM CLR 31/22 A2999 RMK AO1 SLP152 T03110217
METAR KGIF 152353Z AUTO 31007KT 10SM CLR 31/21 A3000 RMK AO1 SLP158 T03060206 10339 20306 53012
METAR KISM 152256Z 28008KT 10SM CLR 31/21 A2998 RMK AO2 SLP154 T03110211 $
METAR KISM 152356Z 30007KT 10SM CLR 30/23 A3000 RMK AO2 SLP158 T03000228 10344 20300 51013 $
(2) Area Forecast Discussion:
814 FXUS62 KTBW 152330 AFDTBW Area Forecast Discussion National Weather Service Tampa Bay Ruskin FL 730 PM EDT Mon Jun 15 2026 ...New UPDATE, AVIATION... .KEY MESSAGES... Updated at 730 PM EDT Mon Jun 15 2026 - Near to slightly above normal temperatures will continue through the next week. - Isolated to scattered thunderstorms will develop each afternoon this week, with the highest rain chances generally over the interior. && .UPDATE... Issued at 730 PM EDT Mon Jun 15 2026 No changes planned for the evening update. Westerly flow across the area today has kept afternoon and early evening convection generally confined to E FL locations with dry conditions prevailing across the local W FL area. Mild temps overnight with lows in the mid 70s to lower 80s with lingering mid/upper clouds. && .DISCUSSION... Issued at 214 PM EDT Mon Jun 15 2026 Strong ridging to our south will keep southwesterly flow in place through much of our work week. This will result in storm chances mainly over the interior and east coast of Florida. If we see any showers on the east coast it will be during our morning hours as storms push on the coast from the Gulf. This regime will also keep our temperatures above average as the southwesterly flow will keep the wind coming off the warm Gulf waters overnight. This prevents overnight lows from dropping keeping most of us around 80 degrees when we wake up. This starts us out warmer then average in the morning, and with no rain showers in forecast, result in warmer afternoon high temperatures. The best shot to see some rain for the west coast will be on Friday as the upper level flow switches more southeasterly for one day. However, this is short lived as winds shift southwesterly once again for the weekend. && .AVIATION... (00Z TAFS) Issued at 720 PM EDT Mon Jun 15 2026 VFR expected across terminals through the period with westerly flow keeping convection generally east of terminals. && .MARINE... Issued at 214 PM EDT Mon Jun 15 2026 Not much changing through our work week. Winds will remain out of the west to southwest around to 15 knots. Best storm chances will be overnight and into the early morning hours along the land breeze boundary. && .FIRE WEATHER... Issued at 214 PM EDT Mon Jun 15 2026 Summertime humidity and heat will continue however we are expecting dry conditions for the west coast of Florida for much of our work week. && .PRELIMINARY POINT TEMPS/POPS... TPA 81 91 81 92 / 10 30 20 10 FMY 78 92 78 94 / 10 10 0 10 GIF 77 95 76 96 / 10 30 20 20 SRQ 80 91 79 93 / 10 10 10 0 BKV 78 93 76 95 / 10 20 20 10 SPG 81 92 81 92 / 10 20 20 0 && Sea Breeze Thunderstorm Regime For Tuesday: 4 Sea Breeze Thunderstorm Regime For Wednesday: 5 For additional information on sea breeze regimes, go to: https://www.weather.gov/tbw/ThunderstormClimatology && .TBW WATCHES/WARNINGS/ADVISORIES... FL...None. Gulf waters...None. && $$ UPDATE/AVIATION...Hurt DISCUSSION/MARINE/FIRE WEATHER...Shiveley DECISION SUPPORT...Oglesby UPPER AIR/CLIMATE...Wynn
- Additional Information:
A review of the Van's RV-3 NTSB records showed that:
- On August 6, 1992, a Van's RV-3, N50WP, suffered an "overload and total failure" of the rear wing attach fittings during a loop maneuver that was described as having an abrupt pitch up motion.
- On October 8, 1995, a Van's RV-3A, N27RV, suffered a failure of the right wing main spar during a steep banking right turn. The recording accelerometer found in the wreckage was indicating .2 G's more than the 9 G ultimate load limit published by the designer of the RV-3 aircraft plans.
- On March 8, 1998, a Van's RV-3, N99HV, suffered an in-flight failure of the right wing spar (for an undetermined reason) as the pilot was performing aerobatic flight. The NTSB stated: "This was 1 of 3 RV-3s built by Tony Duci & the 2nd to structurally fail in flight. Acft had been modified as an RV-3A, but had not been re-certified as such. Aerobatic gross weight limit (1,050 lbs) had been exceeded by an estimated 120 lbs."
- On August 23, 2006, a Van's RV-3, N43EM, suffered an in-flight failure of the right wing spar during aerobatic flight. According to the NTSB: "No evidence of compliance with Vans Service Bulletin (SB) 96-3-1 was observed on the accident airplane. This SB states that "Pilots should perform no aerobatic maneuvers and limit flight G loads to a maximum 4.4 G's (Utility Category). This limitation should be reflected in the Operating Limitations for the aircraft as well as the airframe logbook until such a time that appropriate modifications have been completed. Unmodified aircraft must display an "Aerobatic Limitations" placard referencing the Operating Limitations of the aircraft." No evidence of compliance with FAA Special Airworthiness Information Bulletin (SAIB) ACE-99-10 was observed on the accident airplane. In this SAIB, the FAA outlined the recommendations issued by Van's with regards to wing spar modification and performance of aerobatics. The SAIB went on to address recommended operating limitations for aircraft with and without the modifications such as airspeeds, gross weight, and G limits. An examination of the remaining airplane systems revealed no anomalies."
- On On June 17, 2017, a Van's RV-3, N177TT, suffered an in-flight failure of the left wing due to the owner's use of improper hardware and his improper assembly of the airplane, which reduced the strength of the left wing and resulted in its subsequent failure following a sharp pullup maneuver.
After a series of accidents involving RV-3 in-flight wing separations, Vans conducted extensive testing. The testing showed that the initiating failure of the RV-3 wing was the buckling of the upper spar cap and that bonding the spar caps together as a unit during assembly, which was optional, provided better resistance to buckling. The first modification to the RV-3 wing (CN-1) involved strengthening the rear spar attachment points and carry through and modifying the wing root rib. The second modification to the RV-3 wing (CN-2-I or CN-2-II) involved adding stiffening angles to the main spar.
The RV-3 wing has a NACA 23012 airfoil. The original wing spar (referred to as Type I, circa 1973 to 1983) was mathematically stress analyzed to design and ultimate load limits of 6.0 and 9.0 Gs, respectively, at an aerobatic gross weight of 1,050 lbs (the nonaerobatic gross weight is 1,100 lbs). A test in 1982 verified that it met the 9 G ultimate load criteria. The spar consisted of .040-inch aluminum channel web with a buildup of seven 1/8-inch thick by 1-1/4 inch wide bars held together with 1/8-inch AN470 rivets to form the upper and lower caps. As an assembly option, an epoxy adhesive could be used to bond the seven aluminum bars together to form a single unit to facilitate drilling and riveting the unit to the spar web. (It was later discovered that the adhesive provided some interbar shear and column strength, but the bonding process can deteriorate, so it was not considered in the design as contributing to spar strength.)
On March 16, 1981, the FAA issued General Notice TWA 1/40 SVCB, which prohibited aerobatics in the RV-3. The action was permanent and could not be rescinded. Following this action, Vans issued Change Notice 1 (CN-1) to RV-3 owners and builders. Briefly, CN-1 modified the wing by reinforcing the rear spar attachment point and strengthening the wing root rib. FAA and Canadian Ministry of Transport reports on the RV-3 accidents suggested that these areas could have been the primary failure points. When CN-1 was drafted, it appeared that the only means of regaining aerobatic operating authorization would be for individual RV-3 owners to change the airplane's designation to RV-3A. Soon thereafter, the FAA issued another letter stating that RV-3 owners showing compliance with CN-1 could reapply for aerobatic operating limitations. Thus, the RV-3A designation was adopted by some builders but does not signify any definite main spar structural distinction.
In 1984, Vans redesigned the wing spar (referred to as Type II). It incorporated five 3/16-inch thick by 1 1/4-inch wide aluminum bars held together with 3/16-inch diameter AN470 rivets. Although the primary purpose was to simplify assembly and minimize the possibility of assembly errors, the calculated bending strength was slightly increased. Further, two additional ribs were added in the root rib area to increase torsional stiffness, and the rear spar attachment was strengthened.
Despite the changes, the suggested airspeed limitations remained relatively unchanged. Vne (never exceed speed) is 210 mph. Va (maneuvering speed) is 127 mph (down from 132 mph). Vs (stall speed, clean) is 54 mph. According to Vans, because of the high ratio between Vne and Vs, the RV-3 is more susceptible to pilot-induced overstress than most contemporary light airplanes.
In 1996, an RV-3 wing with a Type I spar was again static load tested. During the tests, the wing failed below the 9.0 G load level. A review of test data revealed that the 1982 test had been performed on a wing whose spar had been assembled with the optional epoxy bonding. The 1996 test had been performed on a wing whose spar had been assembled without the epoxy adhesive. Although the epoxy adhesive had not been calculated to add any spar bending strength, it appeared to have added compression buckling strength. As a result of further static load testing on both Type I and Type II wing spars, Vans issued Change Notice 2 (CN-2-I for Type I spars and CN-2-II for Type II spars), which recommended main spar modifications which it deemed necessary for aerobatic strength. CN-2 included a detailed history, explanation, and recommendations, and was sent to all known RV-3 and RV-3A owners and builders. Vans maintained that both CN-1 and CN-2 (I or II) were necessary to achieve the aerobatic strength of the wing.
No comments:
Post a Comment