Joined: 02 Dec 2005
Location: Lynn Haven, FL
|Posted: Fri Apr 23, 2010 9:28 pm Post subject: N363J - NTSB Probable Cause - Plus - Plus
|Kevin's full and final NTSB accident report follows. I have added the NTSB's full narrative and their Docket Management link (usually not seen in an accident search). This report is factual and as thorough as we could have expected for an experimental aircraft.
Acroduster builders and flyers, read with great attention the incompetent aileron stop comments and pics in the reports.
As some of you may know, Kevin was absolutely meticulous in maintaining 363J, installing new components at the first indication of fatigue problems or other issues, including new design elements when needed (welded cabanes in place of adjustable eye bolts for example). Yet we both failed to connect the dots fully on the incompetent aileron stops - even after a full discussion here on the BB and rebuilding the bellcranks.
A modification we had seriously discussed but not installed was a rollover bar to be incorporated into a new larger turtledeck. That mod "may" have prevented Kevin's death in the inverted flat impact - and I use "may" advisedly - it hit hard, crushing the upper wing to the fuse and the upper fuse and fiberglass turtledeck down to the upper longerons. An upright flat impact may have been survivable except the fuel tank split at impact, dumping its fuel without a fire, and may have had an ignition source in an upright crash?? If the coroner's recovery team had not cut the fuse into several pieces during recovery it might have been salvagable. SA-750's are VERY tough birds!
His last maneuver was one he had done hundreds of times - including the similar incident reported on this BB in December 2002, a torque roll into a tail slide. We had discussed the safety issues involved and he always climbed to at least 3500' for that maneuver. He loved to demonstrate it to willing passengers. It was not a part of his low altitude airshow routine.
The final element here was Kevin's decision to stay with the plane. He was fully strapped-in at impact. Both our printed passenger waiver and our verbal passenger briefing re emergency bailout essentially say: If we give the bailout command do not say "what" because you will be talking to yourself. Only Kevin knows why he did not leave at the same time he ordered his passenger to bail. The inscription on his memorial bench, suggested by his passenger quotes St John 15:13 - Greater Love hath no man than this: That a man lay down his life for his friends.
Bottom line here - if you value your life, do not perform torque rolls or tailslides in an SA-750 unless you are absolutely positive that competent aileron stops are installed, and if you must do them - go high - REALLY high - so you have plenty of excess altitude for spin recovery and if no recovery - enough for the bailout.
PLAN YOUR FLIGHT AND FLY YOUR PLAN.
NTSB Identification: MIA08LA121
14 CFR Part 91: General Aviation
Accident occurred Monday, June 16, 2008 in Panama City, FL
Probable Cause Approval Date: 4/22/2010
Aircraft: MCKEEHAN JAMES F ACRODUSTER II SA750, registration: N363J
Injuries: 1 Fatal, 1 Uninjured.
The passenger reported that the pilot had performed a thorough preflight inspection of the airplane and that after takeoff he performed aerobatic maneuvers over a practice area. Before the last maneuver the pilot asked the passenger if he wanted to perform what he thought was a tail slide. The flight climbed to 3,500 feet and the pilot initiated the maneuver and, after falling for a few seconds, attempted to recover. The pilot appeared to bring the nose level briefly with full power, but the airplane then started rolling to the left and right, as well as up and down, and the pilot announced that there was a malfunction. The pilot informed him to bail out of the airplane, which he did. The airplane crashed inverted in a heavily wooded area, and the passenger was unharmed. Following recovery of the airplane, inspection of the elevator and rudder flight controls by a Federal Aviation Administration inspector revealed no evidence of preimpact failure or malfunction. Inspection of the aileron flight control system revealed that wooden aileron secondary stop blocks were attached to the main spars; however, the shape was different than the stop block depicted in the builder's guide. Additionally, scrape marks associated with each aileron outer bellcrank were noted on structural support tubes inside both lower wings.
The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The pilot's inability to recover from an intentional aerobatic maneuver due to loss of aileron control. Contributing to the accident was the installation of an inadequate aileron secondary stop block against the main spar of both lower wings.
Full narrative available at: http://www.ntsb.gov/NTSB/brief2.asp?ev_id=20080804X01153&ntsbno=MIA08LA121&akey=1
And, the Supporting Docket Materials (including pics at: http://www.ntsb.gov/Dockets/Aviation/MIA08LA121/