N7900VRockwell International S-2R

On September 21, 2020, about 1125 eastern daylight time, a Rockwell S2R airplane, N7900V, was substantially damaged when it was involved in an accident near Hamilton, Georgia. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 positioning flight.

According to the pilot, a new owner had purchased the airplane, and he was ferrying the airplane for him from Cross City Airport (CTY), Cross City, Florida, to LaGrange-Callaway Airport (LGC), Lagrange, Georgia. The pilot reported that before the flight he had looked in the fuel tanks and noted that they were both 1/3 full. He filled the fuel tanks with 72 gallons of fuel “over the top of the wing” and visually double checked that the fuel tanks were full after allowing for equalization. He then departed CTY about 0800. The engine lost total power 1 hour 35 minutes to 1 hour 45 minutes later. According to the pilot, the engine “abruptly quit with no warning.” The pilot established best glide speed, shut off the fuel selector, and landed in a clearing in a forest.

According to witnesses, the engine made a coughing sound, and a white or light grey cloud of smoke exited from the engine area. The airplane then seemed suspended and appeared to stop. The airplane then “dipped the right wing” and spiraled into a glide in the direction from which it came. The witnesses lost sight of the airplane because of trees and moments later heard a loud noise.

Examination of the accident site revealed that the airplane touched down on a magnetic heading of 030°; the right wing then struck the ground and hit a previously felled tree; and the airplane spun to the right. Both main landing gear buckled under the fuselage, and the airplane came to rest on a magnetic heading of 132°.

Examination of the airplane revealed substantial damage to the right wing. The fuselage skin also displayed wrinkling adjacent to the left-wing flap. Flight control continuity was established from the cockpit to all the flight control surfaces. There was no post-impact fire, and the carburetor heat control was found to be tie-wrapped in the closed OFF position.

Examination of the propeller and engine revealed that all three propeller tips were damaged; compression was present on all cylinders; and the drivetrain was intact from the front of the engine to the accessories on the back of the engine. The engine contained oil, and after draining the oil tank, no unusual debris was noted. The oil filter was removed and opened, and no metal was found in the pleated filter material. The carburetor contained 3 to 4 ounces of fuel, and the fuel strainer was clean and devoid of fuel. The spark plugs were removed from the top five cylinders (front and rear), and all appeared normal in color (light tan) and had normal wear.

Both magneto "P" leads were checked for proper operation with the magneto switch. The right magneto "P" lead was found to function normally; the magneto lead positively grounded with the magneto switch in the OFF or L position of the magneto switch and open in the BOTH and R switch positions. The left magneto "P" lead was found to have erratic indications when the magneto switch was placed in the BOTH or L positions and functioned normally in the OFF or R positions of the magneto switch. The erratic operation was traced to a splice in the left magneto "P" lead. The wiring from the left magneto to the splice was a single conductor wire, and the wiring from the splice to the magneto switch was a shielded single conductor cable. The shielding was found to have been crimped by the splice, allowing an intermittent short between the shielding and the center conductor. The wiring shield was terminated to a ground terminal at the magneto switch and a ground lug attached to the airframe side bulkhead.

The magnetos were removed, and no external damage or anomalies were noted. Internal examination did not find any visible damage or anomalies. After being placed on a test stand, the magnetos were operated through all rpm ranges with maximum point gap. They were then each run at 2,150 rpm for 20 minutes. No anomalies were noted during the testing.

The fuel tanks in both wings were visually inspected, and the tanks did not appear to have been breached. There were no signs of fuel in either tank. The gaskets on the fuel caps were dry rotted and hard, and the caps would not fit and lock tight. The fuel tank openings showed signs of rust and scale. Both wing tank fuel drains were in the closed position. There was minor evidence of fuel staining present on the right wing coming from the tank access panels (slight seepage) and the right fuel cap.

According to the previous airplane owner, “if [the pilot] didn’t get any fuel between Cross City and where they crashed, they were pushing the envelope.” He explained that the airplane’s engine was a geared 1340 radial engine that burned a lot of fuel. He said, “if you get one with a 45 [gallons per hour] gph fuel burn you’re doing good. Most of them would run in the mid 50 gph range.” He added that the airplane “had the little tanks on it, only 110 gallons or so, total.” He explained that it was an “as-is” purchase but that he was unaware of any mechanical issues with the aircraft. He also explained that he thought it was “kind of strange to not even go over the aircraft with [the pilot].” He stated that the pilot showed up a day early and left the following morning without meeting with him and going over the airplane. He explained that there was a pilot’s operating handbook (POH) in the airplane.

According to the pilot, the fuel quantity indicating system was inoperative; however, he chose to fly because he "had good data as to what the aircraft's fuel burn should be per hour." He reported that he had over 1,200 hours in the airplane make and model (S2R) and that this was his first flight in an S2R with the 1340 radial engine.

According to the pilot, during the entire flight, he had been cruising at 2,500 ft with a cruise power setting of 30 inches of manifold pressure at 2,000 rpm. Review of the “Pratt & Whitney Engine Check Chart for the Wasp (R-1340) S3H1 and S3H1-G Engines” revealed that the maximum cruise power setting was 26.0 inches of manifold pressure and 2,000 rpm with a fuel burn rate of about 32 gallons per hour.

According to the new airplane owner, he had talked with the pilot on the previous day and suggested the pilot study the POH with regards to fuel burn and suggested that the first leg of the flight be limited to 1 hour in duration to ensure the actual fuel burn was as expected.