WPR11LA172

The pilot's failure to prioritize flying over navigation due to his diverted attention, which allowed the airplane to near a restricted area, which, in turn, led the pilot to enter a rapid avoidance maneuver and subsequently lose airplane control. Contributing to the accident was the pilot's failure to adequately prepare for the flight.

The owner/pilot was cruising on a personal flight in visual conditions and was engaged in correlating the indications of two very high frequency omni-range (VOR) cockpit navigation displays. The pilot also had a handheld global positioning system (GPS) unit mounted in the cockpit. During the VOR correlation effort, the pilot noticed on the GPS that he was about to intrude into restricted airspace. (Although this particular airspace is only restricted at certain times, the GPS always depicts the boundaries, regardless of the airspace restriction status.) He initiated a turn to avoid the restricted airspace and monitored the GPS display to ensure that he would clear the restricted area. When he returned his attention to the airplane, he noticed that the bank angle was about 75 degrees, the pitch attitude was about 20 degrees airplane nose down, and the airspeed was about 190 mph, which was in the yellow (caution) range of the airspeed indicator scale. The pilot leveled the wings and initiated a pull-up, during which he heard three or four "thumps" in rapid succession. After recovery to level flight, the airplane seemed normal, but the pilot's concern about the thumps prompted him to return to his home airport where he landed uneventfully. The pilot estimated that he loaded the airplane to about 2g during the pullout, while a cockpit mounted g-meter registered a maximum loading of about 2.5g. Postflight examination of the airplane revealed that the aft fuselage side skins were wrinkled and that the aft fuselage lower skin was torn. Detailed evaluation of the ruddervator system revealed some minor discrepancies in control surface travel ranges. Damage patterns were consistent with in-flight overload and were not consistent with flutter. Review of airplane certification requirements and the in-flight events indicated that the airplane was in the region of its flight envelope where flight control inputs could result in structural damage. The control surface travel discrepancies did not contribute to the ability of the pilot to induce the observed structural damage. Because the restricted airspace is not continuously active, notification of its active status is provided via a Notice to Airmen (NOTAM), which is issued 2 hours in advance of the restriction. The airspace status can also be determined on a real-time basis via radio communications with the controlling facility. The pilot had not checked the NOTAMs and was not in communication with the controlling facility, and he was therefore unaware of the airspace status at the time of his near-penetration of the airspace. Because he was unaware of the status of the airspace, he took evasive action to avoid it, although such action was unnecessary because the airspace was not restricted at the time of the flight. Adequate preflight planning would have allowed the pilot to determine the status of the restricted airspace and would have obviated the need for the avoidance maneuver, which ultimately resulted in structural damage to the airplane. In addition, when it became apparent to the pilot that he was about to penetrate the airspace, he prioritized avoidance of the airspace above retaining control of the airplane, which was a reversal of the "aviate, navigate" priority hierarchy necessary for safe operation of any aircraft.

HISTORY OF FLIGHT On March 19, 2011, about 1140 Pacific daylight time, a Beech G35, N4211D, was substantially damaged during a recovery from an unintended unusual attitude near Whidbey Island, Washington. The certificated private pilot/owner was not injured. The personal flight was operated under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed for the flight. According to the pilot, he was on a personal flight, cruising at an altitude of 4,500 feet, and was engaged in correlating the indications of two panel-mounted navigation receivers in the cockpit. He also had a third navigation receiver, a handheld global positioning system (GPS) mounted on the flight control yoke assembly, in the lateral center of the cockpit. During the correlation effort, the pilot noticed that he was about to intrude into the restricted airspace for Whidbey Island, designated R-6701. He initiated a turn to the right, with a bank angle that he estimated to be about 45 degrees, in order to avoid the restricted airspace. During the turn, the pilot referred to the GPS to ensure that he would clear the restricted area. When he returned his attention to the airplane's attitude, he noticed that the bank angle had increased to about 75 degrees right wing down, and the pitch attitude had decreased to about 20 degrees airplane nose down. At that point, the pilot noted that the airspeed was about 190 mph, which was in the yellow (caution) range of the airspeed indicator scale. The pilot stated that he leveled the wings, and then initiated a pull-up. During the pull-up, he heard three or four "thumps" in rapid succession. After recovery to level flight, the airplane continued to "fly fine," but the pilot was concerned about the thumps, since he had never heard noises like them in that airplane. The pilot then flew the airplane "gingerly" back to his home field, where he landed uneventfully. After shutdown, the pilot examined the airplane, and noticed that some aft fuselage skins were wrinkled and/or torn. The airplane and airplane maintenance records were retained for additional examination. PERSONNEL INFORMATION Federal Aviation Administration (FAA) records indicated that the pilot held a private pilot certificate with airplane single-engine, airplane multi-engine, and instrument airplane ratings. According to information provided by the pilot, he had approximately 1,188 total hours of flight experience, which included approximately 592 hours in the accident airplane make and model. His most recent flight review was completed in June 2010, and his most recent FAA third-class medical certificate was also issued in June 2010. AIRCRAFT INFORMATION According to FAA information, the airplane was manufactured in 1955, and was first registered to the pilot in 1990. The airplane was equipped with a V-tail configuration instead of the more common cruciform arrangement. The airplane was equipped with the post-delivery capture fairings known as "cuffs" which attached the stabilizers' inboard leading edges to the fuselage. Each of the two stabilizers was equipped with a moveable control surface called a ruddervator, and each ruddervator was equipped with a cockpit adjustable trim tab. Each ruddervator functioned as part rudder, part elevator. Ruddervator inputs were via conventional cockpit controls (rudder pedals and control wheel/column), and actuation was via control cables and a mixer unit known as the differential mechanism. One cockpit control operated both trim tabs. Review of maintenance records indicate that the ruddervators were reskinned and rebalanced in January 1997. The logbook entry for that activity did not explicitly state whether the control system was rerigged, or whether the control cable tensions were checked or adjusted. The records indicated that Airworthiness Directive (AD) 94-20-04-R2 was accomplished in February 2004, when the airplane had accrued a total time in service (TT) of about 2,271 hours. That AD required verification of ruddervator balance, visual inspection of the empennage, aft fuselage, and ruddervator control system for damage, and proper adjustment of the ruddervator system surface travel, cable tensions, and rigging. There were no logbook entries that documented any subsequent cable tension checks or adjustments, control surface travel checks, or control system rigging. As of its most recent annual inspection in August 2010, the airplane had a TT about 4,257 hours. As of the accident, the airplane had a TT of about 4,261 hours. METEOROLOGICAL INFORMATION The 1153 automated weather observation at the pilot's home airport, located about 10 miles south-southeast of the accident location, included winds from 180 degrees at 7 knots; visibility 10 miles; scattered clouds at 3,200 feet; temperature 8 degrees C; dew point 1 degree C; and an altimeter setting of 29.75 inches of mercury. AIDS TO NAVIGATION The Sectional Aeronautical Chart for Seattle graphically depicted R-6701. The tabular chart data indicated that the area extended up to an altitude of 5,000 feet above mean sea level (msl), and that it's "Time of Use" was "intermittent by NOTAM" with 2 hours' advance notice. The chart indicated that the "Controlling Facility" was the Whidbey Island Naval Air Station air traffic control tower (NUW ATCT), and provided the appropriate communications frequency for the NUW ATCT. The airplane was equipped with two panel-mounted very high frequency omni-range (VOR) instrument heads, which the pilot was trying to correlate with one another in flight. Those instruments do not enable a pilot to readily determine the boundaries of the restricted area R-6701. The pilot's handheld GPS did depict the boundaries of R-6701. The boundaries of R-6701 could also be approximated by visual dead reckoning when cross-referenced with the Sectional Aeronautical Chart for Seattle, provided the landforms were not obscured by clouds. COMMUNICATIONS According to the pilot, Restricted Area R-6701 was "normally not active on Saturday" but he had not confirmed the operational status of R-6701 prior to or during the accident flight. There was no evidence to indicate that the pilot checked NOTAMs prior to the flight, or that he was monitoring or in communication with an air traffic control facility at the time of the event. The investigation did not determine whether R-6701 was active at the time of the event. WRECKAGE AND IMPACT INFORMATION Three days after the event, Federal Aviation Administration (FAA) inspectors examined the airplane in the pilot's hangar. The inspectors noted three primary damage sites. On the aft right fuselage, a diagonal wrinkle about 2 feet long extended up and forward from the juncture of the fuselage side and bottom; the wrinkle intercepted the juncture at about the second bulkhead/former forward of the tailcone. On the opposite side of the aft fuselage, the skin was crumpled and dented in the same general region as on the right side, but the deformation did not exhibit the linear pattern observed on the right side. On the lower aft fuselage, the forward bottom skin was separated from its lap joint with the aft bottom skin at the aforementioned bulkhead/former; the skin was torn from the fasteners, which remained in the bulkhead. The FAA inspectors did not observe any indications of pre-event damage or corrosion in the affected areas. A cockpit g-meter that was operational during the event registered a maximum of about 2.5g and a minimum of about minus 0.7g, but the accuracy of the meter was not determined. About 6 weeks after the event, the airplane flight control system and damage sites were examined in detail. One additional damage site was observed, in the form of a small buckle in the lower outboard skin of the left ruddervator. There was no visible damage to any other portion of the aft stabilizers