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On August 30, 2007, about 1340 eastern daylight time, a Piper PA-28-181, N3077Q, was substantially damaged when it overran the wet turf runway after landing at Seymour Air Park (TN20), Sevierville, Tennessee. The certificated private pilot, the sole occupant, was not injured. The flight was being operated under the provisions of 14 Code of Federal Regulations (CFR) Part 91. Visual meteorological conditions prevailed at the termination of the flight, which operated on an instrument flight rules flight plan.
According to the pilot, the flight originated at Scott Municipal Airport (SCX), Oneida, Tennessee, and instrument meteorological conditions were encountered for a portion of the trip. The destination airport did not have any published instrument procedures, but the weather was adequate for a visual flight rules arrival. The pilot reported that the destination weather at the time of the event included scattered clouds at 2,000 feet, overcast at 8,000 feet, light and variable winds, and no precipitation.
The pilot entered the left downwind leg of the traffic pattern for runway 25, and conducted a low approach to observe the windsock and check the runway for standing water. The pilot observed that the windsock was "limp," and that he did not see any standing water on the runway. He then completed another circuit of the traffic pattern, flew a "stable approach" using full flaps and a speed of 65 knots, and landed on runway 25. He stated that touchdown occurred with 1,500 feet of runway remaining. After touchdown, the pilot recognized the reduced braking effectiveness due to the wet grass, and applied heavy braking. The airplane overran the runway, crossed a road, and impacted trees.
The pilot held a private pilot certificate with airplane single engine land and instrument ratings. He had approximately 370 total hours of flight experience, with 140 hours in the accident airplane make and model. The pilot had 36 hours of simulated instrument time, and 11 hours of actual instrument time. His most recent Federal Aviation Administration (FAA) third-class medical certificate was issued in December 2006. The pilot stated that he had previously flown into the accident airport on multiple occasions.
FAA records indicated that the airplane was manufactured in 1977. The FAA certification basis for the airplane did not require the manufacturer to determine or to provide takeoff or landing performance on turf or wet runways. The FAA Type Certificate Data Sheet specified that the Pilots Operating Handbook (POH) was a required document for the airplane.
The 1333 weather observation at an airport located 10 miles west of TN20 reported winds from 360 degrees at 5 knots, visibility 6 miles, a broken ceiling at 700 feet, temperature 23 degrees Celsius (C), dew point 22 degrees C, and altimeter setting of 30.05 inches of mercury. The observation indicated that rain ended at 30 minutes past the hour.
The single runway was turf, and was designated as 7/25. It measured 100 feet by 2,300 feet, and had an elevation of approximately 1,000 feet above mean sea level.
TESTS AND RESEARCH
A Garmin GPSMAP 396 handheld global positioning system (GPS) unit was onboard and operational during the accident flight. The unit stored time, position, and velocity information. The data for the flight was recovered and processed by National Transportation Safety Board recorders laboratory personnel. The unit did not directly record a touchdown time or location.
Information downloaded from the GPS unit indicated that approximately 1 1/2 miles east of the destination airport, the pilot executed a left 360 degree turn, and simultaneously descended from approximately 3,200 feet to 1,600 feet GPS altitude. The GPS also yielded a ground track which conformed to the pilot's description of the low approach and second traffic pattern circuit.
The GPS data indicated that when the airplane was on approach 1,600 feet prior to the runway threshold, it was 150 feet above the airport elevation, with a groundspeed of 86 knots. Eleven seconds later, the airplane was 300 feet beyond the threshold, with a groundspeed of 71 knots. Seven seconds after that the airplane was 1,200 feet beyond the threshold, with a groundspeed of 57 knots. Five seconds later, the groundspeed was 40 knots, with approximately 400 feet of runway remaining. According to the GPS data, the airplane overran the runway at an approximate speed of 23 knots.
14CFR Part 91 Operational Requirements
The operating regulations in 14CFR Part 91 required pilots to be familiar with the airplane performance. Specifically, 14 CFR Part 91.103, "Preflight action," paragraph (b)(1), stated that for aircraft that required an approved Airplane Flight Manual (AFM), "Each pilot in command shall, before beginning a flight, become familiar with all available information concerning that flight. This information must include...takeoff and landing distance contained therein." There were no explicit FAA requirements for the pilot to account for different runway surface types (e.g. turf) or conditions (e.g. wet) when determining takeoff or landing distances, nor were there any explicit prohibitions against operating on such surfaces.
Paragraph (b)(2) of 14 CFR Part 91.103 stated that for aircraft that did not require an approved AFM, the pilot must familiarize himself with "...other reliable information appropriate to the aircraft, relating to aircraft performance under expected values of airport elevation and runway slope, aircraft gross weight, and wind and temperature." While this paragraph did require the pilot to account for certain parameters, there were no explicit requirements for the pilot to account for different runway surface types (e.g. turf) or conditions (e.g. wet) when determining takeoff or landing distances.
POH Stall Speed and Landing Distance Information
Examination of the PA-28-181 POH stall speed chart indicated that at the pilot-reported airplane weight of 2,138 pounds, the airplane would stall at 45 knots with full flaps.
The POH was examined for landing distance information regarding operations on turf and/or wet runways. Paragraph 5.3 of the Performance Section contained the following entries: "The performance charts are unfactored and do not make any allowance for varying degrees of pilot proficiency or mechanical deterioration of the aircraft," and "Effects of conditions not considered on the charts must be evaluated by the pilot, such as the effect of soft or grass runway surface on takeoff and landing performance."
The POH landing performance charts only presented data for a "paved, level, dry runway." The POH did not provide any procedural or performance information regarding operations from other types of runway surfaces, or for wet or otherwise-contaminated surfaces. The POH did not explicitly prohibit operations from other than paved, level, dry surfaces. The PA-28-181 landing performance charts in the POH indicated a total landing distance over a "50 foot barrier" of approximately 1,300 feet, which included a ground roll of approximately 800 feet, for a dry paved runway, and the atmospheric conditions that existed at the time of the accident.
The pilot stated that on final approach he had a "normal sight picture...with sufficient runway for normal ground roll (835' required per landing performance calculation)."
Availability of Supplemental Landing Distance Information for Pilots
Several common pilot-oriented references were examined for information regarding the effects of wet, turf, or wet turf runway surfaces on stopping distance. Five FAA publications and one commercial publication contained no information at all. These were the Aeronautical Information Manual (FAA "AIM"), the Airplane Flying Handbook (FAA-H-8083), the Instrument Flying Handbook (FAA AC 61-27C), the Instrument Procedures Handbook (FAA-H-8261-1A), FAA Advisory Circular 60-22 Aeronautical Decision Making, and the Flight Instructor's Manual (William Kershner, 3rd edition).
One FAA and one commercial publication provided some qualitative information regarding landing on turf or wet runway surfaces. In Chapter 9 of the Pilots Handbook of Aeronautical Knowledge (FAA-H-8083-25), the section entitled "Runway Surface and Gradient" stated that "Although muddy and wet surface conditions can reduce friction between the runway and the tires, they can also act as obstructions and reduce the landing distance." The section entitled "Runway Surface" in Chapter 10 of the commercial ASA publication "The Pilots Manual, Private and Commercial" stated that a "wet runway surface will not allow good braking to occur and so the landing distance required will be longer."