Saturday, June 08, 2019

Glider Tow Event: Schweizer SGS 2-33A, N2832H, accident occurred August 05, 2018 at Harford County Airport (0W3), Churchville, Maryland

The National Transportation Safety Board did not travel to the scene of this accident.

Additional Participating Entity:

Federal Aviation Administration / Flight Standards District Office; Baltimore, Maryland

Aviation Accident Factual Report - National Transportation Safety Board:

Investigation Docket - National Transportation Safety Board:

Location: Churchville, MD
Accident Number: ERA18LA211
Date & Time: 08/05/2018, 1500 EDT
Registration: N2832H
Aircraft: Schweizer SGS233
Aircraft Damage: Substantial
Defining Event: Glider tow event
Injuries: 2 None
Flight Conducted Under: Part 91: General Aviation - Instructional

On August 5, 2018, about 1500 eastern daylight time, a Schweizer SGS 2-33A glider, N2832H, was substantially damaged when it impacted trees shortly after takeoff from Harford County Airport (0W3), Churchville, Maryland. The flight instructor and passenger were not injured. The tow plane, a Bellanca/American Champion Scout 8GCBC, N88059, was undamaged and the commercial pilot was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local instructional flight, which was operated under the provisions of Title 14 Code of Federal Regulations Part 91.

According to the glider flight instructor, while attempting to take off the tow airplane became airborne about 100 ft later than on earlier flights that day. When it became apparent to him that they might not clear trees located about 1,300 ft off the departure end of the runway, he released from the tow airplane, made a right turn to avoid the tree line, and executed a forced landing in a nearby field. He had completed about 130° to 150° of the turn when the left wing impacted trees.

According to the pilot of the tow airplane, the weather conditions were "the worst humidity and heat and slowest rate of flying" and the takeoff roll was long. He stated that they would have normally used a sod runway that was oriented into the wind and longer, but it was water logged, so they were using the grass area paralleling the southern edge of runway 28, taking off and landing in a westerly direction. That area was uphill, shorter, and had some wet areas. He stated the initial climb felt normal given the runway and weather conditions and that he noted no abnormal performance issues with the tow plane. He estimated the glider would clear the trees by 20 ft, but then felt the glider drop off and looked back to see it turning toward an open field. He reported that there were no mechanical malfunctions or failures with the tow airplane that would have precluded normal operation and reported no problems during subsequent flights in the airplane.

Pilot Information

Certificate: Flight Instructor; Commercial
Age: 71, Male
Airplane Rating(s):  Multi-engine Land; Multi-engine Sea; Single-engine Land; Single-engine Sea
Seat Occupied: Rear
Other Aircraft Rating(s): Glider
Restraint Used: 3-point
Instrument Rating(s): Airplane
Second Pilot Present: No
Instructor Rating(s): Glider
Toxicology Performed: No
Medical Certification: Class 2 With Waivers/Limitations
Last FAA Medical Exam: 07/28/2017
Occupational Pilot: No
Last Flight Review or Equivalent: 05/07/2017
Flight Time:  5200 hours (Total, all aircraft), 700 hours (Total, this make and model), 5050 hours (Pilot In Command, all aircraft), 14 hours (Last 90 days, all aircraft), 5 hours (Last 30 days, all aircraft), 1 hours (Last 24 hours, all aircraft)

The flight instructor held a commercial pilot certificate with ratings for airplane single and multi-engine land and sea, instrument airplane, and glider. He held a flight instructor certificate with a rating for glider. His most recent Federal Aviation Administration (FAA) 2nd class medical certificate was issued July 2017. He reported 5,100 total hours of flight experience, with 975 hours in gliders.

The tow plane pilot held a commercial pilot certificate with ratings for airplane single engine land, instrument airplane, rotorcraft-helicopter, and glider.

Aircraft and Owner/Operator Information

Aircraft Make: Schweizer
Registration: N2832H
Model/Series: SGS233 A
Aircraft Category: Glider
Year of Manufacture: 1978
Amateur Built: No
Airworthiness Certificate: Other
Serial Number: 532
Landing Gear Type: Ski/wheel;
Seats: 2
Date/Type of Last Inspection: 05/25/2018, Annual
Certified Max Gross Wt.: 1040 lbs
Time Since Last Inspection:
Engines: 0
Airframe Total Time: 3439 Hours as of last inspection
Engine Manufacturer: 
ELT: Not installed
Engine Model/Series:
Registered Owner: Hardy Truly C
Rated Power:
Operator: The Atlantic Soaring Club
Operating Certificate(s) Held: None 

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: KMTN, 21 ft msl
Distance from Accident Site: 17 Nautical Miles
Observation Time: 1445 EDT
Direction from Accident Site: 215°
Lowest Cloud Condition: Scattered / 6000 ft agl
Visibility:  10 Miles
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: 8 knots /
Turbulence Type Forecast/Actual: Unknown / None
Wind Direction: 150°
Turbulence Severity Forecast/Actual: N/A / N/A
Altimeter Setting: 30.16 inches Hg
Temperature/Dew Point: 32°C / 24°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Churchville, MD (0W3)
Type of Flight Plan Filed: None
Destination: Churchville, MD (0W3)
Type of Clearance: None
Departure Time: 1500 EDT
Type of Airspace: Class G

At 1445, the reported weather at Martin State Airport (MTN), about 17 nautical miles southwest of the accident site, included clear skies, 10 miles visibility, and wind from 160° magnetic at 8 knots. The temperature was 32° C, the dew point was 24° C, and the altimeter setting was 30.16 inches of mercury.

At 1451, the reported weather at New Castle Airport (ILG), about 35 miles east of accident site, included clear skies, 10 miles visibility, and wind from 160° magnetic at 8 knots. The temperature was 32°C, the dew point was 21°C, and the altimeter setting was 30.14 inches of mercury.

The calculated density altitude at the time of takeoff was about 2,500 feet.

According to an FAA Icing Probability Chart, the atmospheric conditions at the time of the accident were "conducive to icing at glide [idle] power."

Airport Information

Airport: Harford County (0W3)
Runway Surface Type: Grass/turf
Airport Elevation: 408 ft
Runway Surface Condition: Wet
Runway Used: N/A
IFR Approach: None
Runway Length/Width:
VFR Approach/Landing: Forced Landing 

Harford County Airport was located 3 miles east of Churchville, Maryland, at an elevation of 408.5 feet above mean sea level. It had two intersecting runways, designated as 10/28 and 1/19. Runway 10/28 was asphalt and measured 2,000 feet by 40 feet. In addition, Runway 28 had a 1.4% upward gradient and 62-foot trees 1,321 ft from the departure end of the runway. The area being used for glider operations was the turf area immediately adjacent and parallel to runway 28.

Wreckage and Impact Information

Crew Injuries: 2 None
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 2 None
Latitude, Longitude: 39.568056, -76.208056 (est) 

Examination of the wreckage by an FAA inspector revealed that the glider was substantially damaged in the accident sequence. The left wing displayed damage consistent with tree impact. The rear portion of the fuselage was fractured just aft of the trailing edge of the wing and rested 90° to the right of the longitudinal centerline of the forward fuselage. The left wing leading edge was impact-damaged in multiple areas.

Additional Information

The Civil Aviation Authority of the United Kingdom published Safety Sense Leaflet 7C, "Aeroplane Performance." The publication cautioned that operating from poor surfaces, such as long or wet grass, mud, or snow, often results in accidents that could be avoided if pilots were aware of the performance limitations of their airplanes. The publication also provided a list of variables that often affect performance and guidelines for calculating the effect of these variables on airplane performance in the absence of guidance from the manufacturer. Among these factors was a 30% increase in takeoff distance on wet grass runways, a 10% increase in takeoff distance with a 2% upslope, and a 20% increase in takeoff distance with a tailwind component of 10% of lift-off speed."

According to FAA Pamphlet FAA-P-8740-2, Density Altitude:

Whether due to high altitude, high temperature, or both, reduced air density (reported in terms of density altitude) adversely affects aerodynamic performance and decreases the engine's horsepower output. Takeoff distance, power available (in normally aspirated engines), and climb rate are all adversely affected. Landing distance is affected as well; although the indicated airspeed (IAS) remains the same, the true airspeed (TAS) increases. From the pilot's point of view, therefore, an increase in density altitude results in the following:

• Increased takeoff distance.
• Reduced rate of climb.
• Increased TAS (but same IAS) on approach and landing.
• Increased landing roll distance.

Because high density altitude has particular implications for takeoff/climb performance and landing distance, pilots must be sure to determine the reported density altitude and check the appropriate aircraft performance charts carefully during preflight preparation. A pilot's first reference for aircraft performance information should be the operational data section of the aircraft owner's manual or the Pilot's Operating Handbook developed by the aircraft manufacturer. In the example given in the previous text, the pilot may be operating from an airport at 500 ft msl, but he or she must calculate performance as if the airport were located at 5,000 feet. A pilot who is complacent or careless in using the charts may find that density altitude effects create an unexpected –and unwelcome – element of suspense during takeoff and climb or during landing.

According to the Glider Flying Handbook (FAA, 2013, p 7-3) "normal takeoffs are made into the wind."

Review of the operator's standard operating procedures for this flight operation indicated that "normal sailplane traffic patterns will be into the prevailing winds" and that "no take-offs or landings are to be made against the normal take-off direction, except in an emergency or for training purposes." Further, the procedures state that "the tow pilot and the glider PIC [pilot-in-command] are both responsible for ensuring that sufficient take-off distance is available according to emergency release possibilities and the PIC's proficiency."

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