Aviation Accident Summaries

Aviation Accident Summary ERA14LA341

Warm Springs, GA, USA

Aircraft #1

N400AZ

LET L 23 SUPER BLANIK

Aircraft #2

N342BA

LET L 23 SUPER BLANIK

Analysis

A landing glider collided with another glider on the active runway. The flight instructor of the glider on the runway stated that he and the student pilot landed the glider and that it came to rest about 1,000 ft from the runway threshold. The instructor was having a conversation with the air boss while the glider was still on the runway when it was struck from behind by the landing glider. The air boss indicated that, during this conversation, he watched the second glider turn from the base to the final leg in the traffic pattern and then land. The flight instructor of the second glider stated that he and the student pilot landed just beyond the displaced threshold markers at the approach end of the runway and that both he and the student applied "maximum braking" but were unable to stop the glider before impacting the glider on the runway. According to both flight instructors, they had performed numerous landings that day in their respective gliders as part of the training requirements for the students. Both glider instructors reported no preimpact mechanical malfunctions or failures with either glider that would have precluded normal operation. The Civil Air Patrol procedures stated that, after landing and coming to rest, each glider was to be removed from the runway and that at no time was a glider to be on the runway while another glider was landing. Federal Aviation Administration regulations and guidance indicated that the landing glider has the right-of-way over all aircraft on the surface and that, after landing, the pilot "should move or taxi the glider clear of all runways." Given that the air boss watched the landing glider turn from base to final leg in the traffic pattern while talking to the instructor in the glider on the runway, it is likely that the instructor would have had sufficient time to move the glider off the runway before the other glider landed, which would have prevented the accident. It is also likely that the instructor of the first glider was distracted by talking to the air boss and that neither he nor the air boss realized that the second glider was a concern until it was too late. The pilot of the glider on the runway should have moved the glider off the runway as soon as possible to allow the landing glider sufficient space to land without the possibility of a collision.

Factual Information

On July 14, 2014, around 1435 eastern daylight time, a Let L23 Super Blanik, N342BA, was substantially damaged when it struck a Let L23 Super Blanik, N400AZ, which was on the runway of Roosevelt Memorial Airport (5A9), Warm Springs, Georgia. The flight instructors and student pilots of both gliders were not injured. Visual meteorological conditions prevailed at the time of the accident. Both gliders were owned and operated by the Civil Air Patrol. Neither of the gliders filed flight plans for the local instructional flights, which were conducted under the provisions of Title 14 Code of Federal Regulations Part 91. According to the flight instructor of N400AZ, he and the student pilot landed the glider and came to rest on the centerline about 1,000 feet past the threshold of the landing runway. As the flight instructor was talking to the air boss after coming to rest on the runway and waiting for ground personnel to help stage the glider for a launch, the glider was struck from behind by the second glider. The glider came to rest on the runway and both occupants of the glider exited without incident. N400AZ sustained substantial damage to the right wing, fuselage, and empennage. In addition, the flight instructor reported no preimpact mechanical malfunctions or failures with the glider that would have precluded normal operation. According to the flight instructor of N342BA, he and the student pilot landed just beyond the displaced threshold markers at the approach end of the runway. Both the flight instructor and the student applied "maximum braking" but were unable to stop the glider prior to impacting N400AZ. In addition, the flight instructor had each of his hands on the flight controls and brake lever respectively, and was unable to use the radio to alert N400AZ of the impending collision. Following the impact, N342BA came to rest on the paved portion of the runway and both occupants egressed without incident. N342BA incurred substantial damage to the left wing and fuselage. In addition, the flight instructor reported no preimpact mechanical malfunctions or failures with the glider that would have precluded normal operation. According to both flight instructors, they had performed numerous landings that day in their respective gliders, as part of the training requirements for the students. One of the flight instructors reported that prior to the accident the wind direction had changed from a quartering headwind to a quartering tailwind while they were in the traffic pattern to land. According to the airboss at the time of the accident, the wind shifted to a tailwind for the airplanes landing on runway 36. In addition, he stated that after the first glider landed and was preparing for an aerotow launch, he went over to discuss the wind shift with the glider instructor. He watched as the second glider turned from the base leg to the final leg in the traffic pattern and then land prior to the numbers on the runway. As the landing glider continued to approach the glider positioned on the runway, he "realized that at less than 300 feet" the landing glider was not going to slow down in time to stop prior to the glider positioned on the runway. The landing glider moved to the right of the centerline in order to avoid a collision with the glider positioned on the centerline of the runway, however, the left wing of the landing glider struck the glider positioned on the runway. According to the chief of safety of the Civil Air Patrol, both gliders were equipped with radios and the pilots were using them prior to the accident. He also reported that the glider procedures indicated that flight operations were to use runway 36. The gliders were to stage in the grass on the west side of the runway, south of the southernmost taxiway. That allowed the tow airplanes to pull onto the runway at that taxiway and pick up the next glider. The gliders were to land short of the southernmost taxiway if possible and push off into the grass to await the next tow. If a glider landed longer than the south taxiway, it would be pushed off into the grass and towed by a golf cart or pushed by hand back to the staging area. "At no time [would] there be an aircraft on the runway when an aircraft [was] landing." 5A9 was equipped with one runway, which was designated as 18/36. The runway was 5,004 feet long, 75 feet wide, constructed of asphalt, and noted as "in good condition." In addition, the airport was not tower-controlled. The weather recorded at 1415 at LaGrange-Callaway Airport (LGC), Lagrange, Georgia, which was approximately 19 miles to the west of the accident location, indicated wind from 260 at 7 knots. In addition, a review of the recorded weather indicated a quartering headwind, wind of 280 at 4 knots, approximately an hour and a half prior to the accident. The Code of Federal Regulations, Section 91.113, right-of-way rules stated, "Aircraft, while on final approach to land or while landing, have the right-of-way over other aircraft in flight or operating on the surface, except that they shall not take advantage of this rule to force another aircraft off the runway surface which has already landed and is attempting to make way for an aircraft on final approach." According to the Glider Flying Handbook (FAA-H-8083-13A), in Chapter 7, Launch and Recovery Procedures and Flight Maneuvers, it stated that after landing the pilot should "move or taxi the glider clear of all runways. If the glider is to be parked for a short interval between flights, choose a spot that does not inconvenience other gliderport/airport users."

Probable Cause and Findings

The failure of the flight instructor to move his glider from an active runway in accordance with procedures due to his distraction by having a conversation with the air boss, which resulted in the landing glider colliding with the glider on the runway.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports