Livermore, CA, USA
N15TA
AVIAT S2
N698SP
CESSNA 172 - S
While taxiing after landing at a controlled airport, a Pitts tailwheel-equipped airplane collided with a Cessna that was standing with its engine operating. Both airplanes were on instructional flights with a flight instructor and a rated pilot who was receiving instruction aboard. The airport was equipped with two parallel runways, designated as 25L and 25R. Taxiway G was situated at the end of 25L, was oriented perpendicular to the runways, and extended slightly south of 25L where it terminated at a parallel taxiway. The air traffic control tower (ATCT) was staffed by four persons serving three positions. One person was serving as controller in charge (CIC), one person was serving as local controller (LC), and two people were assigned to the ground controller (GC) position. A controller-in-training (CIT) was actively performing the GC duties, and he was being trained by a full performance level controller. The Cessna landed on 25L and, as instructed by the LC, exited south onto taxiway G, stopped, and called the GC to obtain clearance to taxi; however, the GC did not respond to the taxi request. The Pitts then landed on runway 25R, and the LC instructed the pilots to turn the airplane left onto taxiway G, hold short of 25L, and remain on the LC's frequency, which the pilots of the Pitts did. At that point, the two airplanes were facing in the same direction, separated by runway 25L and at least 300 feet. About 50 seconds after the Cessna made its taxi request to the GC, the LC cleared the Pitts to cross 25L, and although required to do so, she did not advise the Pitts of the Cessna in its path. The pilots of the Pitts were unaware of the Cessna's presence until the propeller of the Pitts struck the empennage of the Cessna. The pilots of the Pitts did not see the Cessna due to the limited forward visibility of tailwheel-equipped Pitts, their failure to S-turn while taxiing, and the limited tail-on visibility of the Cessna. Had the pilots of the Pitts performed S-turns while crossing runway 25L, the collision likely would not have occurred. In addition, the pilots of the Pitts had no expectation that the Cessna was in their path because they were operating in the movement area of a controlled airport and had not been warned of the Cessna by the LC.
HISTORY OF FLIGHTOn October 20, 2013, about 1359 Pacific daylight time, a Pitts/Aviat S2C, N15TA, substantially damaged a Cessna 172S, N698SP, when it taxied into the Cessna at Livermore Municipal airport (LVK), Livermore, California, after receiving taxi clearance from the air traffic control tower. The Pitts was owned and operated by Attitude Aviation of LVK, while the Cessna was operated by West Valley Flying Club (WVFC) of Palo Alto, California. None of the two persons on board either airplane was injured. Both flights were conducted under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed. According to the certificated flight instructor (CFI) in the right front seat of the Cessna, he was providing a flight checkout for the private pilot in the left seat. Their flight originated from Palo Alto Airport of Santa Clara County (PAO), and they had landed uneventfully on LVK runway 25L. They exited 25L to the south at taxiway G, and then radioed LVK ground control (GC) for taxi clearance. Although GC was contacted by and responded to other aircraft subsequent to that request, GC did not respond to the Cessna crew. About 1 minute and 15 seconds later, having not received a response from GC, the Cessna crew initiated another radio call. During that transmission they heard "a lot of noise" coming from the rear of their airplane, and realized that their airplane had been struck in the empennage by the propeller of another airplane. According to the CFI in the front seat of the Pitts, he was providing aerobatic instruction to the pilot in the rear seat. They landed uneventfully on 25R, and exited 25R to the south at taxiway G. In accordance with the local controller's (LC) instruction, the Pitts crew stopped between runways 25R and 25L, and radioed LVK GC for clearance to cross 25L. The two pilots in the Pitts watched an unspecified experimental airplane land on 25L, and saw that airplane stop and exit 25L to the south at a taxiway east of their position. LVK GC then cleared the Pitts across 25L, but the controller did not advise them of the Cessna that was holding just south of 25L on taxiway G. The Pitts taxied across 25L. Due to the tailwheel configuration and limited forward visibility of the Pitts, neither pilot in the Pitts was aware of the presence of the Cessna until their propeller struck the empennage of the Cessna. After their airplane was struck by the Pitts, the Cessna pilots requested and received GC clearance to taxi to the ramp, which they did. The Pitts shut down in place, and the pilots exited the airplane. After some preliminary scene documentation, the Pitts was relocated clear of the traffic movement area. PERSONNEL INFORMATIONCessna Crew The instructor held commercial and CFI certificates, including an airplane single engine instructor rating. He had approximately 965 total hours of flight experience, including about 50 hours in the accident airplane make and model. His most recent flight review was completed in June 2013, and his most recent FAA third-class medical certificate was issued in July 2011. The pilot under instruction held a private pilot certificate, with an airplane single-engine land rating. He had approximately 141 total hours of flight experience, including about 2 hours in the accident airplane make and model. His most recent flight review was completed in August 2013, and his most recent FAA third-class medical certificate was issued in May 2012. Pitts Crew The instructor held multiple certificates and ratings, including flight instructor. He had approximately 10,500 total hours of flight experience, including about 700 hours in the accident airplane make and model. His most recent flight review was completed in September 2013, and his most recent FAA medical certificate was also issued in September 2013. The pilot under instruction held a private pilot certificate, with an airplane single-engine land rating. He had approximately 701 total hours of flight experience, including about 63 hours in the accident airplane make and model. His most recent flight review was completed in March 2013, and his most recent FAA third-class medical certificate was issued in February 2013. Pitts Crew Statements The pilot receiving instruction taxied the Pitts across 25L. In his written statement regarding the accident, he reported that he looked both east and west for landing or departing traffic, and "looked in front but wasn't looking for an airplane." He reported that he angled slightly to his right, and that his attention was primarily focused on navigating the airplane into the limited confines of its cleared location. The instructor also reported that the pilot angled the airplane to the right near the end of its crossing of 25L, and at first believed that the pilot was executing a clearing S-turn. The instructor believed that there was insufficient lateral pavement clearance for that maneuver, and advised the pilot to "move left," which the pilot did. The instructor then focused his attention to his right side, to monitor the pavement edge. AIRCRAFT INFORMATIONCessna (N698SP) The Cessna was manufactured in 2000, and was equipped with a Lycoming IO-360 series engine. The airplane was a four-place high wing configuration, with tricycle-style landing gear. Pitts (N15TA) The Pitts was manufactured in 2001, and was equipped with a Lycoming AEIO-540 series engine. The airplane was a two-place, tandem cockpit, biplane configuration, with conventional-style landing gear. The configuration of this airplane limited the forward visibility of the flight crew when the airplane was in the taxi attitude. METEOROLOGICAL INFORMATIONThe LVK 1353 automated weather observation included wind from 240 degrees at 4 knots, visibility 10 miles, clear skies, temperature 29 degrees C, dew point 1 degree C, and an altimeter setting of 29.93 inches of mercury. At the time of the accident, the sun was at an azimuth of 201.76 degrees True, and an elevation of 39.13 degrees. Both the sun and the accident location were generally south of the ATCT, separated by about 35 degrees of azimuth; the accident site was to the controllers' right of the sun. AIRPORT INFORMATIONCessna (N698SP) The Cessna was manufactured in 2000, and was equipped with a Lycoming IO-360 series engine. The airplane was a four-place high wing configuration, with tricycle-style landing gear. Pitts (N15TA) The Pitts was manufactured in 2001, and was equipped with a Lycoming AEIO-540 series engine. The airplane was a two-place, tandem cockpit, biplane configuration, with conventional-style landing gear. The configuration of this airplane limited the forward visibility of the flight crew when the airplane was in the taxi attitude. WRECKAGE AND IMPACT INFORMATIONThe collision occurred immediately south of the holding position marking on taxiway G, south of runway 25L. Both airplanes were on the taxiway centerline, facing south, and the Pitts taxied directly into the empennage of the Cessna. The propeller of the Pitts made multiple contacts and cuts in the Cessna's rudder, fin, elevator, and horizontal stabilizer, which resulted in substantial damage to the Cessna. ADDITIONAL INFORMATIONFAA Guidance to Pilots re Taxiing at Tower-Controlled Airports Relevant FAA guidance regarding the responsibility of the Pitts crew to avoid the collision was contained in the Aeronautical Information Manual (AIM). Section 4-3-18 ("Taxiing"), paragraph b, stated that "clearances or instructions pertaining to taxiing are predicated on known traffic and known physical airport conditions. .... Although an ATC clearance is issued for taxiing purposes, when operating in accordance with the CFRs, it is the responsibility of the pilot to avoid collision with other aircraft." FAA System Service Review (SSR) On November 12, 2013, the FAA conducted a formal System Service Review (SSR) of the ATCT, and identified "many lapses in overall performance," including: - While scanning was conducted by Local Control, discussion with Ground Control did not occur to determine the intentions of the Cessna on taxiway Golf prior to issuing instructions for the Pitts to cross runway 25L on taxiway Golf. - The CPC-IT did not scan the entire movement area and did not observe N698SP on taxiway Golf or Pitts N15TA holding between the runways on taxiway Golf. - Crew Resource Management [between local control and ground control] was not employed properly. . - Traffic was not issued in accordance with JO 7110.65, paragraph 3-1-6. - Ground control traffic volume was greater than the CPC-IT's ability - Use of tower team resources: assistance was not requested from the CIC to record and broadcast the ATIS. In addition, actions should have been taken to assist Ground Control. - The OJTI or CIC did not take proactive steps when the CPC-IT fell behind. - The Accident Checklist was not followed nor were required accident forms completed. - During a brief period leading up to the accident, the tower team situational awareness was not maintained. The SSR concluded that "In summary, team breakdowns in communication and coordination were identified as primary reasons for the accident" but "determined that this was an isolated event. There were no other known situations or records where a tail-dragger and another fixed-wing aircraft collided with one another on the movement area." The FAA citation of "an isolated event" refers specifically to the collision, and not the conditions and circumstances that led to the collision. The Pitts instructor reported that nine days after that accident, while instructing in another taildragger at LVK, the accident circumstances were essentially duplicated; his airplane was cleared to cross a runway when there was another airplane in their path on the opposite side of the runway. Although the instructor's pilot accepted the clearance, the instructor over-rode him, and likely prevented a collision. COMMUNICATIONSATCT Staffing and Positions LVK was equipped with an air traffic control tower that was operated and staffed by FAA personnel. At the time of the accident, the ATCT was operating, and both airplanes were communicating with and being controlled by LVK ATCT controllers. At the time of the accident, the ATCT cab was staffed by four persons serving three positions, including two positions of operation. They included a controller in charge (CIC), and the two positions of operation of local control (LC), and combined ground control/clearance delivery (GC/CD). One person each served the CIC and LC positions, and the GC position was staffed by two persons; a full performance level (FPL) controller designated as the "OJTI" (on the job training instructor) and a controller in training (designated CPC-IT). The CPC-IT was actively performing the GC duties and communications, and was being overseen by the GC OJTI. Unless otherwise noted, all references to "GC" communications are from or to the CPC-IT. Review of the LVK ATCT facility operation logs revealed the following duty and position time-related information for the controllers. At the time of the accident: The GC OJTI came on duty at least 03:12 (hours:minutes) prior, and most recently resumed that position 00:15 prior. The minimum duration between the GC OJTI's earliest position sign-on and latest sign-off on that day was 10:09. The LC came on duty at least 06:00 prior, and most recently resumed that position 00:19 prior. The minimum duration between the LC's earliest position sign-on and latest sign-off on that day was 09:53. The CIC came on duty at least 07:10 prior, and most recently resumed that position 00:41 prior. The minimum duration between the CIC's earliest position sign-on and latest sign-off on that day was 11:57. The duty times for the CPC-IT were not provided for the investigation. ATCT Equipment and Orientation The ATCT cab was equipped with four controller stations, designated positions 1 through 4. Position 1 did not have the ability to transmit, and the Position 4 training jack was out of service. The equipment outages were repaired subsequent to the accident. The CIC was plugged into Position 1 wearing a headset. The LC1 and LC 2 duties were combined at Position 2. The GC and FD duties were combined at Position 3 due to the training jack at Position 4 being out of service. Position 4 is the normal GC/FD location. The CIC was monitoring the LC, who was at Position 2. The CIC cannot monitor more than one position at the same time. The ATCT cab was hexagonal, with the four positions situated along three of the sides. Position 3, which was manned by the GC OJTI and CPC-IT, was located on the hex side that faced directly towards the runways (south). The hex side to the right (southeast) contained Positions 1 and 2, staffed respectively by the CIC and the LC. Those positions faced away from the accident location. Unoccupied Position 4 was on the hex side to the left (southwest) of Position 3, and was the ATCT position that most directly faced the accident location. ATCT Positional Responsibilities and Actions FAA Order LVK TWR 7210.9G, issued July 2013 designated the "standard operating responsibilities to specific positions of operation," as well as the sequence for combining those positions as a function of the number of available controllers. The Order stated that the "front line manager/controller-in-charge" had the authority to combine the positions. The Order provided specific information for staffing levels of from one to three controllers. The Order specified that when two controllers were available, the positions of LC1 and GC would be opened, and those positions would assume the duties of LC2 and FD, respectively. At the time of the accident, the ATCT operation was using two controllers, and was in compliance with that portion of the Order. Paragraph 5 b (2) stated that one GC responsibility was to maintain "a close observation of all airport traffic and remains alert to circumstances affecting the movement area." The portion of taxiway G south of runway 7R/25L was the responsibility of the GC. Paragraph 5 c (1) of the Order stated that the LC was "on a permanent basis, delegated control of the portions of taxiway C and G between" the two parallel runways. FAA Order 7110.65, "Air Traffic Control," paragraph 2-1-1 (ATC Service) stated that the "primary purpose of the ATC system is to prevent a collision between aircraft operating in the system and to organize and expedite the flow of traffic." Paragraph 2-1-2 (Duty Priority) stated that controllers were to "Give first priority to separating aircraft and issuing safety alerts." That guidance also contained an explanatory "NOTE" that stated that "controllers must exercise their best judgment based on the facts and circumstances known to them" when prioritizing their actions. Paragraph 2-10-3c (Tower Team Position Responsibilities) delineated the primary responsibilities of the tower team positions. That paragraph stated that GC and LC were to "ensure separation, initiate control instructions, scan tower cab environment, and perform any functions of the tower team, which will assist in meeting situation objectives." Paragraph 3-1-4 (Coordination between Local and Ground Controllers) stated that "Local and ground controllers must exchange information as necessary for the safe and efficient use of airport runways and movement areas." The investigation did not obtain any evidence that the LC or the GC either initiated or coordinated information about the positions or movements of the Pitts and the Cessna with each other. Paragraph 3-1-6 (Traffic Information) required controllers to. "Describe vehicles, equipment, or personnel on or near the movement area in a manner which will assist pilots in recognizing them," and to "Describe the relative position of traffic in an easy to understand manner." When the LC instructed the Pitts to cross runway 25L on taxiway G, he did not provide a traffic advisory regarding the Cessna that was stopped on taxiway G just south of 25L. The Cessna was directly in the path of the Pitts, and was stopped in the location that the Pitts was cleared to. FAA Order 7210.3Y, "Facility Operation a
Failure of the pilots of the Pitts airplane to maneuver the airplane as necessary to observe the taxi route and avoid the Cessna airplane ahead. Contributing to the accident was the local controller's failure to provide the required warning of traffic ahead to the pilots of the Pitts airplane when clearing the Pitts to taxi.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
