HISTORY OF FLIGHT On October 24, 2008, about 1410 mountain standard time, an experimental Kitfox IV 1200, N427ET, and a Taylorcraft BL-65, N27639, collided while taxiing at the Glendale Municipal Airport, Glendale, Arizona. Both airplanes were owned and operated by their respective pilots. The Kitfox sustained minor damage, and the Taylorcraft was substantially damaged. Neither the airline transport certificated pilot in the Kitfox nor the private pilot in the Taylorcraft was injured. Visual meteorological conditions prevailed, and no flights plans were filed. Both airplanes were being operated under the provisions of 14 Code of Federal Regulations Part 91. The Kitfox pilot reported to the National Transportation Safety Board investigator that he was located in the right seat of his conventional gear airplane. The pilot reported that, while in the traffic pattern, he initially informed the local controller he desired to make a touch-and-go landing. Subsequently, he experienced a malfunction with his airspeed indicator. The pilot advised the controller of his airspeed problem, and he was immediately cleared to make a full stop landing. The accident occurred upon completing one circuit of the traffic pattern. According to the pilot and the local controller (as reported to the Safety Board investigator through the Federal Aviation Administration (FAA) coordinator), the pilot touched down on runway 19 pursuant to the air traffic clearance he had received. The airplane exited the runway in a southwesterly direction onto high speed taxiway A6, which terminates at the intersection of taxiway A. During the pilot's approach, landing, and rollout onto the taxiways, the pilot was monitoring the local control tower frequency. The pilot additionally reported that during the accident flight he did not receive any air traffic communication regarding issuance of a hold short instruction. Accordingly, the Kitfox initially decelerated on runway 19, and the airplane further decelerated on high speed taxiway A6. As the airplane rolled clear of taxiway A6 and entered the intersection of A6 and taxiway A, the Kitfox and Taylorcraft collided. (See the airport diagram for the runway and taxiway orientation, and the ingress/egress points between the taxiways.) The Taylorcraft pilot reported to the Safety Board investigator that he was located in the left seat of his conventional gear airplane. He was following the ground control clearance that he had received to taxi from his parked location (west of taxiway A, near midfield) and to proceed toward runway 19, via taxiway A. Accordingly, he was taxiing in a northerly direction toward the approach end of runway 19, where he planned to takeoff. The pilot stated that the ground controller neither directed him to hold his position, nor issued any communication to him regarding the approaching airplane that had been cleared to land on runway 19. In particular, the pilot indicated to the Safety Board investigator that the ground controller did not warn him that an airplane was taxiing toward him from his 1 to 2 o'clock position. The northbound Taylorcraft's right wing and lift struts were bent during the impact sequence with the propeller and engine cowl of the southwestbound Kitfox, which had just landed on runway 19 and was proceeding via taxiway A6 onto taxiway A. The collision occurred on taxiway A. Both pilots reported they did not observe the convergence between their conventional gear airplanes because of a combination of their respective seat positions and taxi paths. ADDITIONAL INFORMATION Airport Design The public-use municipal airport's ownership and operations personnel have the authority to design placement of the taxiways and intersections. The airport is designed in such a manner that airplanes landing on runway 19 may egress (near midfield) utilizing taxiway A6, which terminates at the intersection of taxiway A. Aircraft parked west of the runway, near midfield, whose pilots desire to taxi to runway 19, are directed by air traffic personnel to taxi to runway 19 via taxiway A. Using this route, northbound taxiing aircraft proceed nearly head-on to southwest bound aircraft, which are egressing from runway 19 via A6. Controller Visibility The FAA coordinator reported to the Safety Board investigator that he examined the visibility from the non-federal airport control tower's cab. According to the FAA coordinator, the local and ground controllers had the capability of viewing the landing and taxi paths taken by both airplanes. The accident airplanes were in visible movement areas during their operations and during their daytime collision near the intersection of taxiways A and A6. Air Traffic Controller Duties and Responsibilities Notwithstanding other higher priority duties, the air traffic controllers were responsible for monitoring the taxi paths taken by airplanes under their control, and for issuance of safety instructions to promote avoidance of ground collisions. The FAA coordinator reported to the Safety Board investigator that, after the local controller issued the Kitfox an appropriate landing clearance, the controller's attention was diverted to traffic duties associated with other airplanes near/in the downwind leg. After the ground controller issued the Taylorcraft an appropriate taxi clearance, the controller's attention was directed to issuing an instrument clearance to a waiting airplane. One or both of the controllers observed the converging airplanes seconds prior to the collision. Neither controller issued a safety alert to the airplanes. Pilot Responsibility and Procedures Neither pilot reported experiencing any mechanical malfunction or anomaly that affected the operation of their respective airplanes during ground operation. Pursuant to guidance provided in the FAA's "Aeronautical Information Manual" and the local controller's clearance, the Kitfox was authorized to taxi clear of the landing runway and proceed onto taxiway A, at which time the pilot was to contact the ground controller for any additional clearance. Pursuant to guidance provided in the FAA's "Aeronautical Information Manual" and the local controller's clearance, the Kitfox was authorized to taxi clear of the landing runway. This action was accomplished when his entire airplane proceeded beyond the hold line adjacent to taxiway A. Upon passing this hold line, the Kitfox was on taxiway A and was required to contact the (ground) controller for additional clearance. The Taylorcraft pilot was authorized to taxi to runway 19 pursuant to the clearance he had been issued. The FAA coordinator reported that, notwithstanding the pilots' respective clearances, each pilot still had a responsibility to operate their airplanes safely. Taxi Route and Procedure Changes Following the accident, air traffic control management personnel reported that they modified the taxi route in the vicinity of the accident area. The revision increased separation between taxiing and landing aircraft. Also, controllers received enhanced training on the issuance of taxi instructions to aircraft proceeding northbound on taxiway A, when other aircraft have been cleared to land on runway 19.