ANC05FA008

The private certificated pilot of a float-equipped airplane was the second of two, unrelated Piper airplanes that requested a special VFR (SVFR) clearance from a seaplane base within 1 minute of each other, for a local flight over an ocean inlet that was about 2.3 nautical miles wide. The weather conditions at the airport included overcast skies at 400 feet, and a visibility of 2 miles in mist. About 2 minutes after departure, the accident pilot requested to return to the seaplane base, stating in part, "it's really thick out here." No further communication was received from the pilot. The pilot of the first Piper airplane to depart also decided to return, and spotted the tail of the accident Piper protruding from the water about mid-channel of the inlet. The first Piper pilot notified air traffic control (ATC) of the situation, and then landed on the water to render any assistance. The first Piper was not equipped with any position locating equipment, consequently, the accident location was an estimate by the pilot. The accident Piper sank within about 2 minutes, and no survivor was observed. The accident pilot and the airplane have not been found. A witness located on the shore of the inlet saw the accident Piper appear from the base of a fog bank that was over the inlet. The airplane descended out of the fog about 100 feet above the water in a left bank of about 45 degrees, and about 20 degrees nose down. The airplane descended until it collided with the water about mid-channel, impacting the water with the left wing first, and immediately began to sink. Water search efforts were initiated that involved the use of a 2-crew hovercraft, a Coast Guard rigid-hull inflatable boat (RIB), a fire department rescue RIB, a commercial tug, and a volunteer underwater mapping vessel. The use of helicopters was unsuccessful because of low ceilings and low visibility. The search for the accident pilot and airplane was suspended by the fire department about 1.5 hours after the accident.

History of flight

On October 15, 2004, about 1406 Alaska daylight time, a float-equipped Piper PA-18 airplane, N4126E, was destroyed when it collided with the ocean waters of Knik Arm and sank, about 1.6 nautical miles north of the southern shoreline bordering Anchorage, Alaska. The airplane was being operated as a visual flight rules (VFR) local area personal flight under Title 14, CFR Part 91, when the accident occurred. The airplane was operated by the pilot. The private certificated pilot, the sole occupant, is presumed to have received fatal injuries. Neither the airplane or the pilot have been located or recovered. Instrument meteorological conditions prevailed in the Class D surface area of the accident. The flight originated at the Lake Hood Seaplane Base, Anchorage, about 1403. No flight plan was filed, nor was one required.

The accident airplane was one of two, unrelated float-equipped Piper PA-18 airplanes that departed Lake Hood Seaplane Base within 1 minute of each other for local flights northbound across the Knik Arm of Cook Inlet. This route of flight is commonly used by light aircraft departing the Class D Airspace that encompasses the Lake Hood Seaplane Base. The weather at the time of departure was below VFR minimums. The first Piper airplane to depart Lake Hood, N40463, requested a special VFR (SVFR) clearance for a northbound departure. The departure route utilizes Point Mackenzie, or the hull of a boat located west of Point Mackenzie on the north shore of the Knik Arm, as a VFR reporting point. The distance between the north and south shorelines of the Knik Arm, between Point Mackenzie and Anchorage, is about 2.3 nautical miles. About 1 minute after the first request, the accident Piper airplane pilot made a similar request for a northbound SVFR clearance.

About 1351, the first Piper was given SVFR clearance for a north departure by the Lake Hood Air Traffic Control Tower (ATCT) controller. About 1352, the pilot of the accident Piper contacted the Lake Hood ATCT and requested a SVFR departure, and was subsequently given the clearance: "26E, begin a taxi along the west shoreline for a north departure. Cleared out of the Lake Hood Tower Delta surface area north of Lake Hood Tower via the north shore departure. Maintain special VFR conditions at or below 1,100 feet. Departure frequency, 119.1, squawk 0122."

At 1402:14, the first Piper was cleared for takeoff. The Lake Hood ATCT controller inquired from the pilot of accident Piper if he could maintain visual separation from the departing first Piper, and the accident pilot replied "...Yes I can." At 1403:04 the Lake Hood ATCT controller stated, "Piper 4126E maintain visual separation from the departing Piper, cleared for takeoff." At 1404:03, the Lake Hood ATCT controller advised the accident Piper to contact departure control, and at 1404:10, the controller stated: "and Piper 26E, not receiving your transponder, recycle it please." There was no response on the Lake Hood ATCT frequency from the pilot. At 1404:12, the accident Piper contacted the Anchorage Terminal Radar Approach Control (TRACON) north radar approach controller, followed by the first Piper at 1404:20, as both airplanes proceeded across the inlet toward Point Mackenzie. Neither airplane reported clear of the Class D airspace.

At 1405:16, the accident Piper contacted the TRACON controller and stated: "Piper 26E, I'm turning back, it's really thick out here." At 1405:21, the controller replied, "Piper 26E, I need you to hold outside the surface area and standby." There was no response from the pilot.

At 1405:48, the TRACON controller contacted the Lake Hood ATCT controller and reported: "That Piper, 26E called me, said it's too bad, he's coming back. Now he won't answer me so I don't know where he is."

At 1406:03, the first Piper contacted the TRACON controller and stated: "And departure, Cub 463, I'm also turning around, Point Mackenzie, headed back towards Lake Hood." The TRACON controller inquired if the first Piper had the accident Piper in-sight, to which the pilot replied, "negative, they were behind me, they were to keep me in sight." The controller asked if the first Piper could hold at Point Mackenzie, "for a few turns." The pilot replied, "I can hold along the south shore here. I'd prefer that I don't, I've got clear visibility of Lake Hood and the tower. I can maintain visual separation from that Cub." The TRACON controller inquired if the first Piper had visual sight of the accident Piper, to which the first Piper stated, "not at this time, but I can maintain visual separation from him."

At 1406:52, the first Piper stated to the TRACON controller, "Hold on Lake Hood, hold on. Departure, I gotta check something out here. Do you have, did you talk to the other Cub. Has tower talked to him."

The TRACON controller queried the Lake Hood controller, but no radio contact from the accident Piper was made with Lake Hood tower. Both controllers conferred about the location of both airplanes, and at 1407:11, the Lake Hood tower controller told the TRACON controller, "Alright, let me see if I can, I got, looks like I got something showing up right at mid-channel, but that may be something off Anchorage."

The controller then stated, "Piper 26E, Lake Hood tower." There was no reply. At 1407:38, the Lake Hood tower controller established visual contact with the first Piper as the airplane flew along the south shoreline of the inlet.

At 1408:03, the Lake Hood tower controller established radio contact with the first Piper and requested a position report. The pilot replied, "463 is landing in the inlet. Did you talk to that other Cub." The controller replied to the negative. At 1408:54, the first Piper informed the Lake Hood ATCT controller, "Okay, I have that Cub in sight. They are nose down in the inlet. I'm pulling up to them." The pilot reported his position as, "Directly midway between Point Mackenzie and Lake Hood," and then reported, "Okay, I see no, no people. The Cub is nose down, standby." The Lake Hood ATCT controller told the pilot that rescue personnel were being sent. At 1412:28, the first Piper reported, "Okay, that, that Cub has sank out of sight now. I'll stay here on the area."

The pilot of the first Piper reported to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) that there was an area of fog over the inlet with a base about 400 feet agl, but about mid-channel, the fog layer was about 200 feet. He said that the fog was not as thick further to the west, but was thicker to the east of his position. He indicated he descended below the fog and then began to climb to about 300 feet as he passed mid-channel. As he approached the north shore of the inlet, he said he could see that a thick fog bank was obscuring his destination, and he radioed to TRACON north radar that he was returning to Anchorage. He then proceeded southbound toward Anchorage, and about mid-channel, observed something on the surface of the water. He said that he recognized the tail of the accident Piper protruding vertically from the water. He made a northerly turn near the south shore of the inlet, and proceeded to land on the surface of the inlet and taxied to the accident Piper. He informed the air traffic controllers of the situation and looked for any occupants of the accident Piper. None were visible.

The first Piper pilot said that within about 2 minutes of his landing, the accident Piper sank. The first Piper was not equipped with global positioning system (GPS) equipment. The location, described by the pilot utilizing visually referenced geographic points, was mid-channel, about 2.6 nautical miles north of the Lake Hood Seaplane Base. The first Piper pilot provided the NTSB IIC with a map of the inlet, indicating his estimate of the accident location.

A witness was parked at Airport Park, a small p