DEHAVILLAND DHC-3General Communication Corporation (GCI)

Figure 1 – Weather camera positions with approximate viewing directions (blue arrows). Length of arrows do not indicate distance viewable from camera images in any conditions.Figure 2 – A clear day image from the Dillingham North-facing camera.Figure 3 – Dillingham North-facing camera. Image taken at 1402 ADT.Figure 4 – Dillingham North-facing camera. Image taken at 1412 ADT.Figure 5 – Dillingham North-facing camera. Image taken at 1421 ADT.Figure 6 – Dillingham North-facing camera. Image taken at 1431 ADT.Figure 7 – Dillingham North-facing camera. Image taken at 1442 ADT.Figure 8 – Dillingham North-facing camera. Image taken at 1452 ADT.Figure 9 – A clear day image from the Dillingham Northeast-facing camera.Figure 10 – Dillingham Northeast-facing camera. Image taken at 1400 ADT.Figure 11 – Dillingham Northeast-facing camera. Image taken at 1410 ADT.Figure 12 – Dillingham Northeast-facing camera. Image taken at 1420 ADT.Figure 13 – Dillingham Northeast-facing camera. Image taken at 1430 ADT.Figure 14 – Dillingham Northeast-facing camera. Image taken at 1440 ADT.Figure 15 – Dillingham Northeast-facing camera. Image taken at 1450 ADT.Figure 16 – Dillingham Northeast-facing camera. Image taken at 1500 ADT.Figure 17 – A clear day image from the Dillingham South-facing camera.Figure 18 – Dillingham South-facing camera. Image taken at 1357 ADT.Figure 19 – Dillingham South-facing camera. Image taken at 1408 ADT.Figure 20 – Dillingham South-facing camera. Image taken at 1418 ADT.Figure 21 – Dillingham South-facing camera. Image taken at 1428 ADT.Figure 22 – Dillingham South-facing camera. Image taken at 1438 ADT.Figure 23 – Dillingham South-facing camera. Image taken at 1448 ADT.Figure 24 – Dillingham South-facing camera. Image taken at 1458 ADT.Figure 25 – A clear day image from the Dillingham Southwest-facing camera.Figure 26 – Dillingham Southwest-facing camera. Image taken at 1354 ADT.Figure 27 – Dillingham Southwest-facing camera. Image taken at 1404 ADT.Figure 28 – Dillingham Southwest-facing camera. Image taken at 1414 ADT.Figure 29 – Dillingham Southwest-facing camera. Image taken at 1424 ADT.Figure 30 – Dillingham Southwest-facing camera. Image taken at 1434 ADT.Figure 31– Dillingham Southwest-facing camera. Image taken at 1444 ADT. — page 32 of 53Figure 32 – Dillingham Southwest-facing camera. Image taken at 1454 ADT.Figure 33 – Dillingham Southwest-facing camera. Image taken at 1504 ADT.Figure 34 – A clear day image from the New Stuyahok North-facing camera.Figure 35 – New Stuyahok North-facing camera. Image taken at 1350 ADT.Figure 36 – New Stuyahok North-facing camera. Image taken at 1400 ADT.Figure 37 – New Stuyahok North-facing camera. Image taken at 1410 ADT.Figure 38 – New Stuyahok North-facing camera. Image taken at 1420 ADT.Figure 39 – New Stuyahok North-facing camera. Image taken at 1430 ADT.Figure 40 – New Stuyahok North-facing camera. Image taken at 1440 ADT.Figure 41 – New Stuyahok North-facing camera. Image taken at 1450 ADT.Figure 42 – New Stuyahok North-facing camera. Image taken at 1500 ADT.Figure 43 – A clear day image from the New Stuyahok Southwest-facing camera.Figure 44 – New Stuyahok Southwest-facing camera. Image taken at 1356 ADT.Figure 45 – New Stuyahok Southwest-facing camera. Image taken at 1406 ADT.Figure 46 – New Stuyahok Southwest-facing camera. Image taken at 1415 ADT.Figure 47 – New Stuyahok Southwest-facing camera. Image taken at 1426 ADT.Figure 48 – New Stuyahok Southwest-facing camera. Image taken at 1436 ADT.Figure 49 – New Stuyahok Southwest-facing camera. Image taken at 1446 ADT.Figure 50 – New Stuyahok Southwest-facing camera. Image taken at 1456 ADT.Figure 51 – A near-clear day image from the Lake Aleknagik camera.Figure 52 – Lake Aleknagik camera. Image taken at 1425 ADT.Passenger #4 stated that he and other guests had lunch at about 1300 local time — page 8 of 24Figure 1. The face of the vertical speed indicator received for examination.Figure 2. The airspeed indicator received for examination (left) and an internal view (right). (left)Figure 2. The airspeed indicator received for examination (left) and an internal view (right). (right)Figure 3. The dial of the airspeed indicator (left) and a closer view in the vicinity of the yellow arrow (right). (left)Figure 3. The dial of the airspeed indicator (left) and a closer view in the vicinity of the yellow arrow (right). (right)Figure 4. The face of the attitude gyro (left) and the gyro partially disassembled (right). (left)Figure 4. The face of the attitude gyro (left) and the gyro partially disassembled (right). (right)Figure 5. The face of the attitude indicator (left) and the indicator partially disassembled (right). (left)Figure 5. The face of the attitude indicator (left) and the indicator partially disassembled (right). (right)Figure 6. The twisted arm at the rear end of the caging rod assembly.Figure 7. Markings on the inner surface of the rotor housing (left) and a closer view (right). (left)Figure 7. Markings on the inner surface of the rotor housing (left) and a closer view (right). (right)Figure 8. The display of the terrain awareness annunciator (left) and with the fascia plate removed (right). (left)Figure 8. The display of the terrain awareness annunciator (left) and with the fascia plate removed (right). (right)Figure 9. The circuit board and bulbs in the terrain awareness annunciator (left) and a typical bulb filament, except for the “TERR INHB” bulbs below, (right). (left)Figure 9. The circuit board and bulbs in the terrain awareness annunciator (left) and a typical bulb filament, except for the “TERR INHB” bulbs below, (right). (right)Figure 10. “TERR INHB” bulb filaments “TI-1” (left) and “TI-2” (right). (left)Figure 10. “TERR INHB” bulb filaments “TI-1” (left) and “TI-2” (right). (right)Figure 11. “TERR INHB” bulb filaments “TI-3” (left) and “TI-4” (right). (left)Figure 11. “TERR INHB” bulb filaments “TI-3” (left) and “TI-4” (right). (right)Figure 13. An inner surface of the terrain-inhibit switch fascia (left) and the normally adjacent side of the button (right). (left)Figure 13. An inner surface of the terrain-inhibit switch fascia (left) and the normally adjacent side of the button (right). (right)Figure 14. The inner surface of the terrain-inhibit switch fascia (left) opposite to the surface illustrated in Figure 10 and the normally adjacent side of the button (right). (left)Figure 14. The inner surface of the terrain-inhibit switch fascia (left) opposite to the surface illustrated in Figure 10 and the normally adjacent side of the button (right). (right)Figure 1. Image of a DHC-3 Otter with registration marking IM1708 in India. The caption states ”A DHC-3 Otter [IM1708] lies parked at Palam AFS. Circa late 1950s. These aircraft entered service with the IAF in 1956 and the last of the type Figure 2. A caption states that “This Otter is about to receive the Texas Turbine conversion. It will return to its home base in Alaska.” Source: http://www.airliners.net/photo/Wood-River-Lodge/De-Havilland- Canada/0799124/L/&sid=423c1551afFigure 3: Photo dated February 13, 2005, captioned “This Otter, named "Big Red" has come to Kal Air Repair to be converted to the Texas Turbine engine, then it will return to Alaska.” Source: http://jetphotos.net/viewphoto.php?id=436236&nseFigure 4: Photo dated April 29, 2005, captioned “s/n 206. The Texas Turbine Conversion has just been completed at Kal Air Repair. Quite a difference in appearance as well as performance.” Source: http://jetphotos.net/viewphoto.php?id=465705Figure 1. N455A on western slope of Muklung Hills with an unnamed peak at top of the photo. The pass between the Muklung Hills and the unnamed peak is slightly more than a mile wide. The site was to the left (east) of a pass between the MukFigure 2. View across tundra toward the accident site and the pass of more than a mile in width. The arrow in the upper left points to the approximate location of the accident site. The arrow at the right is placed on the Muklung River and Figure 3. The large white arrow shows the body of water that the airplane came from, named Lake Nerka. The nearest end of the lake is slightly less than 9 miles away. The GCI Lodge would be off the left edge of the photo, and reachable by fFigure 4. Airplane wreckage on hillside, with arrow at upper left pointing at Lake Nerka, to align with Figure 3.Figure 5. The HRM fish camp is to the lower right of the area shown on this portion of an aviation sectional chart. The thin dashed line depicts the western ridgeline of the Muklung Hills, visible in Figure 4. The short red arrow shows the Figure 6. Left side of N455A ventral fin, showing impact marks on leading edge (left edge of what is visible).Figure 7. Pre-accident view of the N455A airplane to show the height of the ventral fin above the rear float spreader bar.Figures 8. Pre-accident view of the N455A airplane to show the height of the ventral fin above the rear float spreader bar. Note the extended flaps and nose above cruise attitude. Using photographs of another Turbine Otter at the DillinghamFigures 8. Pre-accident view of the N455A airplane to show the height of the ventral fin above the rear float spreader bar. Note the extended flaps and nose above cruise attitude. Using photographs of another Turbine Otter at the DillinghamFigure 10. From directly behind the airplane, the small red arrow at the bottom of the photo shows where the first piece of airplane (ventral fin) was found. The white arrows point to the imprints of the floats, the left being the first groFigure 11. The above figure shows bank angle damage measurements. The float photo is cropped from Figure 13.Figure 12. Damage found on bottom of left float, with illustration showing a 30 degree reference line. The heaviest damage is between 15 and 20 degrees pitch, with keel twist extending to about 25 degrees nose up.Figure 13. Left float, showing crush from front.Figure 14. Left float from the left, resting on the crush line The upward deformation to the right float was limited to the forward portion of the bottom surface, in the immediate area of the nose tire. The nose bulkhead of the right float Figure 15. Forward features of the right float. The left float is behind the right float, illustrating the difference in extent of crush damage to the bottom surfaces. Otherwise the float was significantly less damaged and the water rudder Figure 16. Right float appears to be relatively intact when compared to the bottom of the left float (behind the right float).Figure 17. View showing the main fuselage break, across the cockpit to floor level.Figure 18. Modified weight and balance diagram shows configuration of canted bulkhead (A) that carries the forward float attachment fitting, fuel cells (B) seats, mid bulkhead (C) that carries the lift strut fitting, aft bulkhead (D) that cFigure 19. Bottom of fuselage when picked up with forklift, showing the lack of structural integrity. Also visible are: (A) Copilot’s seat bottom, (B) twisted bottom edge of cockpit/cabin bulkhead, (C) Right forward landing gear attachment Figure 20. Damage to left side of the cabin. Arrows point to the approximate displacement of the left float fittings. The aft edge of the cockpit door is normally vertical (above long arrow) and the crush aft of it is how far aft the cockpiFigure 21. Damage to the right side of the cabin. The forward right float fitting was displaced upward and aft (See A), similar to the left fitting, before falling to where indicated by the dashed arrow. (Origin point of solid arrow is apprFigure 22. Prior to recovery. The left wall of the cabin can be seen displaced inward, as looking aft from the cockpit.Figure 23. View from aft of cabin to show disruptions to the left cabin side wall and floor prior to recovery. Figure 22 showing the same features from the other end of the cabin was photographed from the where green foliage can be seen at Figure 24. After recovery and removal of loose items. The right cabin wall displacement and buckling of floor, as looking forward toward the cockpit/cabin bulkhead. See section pertaining to seats for seat numbering and damage descriptions.Figure 25. The upper surface of the left wing and bottom of the right wing, shown respectively from the tip ends. The arrow placed on the right wing shows where a broken control rod was found. Both forward wing spar fittings had broken at tFigure 26. Extensive component and structural damage at the fuselage breach near the flap actuator and control quadrant above what had been the cabin ceiling.Figure 27A. Aft view of airplane, showing tail control surfaces, including trim. The right float is beneath the right side of the fuselage with the keel toward the camera. In the tail of the accident airplane, the horizontal stabilizer posiFigure 27B. Left side of horizontal stabilizer that is shown in Figure 27A, showing closeup of trim setting found.Figure 28. Safety information card found in a seat pocket shows cockpit and cabin arrangements, with approximate relation of seat positions to the windows and doors. The seats are removable and may be omitted from positions shown.Figure 29. Interior of similar Turbine DHC-3 (N361TT) that was modified by Texas Turbines, with minor trim differences.Figure 30. Captain seat pan after cushion removal. The back of the captain's seat was built from bent steel tube with aluminum attachments to each aft corner of the pan. The base of the seatback had broken free of the pan at the inboard/lefFigure 31. Right side of the captain’s seat pan and the area beneath it. Aft is to the left. Visible between the seat pan and floor is a can of CRC spray cleaner, tools, and a water bottle.Figure 32. Cleaning materials, tool, and other items seen beneath the captain’s seat of another Turbine Otter. Note that Figure 31 is a photograph from the area from the other side of the seat.Figure 33. Copilot seat, showing the fractured and missing portions of the seat pan. Seat 3 - forward-most on the left in the cabin. This seat had been above the forward left float fitting and was found up and inward from the original locatFigure 34. Seat #3, the forward most left cabin position, showing absence of floor structure and upward deformation beneath the seat. Seat 4 - forward-most on the right in the cabin. This seat had been above the right forward float attachmeFigure 35. Seat #4, the forward most right cabin position, showing absence of floor structure and upward deformation beneath the seat. Seat 5 - second row on the left in the cabin.Figure 36. Seat #5, this was the second cabin seat on the left and the photo shows absence of floor structure. Seat #7 had been aft of this seat and fell away during recovery. Seat 6 - second row on the right in the cabin. The seat back hadFigure 36. Seat #5, this was the second cabin seat on the left and the photo shows absence of floor structure. Seat #7 had been aft of this seat and fell away during recovery. Seat 6 - second row on the right in the cabin. The seat back hadFigure 38. Photo taken prior to recovery shows branch (lower left corner of photo) penetrating up from cabin floor and through area of aft outboard hinge for seat #7. Seat 8 - third row on the right in the cabin. The seat back had been rippFigure 39. Fragments of seat #9. The arrow points to the broken structure that seat #11 had been attached to. Seats 10 and 11 - aft of the cabin doors. Both seats were collections of fractured tubing. The attachment points for the seatbeltsFigure 40. Aft of cabin with seat fragments, prior to recovery.Figure 41. Aft of cabin, prior to recovery, showing enough seat fragments to account for seats 10 and 11, aft of the cabin doors.Figure 42A. Cockpit, as viewed from above right wing root.Figure 42B. Closer view of the instrument panel as initially found. Closer examination of the control yokes shown in Figure 42A revealed more of both generalized and localized damage to the yoke on the captain’s side. The left handle was foFigure 42C. A cockpit photo that has been magnified and cropped to show the control yokes. No records were found to indicate that the airplane had approval for flight in instrument meteorological conditions. The physical instrumentation andFigure 43. Instrument panel about five years prior to the accident, as provided by the company that modified the airplane (TexasTurbines). Hidden behind the captain’s yokeFigure 44. Primary flight instruments, after wiping away some of the mud that is visible in Figure 42B. The altimeter setting was between 29.51 and 29.52 and the displayed altitude was slightly less than 200 feet. During and after removal, Figure 45. Engine related switches and engine instruments.Figure 46. Electrical subpanel. The lower switch area of the forward instrument panel had a soft body impact that was located forward of where the captain's right knee would have been. Switches found in the ON positions were marked for EngiFigure 49. Log page 1016Figure 47. Log page 1017Figure 48. Log page 1018Figure 49. Log page 1019Figure 50. Log page 1020Figure 51. Log page 1021Figure 52. Radar altimeter setting when found was at 275 feet, after wiping away some mud visible in Figure 42B. Upon descending through the DH, the design provided for both visual and aural annunciations. The visual annunciation was a yellFigure 55. Stretched decision Height (DH) filament from the radio altimeter.Figure 56. Map display when power was first applied. Note the display of 35 nautical mile range.Figure 57. The NAV page #1 display of position, after first application of power. TheFigure 58. Initial display of TAWS information.Figure 59. GNS-530 satellite positional display at initial power application. Pressing the MSG button beneath the bottom of the screen revealed the following text: No altitude input is being received Not receiving input data on 429 Channel Figure 60. Stored waypoints and routes from the Garmin GNS-530, along with Sky Connect data, are shown for the area of Lakes Nerka and Aleknagik.Figure 61. Illustrations from Garmin Pilot’s Guide.Figure 62. Illustrations from Garmin Pilot’s Guide.Figure 63. Illustration from Garmin Pilot’s Guide.Figure 66. This was the TAWS display shown by the Garmin GNS-530 at a test input altitude of 1080 feet msl. Providing altitude was the only difference between this and the displays shown as Figures 57 and 58. The route to the fish camp woulFigure . Figure 67. This was shown when the Figure 60 TAWS display was changed — page 67 of 83Figure 68. Mid-Continent illustration of the TAWS inhibit pushbutton switch.Figure 69. Position of finding the TAWS inhibit pushbutton switch depressed (inhibited position), after clearing away mud that covered the portion of the panel.Figure 70. Empty ELT bracket in tail cone. The hook and loop fastening strap closed. To the left is forward in the airplane. The arrow points to the broken antenna connection. Examination of an identical plastic mount for the ELT on the lefFigure 71. ELT in another Otter, showing gap between the ELT and mount that was created by finger tension. Forward is to the right.Figure 72. Engine after the cowling was removed The oil filter bypass valve was found in the normal (not extended) position. (See Figure 73)Figure 73. Oil Filter By Pass ValveFigure 74. Dirt found in engine inletFigure 75. Damage to the first-stage compressor impeller. All engine mount structures, gearbox and aft, were intact and all mount bolt nuts were secured with cotter pins. All wiring harness connectors were removed along with all lines and tFigure 76. Engine exhaust area and third-stage turbine wheel.Figure 77. Propeller beta tube position Three of the four Hartzell propeller blades were visible and these blades were found attached to the hub. The location for a fourth blade in the hub was downward and could not be seen while on site. AFigure 78. Bending in Propeller Blade, with leading edge toward camera.Figure 79. Propeller blade tip damage. The third blade was bent back but still visible, located underneath the engine nacelle area. There was an area of damage along the trailing edge of the blade, slightly inboard from the tip that was “cuFigure 80. Trailing edge damage to propeller blade. The area of the propeller identification, i.e. serial number and part number, was not accessed. To do so would have required removal of the propeller spinner. The spinner was left in placeFigure 1. The two pieces of the flaperon rod received for examination.Figure 2. A closer view of the fractured end of the flaperon rod.Figure 3. The opposing side of the flaperon rod and clevis illustrated in Figure 1.Figure 4. A closer view of the rub mark contained within the yellow box in Figure 3.Figure 5. The tube fracture face indicated by the purple arrow in Figure 1 (left) and the rod-end fracture face indicated by the yellow arrow in Figure 1 (right).Figure 6. The rod-end fracture face.Figure 1. The altimeter as found at the accident scene.Figure 2. The altimeter as received for examination.Figure 3. The altimeter immediately prior to the examination.Figure 4. The altimeter dial after removal of the glass covers.Figure 5. White marks observed to the left of the 10,000ft flag (left) and a closer view of the marks (right). (left)Figure 5. White marks observed to the left of the 10,000ft flag (left) and a closer view of the marks (right). (right)Figure 6. The inverted 100ft needle centered adjacent to the 10,000ft flag.Figure 7. The scratches on the underside of the 100ft needle (left) and a closer view of the edge indicated by the blue arrow (right). (left)Figure 7. The scratches on the underside of the 100ft needle (left) and a closer view of the edge indicated by the blue arrow (right). (right)Figure 8. The underside of the 100ft needle (center) and closer views of the areas contained in the red (left) and yellow (right) boxes. (1 of 3)Figure 8. The underside of the 100ft needle (center) and closer views of the areas contained in the red (left) and yellow (right) boxes. (2 of 3)Figure 8. The underside of the 100ft needle (center) and closer views of the areas contained in the red (left) and yellow (right) boxes. (3 of 3)Photograph 1. Artex ME406 ELT in mounting tray, secured by Velcro strap.Photograph 2. ELT tray mounted on sidewall of accident airplane.Figure 1 ‐ Satellite Map of Operational AreaAirworthiness Group Chairman's Factual Addendum for Weight and Balance with 13 embedded photos — page 5 of 21Airworthiness Group Chairman's Factual Addendum for Weight and Balance with 13 embedded photos — page 7 of 21Airworthiness Group Chairman's Factual Addendum for Weight and Balance with 13 embedded photos — page 8 of 21Airworthiness Group Chairman's Factual Addendum for Weight and Balance with 13 embedded photos — page 10 of 21Airworthiness Group Chairman's Factual Addendum for Weight and Balance with 13 embedded photos — page 12 of 21Airworthiness Group Chairman's Factual Addendum for Weight and Balance with 13 embedded photos — page 13 of 21Airworthiness Group Chairman's Factual Addendum for Weight and Balance with 13 embedded photos — page 14 of 21Airworthiness Group Chairman's Factual Addendum for Weight and Balance with 13 embedded photos — page 15 of 21Airworthiness Group Chairman's Factual Addendum for Weight and Balance with 13 embedded photos — page 16 of 21Airworthiness Group Chairman's Factual Addendum for Weight and Balance with 13 embedded photos — page 17 of 21Airworthiness Group Chairman's Factual Addendum for Weight and Balance with 13 embedded photos — page 18 of 21Airworthiness Group Chairman's Factual Addendum for Weight and Balance with 13 embedded photos — page 20 of 21Airworthiness Group Chairman's Factual Addendum for Weight and Balance with 13 embedded photos — page 21 of 21

Photographs are NTSB docket attachments — works of the US government, in the public domain. Captions are the Board’s own.

• A-10-169Closed - ReconsideredCLASS IIletter ↗

  TO THE FEDERAL AVIATION ADMINISTRATION: Require a detailed inspection, during annual inspections, of all emergency locator transmitters installed in general aviation aircraft to ensure that the emergency locator transmitters are mounted and retained in accordance with the manufacturer’s specifications.

• A-10-170Closed - Acceptable ActionCLASS IIletter ↗

  TO THE FEDERAL AVIATION ADMINISTRATION: Determine if the emergency locator transmitter (ELT) mounting requirements and retention tests specified by Technical Standard Order (TSO) C91a and TSO C126 are adequate to assess retention capabilities in ELT designs. Based on the results of this determination, revise, as necessary, TSO requirements to ensure proper retention of ELTs during airplane accidents.

• A-11-048Closed - Acceptable ActionCLASS IIletter ↗

  TO THE FEDERAL AVIATION ADMINISTRATION: Consult with appropriate specialists and revise the current internal Federal Aviation Administration guidance on issuance of medical certification subsequent to ischemic stroke or intracerebral hemorrhage to ensure that it is clear and that it includes specific requirements for a neuropsychological evaluation and the appropriate assessment of the risk of recurrence or other adverse consequences subsequent to such events.

• A-11-049Closed - Acceptable ActionCLASS IIletter ↗

  TO THE FEDERAL AVIATION ADMINISTRATION: Correct the deficiencies with the in-service automated weather sensor system (AWSS) stations, specifically the known problems with present weather sensors and ceilometers, to ensure that the AWSS stations provide accurate information as soon as practical.

• A-11-050Closed - Unacceptable ActionCLASS IIletter ↗

  TO THE FEDERAL AVIATION ADMINISTRATION: Implement a collaborative test program in Alaska among the Federal Aviation Administration, the National Weather Service (NWS), the local academic community, and private entities to establish the viability of relaying weather information collected from airborne aircraft equipped with existing data-link technology, such as universal access transceivers, to the NWS Alaska Aviation Weather Unit in real-time.

• A-11-051Closed - Unacceptable ActionCLASS IIletter ↗

  TO THE FEDERAL AVIATION ADMINISTRATION: If the Federal Aviation Administration’s test program recommended in Safety Recommendation A-11-50 establishes that the use of existing data-link technology, such as universal access transceivers, is a viable means of relaying collected information in real-time from an airborne platform, encourage and provide incentives to data link-equipped aircraft operators in Alaska to outfit their aircraft with weather-sensing equipment for real-time data relay.

• A-11-052Closed - Exceeds Recommended ActionCLASS IIletter ↗

  TO THE AIRCRAFT OWNERS AND PILOTS ASSOCIATION: Educate pilots of 14 Code of Federal Regulations Part 91 flight operations about the benefits of notifying passengers about the location and operation of survival and emergency communication equipment on board their airplanes