NTSB Preliminary Report Jim Tweto C-180H July 12, 2023

wind gusts can kill you especially in light aircraft particularly in light aircraft back country and Bush operations it is Wednesday June the 12th my name is Juan Brown you're watching The Blanco lyrio Channel and the preliminary NTSB report is out on the high profile case of what happened to Jim tweeto in his 1969 Cessna 180 near Shack to lick Alaska and it's apparent from this report the gym hit some trees while on departure from a downsloping Backcountry airstrip on a second run in Gusty wind conditions including decreasing performance wind shear let's check it out there are three photographs included in the report which I'll share with you now before we read the report here is one of the small trees that the 180 clipped that's about four inches in diameter we'll have the exact height and the height at which he hit the tree in the report here's the accident aircraft and here on the left stabilizer is the impact damage from that small tree and here's a detailed view of the left elevator again showing the impact from the small tree that brought down the Cessna 180 while on departure here's a picture of Jim's 180 before the accident with the i o 550 engine putting out about 300 horsepower for conditions at the day at the time of the accident they used the shack to lick Airport conditions some 23 miles away from the accident site and it's only 23 foot elevation there at the airport but they show a temperature of 12 degrees an altimeter of two nine or six five giving you an almost standard day density altitude good visibility good ceiling winds gusting out of the North up to 15 knots so I'm going to read straight from the report you can follow along on the link below the accident occurred on June 16th of this year 11 35 local too fatal remember the other fatality was Shane Reynolds from Idaho a well-known and well-revered guide out of Idaho on June 16 2023 about 11 35 Alaska Daylight Time assistant 188 November 91 361 was substantially damaged when it was involved in an accident near Shack to look Alaska the passenger and pilot were fatally injured it was operating under a part 135 Charter on-demand flight the airplane was operated by Golden Eagle Outfitters Inc in support of a remote bear hunting Excursion two hunting guides were waiting on a remote off airport Mountain Ridgeline airstrip near their Camp to be picked up and flown to uniquid after the hunting trip an hour before the accident the pilot had departed with two Hunters slash clients and told the guides he would be back to pick him up when the pilot returned he boarded one of the guides and some of the gear then arranged to return for the other guide and the remaining gear so he's splitting the load up he's got four guys in gear to carry out of there on the first load first thing in the morning hate takes two of the guides in some of the gear and now he's gonna split up the remaining amount of load the guide who witnessed the accident stated the winds were gusting and changing a lot and increased during the hour they waited for the Pilot's return he stated that he had flown with the pilot many times and had witnessed the pilot performed takeoffs and landings from this airstrip many times so this was not a new airstrip this was not an airstrip that Jim couldn't normally get in and get out of under normal conditions the airstrip was about 750 feet long and situated atop of a downsloping rock and grass covered Ridge line the airplane normally landed uphill on about a zero six zero heading to the East and then Departed the opposite direction downhill on about a 2-4-0 heading during previous departures after takeoff the airplane would dip below the airstrip off of the departure and then climb back into view out of the valley so the way I read that report it looks to me something like this and this is pretty common in Back Country flying is to have a slope a sloped runway on the side of a mountain by the way the elevation around here looks to be about 1500 to 2000 feet high at the very highest so with these temperatures the density altitude would not be much of a factor but when you've got these sloping runways in the backcountry you are forced to land uphill and take off downhill regardless of what the winds are doing but this day with the winds gusting out of the North you are encountering a quartering tailwind and potent and potential decreasing performance wind shear also too a wind out of the north on a Runway that slopes down to the West is going to produce downdrafts or down sloping winds the witness watched the initial portion of the downhill takeoff roll and nothing appeared abnormal so he turned away and did not watch the remainder of the takeoff when he did not hear the engine noise during the climb out or see the airplane climbing he ran to the ridgeline's edge and saw the airplane had impacted the tundra 300 feet below the airstrip he sent an SOS alert from his personal GPS tracker then hiked down to the airplane to check for survivors so that explained how the GPS signal got sent out as you saw in the previous update these GPS personal trackers do not automatically send a signal out somebody has to push the SOS button a helicopter pilot who responded to the accident site about 45 minutes after the accident said the winds were unusual that day winds were variable gusting 10 to 12 knots from the north then calmed and then gusted five knots from the south and then the pattern repeated these gusting winds changing 180 degrees is where you get your winch here examination of the airstrip revealed a small cluster of trees now this is kind of hard for me to understand the way this is written getting the lay of the land here examination of the airstrip revealed a small cluster of trees about two-thirds of the distance from the departure end of the runway's left Edge and downslope one tree only 12 feet tall one 12 foot tree about four inches in diameter was fractured about four feet from its base the separated portion of the tree was found next to its trunk and displayed fragments of red paint that matched the accent airplane's paint color and that's this tree right here examination of the wreckage revealed it impacted tundra in a steep nose down winds level attitude at about 1200 feet from the broken tree the wings were displaced by impact the right wing Leading Edge was uniformly crushed along its span the upper and lower wing skins were crushed aft in compression flight control continuity was established through several breaks and the flight control surfaces all breaks and separations were consistent with impact and over stress failure in other words the control continuity was established and does not appear to be a factor in the accident the engine was separated from the airframe and came to arrest inverted behind the left wing the propeller Hub was fractured and the propeller blades were separated from the Hub indicating preliminarily that the engine was producing power the right horizontal stabilizer in elevator did not exhibit Leading Edge impact signatures and the elevator remained attached the left horizontal stabilizer displayed a concave Dent perpendicular to the Leading Edge about one foot outboard from the stabilizer route so very close to the fuselage the trees happen embedded tree fibers were observed in the Leading Edge of the horizontal stabilizer that's the detailed view of the horizontal stabilizer the airplane and its contents were recovered and retained for further examination so again with the way this report's written I'm not real clear exactly where the location of these trees are this will all become much clearer in the final report and using wind from uh airport 23 miles away regardless taking off runway two four zero if you're in calm wind conditions and then that wind pipes up to 15 knots from zero one zero degrees that's going to produce about a nine not Tailwind component and of course he's forced to take off downhill because you can't outrun the mountain and take off uphill into the wind you've got to take off downhill and from that amount of wind shear remember the aircraft cannot react quick enough to these wind shear conditions it's going to lose performance and most likely get pushed off of Center Line to the towards those trees and lose altitude that shoved the airplane through those small trees and then with all that energy and that Tailwind coming down off that mountain produced a fatal crash at the bottom of the valley so wind gusts can kill you in these light aircraft those of us that enjoy doing some back country flying um for recreational purposes this is why we normally like to be down and tied down by 11 o'clock in the morning and we just simply don't go up in these windy conditions but as a very experienced Bush pilot who does this for a living he's compelled to get his clients out of there and he's very familiar with this airstrip he's been in there many times before but he just pushed it one time too hard this time we look forward to the final NTSB report and get some of these ambiguities cleared up thank you so much for your support of this channel especially the folks over on patreon that make this content possible see you here

Channel: blancolirio

Views: 368,492

Keywords:

Id: kYyg1CrI8Ng

Length: 11min 4sec (664 seconds)

Published: Wed Jul 12 2023