C208 vs Smokestack Final Report- Addendum

[Music] hi I'm Scott Purdue and today on Flywire I'm going to step outside my normal Lane so stick with me on [Music] fly I gotten lots of uh comments on the final up report update for this accident um some are good and some are pissed what I can tell from the ones that are pissed are from Mostly seem to be mostly from folks who have a particular affinity for other YouTubers okay fine whatever they have to say that's their thing but I typically don't add material to a video based on comments but in this case I think I'm going to do that I think it's important so based on the negative comments uh the folks that are uh I think that I think that the based on that the folks are losing focus on what is important here okay so here it goes and from my perspective the most important issue here is the Opera operating below the MDA uh Witnesses said the Caravan popped out of the cloud uh it was supposedly at 2300 that was the report the base of the first broken layer and then immediately went into a steam Cloud okay and the aircraft performance report in and for the ntsp investigation they did not count the witness reported uh the reported steamcloud at all and the first view of the runway was about about 40 seconds prior to the impact and the rest of the time uh it was obscured by the dash physical uh interference until approximately 2 seconds prior to impact okay my most important Point here is that if the pilot flew into a steamcloud and was below the MDA then the only choice was to go missed Approach at that point if you lose visual contact with uh the runway its environment lights Etc uh you go around you go missed approach full stop the other thing that is a requirement for the aircraft to be continuously in a position from which a descent to Landing can be made using normal rate of descent and normal Maneuvers at the point of impact the aircraft was 316 ft below the MDA and 112 ft below the nominal uh vertical descent angle it's not a Glide path in this point it's not an in Precision approach it's a a visual segment after the MDA this was a non-precision approach and the vda is more of a visual procedure than an instrument one okay so visual is an issue here at the point of impact the aircraft was 86 ft above the ground and only 46 ft above the threshold Crossing height with 4/10 of a mile uh 2632 ft actually to fly I'm sorry but that's not a normal rate of descent a normal procedure to land on a Runway um in my opinion the missed approach was warranted you may disagree and that's fine if the pilot flew into his theme Cloud the visual contact was lost continuing the approach I think is no longer legal you're entitled to your own opinion and that's fine I think the reason should be obvious at this point about why you can't continue because of the obstacles that you might run into uh how did the pilot get into this situation frankly I must admit it stuns me that any of these Smoke Stacks were located coincident with the Final Approach segment to Runway 20 and the two reports that the fa two studies the fa made concerning this issue they determined that there were 18 separate structures that penetrated the runway 20 approach surfaces varying anywhere from 18 to 37 ft into the protected Zone the accident stack was in the middle of that group at 23 ft it wasn't the highest but directly it was directly in line with the runway and the others were just L off that direct line This created the worst possible situation in low low visibility approach and I'm sure the courts will fight it out and maybe hazards to navigation like these will be eradicated from as a result blam be Al allocated that's in court that's not what we need to learn from this accident okay from here on the existence of the stacks and the penetration into the protected airspace are not material to the analysis frankly we as pilot need to learn what went wrong and how can how we can avoid this situation ourselves okay I'm not a subject matter expert for the lawsuit in this case I wouldn't talk about it if I was that's the whole point we do these analyses is to find out what went wrong and how we can avoid it in the future the ground at the stack was 415781 and the top of the stack was 42 57.8 ft ml it's 100 ft the aircraft performance and investigator observed that the stack to be as I said 200 2,632 ft from the runway two threshold 4/10 of a mile during simulation testing he observed the the stack to be visible to the pilot approximately 2 seconds prior to impact and noted the red light was at the same level as the threshold lights I still maintain that the light paid no factor in this accident and was not likely to be seen in any case if it was a white strobe the fact that it was visible for only 2 seconds would not have left any time to maneuver or avoid it 86 ft above the ground you know my gosh uh any radical maneuver more than about 10 or 15 degrees of bank that's pretty radical you're not going to avoid that prior impact it is debatable what the impact would be at first lur emerging from the clouds you know 40 some odd seconds uh before that uh but speaking about that steam Cloud the notion that density the altitude was a factor in my experience the real issue with smoke stacks is turbulence significant wind shears can exist around stacks and that makes them more of a hazard to navigation than their height you can actually get uh an upset from those those kind of that kind of turbulence very violent uh the effects of turbulence are persistent because of the violent displacement of air volumes and that takes time and distance to dissipate temperatures on the other hand that's what we're talking about density altitude temperature of the gas cloud itself are not longterm it's a physics thing I'm not going to do the math for you right now I don't want you to turn tune off but again referring to the aircraft performance report the investigator looked at the da issue and using an EA EPA provided software product was able to determine that any da effect would be minimal the temperature of the steam Cloud would be 99.7% of ambient outside of 200 ft so if there was any da effect would be within 200 ft of the stack that was emitting the Steam and uh therefore I when I read through it I discarded it the whole notion as not applicable the investig investigator looked closely at both approaches and determined however that there was a significant change in descent rates in the final seconds prior to impact on the accident approach the second approach Juan Brown noted this and posted the da situation inside the cloud or posited that situ uh da situ ins side of the cloud I didn't think it was a factor and I neglected to point out the investigation's findings uh because of that reason because I didn't think it was a factor to me it all boils down to being too low and when the visual contact was lost a missed approach should have been executed but I I'll admit here that I was not as thorough as I should have been okay so what happened using the adsb and the tower impact video to compute a profile that fits the data points the physical data points that they have the adsb message and they have the exact time and altitude etc for the impact the investigator compared both approaches and the first approach was 20 to 50 knots faster than the second both were done with flaps up an argument could be made that both approaches were done in icing conditions and then the book recommended configurations are 95 knots flaps up and 85 knots flaps 10 to 20° okay important Point here he also noted that given the contaminated Runway and the length it was unlikely that the airplane could land and stop on the available Runway using icing condition recommendations okay that's a huge point so it appears that the pilot was trying to fly an approach that would result in not running off the end of the runway she was flaps up but she was slow um the primary result of flying slower without flaps results in a higher higher deck angles higher Ang angle of attack so in other words a larger coefficient of lift that complicates the bot Pilot's abil ability to maintain sight of the runway because you got a higher deck angle okay you're you're slower and you're higher you're trying to maintain visual on the accident approach the indicated air speed was computed to be 80 84 to 86 knots and steady for the last 26 seconds of flight at 832 even just passing jamed the intermediate point on the approach at 4,800 ft MSL there was an increase in pitch angle what with 80 knots uh true air speed uh that was computed referring to the results of the simulation flights done the investigator believes that the pitch chain was done to keep the runway Insight at the edge of the glare Shield just 15 seconds later when the indicated speed had decayed to 85 knots then there was a significant decrease in pitch angle significant decrease in pitch angle that resulted in The Descent rate increasing to nearly 1100 ft per minute Juan got that correct an increase of about 600 ft per minute impact was just over 11 seconds later in my math that results to a loss of about a 100 ft or so and that's pretty significant and I missed it sorry the investigator speculates that this pitch change was likely due to the activation of the stall warning horn the activation range is 5 to 10 knots above the actual stall and that 85 knots in that configuration was right in that green zone in that zone the impact occurred at 76 knots ground speed the pitch change due possibly to that stall warning would account for most of the aircrafts deviant below the nominal Glide path uh sorry vertical descent angle um that she should have been okay it was 98 ft the top of the stack was 98 ft below that Glide path vertical angle they are na20 approach to byi in those conditions certainly was a trap especially given the content the contamination and then using uh icing configuration icing conditions configurations would likely result in running off the Runway please note that the fa does not allow you to depend on thrust reversers or beta thrust to achieve stopping distance you have to compete it with normal brakes and uh using the beta probably she could have been done it but she questionable legal legality for doing that the pilot elected to fly a slower approach that was her solution that resulted in a higher deck angle complicating the Pilot's ability to keep the runway insight and possibly received a stall warning that resulted in an increase in descent rate at a very unfortunate time uh perhaps madmac uh 37 said it best about getting behind the power curve in a heartbeat it happened in a heartbeat for me the takeaway way is still the missed approach especially if a stall warning was received on Final uh hey something's really screwed up my goal is not to hit the ground or anything attached to it and then that close to the ground I'm going to go around and I I wish she had done the same thing um oh by the way it might be a good idea to send critiques of any other poorly designed approaches out there uh that you may run into you never know when it might save a Philip pilot and their family a lot of grief well there you have it that's my updates keep those comments uh coming thanks for watching even if you disagree I don't care uh I'll see you next time on Flywire

Channel: FlyWire- scott perdue

Views: 8,677

Keywords: C208 vs Smokestack Final Report- Addendum, Flywire, flywire online, flywire youtube, scott perdue, beechcraft bonanza, general aviation, Aviation, F33C, F33 Bonanza, A36 Bonanza, V35 Bonanza, Aerobatic Bonanza, Aerobatics, Acrobatics, Flying, pilot vlog, flight training, flying vlog, cockpit, airplane audio, cfi, pilot life, bonanza, private pilot, commercial pilot, airline pilot, ATP, pilot, atc, flying an airplane, airplane accident, n928jp

Id: GO6AHCHvLyg

Length: 12min 48sec (768 seconds)

Published: Wed May 15 2024