Garfly

FAA Emergency AD: https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID139391948320221005002535.0001 EXCERPT [click for full rez] : FAA Under Scrutiny for Timing of DHC-3 AD Transport Canada issued a similar airworthiness directive more than four years ago. https://www.flyingmag.com/faa-under-scrutiny-for-timing-of-dhc-3-ad/

Sorry, it must have been taken down for some reason. It was a regular Blancolirio video. It will probably re-emerge. Here is Kathryn's Report of the same incident: http://www.kathrynsreport.com/2022/09/de-havilland-canada-dhc-3t-turbine.html And here is one pertinent comment from the Blancolirio video: Mark P 2 hours ago Good video! As a young design engineer working at a major aircraft manufacturer, I had a friend ( older and more experience than me) who was in charge of the flutter model wind tunnel testing of the YC-15. One day he stopped by my desk and suggested I follow him to go watch a video of one of their tests. As I watched the video, they incrementally increased the wind speed while sending the horizontal stabilizer a "pulse" (literally pull a string that was attached to it) simulating a gust or other similar disturbance. Finally at one critical speed, the tail failed almost instantly. I couldn't actually see the flutter because it happened so quickly. When he re-ran the video in slow motion, we saw the pulse deflect the stab upward, and then it cycled down and up for about 2 or 3 diverging cycles, and then failed completely. Absolutely NO chance for pilot intervention. The results of this test had already resulted in design changes to stiffen the tail, so the first vehicle rolled out with the stronger tail already in place. That moment was one that will remain in memory and it gave me great respect for flutter for the remainder of my 43 year design career.

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PenName, you're jousting with a straw-man who's not there. Mark is saying no such thing. Anyway, on the subject of experts disagreeing on circuit etiquette and "airmanship" take a look at this recent hard-talk between two prominent YT instructors in the US - Dan Gryder and Jason Miller. The relevant bit is from 07:00 to 36:00.

This is from a 2016 issue of Plane and Pilot: Top 10 Rules Of Thumb Piloting an aircraft requires decision and precision. Quick references to the basics can make both easier. https://www.planeandpilotmag.com/article/top-10-rules-of-thumb/#:~:text=If you haven't heard,an abort is in order.

Yeah, you'd be wise to abandon any testing above, say, 10K DA.

Yeah, I don't think it'd apply particularly well in this case. The uneven slope and variable surface of the 'runway', alone, would make it unreliable. But still, just having any such performance/acceleration check in mind - on any unusual take-off - ought to give pause enough, you'd think. If I was ever so adventurous as that chap, I'd try a solo take-off first and then assess if any more load was feasible and safe. Maybe helped by another rule-of-thumb: For a given situation, for every 10% increase in T.O weight you need 20% more T.O distance. I'm not sure how reliable that one is, either, but one could confirm it, for one's own a/c, experimentally by taking note of two max performance take-off runs (in identical conditions) one with, and one without a load - an instructor, say. The numbers could be extrapolated to roughly prove (or not) the rule, no?

Juan Browne on the 50/70 rule:

Few, if any, doubt it.

Oh, aye ... "All the world is queer save thee and me, and even thou art a little queer."

https://au.news.yahoo.com/pilot-crashes-into-ocean-while-trying-warn-surfer-of-giant-shark-221716311.html

What had he done wrong, exactly?

A very straightforward scenario and a very smart PIC. Warning not waving. Too late.

But also potentially, possibly, about bending a rule to save a life.

Sure it is. Which is why Pprune had a long, impassioned thread on the subject a while back, running the gamut from the 'very straightforward' brigade to posters of the 'very complicated' persuasion. Never the 'twain shall meet. ;- ) https://www.pprune.org/pacific-general-aviation-questions/501671-mercy-flights.html

Hmmm ... visions of would-be rescuees bleeding-out as our scrupulously law abiding aviator attempts to get through on the blower to announce his 'declaration'. But I seem to remember reading that even the old Mercy Flight declaration no longer pertains; that it's now covered under the broader category of a May Day call. Not sure. Something to clarify. In either case, lives could well be hanging in the balance due dodgy radio comms. And given the Air Law joys of strict liability the judge may have to discount any kind of common sense defence. Heck, you might even get done, at the same time, for failing to render assistance. Catch 91.

Mercy flight? (Are they a thing any more?)

An interesting depiction of just that in this happy-ending video from Dan Gryder. But if you object to being toyed with for 20 mins - in the name of 'suspense' - I suggest watching the first minute, jumping to 22:00 for the completion of the forced landing and, if you've a mind to, returning to 'go' for the analysis and discussion with the pilot concerned.

Yes, I suppose flying beyond the J-curve in WAC land (and out of range of real time layer updates) it'd be nice to have PRDs showing up on the chart - paper or tablet versions. I wonder how many such areas are out there, and how many are only activated by Notam. So it may be an improvement after all, especially given that where the clutter is the worst the need for WACs is the least (as Yenn was saying, above).

OME, I can see that if you want to have your contestants limited to WACs, say, for the navigation trial, then having the boundaries of your local Danger areas right on them would be a help. So yes, these new charts might be handy for remote area PRDs ... saves you drawing them in yourself on paper charts like the good old days ;- )

PenName, can you expand on this? What 'layer cake' do you mean? The 36 DME Class C step? That won't be on the new WAC. They're talking PRD areas only. So, presumably, Pine Gap will be there - as it is already on Visual Terminal Chart. And as to FIR frequencies, I'd have thought your OzRWYs/AvPlan plus the ERC Low chart had you well covered in that department. If you want WACs to be all things to all people - especially nowadays - they will lose their particular usefulness. It doesn't take much magenta ink to cover useful detail at 1:1,000,000

Well, yes, I guess that's the point. So you wonder, why would they have bothered. In any case, if only PRDs are shown then the new style WACs are hardly of any use regarding all the other types of restricted airspace. In practice it probably won't be much of a problem for anyone on their EFB charts but there are many places where the Hybrid VFR maps give over to the WACs from VNCs. And I think there may be a lot of PRD boundaries - at some level or another - extending out that far. I just hope it doesn't mean a lot of misleading and useless magenta lines cluttering up those areas.

I enquired with ASA's Aero Charting about this news and they were kind enough to send me this sample image. According to ASA: "The PRD boundaries have been added to bring the WAC series closer to ICAO compliance for this chart type." And "We are hoping that with a planned change in software to create these charts we will be able to update them on a more regular basis in the future." As I understand it, the printing of Aeronautical charts and other documents has now been outsourced to https://www.aipshop.canprint.com.au/ where the new WACs can be bought. On first impressions, I'm not all that impressed. It seems like a lot of unnecessary clutter (given that we have VNCs and VTCs ... and EFBs to boot). Anyway, these will be incorporated in OzRWYs in December. I've heard tell that some in the OzRWYs team are not thrilled by the innovation either. CLICK TO EXPAND: This is the feedback I sent to ASA Aero Charting, yesterday. "On first look at this new WAC format, I wonder how it will be generally viewed by the flying community. To me they look pretty cluttered and I would have thought that the beauty of WACs has been that they were unfussed by airspace detail and dealt mainly with ‘existential’ geography. Also, so much magenta might get a bit much when used with EFBs - which, of course, use magenta lines for other things. I’d have thought that we already have all the airspace info we need in VTCs and VNCs as well as real time overlays (on any and every map) of active PRD areas on EFBs. The boundaries of these, of course, can change on an hourly basis so the electronic real time display is very handy. Anyway, I’d be interested in the thinking behind this move and any discussion within ASA. I’m surprised to hear that WACs do have all that airspace info on them in other ICAO regimes. In any case, at first glance, I'm thinking I might miss the old, uncluttered WACs. But maybe when I get used to them I will come to appreciate the upsides. 🙂 "

Agreed ... or as I'd put it: "with all the variables at play in take-off performance, our sense of normal can be confused ..." And, to paraphrase Nev, with P-charts, it's garbage-in/garbage-out. To me that says a backstop rule is handy. True, but I don't think the video really misses that point. Gryder stresses that a sick engine is only one of several possible causes of unexpected poor acceleration and his 50/70 rule of thumb is meant to catch them all. And, as you say (and the video, too), it's only good as a last line of defence. Nobody denies that stopping immediately anything seems wrong is the way to (not) go. And sure, in the real world, like taking off at Mt. Hotham on a hot summer's day (P-calcs duly done), having a backstop rule-of-thumb to counter "inaccurate feelings" might help. Even - turning it the other way - to prevent a dangerous reject situation which was never, in fact, necessary. (Visions of a cliff-hanger ;- ) Also, you might say that this video demonstrated a case where pulling it off the ground may well have improved the situation. According to the pilot's story, the alternative could have been plowing into the school pick-up event unfolding in front of him. Of course, he's the first to agree that an early reject was what was called for - if only he'd learned 50/70 earlier, he reckons. But yes,, as Dan G says in the video, actually living to tell such a tale is not at all common.