Garfly

From the preliminary ATSB report: At interview, the pilot on board WVV recalled that there was scattered[5] cloud at 1,500 ft on the forecast that would not allow them to track below cloud via the recommended VFR route to Kilmore Gap (elevation 1,200 ft AMSL). Therefore, they elected to take a more direct track to their destination, which took them over Mount Disappointment, to the east of Kilmore Gap https://www.atsb.gov.au/publications/investigation_reports/2022/aair/ao-2022-016/

Oh, really!? Explain this then:

Quite a lot apparently; at least according to this old chap: And this mob: http://www.pilotfriend.com/training/flight_training/aero/aero_res.htm CLICK FOR HI-REZ PIC

That ain't magic ... (THIS is magic ... ;- ) and maybe this ...

Smart watch?

Yeah, I'm also happy to put physics aside in favour of practical stick and rudder know-how. My point (poorly communicated) was just to urge tolerance of alternate explanations when even the physicists can't agree. However, I should have taken my own counsel of a few posts back "(Let's not get started on 'How does lift happen?" ;- ) " Anyway, even if (as argued in the Plane and Pilot article, above) the hazard of the "downwind turn" is a myth "... so long as pilots believe it, they're more likely to pay careful attention to their airspeed when they're close to the ground and especially on low altitude turns ... " So all good.

He has the swagger of one. But a better argument about experts disagreeing on basics is made in this Scientific American article from Feb. 2020 https://www.scientificamerican.com/article/no-one-can-explain-why-planes-stay-in-the-air/ No One Can Explain Why Planes Stay in the Air Do recent explanations solve the mysteries of aerodynamic lift? [excerpt] In December 2003, to commemorate the 100th anniversary of the first flight of the Wright brothers, the New York Times ran a story entitled “Staying Aloft; What Does Keep Them Up There?” The point of the piece was a simple question: What keeps planes in the air? To answer it, the Times turned to John D. Anderson, Jr., curator of aerodynamics at the National Air and Space Museum and author of several textbooks in the field. What Anderson said, however, is that there is actually no agreement on what generates the aerodynamic force known as lift. “There is no simple one-liner answer to this,” he told the Times. People give different answers to the question, some with “religious fervor.” More than 15 years after that pronouncement, there are still different accounts of what generates lift, each with its own substantial rank of zealous defenders. At this point in the history of flight, this situation is slightly puzzling. After all, the natural processes of evolution, working mindlessly, at random and without any understanding of physics, solved the mechanical problem of aerodynamic lift for soaring birds eons ago. Why should it be so hard for scientists to explain what keeps birds, and airliners, up in the air?

You'll just have to learn on the job, then. It can't be that hard.

Oh, wait ... Nope, still hard to understand. Even on the basics, experts disagree: YouTube Comment on "Airflow across a wing": 37rainman The "actual force upward" is caused by air molecules (mass) colliding with the wing and causing lift due to an equal and opposite reaction. Lift is not created by something happening somewhere "beyond the trailing edge". This does not in any way serve to deny that a part of the lift is attributable to the "shaped wing" concept, explainable by Bernoulli's principles.

But F10's scenario involves "turning rapidly" so your leisurely 360 on AP is probably not going to test the theory. Anyway, I have my doubts about the phrase "you will see a drop in IAS in a light aircraft". Really? But how, in practice, can you see that? Surely in any, quasi-emergency rapid 180, the ASI will be doing a merry jig (while we aim to tame the beast) so who's to say which jig, this way or that, indicates the "downwind turn effect" as opposed to, say, our ham-fisted stick work, that time? Plus, I just can't conceive of an aerial reversal quick enough to approximate the 'shear' effect. Soaring hawks don't turn on a dime and neither do Skyhawks. But who knows!? If we could only see the damn air it'd be a lot easier to understand.

Actually, that was F10's main point. It was the second part that stirred the possum.

For what it's worth, back in 2008, a couple of long running threads about this issue on Supercub.org involved some pretty sophisticated aeronautical theory, on both sides. The arguments got pretty heated such that one contributor was prompted to write: "I think the single biggest problem with these type of discussions is that folks get so passionate about their stance that they begin to make blanket statements that are absolute and ambiguous at the same time." https://www.supercub.org/forum/showthread.php?33563-Downwind-Turns&s=4e085b14b628e1138e78f6dcfce72693 https://www.supercub.org/forum/archive/index.php/t-33563.html And the beat goes on: an article in last month's Plane and Pilot The Downwind Turn: Hazard Or Fiction? https://www.planeandpilotmag.com/article/downwind-turn/

Of course, SP, I'll even fly with students if it's free. Have you got a C150, now? (They're what they call the poor man's Skyranger, no?)

I knew you'd have your reasons and your reasoning, F10. I've followed this interesting debate among aeronauts for years. But frankly, the 'parcel of air' conception still makes more sense to me, whether we're close to the ground or not. As I understand that idea, the wing, along with its associated pitot/ASI, cares nought for the landlubbers' 'wind' nor the ground, for that matter. It cares only about the air molecules flowing by relative to itself. After all, when we take off in a stiff cross-wind, as soon as the wheels unload we're in no doubt that our aircraft has hopped aboard the air-mass train. We're instantly off in THAT direction unless and until we do something about it. Yes, I suppose like the fly in the speeding train carriage we're slipping through the air but like the fly, surely we can never just "forget our TAS" (in favour of GS) while we're still flying. Yes, it's the ground that may rise to smite us but only when the air decides to drop us. By the same token, then, I can't see a special need to "accelerate into our turn, downwind". But always happy to learn by being corrected. ;- )

Yep, that's all.

That's all you've got, Flighty?

Geez, Flighty, even when you come across a recreational flyer with first class stick and rudder skills (and an exemplary safety message) you still manage to pull a negative message from it. You're never happy, are ya! Truth be told, I'd fly to any strip with that BC182 bloke, in a heartbeat, given the chance. (Or, for that matter, with any experienced, right minded, PNG pilot on their daily mountain milk run.) BC182 sums it up in the vid: "Flying in the mountains can be very rewarding but you've got to do your homework and you've got to get the training." Done right, there's no reason we can't seek that kind of reward in OZ - without, necessarily, strewing bodies everywhere. (Anyway, at our age, we're not even safe in a simulator. ;- )

Yeah, we all totally agree, but that's another issue altogether. What we're talking about is contained in these few words: "you will have to be able to accelerate in the turn to maintain a safe IAS, as you turn downwind"

On this point we are all in furious agreement. But given F10's savvy and experience he must have his reasons for complicating conventional wisdom with his practical observations. Which is why I asked about the wind-shear 'exception'. I wondered if he meant that a quick 180 is a bit akin to rolling your own wind-shear. Anyway, the theory around rapid turns within an air mass has long been debated. Experts seem to disagree; that's nothing new in aeronautics. (Let's not get started on 'How does lift happen?" ;- )

Yeah, I don't think this issue has anything to do with the ground per se. It's a rehash of the old debate as to whether 'turning downwind' is even a thing in aeronautics (apart from obvious ground considerations). Typical of the argument (between experts, it seems) is this contribution to the Comments section of the video below. "The animation does not clearly show that an airplane can only experience wind shear at the moment it flies from one airmass into another one. INSIDE an airmass the airplane does not experience headwind, tailwind or crosswind."

Normally we don't directly relate IAS with 'wind', when it comes to aircraft performance and control. We think of operating within moving parcels of air and so we only factor 'wind' into ground speed considerations. But I guess what you're pointing out is that in a sudden upwind >> downwind turn-back you're creating a kind of wind-shear situation for yourself and so you must be ready for the big push to be bigger and faster at the turn than it would be straight ahead. Is that right? Would you care to elaborate?

Yeah, I knew it'd been replaced but figured if there were some still around, they'd be a good deal. (Like < $300 or so) But, yeah, for sure, the 16 will be better. I reckon the accessory that lets you attach a normal headset is great to have. Also the battery pack that lets you use 6XAAs in case you're away from mains power. But they do push the price up quite a bit. Anyway, all the best. Good to see you back. ;- )

If you can still find the (superseded) Icom IC-A15 I reckon that'd be the best bang for the buck. I can't see them on the Clear Prop site anymore but it looks like this mob might have them: http://www.aircraftradio.com.au/products/icom/ica15

More info on the Sherwood eKub in this article https://flyer.co.uk/britains-sherwood-electric-kub-makes-first-flight/ It even makes mention of an electric Skyranger that's in the works. "Also heavily involved is Flylight led by Paul Dewhurst (who is well on with the build of the second aircraft, the electric SkyRanger Nynja)." This Royal Aeronautical Society article https://www.aerosociety.com/news/the-way-ahead-for-general-aviation/ says that the Skyranger project involves a hybrid type: "The EnabEl plan is to explore the design, build, fly and certification of electric microlights with two companies: electrifying the TLAC Kub and making the Flylight Nynja hybrid capable." This is the brochure for the (ICE powered) Kub: Sherwood-KUB-flyer.pdf https://www.g-tlac.com/wp-content/uploads/2017/10/Sherwood-KUB-flyer.pdf