The Great Ongoing Aviation Thread (general and other)

Miscellaneous and Personal Stuff I Must Share
2803

I would think being able to hover, or get close to it, thereby minimising forward speed at impact, would be a significant advantage for a helicopter in a ditching. On the other hand, having two big wings (likely) filled with air would be an advantage post impact in a fixed wing machine.

I’ve spent about 4500 hours somewhere between 100 and 1500’ above the ocean for legitimate operational reasons. My main concern, regardless of why you’re there or what you’re flying, is to have the life jacket ON the whole time rather than just available. I was never particularly comfortable when we went from this sort of thing that only required a pull on the cord to inflate:

to these, that involved opening the bag, pulling over your head, then inflating.

When you have a ditchable problem in the air, first you’re going to be trouble shooting, then flying it to the impact site, then trying to sort out which way is up and how to get the hell outa there. The last thing you need is extra steps to get your floaties on.

2804

That is a cool ref to a cool adventure. Thank you.

But there are two sorts of altitude: height above sea level and height above the land/water surface immediately below. Your ref is all about the former sort of altitude. My comment was directed at the latter sort.

You can inadvertently hit zero feet above the surface in Egypt’s Qattara Depression, in the ocean, or at the top of a mountain. But you can only do it once. Different altimeter readings, same outcome. Crunch!!

2805

An airplane doesn’t need a runway either. The difference is you have to use up a large chunk of stored energy in a helicopter to arrest forward speed and then have enough left over to stop the descent.

at 500 feet above the water I don’t see it ending well in a helicopter.

2806

Autorotations are practiced with great frequency. Energy management is very important, especially in an R22 or Schweizer 300 that has a low-inertia rotor system. Also, autorotations are a lot of fun. :sunglasses:

A helicopter probably isn’t going to flip when it ditches, unlike an airplane with fixed undercarriage. Also, you hit the water at zero, or close to zero, airspeed, having managed your energy to perform an autorotation. In an airplane, you still have 60 knots of energy to get rid of when you hit the water.

Incidentally, the drill is to autorotate, then bank when you touch the water to stop the rotor blades.

2807

No, the faster the better, within reason.

You need to be out of the red zone. 500’ and cruise speed is going to be just fine, provided you know what you’re doing.

2808

I stand corrected on airspeed.

2809

This is an interesting video (all of it…about 14 minutes long). I still wonder why lead cannot get out of aviation gas. I am not saying it gets out at the flip of a switch but surely the industry should be working towards this since the 80s/90s but…nope (tl;dr there has been no regulation of it).

2810

I missed the edit by seconds. This video, part 2, is 15 minutes long.

2811

The answer is simple: economics. Or more precisely, hopeless economics.

There is no meaningful profit to be had in developing, certifying, then selling a substitute fuel for such a tiny fleet. There is no economic way to replace all the engines and fuel systems to burn ordinary automobile gasoline.

Decades ago, politicians were lobbied to (for once) recognize that hopeless economic reality and simply ignore piston aviation’s comparatively microscopic contribution to national and international air pollution. The hope / expectation was/is that the piston GenAv fleet will simply eventually corrode into a heap of dead airplanes nobody flies anymore and the pollution problem will die a natural death along with the planes.

It’s taking longer than they/we thought. Way longer.

And meanwhile so much else ecologically has gotten so much cleaner over that time that what had once been a negligible rounding error is now a glaring sore thumb, morally if not quite in terms of total tonnage vs all the garbage humanity dumps in the atmosphere today.

2812

FYI, a somewhat similar battle is going right now in turbine aviation about so called “SAF” meaning either substitute aviation fuel or sustainable aviation fuel depending on who you ask.

The idea is to create a chemical mixture so identical to petroleum-based jet fuel that it can be used everywhere by everyone in everything without needing to test (and possibly modify) each and every aircraft + engine combination to prove to the regulators’ satisfactions that the substitute fuel is exactly as safe as traditional fuel (“fossil jet fuel” in the argot).

Meanwhile this new fuel must be from a “green” source. and must not be monstrously more costly than petroleum-based fuel. And must be able to be ramped from laboratory scale to fulfill all of current consumption within a decade or two.

Which current consumption is very roughly 14 giga-pounds or 28 giga-liters per year.

A tall order to be sure. Imagining we’re going to collect 28 giga-liters of used deep-fryer oil from restaurants is simply fanciful. Much less to assume that collection and refinement can be done cheaply.

2813

There are lots of small airplanes already running on unleaded auto gas. My flying club was one of the pioneers in using Mogas in training aircraft in the 1980s. I did most of my flight training in aircraft powered by unleaded auto gas. The only issue I remember was an increase in carb icing risk, and we had to adapt procedures for carb ice as a result.

But auto gas doesn’t work in all piston engined airplanes.

2814

Amazed this hasn’t happened yet… hope it can be ASAP.

2815

Unleaded auto gas works great in the simpler engines with relatively low power output. Such as what @Sam_Stone reports.

Those are also the types of airplanes available in more volume so there is a at least plausible economic case for somebody to spend the money to certify autogas in, say, 1960 to 1970 production Cessna 150s. Or in the new smaller aircraft running what are effectively improved automotive or motorcycle engines.

Unleaded fuel simply doesn’t work in the traditional bigger fancier aero-engines in the bigger fancier piston airplanes. Nor are there enough survivors of any given type to close the economic case for the required development, testing, and certification of some sort of alternative fuel.

2816

Well, yeah; if the engines were like 1930s technology, then… Oh, wait…

2817

You know the issues.

It’s not that we can’t get high HP out of motor fuel. My box-stock factory car produces over 600hp with a single 4.4 liter V8 engine. Conversely, one of the most powerful piston aero engines today is the

series, which tops out at about 375hp with an 8.8 liter displacement.

The problem isn’t that industry couldn’t build high powered piston aero engines. It’s that for such a tiny market they can’t earn back the development costs. Piston GenAv has shrunk below the critical mass where tech innovation can pay for itself.

And that’s even before we consider the FAA-enforced tech stasis field that decrees that 1940s engineering is as good as it’s permitted to get.

My bet is we’ll get electric retrofits to replace the big piston engines entirely before we get an alternative unleaded fuel for them to burn, or some kind of modification kit to have them survive on unleaded auto fuel.

2818

If they (someone… not necessarily the Big Three) could make an affordable two-seater, they might use a Rotax 914. It’s an FAA-certified 115 h.p. engine that can run on mogas. (Actually, according to the Wikipedia article, unleaded mogas is recommended.

2819

Rotax engines are used in a variety of LSA certified light aircraft. And they are heavily used in the homebuilt industry, which is already producing more light single aircraft than the traditional light aircraft makers are putting out.

In 2019, 1200 new homebuilts were registered. In the same year, the traditional aircraft manufacturers only sold 1320 piston aircraft. That includes light singles, twins, cargo planes, executive transport, you name it.

The most popular general aviation plane in history, the Cessna 172., only registered 126 copies last year. Van’s aircraft, the largest homebuilt manufacturer, registered about twice as many.

That’s what happens when regulations strangle an industry. The LSA and homebuilt explosion are the reaction to a crippled industry.

2820

I disagree that regulations strangled the industry. Things were going along quite well for decades, until ambulance-chaser lawyers pushed insurance costs to like half the price of a new airplane. And then airplane manufacturers shot themselves in the feet by not making piston singles for eleven years. By the time GARA was passed and they started making airplanes again, they’d forgotten that they were competing against themselves and priced their aircraft outside of their target audience. They’ve been in a death spiral ever since. And also by the time they started building airplanes again, we had the Internet, cellular phones, video game consoles, ATVs, more cable channels than ever, and lots of other things that are easier and cheaper than flying.

2821

I’ll split the difference. IMO …

Regulation didn’t kill the lightplane industry. But once they’d been driven to the edge of extinction by excessive litigation as @Johnny_L.A says, the oppressive regulations served to hold their drowning heads underwater until it was too late. They’re now face-above-water and gasping, but their lungs are half-full of water and it’s only a matter of time before they succumb.

LSAs and outfits like Cirrus have proven it’s not impossible to sell new light airplanes in 2022. But it’s a very, very different value proposition compared to the 1960s heyday.

Nowadays the upwardly mobile middle class is something young people hear their grandparents reminiscing about. Not something they’re expecting to experience for themselves. GA is but one of many, many industries who are victims of that fundamental change in our society.

2822

It’s all of those things, plus a big one not mentioned: the way airplanes are maintained means that there has been a constantly growing used supply of aircraft competing against new ones.

Where regulations come in is that they prevented the light aircraft industry from innovating and making the used fleet obsolete. Auto manufacturers introduce new models and upgrades constantly to degrade the value of used cars and keep people wanting to buy the latest thing. In aviation that was impossible because a type certificate was incredibly expensive and time consuming to attain, and even the assembly line had to be fixed from change and approved. If a change couldn’t be done through an STC, it wasn’t done.

Type certificates are so valuable that when aircraft makers go bankrupt their type certificates are sold on the market and new companies form to make the same aircraft rather than design one of their own. The Grumman Cheetah started life being built by American Aviation. They went under, and the type certificate and tooling was sold to Grumman. When Grumman-American failed, Gulfstream bought the type certificate and tooling and tried to sell them. That didn’t work out, so a new company, American General formed to buy the TC and tooling and make them. They failed as well, but then Tiger aircraft did the same.

The old tooling and Type Certificate were so valuable because getting new ones for a new aircraft under the old regs was damned near impossible. Porsche just about went bankrupt just trying to certify a new type of engine.

The result was that a Cessna 172 from 1970 looks and flies almost identically to one built in 2022. And with maintenance being done the way it is, it is just as reliable and usable. There are tens of thousands of 172’s out there, and you can buy a good used one for under $100,000. A new one is half a million dollars - in part because of liability insurance, but mainly because of a death spiral - as more people opted for used airplanes, fewer new ones were sold, driving up the unit cost and pushing even more people into used airplanes.

Enter homebuilts and LSA. The FAA finally relented on regulations and allowed new innovation, and cheaper aircraft with more modern engines and airframes started showing up. If product liability was the main factor, this wouldn’t have happened because LSA manufacturers face the same liability issues as the old manufacturers. Some, like Cessna, have deep pockets.

The difference now is that you can buy an LSA plane for a lot less, and it will fly better and be cheaper to operate. The Cessna Skycatcher is an LSA that origincally sold for $111,000, then the price was raised to $149,000. Still a third of the price of a 172. It’s essentially a modern Cessna 150, complete with a Continental O-200. BUt it’s faster, climbs better, lands shorter, has more useful load and range.

A better example might be Van’s RV-12is, a factory built or homebuilt light sport aircract with a modern Rotax 912. It cruises at 144 mph on 100 HP, can carry two standard adults with full fuel (20 gal), has a cockpit 5" wider than a 150, 30% more range, a glass cockpit, and you can get one of those for just over $100,000. The difference is the regulatory environment.