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Comment by base698 | Hacker News Reader

I think of planes as having a CAP Theorem like trade off between speed, safety, utility (can I take a family of 6), and price. A used 172 is pretty safe but greatly lacks in other categories. A Lancair 4P optimizes for speed, but greatly sacrifices safety. a Pilatus maximizes all but price, yet it costs $3 million. Bonanzas are pretty good on speed, and utility but a bit more expensive than most piston singles, decent used ones cost $350k+.

I own a Mooney, which burns 10 GPH and does 160kts. Fits two people just fine and three if you sacrifice fuel. A good trade off over all. Definitely think the 172 is the least badass plane with almost no upsides other than being a good trainer.

https://en.wikipedia.org/wiki/Beechcraft_Bonanza

https://en.wikipedia.org/wiki/Mooney_M20

https://en.wikipedia.org/wiki/Lancair_IV

https://en.wikipedia.org/wiki/Pilatus_PC-12

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Totally agree with you it's all about what you are looking for (range, payload, power, efficiency). The 172 is a fine trainer, but it really doesn't excel in several dimensions. That may be fine for some folks missions, but for others you are going to have to spend a bit more if you want to be good in a few of those. When I got my private cert and started focusing on my instrument training and flying in hard IMC and potentially deal with icing, I had to step up my requirements.

Disclaimer: A Mooney owner myself.

Does your Mooney have the TKS system, or are you saying there's a general benefit to a M20 over a 172 in terms of icing?

Any turbocharged airplane with a hot prop will be better than a 172 in icing. Turbo gives you altitude flexibility and power to get out of the ice (rarely more than 4000’ thick vertically) and the hot prop will help you pull through it.

(I have a turbo and TKS on my A36. Almost never need the TKS.)

Thank you! (PPL student here, still lots to learn).

It’s worth noting that single engine FIKI is a little controversial.

Having TKS (or boots) is definitely a safety benefit in case you end up in inadvertent icing, but remember that the system can still get overwhelmed.

Avoiding icing conditions is still a good idea, even with TKS. :)

At a certain point you can question the suitability of the traditional twin engine piston IFR types for true commercial level FIKI. Not least because most of the examples are well into their middle age, most types are somewhat marginal on one engine, and single engine mishandling is rarely survivable.

In reality most people who can afford to run a piston twin are moving down to a Cirrus or moving up to a turbine single.

I think the move up to a turbine single is driven by maintenance dispatch reliability ("will the airplane work when I show up to fly it?") more than weather dispatch reliability ("is the airplane equipped and powerful enough for the weather challenge I'll face today?").

Turbines give you much higher power reserves at low altitude, so they are better in icing on departure and approach, but that difference doesn't come up nearly as often as generalized maintenance issues. (Owning a 1976 piston twin was an overall negative experience. I loved the airplane, but it was a maintenance hog, mostly aging systems and aging design philosophy related.)

I agree 100% that the piston twin is a dying breed, but I think it's almost never to do with FIKI (flight-into-known-icing) issues.

100% this! If I expect icing beyond trace/light, waiting or flying around it is my plan on anything with props. (I didn’t buy TKS to fly in ice; I bought TKS because it was already on the airplane that I otherwise wanted and having it was not a deal-breaker.)

Have TKS. I don't believe you can get that on a 172 (but a 182 you can).

That said I've heard anecdotally a 172/182 can carry ice better than a lot of other aircraft (I've only been iced up in a 172, never on a Mooney). That shouldn't matter anyways since you should avoid ice as much as possible.

I've worked on Mooney's and sat in them but never flown one. They're slick but I find then cramped and difficult to work on.

I'd take a Commache 260 over a Mooney any day of the week. Not quite as fast/economical, but much more comfortable, cheaper, and easier to work on.

I owned a Twin Commache and it was a thing of beauty... but a different animal to the singles.

My father flew a lot and owned a Comanche B and later a Twin Comanche turbo. I spent a lot of time in and around Comanches. Great looking airplane and nice to fly in.

What drives unit costs of those aircrafts? Low quantities built?

I would guess safety standards are much higher too, but I generally don't understand why they're so expensive.

I guess the piston engines are very different from the ones you find in cars.

Low quantities, certification costs, mandatory maintenance (engine and prop overhaul/replacement after {X} hours)

Liability as well. Aircraft used to be cheaper (in real terms). At some point the law changed so that aircraft manufacturers could be sued if someone died in a crash. I don't remember the specifics, but this caused several companies to go out of business and others to raise their prices.

Edit: probably the manufacturer could always be sued, but the change made it easier. I can't remember the specifics.

Regulations, it seems. Here's an article that provides some clues: https://generalaviationnews.com/2012/09/09/the-cost-of-certi...

As I understand it, the most lenient certification to allow someone to sell planes to masses in USA is the (special) Primary Category¹, for the General Aviation, which Cessna's two-seat 152 model seems to be in. Cessna's four-seat model 172, however, is on another category, the so-called "Utility Aircraft", which required the more costly Standard Certification². With a broader (legally permitted) use, it's kind of natural to expect an appropriate price difference.

¹ https://www.faa.gov/aircraft/air_cert/airworthiness_certific...

² https://www.faa.gov/aircraft/air_cert/airworthiness_certific...

overall i agree with you, i'd love a mooney, and would probably buy one (or a used cirrus) if i was in the market for an airplane.

but i think the 172 does have some upsides:

- docile handling

- availability to rent, pretty much globally

- availability of a&p who are super familiar with it

- low insurance rates and superior safety record

- landing gear can take a lot of abuse

Retract on any aircraft is going to drive up insurance.

The number of gear up landings on Mooneys surprisingly high. As for cirruses, they are rather unforgiving, and I think people get some confidence with the parachute--every time I hear about an accident, I feel I'm reading about another Cirrus.

Another reason there are so many Cirrus accidents is that in an effort to improve its safety record, Cirrus began advising its pilots to use the parachute whenever in doubt. I don't mean this as a knock in the slightest -- the statistics are very convincing that this is saving lives[1]. But a funny side effect is that you see a bunch of accidents where someone parachutes a Cirrus into a field that any other airplane would have just landed in.

[1] https://airfactsjournal.com/2016/08/whats-right-cirrus-pilot...

Yeah, I recently went through Cirrus training, I'm quite current for a GA pilot (150 hours a year, commercial and instrument ratings) and personally feel it's a lot of plane. Most of the avionics and checklists, while great if you are used to it could easily task saturate you. It could probably also lure you into thinking it's a Tesla and not an airplane.

A Cirrus is an easy plane to get behind in. Jumping from a C152 that putters along at 90kts leaves you with a lot of time to work the checklists. When I started flying the high performance aircraft it was really easy to miss things because everything was faster. The cirrus was fun but you have to pay attention.

Yeah, this is not to be underestimated

There was a huge difference in trying (and often failing) to stay ahead of the plane even moving from a 172 to a 182.

I've heard once you get down nearing stall speed, the Cirrus gets pretty difficult to control?

My uncle did that in his Mooney, in fact, not terribly many years ago. He was super embarrassed, but it is, as you say, pretty common. The gear-up landing was a non-event from a safety POV, but was essentially financially terminal for the plane -- prop hit the ground, etc.

As you can buy a one ray lidar sensor for about a $100 for drones, with about 50m of range, I wonder why it can't be used in full scale airplanes? It could be used to point down at the ground, and when the lidar is confident of the range and if the gear is up, then trigger an alarm.

I get that there's more things involved for a practical implementation (weight, reliability, added complexity) but still... What am I missing?

There are similar (but more basic) systems built into some retractable gear aircraft. They generally provide an audible alert if the plane appears about to land but the gear is still up.

Pilots still land gear up, even with the alarm sounding. There is (or at least was) even a public (YouTube) video of this happening from a passenger filming.

Landing a plane is not difficult (source: I’m a pilot) but there’s a lot going on. This is clearly a UI/UX issue but innovation is relatively slow in the certified market.

The anecdote I've heard is that the gear up / low throttle alarm is usually the component to break and people fail to replace it, which leads to gear ups.

Just search for "gear up landing"; this situation is...plentiful. https://www.youtube.com/watch?v=2hMn7ZweF6s

And yeah, before anyone says "but the beeping!" - yup, people are fallible. I've managed to scratch a car in a similar but far cheaper setting: start up...set navigation...go into reverse...think about the traffic announcement...think about garage keys...hear parking sensors beeping...beeping intensifies...CRUNCH...facepalm, dammit I was supposed to brake! In my case, this was a low-speed, low-energy collision, so just a tiny scratch on plastic, but I can definitely see how a minor distraction can turn into a major accident.

Task saturation. It's windy, turbulent, your wife is uncomfortable and giving you looks. Someone cuts you off as you are landing, you go around. The field is busy and as you come back around for landing you're focusing about being unable to get your radio calls in. You land to the sounds of grating metal... Just one of 1000 scenarios.

As mentioned there are alarms already, but you can drown it out if sufficiently overloaded. Its best to recognize overload, take a deep breath and go back when calm.

Doesn't a used 172 optimize both cost and safety? Are there any planes that are more affordable than a used 172?

A used 150/152.

you know what always grinds my gears... the fact that everyone stops short of reminding the normals that litigation in private aviation lead to the fact that the final Cessna 152 was produced in 1985

Normal here. Can you explain?

Cessna ceased production of all light aircraft in 1986, citing increasing lawsuits and legal liability for things it could not control in any practical sense. This had a huge negative impact on the GA economy and culture, because until that point, Cessna was producing more aircraft than any other company in history, and its 152 and 172 models were the most widely used trainers and safest GA aircraft ever made.

In 1994, Congress passed GARA[1], and two years later Cessna began producing new aircraft again. But having been out of the industry for a decade, Cessna lacked some combination of the means and confidence to bring back its entire fleet; so it focused on the 172 for the training market and abandoned the 152, which never saw production again.

https://en.wikipedia.org/wiki/General_Aviation_Revitalizatio...

How about Vans Aircraft? Homebuilt are often overlooked, but an RV-10/14 gives you some good options. Only downside with homebuilt IMO is lack of ability to train in them.

I wanted an RV7 when I started flying. Partly due to the price, it seemed like a good trade off to be practical. I've flown a few of them, but never long term. We saw several in the 2 years of shopping and one was pretty sketch in terms of build quality.

My wife got her PPL and all the sudden had an opinion on what to buy. :) She's now a CFII so her opinion matters.

I still would be into getting one if my wife was sold on home built.

Another benefit of E-AB category is that you can do your own maintenance and annual condition inspections (if you are the builder), saving you a gazillion in recurring costs.

Plus the freedom to modify. In a Cessna, you can’t so much as run a USB charger out to the panel without the FAA coming down on you like a ton of bricks. On an experimental, if you want the latest electronics or if you want to swap in a different engine, go right ahead, sparky!

(Disclaimer: I’m 3.5 years into a RV-7 build so I’m biased)

> you can do your own maintenance and annual condition inspections (if you are the builder), saving you a gazillion in recurring costs.

You're not kidding. I think the cheapest annual inspection I've ever seen was around $2,000 for an old, clean 172 that needed zero actual work. More typical is ~$4,000-$10,000 for a modern-ish 4 seater, depending on what they need to do. Throw in $20,000 every several years for an engine overhaul. If you have a G1000 and they need to touch it, it's going to cost you at least half a car.

I have an RV-10, and it’s amazing. I can take 4 adults at 160kts burning 10gph, it’s easy to handle for a high performance airplane, and it’s such a simple design that maintenance costs are low.

Lancair 4P

What does turbo-normalised mean in this context?

https://en.wikipedia.org/wiki/Lancair_IV

In aircraft engines, turbocharging is commonly used to maintain manifold pressure as altitude increases (i.e. to compensate for lower-density air at higher altitudes). Since atmospheric pressure reduces as the aircraft climbs, power drops as a function of altitude in normally aspirated engines. Systems that use a turbocharger to maintain an engine's sea-level power output are called turbo-normalized systems. Generally, a turbo-normalized system attempts to maintain a manifold pressure of 29.5 inHg

Many turbo cars can do this too. The turbos are not sized to the bare minimum to make rates powe at sea level, so they can compensate.

His is one of the reasons why turbodiesels are valued for hauling. They can still make (near) rated power across the Rockies, where an NA engine might be down 30-40%

My best guess is turbocharged to bring pressure at the carburetor to atmospheric pressure at sea level (1 atm.). So, you're not putting much more stress on the engine than it would get without the turbo at sea level, but you get constant engine performance up to a good altitude.

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