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Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

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Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#591
post #567

Earlier quoted context omitted.

I feel that your third paragraph justifies the sentiment in the second? If left to their own devices, a functionary will add enough regulation to kill any fun activity, because they are not affected by the decisions they make. Another example is the new 406 MHz ELTs; it's not clear how effective ELTs are at saving lives, despite their 'obvious' utility, but now the price is higher, they have batteries that require re…

I'm curious about your comment about 406 MHz ELTs[1]. (I'm not a pilot, though I know a few.) (First, a clarification, the old 121.5 MHz ELTs also require their manufacturer approved batteries to be replaced every few years in order to maintain their certification.) (I also don't know the stats on whether ELTs are effective at saving lives or not. I can only assume they are though as anything that can speed the rescu…

What a great reply. Thanks for the explanation!

My point (which probably ends up taking away from my main point of death-by-a-thousand-cuts) of ELTs being marginally useful is based on an article in one of the flying mags I read earlier this year, I forget which magazine unfortunately, that performed an analysis of aircraft accidents with the goal of analyzing ELT usefulness. For an ELT to be useful, that is in order for it to accelerate the rescue of survivors in the case of an accident, it needs to be the type of accident that is survivable and in which the ELT survives and is heard by a rescue agency. But, also the type of crash that incapacitates the passengers so they cannot activate emergency services by other means, or that emergency services are not already activated by for example a mayday call or missed flightplan, or by a ground witness (so, it must be away from a populated area).

ELTs may also help locate aircraft where there are no survivors but then it could be argued that the usefulness is not pertinent to the pilot. Also, the crash has to be the type that kills the occupants but allows the ELT to survive.

It turns out the numbers are sketchy because the FAA does not always (and not often, if I remember from the article) track ELT activation or whether the ELT aided in the recovery of the aircraft or survivors, and so it's hard to come to a conclusion on ELT usefulness based on statistics.

But it's the kind of thing that aircraft owners have to worry about, even if they fly alone in densely populated areas and file a flight plan, that makes aviation cumbersome due to regulations. I have an ELT, and I buy the damn batteries. I'm also not sure I would fly without one. But it does feel overbearing to have it as a requirement.

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#592

Earlier quoted context omitted.

We are starting in experimental, working with Sling Aircraft for the airframe, factory build assist, etc to prove out the exact product that we want to take to certification in the future.

Thanks for the reply. This is a super interesting project and I wish you great success. As a builder/pilot I have so many little questions, mostly around how you're making all the trade-offs and decisions that pilots make based on the situation in the air (leaning for cruise / power, climb and descent rates, weather-related decisions, switching tanks, and so on). Do you anticipate equipping / certifying the airplane…

I'd love to chat through your questions directly--feel free to book a call with us through our website (just mention this HN post) and I'm happy to talk through everything

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#593

If there’s no rudder controls, how does one do cross wind landings?

The control system knows what the rudder should be at all times for coordinated flight in the air, and keeping the nose and ground track aligned when near the ground for landing, performing the slip necessary when landing in a cross wind.

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#594

Earlier quoted context omitted.

> proficiency is a fundamental issue Have y'all considered that a fully digitized, fly-by-wire aircraft, of the type that you're proposing to build, would also essentially be a ridiculously high-fidelity flight simulator whenever and wherever it is sitting still with the engine off? This could be part of your pitch—the pilot could program in a flight plan and then fly it in simulation, practice all the radio work etc…

we've definitely thought about that! the force-feedback fly by wire makes it really easy to replicate the feel of flying the real thing very well. What you see outside though will be fixed, so maybe for instrument training it would be good, though I'm not sure about using the actual plane vs recreating the cockpit in an indoor simulator

My aviation major roommates in college drilled for their upcoming flights with, I kid you not, a large poster depicting their instrument panel taped to the wall of our quad and a folding chair. Training does not require VR-like immersion to be supremely valuable. :)

Especially when it comes to practicing radio calls, it's the repetition that breeds competence and therefore confidence.

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#595
post #205

This reminds me of programming languages designed with an English-like syntax in the hope that people would be able to develop software without learning to code. It also reminds me a bit of the Ercoupe, an airplane designed in 1937 with the ailerons and rudders mechanically coupled so that pilots would have fewer controls to operate and reduced ability to put the airplane into uncoordinated flight. Neither approach h…

Oh wow. The Ercoupe. Sadly, the original design was found to be an unsafe plane due to very poor spin recovery, but mostly due to being under-powered for its airframe. It actually ended up having a higher-than-mean accident rate for the time which defeated its raison d'etre. There are still more than a few (~200) actively FAA registered today though I'm certain with engine power and control surface upgrades. It turns…

> The general aviation market is TINY

Airhart seems to be planning to expand that market by selling a $500K version of an airplane that normally costs about $250K. I wish them good luck in finding a viable pivot when than plan goes as well as can be expected.

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#596

Earlier quoted context omitted.

One expensive laser-ring gyro, or 3+ independent MEMS gyros? I’ll take the multiple independent gyros, thanks.

What vibration rating do those MEMS gyro stay functional, is it airplane adequate?

Well, some are rated to be able to sustain shocks of 10,000g while powered, and maintain accuracy through lesser shocks that would still vaporize the rest of the airframe, so yes.

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#598
post #584

Earlier quoted context omitted.

How do you deal with failures of the control scheme? You mentioned elsewhere that redundancy means this is unlikely, but is there ever a reversion to "direct law"? Does the plane still have manual trim/rudder/throttle to deal with this, and are the pilots expected to periodically practice using the controls in "direct law"? Do you have a working plane available for a test flight? :)

You can revert to a "direct law" in an emergency should multiple faults occur that reduce the capability of the flight controller. However, there's a question of is that the right move--if a pilot isn't regularly practiced in flying in a direct control, its probably more dangerous to revert to direct law than to say, pull the parachute, so it would be up to the pilot to determine the best course of action. The system…

Thanks for the reply. I'd love to try out the different modes at some point.

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#599
post #413
post #275

Earlier quoted context omitted.

> I'm going to be calling my local government representatives to raise it back up by two with taxes and fees. Sometimes I think this sort of approach is why so many people on the right are sick of global warming. Sure, global warming is a serious problem, but that doesn't mean that taxing things you don't like is wise, fair, effective, or in any other respect a good idea. If you have a problem with emission of gasses…

Plane fuel does not have the same taxes than the fuel you use on your car. Should car and plane fuel have the same tax level if used as personal transport?

Depends whether you think it’s reasonable for fuel tax to also price in road maintenance and local pollution along the route. Airplanes don’t make potholes in the sky, and the cruising portions of their routes don’t expose anyone to any appreciable concentration of particulate, NOx, etc emissions from planes.

Re: Launch HN: Airhart Aeronautics (YC S22) – A modern personal airplane

#600
post #559

Earlier quoted context omitted.

> How do you get seven times? I asked chatgpt what the average consumption of a car is; the answer was 0.5-1 gallon on a highway.

Don't confuse gallons per hour with gallons per mile.

I think I did not.

https://i.imgur.com/4Ik69ki.png

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