Buying aircraft- 80 % / 100 % use case ?

[RFguy]

Thanks M61 for the write up. Understand. I'm going to get a small small to start with, I figure that I will need to get some genuine perspective from my own eyes as what I really need over the first 6-12 months.

 

One of thing things I want to determine is how important are STOL characteristics for me ? IE just how often am I going to see to land at one of these short strips ? I will only know that after running the real life participation.

 

On the VA limit- Amen- I made a post yesterday about this - I noticed much of the fantastic plastic is very like Va compared to Vcruise.

 

https://www.recreationalflying.com/threads/va-and-fantastic-plastic.72810/#post-571131

 

off to Cowra.

[M61A1]

One of thing things I want to determine is how important are STOL characteristics for me ? IE just how often am I going to see to land at one of these short strips ? I will only know that after running the real life participation.

It’s not necessarily STOL that is required. There are many places with strips that are plenty long, but in very average condition. Little tiny wheels and a fragile undercarriage will prohibit operation from a lot of rural and outback places. It will be ultimately up to you and what you want to do with the aircraft.

[facthunter]

There's a downside to STOL so don't rush in there. IF the wind gets strong and gusty, you'd wish you hadn't chosen to fly that day. Really low wing loadings, you get blown away. A C-152 will land in less than 3 tennis courts if you are used to it and practise. The main aspect in all of this is HOW well do YOU fly.? (whatever plane you fly). Nev

[skippydiesel]

All these generalisations - to what end?

 

There are aircraft that have BOTH low stall and high cruise. Fantastic control authority and very robust undercarriage.

 

(I am sure Nev will take me up on the following;)

 

As for the comments on V rating (Va speeds) - leaving low speed/ stall asides, In my humble opinion the important V ratings for RAA type aircraft are those that relate to the margin between NEVER EXCEED SPEED (Vne)/ and normal operating speeds. So;

 

(Vh) MAX STRUCTURAL CRUISE @ MAX CONTINUOUS POWER is an easy performance point to reach.

 

IF the Vh is close to the Vne, you have only a small margin of error where an over speed, resulting in structural damage, might occur. So look for an aircraft with a wide margin.

 

Other important V ratings are DESIGN MANOEUVRING (Va) MAX MANOEUVRING (Vo) DESIGN MANOEUVRING FOR MAX GUST (Vb) as these relate to turbulent air penetration speed limits.

 

The above figures, when analysed and not taken in isolation, for the aircraft under consideration are indicative of structural integrity at the higher speeds that you may expect to encounter.

 

True all aircraft are a performance compromise but some require far greater compromise than others

[facthunter]

They aren't generalisations. I specifically mentioned WING LOADINGS in relation to gust sensitivity not stall speed.. To get low stall and good cruise speeds you need an efficient flap system. The High wing Cessna's have the best of the normal ones. "Fowler".. One of the worst aspects of a popular plane is max flap speed above clean turbulence penetration speed.. You need to get too slow to extend flap. Low wingload planes are also rough riding in turbulence and very unpleasant on any longish trip. as they have too much potential extra lift available at a small increase in relative A O A.. They also respond too easily to a gust when trying to land if they can't DUMP all or a significant amount of the excess lift available when you touch down, Nev

[Yenn]

RF guy. put yourself in Jabiru shoes. Over the years Jabiru have built up a big fleet of Australia built aircraft, even though there has been a big group of knockers trying to pull them down. These aircraft have worked well and have a good name, especially in the USA. Jabiru also sell their engines into the US market and have a good name.

Go to Jabiru and tell them that you have the answer to all their problems and they may listen to you. They may also say to themselves " here comes another Knocker"

I think you will need to show a really good reason for them gettign involved with another unknown "Expert"

I m not trying to knock you as I think you may be onto something, but nobody likes someone telling them they don't know what they are doing an I am your saviour. You will need clea reasoning for what you propose, how it will work and why it is better than what we have at present.

[M61A1]

All these generalisations - to what end?

 

There are aircraft that have BOTH low stall and high cruise. Fantastic control authority and very robust undercarriage.

 

(I am sure Nev will take me up on the following;)

 

As for the comments on V rating (Va speeds) - leaving low speed/ stall asides, In my humble opinion the important V ratings for RAA type aircraft are those that relate to the margin between NEVER EXCEED SPEED (Vne)/ and normal operating speeds. So;

 

(Vh) MAX STRUCTURAL CRUISE @ MAX CONTINUOUS POWER is an easy performance point to reach.

 

IF the Vh is close to the Vne, you have only a small margin of error where an over speed, resulting in structural damage, might occur. So look for an aircraft with a wide margin.

 

Other important V ratings are DESIGN MANOEUVRING (Va) MAX MANOEUVRING (Vo) DESIGN MANOEUVRING FOR MAX GUST (Vb) as these relate to turbulent air penetration speed limits.

 

The above figures, when analysed and not taken in isolation, for the aircraft under consideration are indicative of structural integrity at the higher speeds that you may expect to encounter.

 

True all aircraft are a performance compromise but some require far greater compromise than others

There are quite a few previous threads here about the importance of Va.

I've just had a look at the Atec site and it has a Vra for the Z2000 (V rough air) of 107 knts which is considerably quicker than the listed Va of 80 knots.

Perhaps someone more familiar with design engineering could explain the difference?

[Thruster88]

There are quite a few previous threads here about the importance of Va.

I've just had a look at the Atec site and it has a Vra for the Z2000 (V rough air) of 107 knts which is considerably quicker than the listed Va of 80 knots.

Perhaps someone more familiar with design engineering could explain the difference?

Turbulent air penetration speed and max maneuvering speeds are different.

[M61A1]

Turbulent air penetration speed and max maneuvering speeds are different.[ATTACH type=full" alt="Resized_20200828_180728_3863.jpg]55864[/ATTACH]

Yes...but How is Vra defined and calculated?

[Thruster88]

Yes...but How is Vra defined and calculated?

I have not heard of that one and a google search produced nothing. We all ready have enough V speeds without manufacturers inventing more. Smarter people than me work out Vno. If Va was also marked on the ASI it may have saved a few in flight failures on aircraft like the c210.

[RFguy]

This morning I wrote " very like Va to Vcruise. But I meant "very LOW Va to Vcruise".

 

First 3 hours of flying today... (3 landings)

with Rob Glenn at Cowra tn the Brumby 610. Great CFI we got on well.

 

Surrounded by 4 x AG planes that were busy....who are clearly highly skilled and very obviously completely nuts from my POV.

 

The first 20 minutes were the most demanding of my entire life. Then it got easier.

 

Now, I always used to wonder after reading many accident reports, "how the **** did the pilot do that ?"

 

Well, now I know that it is easy for a pilot to **** up.

Edited August 28, 2020 by RFguy

[skippydiesel]

They aren't generalisations. I wasn't aiming at you specifically but all of the subjective and very general proceeding comments, stated almost as if fact

 

I specifically mentioned WING LOADINGS in relation to gust sensitivity not stall speed.. Agreed

 

To get low stall and good cruise speeds you need an efficient flap system. Agreed and such RAA aircraft have existed for 20 years or so

 

The High wing Cessna's have the best of the normal ones. "Fowler".. One of the worst aspects of a popular plane is max flap speed above clean turbulence penetration speed.. You need to get too slow to extend flap. Agreed

 

Low wingload planes are also rough riding in turbulence and very unpleasant on any longish trip. as they have too much potential extra lift available at a small increase in relative A O A.. They also respond too easily to a gust when trying to land if they can't DUMP all or a significant amount of the excess lift available when you touch down, Nev In theory you are correct, however in my actual real life experience of this type of aircraft you are not. The situations you mention, can be readily managed, by any competent pilot, who takes the time to read & apply the POH, and take some aircraft specific handling advice when transitioning to an unfamiliar aircraft.

 

All to often pilots become type specific in their aircraft handling responses/skills - this results in the unfamiliar aircraft being blamed for the pilots unwillingness to adapt/learn. I do not exclude myself from this tendency but at least I am ware of it and strive for objectivity when commenting on an unfamiliar aircraft's performance.

[M61A1]

 

I didn't state it as "almost as fact" it is a fact, that Va is often much lower than Vno, especially in lightweight aircraft, many of which are European. Generally because the aircraft are built down to a weight and designers squeeze every bit of useable load out of them.

During Australian summers turbulence (and often almost any other time of year) is quite real, and such aircraft become severely limited unless you actually want to find the point where the wings fall off.

 

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[skippydiesel]

I didn't state it as "almost as fact" it is a fact, that Va is often much lower than Vno, "Often" meaning not all, possibly a few especially in lightweight aircraft, many of which are European. - Generally because the aircraft are built down to a weight and designers squeeze every bit of useable load out of them. You have taken a few examples where this is true and extended this to all - hardly fair and far from factual.

In fact the aircraft that I represent and those of similar capability have high Vne (never exceed) relative to Vh/Nno/Vc (max cruise) and relative to many other RAA types high turbulent air speeds (Va/Vo/Vb) eg ATEC Faeta 321: Vne 159 knots, Vc 134 knots, Va 89 knots.

During Australian summers turbulence (and often almost any other time of year) is quite real, and such aircraft become severely limited "Limited" what does this mean? unless you actually want to find the point where the wings fall off.

My experience may be limited to a few smaller GA and a couple of RAA types but ALL my training would suggest that ALL aircraft/pilots slow down to recommended rough air penetration speed in turbulence - so how is this different for these other aircraft you allude too?

 

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[facthunter]

Skippy, the points you question in my post are widely accepted by everybody with experience in training and aircraft design and analysis. I'm not making up NEW stuff anywhere here. Pat yourself on the back for "objectivity" but keep working on it.

By the way where are these RAAus types with efficient flaps that also cruise at high speeds and I question the ACTUAL TAS of many of the "CLAIMED 30 kt stall speeds we hear of. (as do many others)... I do wish you would read my posts more carefully before launching into a condemnation of what I'm "supposed" to have meant .

SO just WHY does YOUR "real life" experience contradict just about every experienced pilot, instructor, designer who comments on these matters? Have you instructor time? You learn fast when you start doing that.. Nev

[skippydiesel]

Skippy, the points you question in my post are widely accepted by everybody with experience in training and aircraft design and analysis. I'm not making up NEW stuff anywhere here. Pat yourself on the back for "objectivity" but keep working on it.

By the way where are these RAAus types with efficient flaps that also cruise at high speeds and I question the ACTUAL TAS of many of the "CLAIMED 30 kt stall speeds we hear of. (as do many others)... I do wish you would read my posts more carefully before launching into a condemnation of what I'm "supposed" to have meant .

SO just WHY does YOUR "real life" experience contradict just about every experienced pilot, instructor, designer who comments on these matters? Have you instructor time? You learn fast when you start doing that.. Nev

 

Nev; I can not hope to achieve your level of aircraft technical know- how/wisdom, however as many have said befor me "I know what I knows" - should it ruffle the feathers of accepted wisdom, so be it.

 

Ref: I do wish you would read my posts more carefully before launching into a condemnation of what I'm "supposed" to have meant . Right back at you Nev - offer alternative opinion yes - question yes - condemn no - me thinks you mount yourself on a very high horse.

 

Case in point: Faeta aircraft being used for training. Aircraft new to school. Instructors not happy with aircraft performance - Why? Faeta "wont land", "remains in ground effect for too long", considered to be an "advanced trainer" - what does this mean to you? To me its a case of instructor failure to read/absorb/apply POH, who, unthinkingly, are applying other aircraft handeling characteristics to the Faeta. In short not making the necessary transition. The fault is all the instructors, non is the Faeta's. This is not uncommon - how often have you come across a flight school; all Cessna, Piper, Jabiru, Technam - the instructors/students swear their aircraft are the best, wouldn't look at another, come up with all sorts of "factual" hearsay about the alternatives. This is human nature - we gravitate to the familiar. I suggest, that all commercial aircraft operators are familiar with this scenario and require considerable transition training/time when a pilot moves from one type to another - are they wrong?

 

Ref "By the way where are these RAAus types with efficient flaps that also cruise at high speeds and I question the ACTUAL TAS of many of the "CLAIMED 30 kt stall speeds we hear of. (as do many others)"My thanks to you for asking (an thereby giving me the opportunity)- ATEC & Pipistrel aircraft are the ones that come to my mind. There are quite likely to be a few others. Every confidence that these aircraft can perform as claimed (unlike so many others).

As an ATEC rep I offer you: ATEC Aircraft - Czech manufacturer of light sports aircraft | ATEC Aircraft

The aircraft POH are available in Downloads. The English can, at times, be a little changeling however the figures quoted are factual..

[facthunter]

Surely your involvement with those aircraft means your comments are NOT free of personal interest.. Don't blame ME for what some instructors say.. Slippery /clean aircraft ARE difficult to wash off excess speed. Carrying extra to make the approaches safer / easier to control is a common bad habit. Put the 2 together and you have something that must be corrected or it will show in the statistics.. That's NOT a critcism, just a fact. I ask again. Have you done any instructing? Because I think it has a bearing on this.. and you are ignoring instructors inputs and discrediting them in a desire to deflect concerns about a product you sell. Nev

[M61A1]

Case in point: Faeta aircraft being used for training. Aircraft new to school. Instructors not happy with aircraft performance - Why? Faeta "wont land", "remains in ground effect for too long", considered to be an "advanced trainer" - what does this mean to you? To me its a case of instructor failure to read/absorb/apply POH, who, unthinkingly, are applying other aircraft handeling characteristics to the Faeta. In short not making the necessary transition. The fault is all the instructors, non is the Faeta's. This is not uncommon - how often have you come across a flight school; all Cessna, Piper, Jabiru, Technam - the instructors/students swear their aircraft are the best, wouldn't look at another, come up with all sorts of "factual" hearsay about the alternatives. This is human nature - we gravitate to the familiar. I suggest, that all commercial aircraft operators are familiar with this scenario and require considerable transition training/time when a pilot moves from one type to another - are they wrong?

As you say, that has everything to do with the instructor. All aircraft are what they, are and the pilot has to live with what that is. That is pretty much the point of this thread.

Someone is trying to find and aircraft they can live with. My friend has a lovely aircraft it has very similar qualities to the Faeta, and I love flying it, but it won't do what I want to do and stay in one piece.

I fly whenever I can and a lot of those days are hot and blustery, days when many people might just stay at home with the aircon on. I fly to a lot of places with unprepared strips, but that's just me (and a lot of others).

I've seen what happens to aircraft like the Faeta when they are landed somewhere inappropriate.....not pretty.

These points I raise are just things for the OP to consider. Things that I hadn't given a lot of thought about when I bought what I've got. They are not a personal attack on you or your aircraft.

[facthunter]

Asking you to read my posts carefully before you attack me and them over the content .Is THAT too much to ask of you..? Seems entirely reasonable to me. Not appropriate for you to bring the" High Horse" up either, thanks. I'm not pulling rank as it doesn't exist here as far as I'm concerned and it's NOT my style. anyhow. I will be judged by what I actually say here and it's all up for discussion and not a contest. Nev

[skippydiesel]

Surely your involvement with those aircraft means your comments are NOT free of personal interest.. Don't blame ME for what some instructors say.. Slippery /clean aircraft ARE difficult to wash off excess speed. Carrying extra to make the approaches safer / easier to control is a common bad habit. Put the 2 together and you have something that must be corrected or it will show in the statistics.. That's NOT a critcism, just a fact. I ask again. Have you done any instructing? Because I think it has a bearing on this.. and you are ignoring instructors inputs and discrediting them in a desire to deflect concerns about a product you sell. Nev

There is no pleasing/placating you is there.

You have a great deal to offer but your knowledge is tarnished by your inability to allow other opinions, very sad.

You have never been attacked - your own thin skin seems to make you see every differing opinion/ criticism as an attack - get over it.

You take a third party story and you see it as a reflection on yourself - you are not that important

No, I have never done flight instruction - does that disqualify me from rational, logical, objective comment??? Sound's like it.

Whats all this BS about - "and you are ignoring instructors inputs and discrediting them in a desire to deflect concerns about a product you sell." where did that come from ?????

Sure I am passionate about my product , never denied that, but to suggest that I cant make an objective comment, because I try to sell aircraft is... well mountains of bulls excrement comes to mind.

I give you a reasoned argument with examples and that's the best you can do - perhaps your (over) confidence in your own knowledge is clouding you ability to see matters from an other perspective. It certainly doesn't inhibit you from making quit outrageous statements/ deductions from an otherwise simple example.

[RFguy]

Golly !

Today's work. 3.3h...... circuits are hard work. 10 landings total. several touch and goes. Last two were my best, actually got thing lined up onto the ground with a good circuit.

Change of aircraft behaviour when flown slow in the final take time to adapt to.

 

Workload per flight climbs, although stalls were not a high workload. felt like a break.

takeaways from today:

-aircraft takes time to catch up with small inputs. inertia

- errors cascade (esp. in circuit work)

- correct speed over the fence is super important

- book stall speed (S&L flight) is at best a guide to what it might do in all other scenarios .

 

Now.back to the STOL need question.

From today, I feel that aircraft can land in 200m and stop , IF you get the approach JUST RIGHT.

 

this is not a "STOL' plane by today's speak. just has to have a tough enough undercarriage for roughness.

[facthunter]

3.3 hours is too much for a concentrated effort. Take a break after about one hour or you are wasting money and risk getting unimpressed by your progress. U/L undercarriages are not very strong. Try to hold it off for as long as you can ,but don't balloon it. Nev

[Jack in Arizona]

There's a general theme of advice directed at aspiring long distance sailors you might want to consider: Buy the 'last boat' first and then keep it. One learning curve to master plus more learning sooner given the boat's expanded mission capabilities. One set of costs for upgrading and one set of efforts for personalizing, plus you'll find it easier to make quality choices for upgrading kit since you know you will be living with the boat longer. Your devotion to the boat's care may be stronger since you know it will be yours longer. If you can bear the cost of the 'eventual' boat first, the purchase will be outright cheaper, sooner vs. later, and you'll avoid the buy-sell-buy again sequence that can add even more cost to the equation. You'll notice one of your first responders' comments, regretting he didn't build a RV-10 'first' and now is a bit 'stuck' by buying the 'first plane first'.

 

I think this theme makes even more sense for planes than boats. You are starting with known geographic limits (flying within Oz) while, with a boat, distances are essentially unknown initially. There are multiple plane choices to meet your requirements within reach of financial mere mortals. Some ongoing costs (e.g. hangar or ramp storage or an avionics upgrade) are independent of a plane's size (unlike boats where 'more' truly does seem to cost more), and you can buy the larger airframe/engine capable of that 10% mission ( perhaps initially with less avionics and/or cosmetic upgrades to be budgeted over time) whereas with a boat you may need for it to have the structural requirements for an ocean crossing, even if that may only be a 'one day' goal.

 

Jack

Prescott AZ USA

[RFguy]

3.3 hours is too much for a concentrated effort. Take a break after about one hour or you are wasting money and risk getting unimpressed by your progress. U/L undercarriages are not very strong. Try to hold it off for as long as you can ,but don't balloon it. Nev

clarification : 3 x 1.1 sessions with 1.5h min gaps.

[RFguy]

hi jack,

your comments are useful . I have a friend in locally who is chomping to go halves in a plane. He just sold his Cirrus. There is much much more to this story , but the ultimate result is symbiotic So I will end up being a co owner and happily.

 

but.

 

The additional complication is that I also want to experiment with some different ideas (modifications) and do my own maintenance, this is one of the reasons I went down this track. and I don't really want to a involve a hands-off style co owner in on that aspect of my ownership .

 

so I will end up with two planes , most likely. now, this aspect might assist with the 80/20 problem.