Discussion in 'Hangar Flying' started by Inverted Vantage, Nov 15, 2009.
Angle of attack and horsepower? Lol
OK - those wings will produce lift. They will stall at a relatively low AOA, and they'll have a lot of drag, but pretty much anything at an AOA will produce lift. Stick your hand out of your car window and angle it upward a bit - does the relative airflow push your hand up? Is your hand, held sideways, shaped like an airfoil? No, mine either, but yet...
flat plate wing
and let us know what you find. Also, take a look at figure 4.36 in this discussion:
Clearly lift producing.
There may be multitudinous issues with the man's airplane - without knowing more about it, I certainly can't say. But not being able to produce lift isn't one of them.
A maximum lift coefficient of 0.5 on wings that small, with a sharp low angle of stall borders on "no lift". Sometimes the practical answer is more useful than the technical answer. That's to say, you're not wrong, just... it's still not going to fly, and if it does fly, it's going to be vicious, nasty, and fast.
I thought it was interesting, I was reading an article from Flying magazine earlier today. I'm not certain the age of the article as I found it in an archive online, but it was saying that in the 60's a homebuilt aircraft took an average of 3000hrs to build and cost an average of $10,000 to complete. At the time of writing the average was 1000hrs to build and "10 to 20 times that cost," substituting money for time. The author did not go on to say whether this was a good or bad trend, but I thought it was interesting and worth sharing here.
Much of that extra cost is certainly due to inflation. The shorter build time could be good or bad depending on ow much you enjoy building.
The “average” homebuilt in the 1960’s was nothing like the majority of HBA today. 4130 steel tubing was purchased from surplus outlets. Wheels and brakes were salvaged from wrecked certificated aircraft. The instrument panel consisted of salvaged AS, ALT, compass, and oil temp / pressure gauges. Very few had any electrical; they were strictly day VFR. Comparing them to today’s HBA is not realistic.
But yes, new airplanes today, E-AB and Type Certificated alike, are expensive.
It would be interesting to do an apples to apples comparison with an aircraft built the same way as an old one.
People bought houses that were close to $10,000 in the 60s, so a top plane was still expensive. That’s why Teenie Twos, VPs, and Rand VW planes sold so many plans. Dream of the sub $1000 airplane. Cheap planes have always been the dream, with performance. Think of the performance difference of a $500 Cub and a T2. That was what people looked at. 3000 hr airplanes are ones you make every part yourself. They really are all 3000 hr to build airplanes. Fast build just means some factory built 2000 hrs of it before you got you kit. It still adds up.
Here is an apples to apples comparison. In 1974 the reported price of materials to build a CriCri was USD $1000 including engines and instruments. I haven't added up the costs for mine lately but I think it will be close to USD $20,000 (approx NZD $30,000, ZK-CRI was NZD $35K a few years back). Even if it ended up costing USD $1500 in 1974, there is still a big difference in price today and that also doesn't count that non-certified digital instruments are far cheaper today, relatively speaking....
$1000 in 1974 inflates, in the USA, to $4160 today. That doesn’t come close to accounting for the total cost increase.
How about comparing the cost of a sheet of aluminium in 1974 and a sheet of aluminium today for the price increase?
The government CPI statistics are known to be corrupt on how they calculate inflation, much better to use the same goods to compare the price increases as inflation in the statistic is vastly understated. Here in NZ inflation is said to be something under 2% according to government statistics, but actual prices here can easily double in as little as 10 years, putting inflation up to as much as 7% per year when you look at real goods and services.
Aluminum has not increased much.
Very low cost aircraft material. I think I can build a wing for about $100 in aluminum and cover it with fabric.
Do you then use the CPI as inflator?
You may reach a different number closer to todays actual cost if you use the M2 monetary inflation as inflator.
(Rant, CPI is not a measure of inflation if the old definition of inflation is used. Inflation was once defined as the increase in volume of money.)
CPI inflates to $5156.
Choose your favorite; each has its limitations.
Doesn’t change the conclusion, stated in post 1291:
Comment: 1295 posts to make / support the point that airplanes cost more than we want them to. Perhaps we need to spend more time earning money.
That was until the economist discovered that simply increasing the money supply didn't always result in increased CP - at least as quickly as desired. Economist are right in there with weathermen, politicians and homebuilt aircraft vaporware developers.
I've discovered that my Daffodils last longer than my Tulips.
Does anyone in retirement want to go out and earn more money just to buy a new airplane?
The real issue is that cost of manufacturing of aircraft is excessive, they are not injury proof.
So excessive so-called safety regulation and product insurance has forced the price to be always increasing, as court awards and regulation are never limited.
On the other hand a new iPad is on sale for $249 (half original price almost)
The manufacturing is a variable we can choose to manage though.
The lowrider/MPCNC are sub 500$ cnc routers, there's some skill involved in learning to operate and program - but retired means you do have time to learn. Carbon fiber (stranded) PETG filaments for 3d printing makes strong structural and bits and pieces very economically. A intro course at the college to fusion360 is 200$ and will get you somewhere between airplane and engine design basics, with some FEA understanding.
Look at fritzw's designs for jigs and build assists for his ranger design - 2000$ for a fancy wing jig alignment table or 200$ in printed parts and fasteners? It just requires a little rethink in how you approach the issue.
You can pay 1000$/hr machine time + retail wood cost for a kit to have it kitted for you, or spend a bit and be able to manufacture at home...
We're in an era where we should be able to do a lot more ourselves than ever before if we would just buckle down and learn it..
Thank you for participating on this forum.
$5,000 for a pre-fab fuselage kit... including landing gear, covering, and machined parts... is very reasonable for someone who prefers or needs all of that work and material done for him/her. For someone on an oppressively tight budget that may be more than they can pay, but all that means is that a pre-fab kit is not right for them and they need to be scratchbuilding.
Earning more money is mostly a course of action that an individual can (or did) make to affect his ability to have or rent an airplane.
Other than whine, there is not much that an individual can do about current costs.
Separate names with a comma.