Why No List Your Set Up Section For IC

[Motorman]

Would be nice to see what engines/props are pulling what planes with wing area and weight. Not everybody knows what's out there.

MM

[Tim Wescott]

Not a bad idea, although if Randy blesses it we should probably include what sort of run (wet 2, 2-4-2, etc) we aim for.

There is a "list your 46 LA" thread, which is handy.

[john e. holliday]

And a lot depends on which part of this great land you fly in.

[Tim Wescott]

And a lot depends on which part of this great land you fly in.

Good point -- if you read enough of the engine setup threads you'll see comments about altitude, humidity, temperature, and the unfortunate effects of all three for competitors from the Pacific coast coming to the Nats for the first time.

'lectrics are susceptible to the same factors, but to a lesser extent, because only the prop and airframe are affected; you don't have an airframe that needs more power being pulled by a motor that can't produce it as well any more.

[Brett Buck]

Good point -- if you read enough of the engine setup threads you'll see comments about altitude, humidity, temperature, and the unfortunate effects of all three for competitors from the Pacific coast coming to the Nats for the first time.

  Interestingly, while we certainly lose power until we get the nitro up, overall, the engines run a bit more smoothly and a lot of the odd funnies (like the inside/outside run symmetry) tend to be reduced.

I also generally fly a bit more slowly for a given control feel, maybe .1 - .15  seconds a lap. In good air, I usually average around 5.25 or so here, and 5.35-5.4 most of the week at the NATs. David also slowed a bit, and many of us have noted the same thing over the years. Both of them seem to be because the engine runs even "flatter" than normal, you can run it harder on average without having it break.

  Even in the heavy air on Friday this year, I cranked it up a bit, but was still only 5.27 and 5.21 on my two flights and it was pulling solidly even at the top of the round 8 and I never had any real issues with either whip-up or any concern it wasn't going to make it. And I didn't seem to have the extreme overkill line tension that made Orestes' finger go numb!

   Brett

[Steve Fitton]

Good point -- if you read enough of the engine setup threads you'll see comments about altitude, humidity, temperature, and the unfortunate effects of all three for competitors from the Pacific coast coming to the Nats for the first time....

I just want to know what sort of wristwatch Brett has that he can look at it for density altitude readings....

[Brett Buck]

I just want to know what sort of wristwatch Brett has that he can look at it for density altitude readings....

   The pressure altitude also matters.

    Brett

[Eric Viglione]

Yeah, add "me too" to that question Brett... since DA (density altitude) is essentially PA (pressure altitude) corrected for nonstandard temperature, no? Not disagreeing, I am just trying to understand the relationship better as you alluded to.

I did notice Kestrel ads additional functions to their "racing" model. The 4250 Racing unit for $10 more than the well known 4200 has a few extra measurements for humidity grains and relative air density, but drops barometer for absolute pressure instead, which I thought was interesting

This past Nats was a good example to use... it was cool, not typical burn your feet on the Lpad Muncie in July, yet, I "think" one of the other elements was on the move, like the pressure altitude was on a swing or something, and the humidity was high, despite the cooler temps, where you would think the DA might have been reasonable.  I noticed several people were looking for nitro in conditions we wouldn't normally expect. (witness bottles of RotoRage Helli fuel on the LPad)

Inquiring minds want to know!
EricV

[Steve Helmick]

Many people post asking for advice on their setup but don't tell where they live, what altitude, temps, etc., so what advice they get may or may not apply. Some just list the name of their town, which is useless. Lots of towns have the same name in different states...and a few even in the same state! One nut job gives only his latitude and longitude, thinking he's being clever. It's not, Tim!  Steve

[Tim Wescott]

Many people post asking for advice on their setup but don't tell where they live, what altitude, temps, etc., so what advice they get may or may not apply. Some just list the name of their town, which is useless. Lots of towns have the same name in different states...and a few even in the same state! One nut job gives only his latitude and longitude, thinking he's being clever. It's not, Tim!  Steve

Hey!  That lat/lon is about 10 feet from where I'm sitting right now -- how much closer can I get?

You liked it better when it said "Right here"??

[Steve Helmick]

No, it makes sense to just have your profile show where you live, whether it's Boring, Damascus, Molalla, Estacada, or Happy Valley. Whatever is your mailing address. That way, it's easy enough to find the local airport and find out what the altitude is, check the NOA weather site and see what the temps and humidity is, etc. It would be much more useful to know if yours is similar to somebody else's geophysical data. Especially "out West" where altitudes and temps can be so different.

Most importantly, some guy might just find out that he lives nearby your location and suddenly you have a new flying buddy! But say, shouldn't you be working?  Steve 

[RandySmith]

Would be nice to see what engines/props are pulling what planes with wing area and weight. Not everybody knows what's out there.

MM

If you want to know about a certain size weight span etc  all you need do is  ASK

it would be very very hard/time consuming to list the millions of setups that can be used

Regards
Randy

[Brett Buck]

Yeah, add "me too" to that question Brett... since DA (density altitude) is essentially PA (pressure altitude) corrected for nonstandard temperature, no? Not disagreeing, I am just trying to understand the relationship better as you alluded to.

  It's 3000 feet for every 15 degrees above 59F, roughly. So a pressure altitude of 1000 feet at 104 degrees is a density altitude of roughly 4000 feet (ignoring the temperature lapse rate which is pretty small for this purpose). Easy, and in particular, you really only care about the relative change, not the absolute number for air density.

   Brett

[john e. holliday]

Look at my posts to see where I live.  I think my new circle is probably 100 feet lower than where I live.  Right now temp shows 84F degrees. 

[Eric Viglione]

  It's 3000 feet for every 15 degrees above 59F, roughly. So a pressure altitude of 1000 feet at 104 degrees is a density altitude of roughly 4000 feet (ignoring the temperature lapse rate which is pretty small for this purpose). Easy, and in particular, you really only care about the relative change, not the absolute number for air density.

   Brett

I think i got it, as long as that was a typo and you meant 1000ft for every 15deg ?
EricV

[Jim Hoffman]

I have an AP on my IPhone called AUTO DENS

AUTO DENS provides:
•   Density altitude
•   Pressure altitude
•   Temp
•   Barometric pressure
•   Elevation
•   Dew point

AP is free.  It seeks out the nearest weather station, usually an airport, and reports that data

Hope this is helpful

Jim Hoffman

[Joe Hamorski]

You can always call the nearest FBO for that information. If you are a traveling flier, the altitude can very greatly. Definitely worth noting what it is wherever you are flying. Playing professional golf for many years, altitude is very important for distance control. Just sharing some thoughts