who knows is this accurate? or is there a better way?

when i am at a back country strip no altimeter setting. i take my altitude off my 430W or sectional. crank that into the altimeter. then l look in the Kollsman window and use that barometric pressure in the 430W. plug in the temp and woo la 430W spits out DA

g'day

Sportys sells a very simple, cardboard, Take Off Performance calculator that factors in wind, weight, slope, and runway surface. To use it you start with either your type or your actual, personal, SL take off performance and set the rest for conditions. I used it on my last trip to Idaho. I started out doing about six, measured, GW take offs at my home town sea level airport. Then, on my way east I did some testing at different hotter and higher airports. I used my longest SL roll and the calculator. The calculators estimate of what I should do based on those conditions, was very close to what I did do. The calculators sell for about $25 and were recomended to me at an FAA DA seminar. I love the thing.
I think density altitude related crashes are the number one fatal category in the eleven western states. Something like that anyway. Serious stuff!
FZ

flyingzebra wrote:Sportys sells a very simple, cardboard, Take Off Performance calculator that factors in wind, weight, slope, and runway surface. To use it you start with either your type or your actual, personal, SL take off performance and set the rest for conditions. I used it on my last trip to Idaho. I started out doing about six, measured, GW take offs at my home town sea level airport. Then, on my way east I did some testing at different hotter and higher airports. I used my longest SL roll and the calculator. The calculators estimate of what I should do based on those conditions, was very close to what I did do. The calculators sell for about $25 and were recomended to me at an FAA DA seminar. I love the thing.
I think density altitude related crashes are the number one fatal category in the eleven western states. Something like that anyway. Serious stuff!
FZ

Found it! I thought I had seen every mechanical slide rule flight computer ever made, but this is a new one to me.
http://www.sportys.com/PilotShop/product/9305

I have used one of these as a curiosity gizmo for 3-4 years now. I figured the book numbers as a reference, then compare what this spits out. I've found it to be pretty close to actual performance. Pretty cool little gadget to have.

Regarding another earlier comment, if you are at 9,000 ft. and FULL rich, you won't be at max power.

Grassstrippilot wrote:
Regarding another earlier comment, if you are at 9,000 ft. and FULL rich, you won't be at max power.

As painfully illustrated in
hd by a Stinsen pilot recently.

Thanks for posting the refresher.

I've always read it's a good idea to add a fudge factor to the POH numbers since those are determined by experienced test pilots on fresh engines and most of us are not and have engines that have quite a few hours under its cylinders. But I'm fuzzy on a general rule of thumb. Add 20%? 50%? Add the fudge factor of the climb over 50 feet to both ground roll and over 50 foot numbers?

kevbert wrote:

flyingzebra wrote:Sportys sells a very simple, cardboard, Take Off Performance calculator that factors in wind, weight, slope, and runway surface. To use it you start with either your type or your actual, personal, SL take off performance and set the rest for conditions. I used it on my last trip to Idaho. I started out doing about six, measured, GW take offs at my home town sea level airport. Then, on my way east I did some testing at different hotter and higher airports. I used my longest SL roll and the calculator. The calculators estimate of what I should do based on those conditions, was very close to what I did do. The calculators sell for about $25 and were recomended to me at an FAA DA seminar. I love the thing.
I think density altitude related crashes are the number one fatal category in the eleven western states. Something like that anyway. Serious stuff!
FZ

Found it! I thought I had seen every mechanical slide rule flight computer ever made, but this is a new one to me.
http://www.sportys.com/PilotShop/product/9305

An embarrassing number of comments on that sales website read:

returned, too complicated

ahahaha!

Thanks for posting Avid - I have just cut and pasted that figure into my POH. Handy to have.

Nosedragger wrote:

Grassstrippilot wrote:
Regarding another earlier comment, if you are at 9,000 ft. and FULL rich, you won't be at max power.

As painfully illustrated in
hd by a Stinsen pilot recently.

Sorry ND. I misread your earlier comment. Yes, he painfully did demonstrate that.

An embarrassing number of comments on that sales website read:
returned, too complicated

That is sad. I don't know what percentage of pilots there are out there that are like this, but I've come across more than one that want to fly airplanes but don't want to do the homework to understand what makes them fly.