Estimating Density Altitude

[coppercity]

Here is a "Rule of Thumb" estimate for density altitude for those that may not have it displayed on their Dynon.

 

1. Set your altimeter to 29.92 to determine current pressure altitude. (dont forget to set it back to the current local altimeter setting)

2. Determine the standard temperature for your pressure altitude based on 15C at sea level and a 2C decrease for each 1000' above Sea Level you are.

3. Subtract the standard temp from step 2, from the current OAT then multiply that result by 120.

4. Add the number you get in step 3 to the pressure altitude in step 1, and the result is a estimate of the current DA.

 

Remember you still fly the same indicated approach speeds and climb speeds regardless of DA, but your True airspeed will increase with DA, along with takeoff and landing distances. We have a great performing airplane but it is not immune to the effects of DA, so be careful out there! Plan ahead and dont be caught off guard.

 

Regards

[Ed Cesnalis]

point of reference

 

at 7,100' and DAs ranging up to 11,000'DA I find that I can get up to 1,200fpm climb from runway when solo, low fuel, and min baggage.

 

if full fuel and max gross my climb rate is cut to ~500fpm

 

performance based on climb rate is still in the "high performance" range. low performance aircraft can't even get off the ground here on a hot summer day or when overloaded.

 

as Eric says the ct has good performance but performance is reduced as DA increases.