Top of climb

[Brian M]

I am having trouble with the TOC calculation. My field elevation is 2200 and climbing to 10,500. Do I calculate from field elevation or density altitude? We have high DA out in the desert.

 

[RyanB]

If you want to calculate it manually use this simple equation.

TOC=GS/60xCRZ/VS

GS-Ground Speed
CRZ-Crusing Altitude
VS- Vertical Speed

Here’s an example: 115kts/60x5500/600FPM gives you a rough TOC estimate of 17.5nm.

Of course there’s calculators on the web that will do it for you too.

 

[Clip4]

I am having trouble with the TOC calculation. My field elevation is 2200 and climbing to 10,500. Do I calculate from field elevation or density altitude? We have high DA out in the desert.

Ideally you want to use the DA for the departure airport and cruise altitude. The reason is at high DA climb performance suffers. Your aircraft POH should give you the procedure.

 

[luvflyin]

Ideally you want to use the DA for the departure airport and cruise altitude. The reason is at high DA climb performance suffers. Your aircraft POH should give you the procedure, although some manufactures use PA.

View attachment 65612

I don’t think I would plug the density altitude at the airport in as the ‘field elevation’ in the equation. But I would use it calculate the Verticle Speed to be plugged in. Not sure if it would make a difference. My answer is really a question

 

[Clip4]

I don’t think I would plug the density altitude at the airport in as the ‘field elevation’ in the equation. But I would use it calculate the Verticle Speed to be plugged in. Not sure if it would make a difference. My answer is really a question

You might notice DA on the left margin. It really depends on how accurate you want your estimate to be. 50-100 fpm error?