Save fuel and money by leaning your fixed prop engine at cruise – regardless of altitude – easily with PilotGEEK's TachCalc. Aircraft POH's recommend leaning above 5000 feet to protect the engine from damage. TachCalc lets you quickly and easily calculate your target RPM for the power setting desired for your current altitude.

And TachCalc simplifies your fixed prop flight planning by allowing you to determine both the best power setting for cruise at your selected altitude and the TAS to file.


  1. -Supports fixed pitch propeller aircraft

  2. -Calculates and displays engine speed for density altitude

  3. -Calculates and displays density altitude for altitude and temperature

  4. -Calculates and displays true airspeed (TAS) for power setting

- Simple user interface allows easy in-cockpit use

- Supports multiple user selected aircraft profiles

  1. -10 aircraft profiles available

- User editable aircraft profiles

- Easy aircraft profile creation

Supplied Aircraft Profiles


  1. -C152

  2. -C162

  3. -C172H (O360)

  4. -C172N (O320)

  5. -C172R (IO360)

  6. -C172SP (IO360)


  1. -AA-5B Tiger


  1. -PA28-140

  2. -PA28-150/160

  3. -PA28-180C

  4. -Warrior II

  5. -Archer II

Selecting A Profile

Click Profile button on main screen

  1. -Cancel: Returns to main page

  2. -Select:  Selects the highlighted profile

  3. -Edit Selected Profile: Opens “Edit Profile” page

  4. -Delete Selected: Deletes the selected profile

  5. -New Profile: Opens “Select New Profile” page

Selecting A New Profile

  1. -Cancel: Returns to main page

  2. -Add Selected Profile:  Adds the highlighted profile to user profile

  3. -Create New Profile: Opens the “Create New Profile” page

Editing/Creating A Profile

Allows you to modify an existing profile or create your own profile from scratch.  TachCalc uses linear interpolation of the POH data to determine the RPM and TAS.

To create a new profile, or edit an existing profile:

  1. 1.Enter the Manufacturer’s Name

  2. 2.Enter a unique identifier for the Profile Name

  3. 3.From the aircraft POH, determine the RPM and TAS for a high and low percent power for the same density altitude and enter

  4. 4.Repeat for a high density altitude

  5. 5.Click “Update” to save or “Cancel” to cancel the edit

NOTE:  Bug Found in Version 1.0 Default User Configuration File!

To fix all old user profiles must be deleted.

  1. 1.Select Profile button from main screen

  2. 2.Select New Profile button from user profile screen

  3. 3.Add a new profile, not in the user profile list

  4. 4.Select Profile button from main screen

  5. 5.Delete original profiles

This issue will be addressed shortly.  Sorry for the inconvenience.