EAI WebApp v1.5
Experimental Aircraft Info - Pilot Tools

Pilot Tools Web Application

This WebApp is an add-on to our extensive site and focusses on the aviation calculators we provide on our pre-flight information, weather and navigation pages but now aimed towards mobile devices. Running as a WebApp means these tools are easier to use, device independent and some even work when your are not connected to the Internet!
The app is also installable on the home screen of your device, your browser will notify you if that is possible.


Notices for Airmen (women too) are an important piece of last minute aeronautical information to be obtained during the pre-flight phase. This tool reads a comma separated list of ICAO airfield codes and retrieves the NOTAMs from the Defense Internet NOTAM Service.


Current weather through METAR and TAF forecast is obtained from Aviation Weather REST API (AVWX) sourced by aviationweather.gov where data is error corrected and certain fields added (FlightRules). It is restricted to one airport per request to limit the amount of data shown on the page. We also provide a flight rules color decoding table to assist you assessing the weather.

Keep in mind: TAFs are updated every 6 hours (occasionally 3) and are valid up to 24 / 30 hours. METARs are normally generated every hour, once in a while even 30 min. (SPECI), and may include a forecast TREND valid for 2 hours.

These tools require Internet connectivity.

Runway Crosswind

All aircraft have a published demonstrated maximum crosswind limitation which is determined during the test and or certification flights of the aircraft. Pilots should adhere to this limit. This calculator shows the crosswind and headwind component with regards to the selected runway heading and wind speed / direction.

Pressure / Density Altitude

Most performance calculations start with determining the actual pressure altitude the aircraft currenlty is, this is referenced against the ISA 1013 hPa pressure level. This calculator also takes pressure lapse rate into account.

To correct for the mostly non-standard temperature at the current pressure altitude, we apply a correction factor of 120 ft for every degree the OAT deviates from the ISA temp at that altitude. Remember that in ISA the temperature decreases 1.98 °C per 1000 ft.

VFR Navigation

These tools helps you with completing the navigation flight log. True Air Speed, Heading, Wind Correction Angles and Ground Speed are calculated for you after entering your indicated air speed (IAS), Wind data, Altitude, and Course. The last calculator does the reverse, it gives you the Course, GS and WCA based on Heading, TAS and Wind data.

Pressure, Temperature, Humidity Conversions

Converting temperature between Fahrenheit/Celsius and Dewpoint/Humidity is usually done with a separate calculator, if you are familiar with the formulas. Here we present our own neat little conversion tools.


The pressure/density calculators are based on the following formula's and constants:

Pressure Lapse Rate = 96 × ( T in Kelvin) / QNH

Pressure Altitude = Altitude + (1013 - QNH) × PLR

Density Altitude = Pressure Altitude + (OAT - ISATpa) × 120

where: ISA QNH is 1013 hPa, Temp is 15 °C at sea level and Celsius to Kelvin differs with 273 °C.

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