iPhone Screenshots


L/D Magic is an app for wingsuiters, trackers, canopy pilots, and enthusiasts of other gliding airsports alike that turns your iOS device into a fast, precise, and wind-independent lift-to-drag and glide ratio measuring device. It can also measure polar curve, lift and drag forces and coefficients, and a host of other flight parameters. Record, replay, and even reprocess your flights with Flight Data Recorder (an optional in-app purchase). The app runs Kalman Filter based on Wingsuit Equations to determine flight parameters. Various Kalman Filter models are available that use combinations of sensors - accelerometer, gyroscope, GPS, and magnetometer. The app provides instant visual and audio feedback to the pilot. L/D Magic turns the sky into your personal research wind tunnel!

For Kalman Filter models using GPS it is highly recommended to use external GPS accessories capable of at least 5Hz sample rate. The app now supports 10Hz sample rate for Bad Elf GPS and Dual XGPS160, 5Hz for Dual XGPS150A and Emprum UltiMate GPS.

What's New

Version 1.1.6

- fixed app getting stuck on launch screen
- fixed empty app icon on iPad

Ratings and Reviews


*** WS BASE Forever ***

Wow, didn't even know such a thing existed! (thought to myself, is there any performance app for wingsuit pilots out there? searched for "wingsuit" and found THIS gem among all those crappy wingsuit games)

Still learning this app but the potential is huge! At first, tried it on a skydive but didn't get any data out of it that made sense. Turns out (after emailing the developer) that you need a good external GPS, the internal GPS is simply not fast/accurate enough for freefall. Bought Dual XGPS150 and now the data is much much better (5Hz, quick acquisition, and the included wrist band helps with maintaining the signal - just put your hand near plane's window or door).

Quickly found out that parameters need to be selected carefully for Kalman filter to work well, so flight recorder feature is a must - you can reprocess the same data over and over again with different params and get better output.

Audible feedback is awesome! Need to buy an amplifier, though - my headphones are hard to hear in freefall. And probably a Bluetooth receiver as well, so I don't have to awkwardly route the cord under my wingsuit.

While the app includes some documentation, it's still not very obvious how to use the app, especially "Air Reference" vs. "Ground Reference" Kalman models. The developer explained it in an email: Air Ref. means that the iPhone needs to be mounted on a weathervane-like mount on a stick (like half a meter away from the body, to reduce boundary layer effect) that you need to make yourself, so the iPhone always points into relative wind; Ground Ref. means iPhone can be in your pocket as it only uses GPS. Hopefully, it will be made more clear in the documentation in the next version.

Very impressed by this app. Can't wait to take this on a BASE jump and work on my performance!


PFM Technologies LLC
64.7 MB
Requires iOS 9.0 or later. Compatible with iPhone, iPad, and iPod touch.
English, Russian
Age Rating
Rated 4+
© 2016 PFM Technologies LLC
In-App Purchases
  1. Kalman Filter #4: Accelerometer•GPS•No Wind $0.99
  2. Kalman Filter #2: Accelerometer•Gyro $0.99
  3. Flight Data Recorder $9.99


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

More By This Developer

You May Also Like