Crabwise: E6B Flight Computer

Crosswind, weight & balance

Free · In‑App Purchases · Designed for iPad. Not verified for macOS.

Wind, density altitude, true airspeed, weight and balance, fuel and crosswind: exact math and the classroom rule of thumb, side by side. No ads, no account, bought once. Crabwise is an offline E6B flight computer built for student and private pilots: the six calculations you learn on paper, with type large enough to read at a glance. WIND & GROUND SPEED Solve the wind triangle both directions: find your heading and ground speed, or work backward from heading, track, and ground speed to find the wind. PRESSURE & DENSITY ALTITUDE See the classroom rule of thumb and the exact ICAO Doc 7488 answer side by side, so you know how much margin you actually have. TRUE AIRSPEED & MACH The quick 2%-per-1000-ft approximation and the exact compressible calculation, together. FUEL / TIME / DISTANCE Solve for any one of the three from the other two. CROSSWIND Headwind and crosswind components for any runway and wind. CONVERSIONS Seven unit families: distance, speed, altitude, temperature, pressure, weight, volume. CRABWISE PRO, ONE-TIME PURCHASE ($9.99) - Aircraft profiles: save cruise speed, fuel burn, usable fuel, empty weight and arm, and limits for every aircraft you fly. - Leg planner: chain legs from true course to compass heading, with running totals for time and fuel. - Weight & balance: plot your loading against your aircraft's envelope, checked live as you type. - History & export: save any result and export it as text or CSV. Free forever: all six calculators, every unit, every language, extra-large type. No ads, ever. No trial timer, no subscription. For training and planning cross-checks. Always verify against your aircraft flight manual and official sources. Not for primary navigation. No account. No ads. No tracking. Works offline. Available in English, Spanish, and Polish.

Ratings & Reviews

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Now stays upright on iPhone so every screen fits. The leg planner scrolls properly in the Pro preview. Spanish and Polish text now shows proper accents.

Version 1.0.2

The developer, Pouya Marvasti, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

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    Information

    Seller
    Pouya Marvasti
    Size
    6.3 MB
    Category
    Utilities
    Compatibility
    Requires iOS 15.0 or later.
    • iPhone
      Requires iOS 15.0 or later.
    • iPad
      Requires iPadOS 15.0 or later.
    • iPod touch
      Requires iOS 15.0 or later.
    • Mac
      Requires macOS 12.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    English
    Age Rating
    4+
    In-App Purchases
    Yes
    Copyright
    © 2026 Peter Marvasti
  • Developer Website
  • Privacy Policy

    • More by Pouya Marvasti

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