E6B Nav Computer: Crabwise

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Crabwise is a navigation computer for iPhone that does the job of a whizz wheel, and then shows you how it got there. Made for PPL students, private pilots and flying instructors. WIND TRIANGLE (FREE) • Solve for heading: TAS, true track and the forecast wind give you the drift correction, true heading and groundspeed • Solve for the wind: heading, TAS, track made good and groundspeed tell you the wind you actually met en route • A vector diagram draws the air, wind and ground sides of the triangle UNIT CONVERSION (FREE) Nautical miles, statute miles and kilometres; knots, mph and km/h; pounds and kilograms; US gallons and litres; °C and °F; hPa and inHg; feet and metres. Fuel mass for avgas and Jet-A at standard planning densities. CROSSWIND FOR THE RUNWAY IN USE Runway number plus the tower or ATIS wind gives the crosswind from the left or right, the headwind or tailwind, and the figures in gusts. A reminder that runway numbers and ATIS winds are magnetic. ALTITUDE AND AIRSPEED Pressure altitude from elevation and QNH in hectopascals. Density altitude worked from the full ISA density ratio rather than a rule of thumb. True airspeed from calibrated airspeed, and Mach number. TIME, SPEED, DISTANCE AND FUEL Find the missing value on any leg. Fuel used, fuel flow, endurance, and total fuel required including taxi and reserve. Litres, gallons or pounds. MASS AND BALANCE Enter each station's mass and arm to get moments, total mass and the centre of gravity. Add the envelope corner points from your POH or flight manual and check whether the CG sits inside it. THE WORKING, NOT JUST THE ANSWER Open any result to see the formula and the substituted figures, step by step. Handy when revising for the navigation, flight performance and planning exams. ON YOUR IPHONE, OFFLINE No account, no adverts, no tracking and no signal required. Light and dark themes. FREE AND PRO Free: wind triangle in both directions and unit conversion. Pro: crosswind, time-speed-distance, fuel, altitude and airspeed, mass and balance, and step-by-step working for every calculator. Crabwise Pro is available weekly, monthly or yearly, or as a one-time lifetime purchase. The yearly plan starts with a 3-day free trial. Payment is charged to your Apple Account at confirmation. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the current period, and your account is charged for renewal within 24 hours before that. Manage or cancel them in your App Store account settings. The lifetime purchase is a single payment and does not renew. Not for navigation. Crabwise is a training and reference aid only; always cross-check against your flight manual, current charts and official publications. Crabwise is not affiliated with or endorsed by the UK CAA or EASA. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://vomcore.com/crabwise/privacyRead more

Crabwise is a navigation computer for iPhone that does the job of a whizz wheel, and then shows you how it got there. Made for PPL students, private pilots and flying instructors. WIND TRIANGLE (FREE) • Solve for heading: TAS, true track and the forecast wind give you the drift correction, true heading and groundspeed • Solve for the wind: heading, TAS, track made good and groundspeed tell you the wind you actually met en route • A vector diagram draws the air, wind and ground sides of the triangle UNIT CONVERSION (FREE) Nautical miles, statute miles and kilometres; knots, mph and km/h; pounds and kilograms; US gallons and litres; °C and °F; hPa and inHg; feet and metres. Fuel mass for avgas and Jet-A at standard planning densities. CROSSWIND FOR THE RUNWAY IN USE Runway number plus the tower or ATIS wind gives the crosswind from the left or right, the headwind or tailwind, and the figures in gusts. A reminder that runway numbers and ATIS winds are magnetic. ALTITUDE AND AIRSPEED Pressure altitude from elevation and QNH in hectopascals. Density altitude worked from the full ISA density ratio rather than a rule of thumb. True airspeed from calibrated airspeed, and Mach number. TIME, SPEED, DISTANCE AND FUEL Find the missing value on any leg. Fuel used, fuel flow, endurance, and total fuel required including taxi and reserve. Litres, gallons or pounds. MASS AND BALANCE Enter each station's mass and arm to get moments, total mass and the centre of gravity. Add the envelope corner points from your POH or flight manual and check whether the CG sits inside it. THE WORKING, NOT JUST THE ANSWER Open any result to see the formula and the substituted figures, step by step. Handy when revising for the navigation, flight performance and planning exams. ON YOUR IPHONE, OFFLINE No account, no adverts, no tracking and no signal required. Light and dark themes. FREE AND PRO Free: wind triangle in both directions and unit conversion. Pro: crosswind, time-speed-distance, fuel, altitude and airspeed, mass and balance, and step-by-step working for every calculator. Crabwise Pro is available weekly, monthly or yearly, or as a one-time lifetime purchase. The yearly plan starts with a 3-day free trial. Payment is charged to your Apple Account at confirmation. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the current period, and your account is charged for renewal within 24 hours before that. Manage or cancel them in your App Store account settings. The lifetime purchase is a single payment and does not renew. Not for navigation. Crabwise is a training and reference aid only; always cross-check against your flight manual, current charts and official publications. Crabwise is not affiliated with or endorsed by the UK CAA or EASA. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://vomcore.com/crabwise/privacy