These tools are designed for students who want to do drill exercises over and over again. While there are many tools available Decision Speed’s tools not only solve the calculation but can create a near infinite amount of problems for you to solve. This method ensures you build speed and accuracy, learning the method rather than rote learning multiple choice answers, useless come test time. We also provide the formulas used so you can check what you are getting wrong.

ISA +/- is sometimes used by instructors and textbook authors as a value from the ISA temperature at that pressure height. For example* *ISA +15 at sea level is an OAT of 30°C.

All heights are in feet and temperatures in Celsius. ISA MSLP 1013.2 and 15°C used in all calculations. Heights rounded to the nearest whole feet. Automatically calculated values are in orange. Educational tool only, not to be used for operational calculations. For commercial use please contact for licensing inquiries.

© Decision Speed. All rights reserved. Non-Commercial Use Only.

### FUTURE & FORMULAS

There should be more tools added in the future to help students with learning, we are aiming to provide tools to not only cross check calculations but also generate a continuious supply of random problems for drill exercises. This takes time to build but for now here is a list of formulas, some of which may become tools.

### COMPLETED

$$Pressure\;Height(ft) = (1013.2mb – QNH(mb)) \times 30ft + Elevation(ft)$$

$$Density\;Height(ft) = (OAT°C – ISA\;Temp°C) \times 120ft + Pressure\;Height(ft)$$

### GENERAL

$$Runway\;Slope\,\% = {Elevation\;Change(ft) \over Length(ft)}$$

$$Air\;Nautical\;Miles\;Per(L/USG) = {TAS(kts) \over Fuel\;Flow(p/h)}$$

$$Ground\;Nautical\;Miles\;Per(L/USG) = {GS(kts) \over Fuel\;Flow(p/h)}$$

### RATE OF CLIMB, CLIMB GRADIENT & CLIMB SPEED

$$Climb\;Gradient(\%) = {Rate\;of\;Climb(fpm) \over Speed(kts)}$$

$$Rate\;of\;Climb(fpm) = {Climb\;Gradient(\%) \times Speed(kts)}$$

$$Speed = {Rate\;of\;Climb \over Climb\;Gradient}$$

### DISTANCE, TIME & SPEED

$$Time(m) = {Time(hr) \times 60}$$

$$Distance(nm) = {Time(m) \over 60} \times Speed(kts)$$

$$Distance(nm) = Time(hr) \times Speed(kts) $$

$$Speed(kts) = {Distance(nm) \over Time(m)} \times 60$$

$$Speed(kts) = {Distance(nm) \over Time(hr)}$$

$$Time(m) = {Distance(nm) \over Speed(kts)} \times 60$$

$$Time(hr) = {Distance(nm) \over Speed(kts)}$$

### AIRCRAFT ECHO

$$Max\;Cargo\;Item\;Weight = (Length(m) \times Width(m)) \times 450kg/m^2$$

$$Floor\;Loading(kg/m^2) = {Weight(kg) \over Length(m) \times Width(m)}$$

$$Cargo\;Item\;Area(m^2) = {Weight(kg) \over 450kg/m^2}$$

$$Missing\;Side\;of\;Cargo\;Item(m) = {Area(m^2) \over Known\;Side(m)}$$

$$CG\;as\;MAC\;\% = {CG\;Position – 2190mm \over 1900mm} \times 100$$

### WEIGHT & BALANCE

$$CG\;Position = {Sum\;of\;Moments \over Gross\;Weight}$$

$$Weight\;Shift = {Gross\;Weight \times Desired\;GC\;\Delta\;Actual\;CG \over Current\;Station\;\Delta\;New\;Station}$$

$$Weight\;Add = {Gross\;Weight \times Desired\;GC\;\Delta\;Actual\;CG \over Desired\;CG\;\Delta\;Station\;Adding\;To}$$

$$Forward\;CG\;Limit = (Gross\;Weight – 2360kg) \times 0.27 + 2400mm$$

### EQUI TIME POINT(CP) & POINT OF NO RETURN

$$ETP\;Distance(nm) = Distance(nm) \times {Home\;Speed(kts) \over Out\;Speed(kts) + Home\;Speed(kts)}$$

$$ETP\;Time(m) = {ETP\;Distance(nm) \over Home\;Speed(kts)} \times 60$$

$$PNR\;Time(m) = Safe\;Endurance(m) \times {Home\;Speed(kts) \over Out\;Speed(kts) + Home\;Speed(kts)}$$

$$PNR\;Distance(nm) = {PNR\;Time(m) \over 60} \times Out\;Speed(kts)$$