The Drehmeier, such as the frequently used model ASA E6-B Flight Computeris one of the best-known and most frequently used aids in aviation. Despite modern electronic alternatives, the classic rotary encoder has a firm place in private pilot training (PPL) and light aircraft pilot training (LAPL). Its versatility, reliability and ability to perform numerous important calculations make it an interesting tool - at least in training and the theory test it is a must. In real-life flying, you are more likely to switch to software solutions.
In this article, we go into the structure and use of the Drehmeier and explain use cases such as the conversion of units or the calculation of ground speed and true heading. We show you how to get the best out of this device and illustrate its use with practical examples and visual support.
1. the structure of the ASA E6-B Flight Computer
The Drehmeier has two main areas:
1.1 The calculating disc (front)
You use the front side for mathematical calculations. Here you can, for example:
- Convert units (e.g. litres to gallons, nautical miles to kilometres),
- Calculate fuel consumption,
- Estimate flight times,
- Determine speed and distance relations.
The outer scale is movable, while the inner scale is fixed. By turning the outer scale, you can set values in relation to each other and read off the results directly.
1.2 The wind drift side (rear)
The reverse side helps you to calculate wind corrections and speeds. You can use it to:
- Determine your ground speed,
- calculate the true heading (true price),
- Carry out wind corrections,
- analyse the wind components in relation to your True Airspeed.
The wind drift page has a rotating disc with degree markings and a transparent template with coordinate lines to help you place wind markings.
2. important basics for using the rotary egg
Before we get to the application examples, a few basics:
- Reading the scalesThe outer and inner scales work together. Depending on the task, you can read the time, distance, speed or other values.
- AccuracyPrecise work is important, as small deviations can have major consequences in aviation.
- Understanding principlesThe Drehmeier is based on mathematical and geometric concepts. A basic understanding of these principles will help you to use the device safely.
3. step-by-step instructions: Use cases of the ASA E6-B
3.1 Conversion from litres to gallons
When preparing for a flight, it is often necessary to convert fuel quantities. In aviation, fuel is often measured in gallons, whereas you may be working with litres.
ExampleYou want to convert 50 litres into US gallons.
- Set scales:
- Turn the outer scale so that the mark for 1 litre on the inner scale matches the mark for 0.264 on the outer scale (1 litre = 0.264 gallons).
- Read value:
- Find the number 50 on the inner scale.
- Read the corresponding value on the outer scale: about 13.2 gallons.
- Note the result:
- Transfer the value to your flight planning.
TipThis principle also works for other unit conversions, e.g. from nautical miles to kilometres.
3.2 Calculation of ground speed and true heading
Calculating wind drift is one of the most important tasks, especially when flying with crosswinds or headwinds. You can determine ground speed and corrected course with the rotary encoder.
Given:
- Wind direction: 210°
- Wind speed: 15 knots
- True Course: 120°
- True airspeed: 110 knots
Steps for calculation:
- Enter wind direction and speed:
- Set the wind arrow on the wind drift side to 210°.
- Mark the wind speed (15 knots) on the appropriate line of the transparent template.
- Set True Course:
- Turn the disc until the True Course (120°) is displayed at the top.
- Consider True Airspeed:
- Move the wind marker along the line until it coincides with the True Airspeed (110 knots).
- Read ground speed and true heading:
- Read off the ground speed (approx. 102 knots) and the corrected course, the true heading (approx. 125°).
4. further application possibilities
The Drehmeier is incredibly versatile. Here are a few more examples:
- Fuel consumptionCalculate how much fuel you need for a certain flight distance.
- Flight time: Determine the time required for a route based on your ground speed.
- Density heightEstimate the performance of your aircraft, taking temperature and pressure into account.
5. Useful YouTube videos
Here are a few videos that explain how to use the Drehmeier even better:
- ASA E6-B Flight Computer - Basics
- Introduction to the basic functions.
- Using the Wind Side of the E6-B
- Detailed instructions for wind drift calculation
Conclusion
The Drehmeier - here the ASA E6-B as an example - is an indispensable tool that will serve you well in your flight training. With a little practice and routine, you will realise how versatile and helpful the Drehmeier is. Familiarise yourself with its functions and practice using it together with other flight students.