DE4041395A1 - Rotating disc instrument indicating aircraft wind correction angle - uses rule of thumb formulae to achieve high accuracy ground speed calculation - Google Patents

Abstract

The rotatable disc consists of three concentrically mounted circular scales. The inner scale is used to calculate Wind Correction Angle (WCA). The middle scale represents a 0-360 degree compass rose, and the outer scale is provided for Ground Speed (GS) calculations. The rotatable disc is used in conjunction with predetermined 'rule of thumb' formulae, and by setting in wind direction, wind speed, aircraft speed and heading, the values for WCA and GS are speedily resolved to an accuracy of better than 90 percent. USE/ADVANTAGE - Quick, method for determining WCA and GS. - Pilots attention can be concentrated on flying and not on akward, sometimes time consuming calculations.

Description

Genre of the object of registration

The invention relates to the turntable with the corresponding Scales for wind correction angle and basic speed with a rule of thumb to calculate of important flight data before and during the flight.

Information on the genus

With the help of this turntable and the corresponding ones The pilot calculates rule of thumb from the known data such as:

- wind direction
- wind speed
- True airspeed
- Card course

the values for:

- Wind correction angle
- basic speed.

With the data obtained, an exact flight is carried out achieved by the pilot, especially the private pilot, corrected the influences of the wind.  

State of the art with sites

The values for wind correction angle and base speed could previously graphically, using sine theorem and solved by computer technology:

graphic solution:
- with the ARISTO-AVIAT 613-617-618-647 wind diagram
- with the wind diagram CSG computer
- With the wind diagram air tour computer CRP 1 and 5
- with the wind diagram of the STEPHAN NAVIMAT 501
Using the chart slider and the rotating drawing area, you can graphically calculate the searched values, such as WCA and GS, in the form of a triangular task in the wind triangle.

Computational solution using a sine law:
- with the Jeppesen CR computer
using the SPEED and SINUS scales, the WCA and GS values can be calculated on the basis of the sine theorem of plane trigonometry.

Computational solution using a computer:
- with the CX - 1 Pathfinder
- with the AVSTAR and PROSTAR from Jeppesen
- with the SHARP navigation computer
Using the keyboard input of the values of wind direction, wind speed, true airspeed and map course, the computer calculates the values of angle correction angle and basic speed.

All computing devices listed here are in the catalog No. 48 (1989/90 edition) from the company SIEBERT Luftfahrtbedarf, Rektorratsweg 40 in 4400 Münster, included.  

Critique of the state of the art

In private aviation, the determination of wind correction Angle and basic speed for one Good flight planning and flight operations are just as important as in commercial aviation (see genus). The latter uses large and expensive on-board computers, to determine exactly the values you are looking for. The private pilot therefore uses the graphic or computational aids (see prior art) back, which are significantly cheaper.

Handling in the use of these "tools" is still too time-consuming and still in flight very inconvenient.

• 1. With the graphic solution with the specified Wind diagrams with or without a chart slider first the construction of the wind triangle the known values such as wind direction and wind speed, true airspeed and legal tax rate are prepared, before looking at the WCA and GS values at the corresponding scale can read.
• 2. With the computational solution using a sine law are at least two setting and two reading processes with a high concentration in mapping and evaluation of the corresponding scales necessary.
• 3. Are in the arithmetic solution by computer the individual given values in the numerical Type in order. The searched data will accessed using the appropriate key. These dates but refer only to those previously entered Values; for variations you have to enter information again and query again, an action which again is very time consuming and typing requires high concentration.

Task and solution

The invention has for its object with only one setting, namely screwing in the turntable to the given wind direction, the values for Wind correction angle and base speed through Read off the relevant factor and calculate the respective rule of thumb, quickly, with at least 90% certainty to determine.

With the frequent change of the card course on the pilot does not need the turntable on the flight route to adjust; the values sought are then quick calculated.

The at least 90% security is for the wind correction Angle and for the basic speed fully sufficient, because the flight weather data from the Aviation weather advice never meets on the flight route 100% too; there are always deviations from the forecast.

Achievable advantages

The advantages achieved with the invention exist in particular in that a simplification of the provision of values such as wind correction angle and base speed is available. The most variable value in the flight conduct is the flight path. Many too Changes in the card price remain the provision of the searched data is very simple and can be carried out quickly. It does not require a great deal of concentration Mental arithmetic to get the result; full attention there is no distraction for what is happening in the cockpit. Drawing and arithmetic solutions by means of Sinus rate or computer require more time, more manual Activities and more concentration.  

Arrangement of the scales to each other

The turntable consists of three concentrically arranged circular scales.

The inner scale is on the transparent Turntable. It is used to calculate the wind correction Angle (WCA = wind correction angle).

The middle scale is printed on the white base plate. It represents the compass rose from 0 ° to 360 °.

The outer scale is again on the transparent Turntable. It is used to calculate the basic speed (GS = Ground Speed).

Fine division of the corresponding scales Outer scale

The outer scale is divided into four right-angled sections divided. Each section, in turn, is by quarter circle lines in an outer, capitalized and an inner, numbered concentric Structured area. The range of letters is linked to the number range.

The division of each rectangular section is listed below and is clockwise specified:

first right-angled section:
- Letter area outside: factor crs - 1/2 WCA
- Letter area inside: GS = TAS - X
- Number range: 10 to 0, where the number fields of the numbers:
10 to 0, where the number fields of the numbers:
10 = 18.5 °
9 = 13.0 °
8 = 10.0 °
7 = 8.0 °
6 = 7.0 °
5 = 7.0 °
4 = 6.0 °
3 = 6.0 °
2 = 6.0 °
1 = 6.0 °
0 = 2.5 °.

second right-angled section:
- Letter area outside: factor crs - 1/2 WCA
- Letter area inside: GS = TAS + X
- Number range: 0 to 10, where the number fields of the numbers:
0 = 2.5 °
1 = 6.0 °
2 = 6.0 °
3 = 6.0 °
4 = 6.0 °
5 = 7.0 °
6 = 7.0 °
7 = 8.0 °
8 = 10.0 °
9 = 13.0 °
10 = 18.5 °.

third right-angled section:
- Range of letters outside: factor crs + 1/2 WCA
- Letter area inside: GS = TAS + X
- Number range: 10 to 0, where the number fields of the numbers:
10-9-8-7-6-5-4-3-2-1-0 match the size of the number fields of the first right-angled section.

fourth right-angled section:
- Outside letter area: factor crs + 1/2 WCA
- Letter area inside: GS = TAS - X
- Number range: 0 to 10, where the number fields of the numbers:
0-1-2-3-4-5-6-7-8-9-10 match the size of the number fields of the second right-angled section.

Between the first and fourth right-angled Sections are two directed towards the center of the disc Position arrows attached. They serve later for setting the wind direction.

Medium scale

The middle scale is in the form of a compass rose of 000 ° printed on the base plate up to 360 °. Every ten The numbers are fully written out in degrees.

Inner scale

The inner scale, like the outer scale, is in four rectangular sections divided. Every section is again through a quarter circle line into one outer, numbered and inner, with Lettered concentric area. The number range is fixed with the letter range in connection.  

The division of each rectangular section is listed below and is clockwise specified:

first right-angled section:
- Number range: 1 to 6, where the number fields of the numbers:
1 = 10.5 °
2 = 10.0 °
3 = 10.0 °
4 = 10.0 °
4.5 = 10.0 °
5 = 10.0 °
5.5 = 10.0 °
6 = 19.5 °.
- Letter area: wind from the left front = -

second right-angled section:
- Number range: 6 to 1, where the number fields of the numbers:
6 = 19.5 °
5.5 = 10.0 °
5 = 10.0 °
4.5 = 10.0 °
4 = 10.0 °
3 = 10.0 °
2 = 10.0 °
1 = 10.5 °.
- Letter area: wind from left behind = -

third right-angled section:
- Number range: 1 to 6, where the number fields of the numbers:
Match 1-2-3-4-4.5-5-5.5-6 with the size of the number fields in the first section.
- Letter area: wind from right behind = +

fourth right-angled section:
- Number range: 6 to 1, where the number fields of the numbers:
6-5.5-4.5-4-3-2-1 match the size of the number fields in the second section:
- Letter area: wind from the right front = +

Between the first and fourth right-angled Sections are two directed away from the center of the disc Position arrows attached. These position arrows are opposite the arrows on the outer scale. The corresponding sections are thus also aligned opposite the inner and outer scale.  

Embodiments

The following formulas are available for all calculations:

GS = TAS +/- X
X = ¹ / ₁₀ V _w × factor _{(crs +/- ½ WCA)}

Description of the abbreviations

WCA = Wind Correction Angle
VW = wind speed (Velocity of Wind)
TAS = True Air Speed
GS = Ground Speed
CRS = Legal Course = Card Course (True Course)
HDG = True Heading
= Chart course +/- wind correction angle
= CRS +/- WCA

Embodiments 1st example

Opp .:
Wind direction: 270 °
Wind speed: 30 kts
TAS: 80 kts
Crs: 050 °
Ges .:
WCA and GS
Solve:
- Place the arrows on the turntable over 270 ° on the compass rose
- On the inner scale:
Read the factor below 050 °
= Factor 4
- Calculate according to the WCA formula: = 15 °
- wind from left behind = -
= Crs - WCA = Hdg
Hdg = 050 ° - 15 ° = 035 °
- On the outside scale:
Read the factor crs - ½ WCA
above 042 ° = factor 7
- Calculate according to the X formula: = 21 kts
- Calculate according to the GS formula:
GS = TAS + X = 80 + 21 = 101 kts
Navigation computer values:
Hdg = 036 °
GS = 101 kts
Turntable values:
Hdg = 035 °
GS = 101 kts

Embodiments 2nd example

Opp .:
Wind direction: 270 °
Wind speed: 40 kts
TAS: 120 kts
Crs: 240 °
Ges .:
WCA and GS
Solve:
- Place the arrows on the turntable over 270 ° on the compass rose
Reading the factor below 240 ° = factor 3
- Wind from the right front = +
= Crs + WCA = Hdg
Hdg = 240 ° + 10 ° = 250 °
- On the outside scale:
Read the factor crs + ½ WCA
above 245 ° = factor 9
- Calculate according to the X formula: = 36 kts
- Calculate according to the GS formula:
GS = TAS - X = 120 - 36 = 84 kts
Navigation computer values:
Hdg = 250 °
GS = 84 kts
Turntable values:
Hdg = 250 °
GS = 84 kts

Embodiments 3rd example

Opp .:
Wind direction: 270 ° C
Wind speed: 20 kts
TAS: 100 kts
Crs: 320 ° C
Ges .:
WCA and GS
Solve:
- Place the arrows on the turntable over 270 ° on the compass rose
- On the inner scale:
Read the factor below 320 °
= Factor 4.5
- Calculate according to the WCA formula: = 9
- wind from the left front = -
= Crs - WCA = Hdg
Hdg = 320 ° - 9 ° = 311 °
- On the outside scale:
Read the factor crs - ½ WCA
above 315 ° = factor 7
- Calculate according to the X formula: = 14 kts
- Calculate according to the GS formula:
GS = TAS - X = 100 - 14 = 86 kts
Navigation computer values:
Hdg = 311 °
GS = 86 kts
Turntable values:
Hdg = 311 °
GS = 86 kts

Embodiments 4. Example:

Opp .:
Wind direction: 270 °
Wind speed: 30 kts
TAS: 150 kts
Crs: 110 °
Ges .:
WCA and GS
Solve:
- Place the arrows on the turntable over 270 ° on the compass rose
- On the inner scale:
Read the factor below 110 °
= Factor 2
- Calculate according to the WCA formula: = 4
- Wind from right behind = +
= Crs + WCA = Hdg
Hdg = 110 ° - 4 ° = 114 °
- On the outside scale:
Read the factor crs + ½ WCA
above 112 ° = factor 9
- Calculate according to the X formula: = 27 kts
- Calculate according to the GS formula:
GS = TAS + X = 150 + 27 = 177 kts
Navigation computer values:
Hdg = 114 °
GS = 178 kts
Turntable values:
Hdg = 114 °
GS = 177 kts

Claims (3)

1. Turntable for determining the wind correction angle (WCA) and basic speed (GS) with the corresponding rule of thumb, characterized in that the turntable from the fixed middle scale with the compass rose on the base plate and the two scales for WCA and GS on the transparent turntable is composed. On the turntable, the specific scale for the wind correction angle forms the inside scale and the specific scale for the basic speed forms the outside scale. 2. Turntable according to claim 1, characterized in that the rule of thumb in connection with the wind correction angle scale is: 3. Turntable according to claim 1, characterized in that the rule of thumb in connection with the basic speed scale is: GS = TAS ⁺ / _- X
X = ¹ / ₁₀ V _W × factor _crs +/- 1/2 WCA)
Abbreviations:
WCA = Wind Correction Angle
VW = wind speed (Velocity of Wind)
TAS = True Air Speed
GS = Ground Speed