VLA
Cockpit HMI of the Very Ligh Aircraft
This project examines human interaction of the aircraft's cockpit compartment as part of the Very Light Aircraft Project. It mostly describes three-dimensional representation of the geometric space required by the specified range of pilots, determines the allowance necessary for seat and control adjustment, and describes those volumes where controls, displays and other components may be placed.
University (METU) - Industry (TAI) cooperation project
2019-2022
There is a project report we have written to explain the work we have done in the project, for the students to whom we will transfer the project later, and most importantly to prove that the project complies with CS-VLA EASA standards.
Below are my own sections attached to the report. However, since the original report I wrote was very detailed and long, only a part of it is given below.
Percentile Selection
5th and 95th Percentile
Anthropometry is a branch of human sciences that studies the physical dimensions of people, through the systematic measuring of size, weight, and proportions of the human body with the goal of achieving comfort, fit, and usability in design, which can be used to help ensure fit for a broad range of target populations by providing the range and limits of the target population. Given the commonly occurring need for anthropometric information, when considering design criteria, many anthropometric databases have been created. A percentile is a statistical method for describing a value’s rank within a population, specifically the percent value above and below the given value. It is common for designers to refer to tabled percentile values for user body dimensions, and to use the 5th percentile value as a minimum and the 95th percentile value for a maximum. This method can be referred to as the “5th-95th percentile approach”. This knowledge is critical for the cockpit design process, and for improved anthropometric accommodation and addressing biomechanical issues.
During the study, the percentile was determined with the information obtained from the anthropometric data specified from a document which is published by AGARD (Advisory Group for Aerospace Research and Development). This document includes 153 different body dimensional data of more than 1400 subjects. The document contains anthropometric data of German Air Force and US Air Force flying personnel.
Zone Division
Reach Zone Envelope Methodology
NRSP Creation and measurements
On the seat, critical points that represent the pilot's body extensions, NRSP and DEP, are identified. After NRSP was determined, the back-tangent line was positioned at an angle of 13 degrees. Body measurements in the AGARD document are based on pilot measurements in the 50% section. DEP was determined based on the body size from the sitting surface to eye level and then the body size from the back of the head to eye level. The seat is attached to the cockpit at an 8-degree angle. It can go 3 inches forward and backward horizontally.
MIL-STD
VLA
Instrument Classification
While placing the instruments to the panel, attention was paid to grouping as well as access consideration in order to avoid confusion of crew members. As can be seen in the above figures, the operations that the pilot will perform in the first stage are positioned to the left, and switches and equipment are positioned according to the steps to be followed respectively from left to right. The initial stages were gathered as a group, such as pushing the park brake knob after the airplane was actuated with the ignition switch and then (if at night) arranging lighting settings.
In addition, all switches are gathered at the bottom of the panel to avoid confusion. Here, fuel operations are grouped in the center line by positioning the fuel switches in line with the fuel selection valve which is located on pedestal. Since the fuel selection valve is also used in case of emergency, an emergency grouping has been made by positioning it at the centerline as the parachute activation handle. Above the switches avionics instruments have been located.
Layout
Analysis
Clearance Analysis
Overhead Clearance
When calculating the clearance between the canopy and the pilot, the highest point of the pilot's head elevation was determined by looking at the distance from eye level to the end of the head and the distance from the back of the head to the ear level, from the AGARD document. When the results are controlled over manikin in CATIA, they match each other. As a result of the analysis, it is observed that the calculated vertical clearance becomes 43mm.
Vision Analysis
5th Percentile
95th Percentile
Side-by-side vision plot
Control panel-human relationship
External Vision
Access Analysis
Emergency Access
Since parachute activation handle is an emergency handle, it is placed at 1st zone and placed to be clearly visible to the eyes of the crew, without extreme head rotation needed. Thus, handle is located:
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In the middle of two pilots on the centerline of the pedestal to have equal access.
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At the upper side of the pedestal to be clearly visible.
The activation handle must not be close to other controls. There must be sufficient clearance around the handle to allow easy grasping. Therefore, it is positioned so that the throttle lever or the fuel selection valve does not come into contact when activating the handle. For this reason, it was embedded slightly in the pedestal body.
Primary Flight Control Access
Primary flight controls are pedals, control stick and throttle for this project. For each of them detailed access analysis were made.
The manikin is placed in such a way that the heel ball will fit on the protrusion of the pedal during the pedal access. In these measures, when the pilot pushes left pedal forward and the other pedal comes back repeatedly, the pilot can reach both pedals without any abnormality observed.
As the data of the UKS team was examined, it was seen that the maximums of forward and backward movements of the control stick were entered as 10 degrees, the analysis was provided accordingly. Approximately 2.5 inches of console clearance is provided.
Switch Placard Creation
The texts below are the same as the text specified and requested in the CS-VLA and positioned in the area visible to the pilot.
As stated in CS-VLA, the keys should be supported with placards and their functions should be written in order to be understandable. In these placards, main titles are written in 4mm length, while subtitles are written in 3mm.
Flight Displays
Throughout the decision taken from the avionics team, the avionics equipment was taken readily. Therefore as cockpit team, we have examined the usage and features of these displays. "Which information is given?", "How shoud we arrange its placement accordingly?", "Is it enough for the pilot?", "How can we simplify the information in order to reduce the confusion?"; Such questions are asked during the studies of avionics.
There are 2 main flight display. One is Garmin G500 TXI 10.6”, while other is Garmin TXI 7” portrait. The modellings are shown below.
Garmin G5 Unite is located on panel which can be configured in attitude, DG/HI/HSI and turn coordinator positions. This device is of great importance in order to continue the operation in any power cut. For this reason, it is placed in the middle and on the upper part so that both pilots can see it.
