ISSUE DESCRIPTION
Description of the issue
There is currently no helium management system in the simulator.
Expected behavior (real aircraft)
Helium volume is one of the most important operational parameters of the Zeppelin NT, as it is for any airship.
The amount of helium inside the envelope determines the available static lift and therefore directly affects payload capability. However, an equally important aspect is the resulting ballonet fill level.
The ballonets must contain enough air to allow the airship to compensate for changes in helium volume during flight:
- If the ballonets are nearly empty before takeoff, the helium already occupies almost the entire envelope. As the airship climbs and atmospheric pressure decreases, the helium expands further. With little or no air left to vent from the ballonets, the helium has no room to expand, causing envelope pressure to rise rapidly. This severely limits or completely prevents further climb.
- If the ballonets are nearly full before takeoff, there is little reserve volume available for additional air. During descent or cooling of the helium, the ballonets must inflate further to maintain envelope pressure. If they are already close to full, the system can no longer compensate, making it impossible to maintain the required envelope pressure.
For this reason, the correct helium volume is a compromise that provides sufficient lift while leaving adequate ballonet capacity for both climb and descent.
In real operations, the required helium volume is calculated before every flight, taking into account factors such as:
- Atmospheric pressure
- Outside air temperature
- Airfield elevation
- Payload
- Fuel load
- Expected Superheat
These calculations are particularly important on cross-country flights. Even relatively small changes in pressure, temperature, or destination elevation can significantly reduce the available flight altitude or, in extreme cases, make safe flight impossible because envelope pressure can no longer be maintained within operational limits.
Current behavior in the simulator
The simulator does not model helium management, and the helium volume cannot be adjusted.
As a result, one of the most important aspects of Zeppelin NT flight planning and operation is missing. The interaction between helium volume, ballonet fill level, payload, and environmental conditions cannot be reproduced.
FREQUENCY OF ISSUE
Every time on sim load
REPRODUCTION STEPS
Please list clear steps you took in order to help our test team reproduce the same issue:
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Load Zeppelin NT
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Observe no Helium management on EFB