infobox Aircraft |image =Zeppelin_NT.jpg |name =Zeppelin Luftschifftechnik LZ N07 |type =Airship |authors =Anders Gidenstam |fdm =JSBSim |status =Development |fgname =ZLT-NT}}
==Important controls / keys==
* Rudder (Aileron input is transferred to the rudder
for convenience.) At low speed the rudder is automatically augmented by a tail mounted side thruster controlled by the flight control system.
* Elevator (The elevator trim is seldom used see below for pitch trim.)
===Engines and thrust vectoring===
The Zeppelin NT has a non-standard set of engine controls. The engines' throttles are controlled by govenors - the throttle levers select the desired RPM.
* RPM select levers (PgUp/PgDown) - Increase/decrease selected engine RPM.
* Mixture levers (M/m) - Leaner/richer mixture.
* Side engine swivel ([/]) - Swivel side engines up/down. 0 - 120 degrees.
* Aft engine swivel (G/g) - Swivel aft engine down/up. -90/0 degrees.
The levers in the cockpit can also be controlled via the mouse pointer, either by clicking on a lever (left mouse button increases / middle mouse button decreases) or pointing at it and rotating the scroll wheel.
* F/f - Open/close the gas valve.
The fore and aft ballonets (air-filled bags inside the envelope) serve two purposes: (i) by inflating/deflating they maintain the pressure differential and volume of the envelope when the gas changes volume; and (ii) the trim of the airship can be changed by the relative inflation of the ballonets. While the required envelope pressure dictate the total volume of the ballonets the airship can be trimmed by having one ballonet more or less inflated than the other.
====Envelop pressure management====
When the airship rises the gas in the envelope expands and consequently the the total volume of the ballonets has to decrease or the envelope pressure will increase. There are pressure relief valves that automatically open when the pressure in the ballonet exceeds a set limit (which is lower than that of the gas relief valve to prevent gas being valved before both ballonets are empty) but the prudent airship pilot would rather use the manual ballonet valves than rely on the relief valves.
When the airship descends the increasing ambient pressure causes the gas in the envelope to contract and to maintain the envelope pressure above the ambient pressure total volume of the ballonets has to increase. The pilot has to set the ballonet controls for inflation. If the envelope pressure drops too low an alarm will sound. Monitor the gas pressure gauge!
====Pitch trim====On the Zeppelin NT pitch trimming is done via the relative fore/aft
ballonet inflation rather than with the elevator trim.
* To trim towards nose heavy - set the fore ballonet valve for inflation and/or the aft for deflation.
* To trim towards tail heavy - set the aft ballonet valve for inflation and/or the fore for deflation.
The Zeppelin NT has no ballast approved for inflight adjustment. Use on ground only.
* D/d - Drop ballast in 1%/0.1% decrements.
===Ground crew / Mooring mast===
* Y - Release mooring mast connection or wire.
The mooring mast is visible over the multiplayer network. It is also possible for other pilots using Zeppelin NT to dock with your mast.
This can be done in preferences.xml by modifying the line
==Cockpit and instruments==
==Multiplayer dual control==
This aircraft is equipped for [[Dual control]] over the FlightGear multiplayer network.
fgfs --aircraft=ZLT-NT-copilot --prop:/sim/remote/pilot-callsign="anybody"
1. The Co/Pilot dialog is only available in FlightGear
/CVS and might still have some flaws. Switching between different copilots might sometimes cause problems.It is usually enough if the copilot restarts her/his FlightGear instance in these cases.
2. If the pilot sets /sim/remote/pilot-callsign at runtime the copilot should join MP
<i>after </i> the pilot set /sim/remote/pilot-callsign or things won't work correctly. This will be improved in a future version.
3. Using the ZLT-NT-copilot it is possible to hitch a ride with any ZLT-NT on MP. However, unless you are the pilot "approved" copilot you will only be an observer (and will not, if there is no approved copilot, receive the full aircraft state from the pilot).
Unfortunately the pressure alarm will sound at startup since the envelope isn't initialized in a pressurized state . The ballonet inflation levers are preset to maximum inflation so the operating pressure is usually reached within 60 seconds. (Solved in FlightGear/CVS) * The engines sometimes behave oddly, in particular in landing configuration (high RPM and varying blade angles). The engine sound is also too loud and a bit strange as well. Work in progress.
* The mooring force calculations are sensitive to long frame times (i.e. very low fps), which can cause FlightGear to crash during startup or make the airship start in a bad state.
Obsolete copies of mp_broadcast.nas ( e.g. from the WildFire or Air racing add-ons) could cause problems. The up to date version now resides in <tt>$FG_ROOT/Nasal/mp_broadcast.nas</tt>. Remove the others - there should be no need for them.
* [http://www.gidenstam.org/FlightGear/Airships/ Download page with other lighter-than-air aircraft for FlightGear.] Requires the LTA support available in FlightGear 1.9.0 or
FlightGear/CVS. <b>Note: The most up to date version of the Zeppelin NT is available in FlightGear/ CVS. </ b>
* [http://www.gidenstam.org/FlightGear/DualControl/ More on multiplayer dual control].