Cessna 337G Skymaster: Difference between revisions

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{{infobox Aircraft
{{:{{PAGENAME}}/info}}
|image = Cessna337_01.png
|name = Cessna 337G Skymaster
|type = Piston, civilian aircraft
|fdm = JSBsim
|fgname        = Cessna337
|status-fdm = 3
|status-systems = 3
|status-cockpit = 5
|status-model = 5
|authors = Fernando Espinosa, Pavel Cueto
|download = http://www.vivefg.org/index.php?option=com_content&view=article&id=48:cessna-337-skymaster&catid=35:hangar&Itemid=40
}}
The '''Cessna 337''' is a twin-engine [[aircraft]] built in a push-pull configuration. Instead of the engines being mounted on the wings, one is mounted on the nose and the other at the rear of the pod-style fuselage. The stabilizers are mounted on booms that extend from the wings. The Skymaster has a retractable undercarriage that gives it that little bit of extra speed.
The '''Cessna 337''' is a twin-engine [[aircraft]] built in a push-pull configuration. Instead of the engines being mounted on the wings, one is mounted on the nose and the other at the rear of the pod-style fuselage. The stabilizers are mounted on booms that extend from the wings. The Skymaster has a retractable undercarriage that gives it that little bit of extra speed.


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=== Aircraft keys ===
=== Aircraft keys ===
 
{| class="keytable"
* '''d''' - Open/close cockpit door
! Key                                  !! Function
* '''c''' - Open/close front cowl flaps
|-
* '''C''' - Open/close rear cowl flaps
| {{key press|d}}                      || Open/close cockpit door
* '''m/M''' - Adjust fuel mixture
|-
* '''n/N''' - adjust speed governor (propeller pitch)
| {{key press|c}}                      || Open/close front cowl flaps
|-
| {{key press|C}}                      || Open/close rear cowl flaps
|-
| {{key press|m}}/{{key press|Shift|M}} || Adjust fuel mixture
|-
| {{key press|n}}/{{key press|Shift|N}} || Adjust speed governor (propeller pitch)
|}


=== Limits ===
=== Limits ===
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== Normal procedures==
== Normal procedures==
[[File:Cessna337-cockpit.png|thumb|250px|General view of the Skymaster cockpit]]
[[File:Cessna337-details.png|thumb|250px|The model is pretty detailed, and users can select between 5 HQ liveries]]
[[File:Cessna337-details.png|thumb|250px|The model is pretty detailed, and users can select between 5 HQ liveries]]
[[File:Cessna337-night.png|thumb|250px|Nice view of the Skymaster cockpit at night]]
[[File:Cessna337-night.png|thumb|250px|Nice view of the Skymaster cockpit at night]]
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=== Avionics ===
=== Avionics ===


Our Skymaster release is provided with a working Bendix/King avionics pack, capable to full IFR night navigation:
The Skymaster release is provided with a working Bendix/King avionics pack, capable of full IFR/night navigation:
 
* 2 KX-155 COMM/NAV Radios, attached to a pair of KI-206 VOR locators
* 2 KX-155 COMM/NAV Radios, attached to a pair of KI-206 VOR locators
* KN-62A DME receiver (in development, attached to NAV1 only)
* KN-62A DME receiver with internal frequency hold and NAV1 remote operation
* KR-87 ADF receiver, attached to a KI-227 ADF locator
* KR-87 ADF receiver, attached to a KI-227 ADF locator
* KMA-24 Audio panel (not useful in FlightGear yet)
* KMA-24 Audio panel
* KT-76A Transponder (not useful in FlightGear yet)
* KT-76A Transponder, with radar sweep simulation
* KI-250 Radar altimeter, capable to mark decision height for low-visibility landings
* KI-250 Radar altimeter, capable to mark decision height for low-visibility landings
* Hobbs Meter


=== ELT ===
{{Note|A full KMA24 audio panel implementation was added in January 2017. The knob on the right of the unit switches the speaker amplifier on and off and also controls the marker beacon receiver. To hear ATIS broadcasts, either switch the comm radio output using the COMM phone switch, or use the COMM speaker switch with the knob in any position other than off. To hear marker beacon idents, the knob must be in any other position than off and one of the MKR switches selected on the panel.}}


The [[ELT]] (Emergency Locator Transmitter) is a device which send a message in case of aircraft crash. That message contains info about aircraft model, owner and approximate coordinates of the crashed plane, and it is made to request SAR (Search and Rescue) services. The Cessna Skymaster is the first plane equiped with a functional ELT on FlightGear.
Radio stack instruments are modelled according to the Bendix King pilot guides. Refer to those guides for operating instructions. [http://www.bendixking.com/HWL/media/Pilot-Guides/006-18110-0000_5.pdf]


=== Navomatic 400A Autopilot ===
=== Autopilot ===


''This autopilot is only available in the latest version of the aircraft from the Git repository. It should become generally available in Flightgear 3.10.''
The [[Cessna 337G Skymaster/Navomatic 400A]] autopilot has a fully working 3D panel and dialog.


The Navomatic 400A is an autopilot manufactured by Cessna in the early 1970s. It is a basic unit but well-designed and simple to use. The Flightgear version has been developed to match the operation of the autopilot as described in the Navomatic operating manual.
=== ELT ===


On the Cessna 337G Skymaster, the cockpit panel is located on the center pedestal below the throttle levers. It consists of a pitch wheel, push-pull heading dial (which switches between lateral modes), and three on-off switches marked AP ON, NAV and ALT. The position of the panel is awkward for a simulator pilot but you can also control the autopilot using the autopilot dialog. This is laid out and works almost exactly the same as the 3D panel.
The [[ELT]] (Emergency Locator Transmitter) is a device which send a message in case of aircraft crash. That message contains info about aircraft model, owner and approximate coordinates of the crashed plane, and it is made to request SAR (Search and Rescue) services. The Cessna Skymaster is the first plane equiped with a functional ELT on FlightGear.
 
[[File:Navomatic-3d.png|thumb|Navomatic 400A 3D panel.]]
 
[[File:Navomatic-dialog.png|thumb|Navomatic 400A dialog]]
 
The autopilot is turned on and off using the AP ON switch. Note that, unlike
some other autopilots, the Navomatic does not necessarily bring your wings level
and maintain pitch when it is turned on. It does whatever you have set on the
various controls. So check them carefully before engaging the autopilot.
 
==== Lateral Modes ====
 
The push-pull dial controls the lateral modes. It is pulled out using the
middle mouse button (alt-click on a Mac) and pushed in using the left mouse
button.
 
When the push-pull dial is pulled out, the bank angle of the aircraft is controlled by the dial. When it is centered, the autopilot levels the wings. When it is turned left or right, the aircraft turns left or right. Full rotation produces a standard rate turn. In Flightgear this is a stepped control where each step produces 5 degrees of bank.
 
Note that the dial has a center detent position which prevents it being pushed in when it is rotated. You need to return it to center (wings level) before pushing it in.
 
When the push-pull dial is pushed in, the autopilot either follows the
heading bug on the directional gyro, or tracks a radial on the first NAV radio.
The NAV switch on the right side of the panel switches between these two
modes. It is not possible to rotate the dial when it is pushed in.
 
Note that when following a VOR radial using the NAV mode, the radial must
be dialled as the omni bearing on the course deflection indicator (CDI)
AND the heading bug on the directional gyro (DG) must be set to the same
heading.
 
==== Vertical Modes ====
 
The pitch wheel controls the vertical pitch of the aircraft when the autopilot
is engaged. When at the center detent position, the aircraft will be pitched
for level flight. You may also need to adjust pitch trim (large vertical
wheel next to the gear up/down lever).
 
The pitch wheel is rotated by scrolling using your mouse or trackpad. When rolled
backward, the aircraft pitches nose upward. When rolled forward, the aircraft  
pitches down. Each step on the wheel is 0.5 degrees of pitch. To return to the
center detent, click anywhere on the pitch wheel with the left mouse button.
 
There is no indication of the set pitch because there is no indication on
the real thing!
 
To hold an altitude, switch the ALT switch to the right. Note that this will
only hold the current altitude if the pitch wheel is at the center detent
position.
 
If the ALT switch is on and the pitch wheel is moved away from the center
detent, the aircraft adjusts pitch as normal. When the pitch wheel is  
returned to center, the new altitude is held.
 
==== ILS Approaches ====
 
The Navomatic autopilots do not have a specific approach mode but the
Navomatic 400A will track an ILS and glideslope. Navigate to the ILS and ensure
the autopilot is in NAV mode (push-pull dial pushed in and NAV switch on) and
holding a suitable altitude (ALT switch on and pitch wheel centered). A green
light appears on the main panel when the glideslope is captured. There is no
need to wait for the glideslope needle to come down before engaging ALT and
NAV modes -- the autopilot will not climb up to the glideslope.
 
The autopilot does not disengage automatically, so you must disengage by switching the AP ON switch to off before landing.
 
Note that there is no back-course mode.
 
==== Usage Notes ====
 
* The Navomatic 400A manual describes how a VOR radial is intercepted and this Flightgear simulation simulates that. When the course deflection is greater than 10 degrees (full scale on the CDI), the autopilot will turn to intercept at 45 degrees. When the deflection goes below 10 degrees, it will fly a smooth arc intercept to the radial. (So expect gentle curves to the radials, not last minute 30-degree bank turns).
 
* With any autopilot there is a "zone of confusion" when you are very close to a VOR station, e.g. less than 2nm. Expect course swings if you leave the autopilot in NAV mode. It is usually a good idea to pull the push-pull dial out for wings level if you are passing over a VOR station in NAV mode, resetting the omni bearing and heading bug to the new course as required.
 
* In a strong crosswind, the autopilot may track to one side of the radial and the CDI needle may not center. This is consistent with the Navomatic manuals. To assist the tracking in a crosswind, rotate the heading bug into the wind (in the direction of the CDI needle) by 5-10 degrees. The aircraft will then crab into the wind along the radial.
 
* To avoid unnecessary changes of course, it is recommended to pull the push-pull dial out for wings level before changing lateral modes.
 
* The autopilot automatically retrims the aircraft for zero elevator when the autopilot is disengaged so that joystick users don't experience sudden dips and climbs when they pick up the controls.
 
* Do not try and engage any mode of the autopilot on the ground, other than for checking it is operable. Return all controls to center after turning the autopilot off again.
 
* Recommended configuration for takeoff is push-pull dial out (for wings level), with pitch wheel rotated backward 4-6 steps for 2-3 degrees upward pitch on engagement. Alternatively, you can take off with the push-pull dial pushed in, heading bug set to runway heading and NAV switch off. Note that if you do not move the pitch wheel before takeoff, the autopilot will level your pitch when you turn the autopilot on.


== External links ==
== External links ==
* [http://forum.flightgear.org/viewtopic.php?f=4&t=12733 Cessna 337G official forum post]
* [http://forum.flightgear.org/viewtopic.php?f=4&t=12733 Cessna 337G official forum post]
* [http://www.youtube.com/watch?v=-ijJa0G5NgQ Video Cessna 337G MPG HD]
* [http://www.youtube.com/watch?v=-ijJa0G5NgQ Video Cessna 337G MPG HD]
* [http://www.bendixking.com/HWL/media/Pilot-Guides/006-18110-0000_5.pdf Bendix King Silver Crown Plus Avionics Systems Pilot’s Guide]


{{Cessna}}
{{Cessna}}


[[Category:Civil utility aircraft]]
[[de:Cessna 337G Skymaster]]
[[Category:Push-pull aircraft]]
[[Category:Twin boom aircraft]]
 
[[es:Cessna 337G Skymaster]]
[[es:Cessna 337G Skymaster]]
[[fr:Cessna 337G Skymaster]]
[[fr:Cessna 337G Skymaster]]

Revision as of 13:27, 14 January 2017

Cessna 337G Skymaster
FGAddon
Cessna337 01.png
General view of the Skymaster cockpit
General view of the Skymaster cockpit
Type Civil utility aircraft
Configuration Twin boom aircraft, High wing aircraft
Propulsion Push-pull aircraft, Propeller aircraft
Manufacturer Cessna
Author(s)
  • Fernando Espinosa
  • Pavel Cueto
FDM JSBSim
--aircraft= Cessna337
Status Production
 FDM Stars-3.png
 Systems Stars-3.png
 Cockpit Stars-5.png
 Model Stars-5.png
Development
 Website The website for the Cessna 337G Skymaster developments.
 Repository The development repository of the Cessna 337G Skymaster.
Download Download the Cessna 337G Skymaster aircraft package for the current stable release (2020.3).
License GPLv2+

The Cessna 337 is a twin-engine aircraft built in a push-pull configuration. Instead of the engines being mounted on the wings, one is mounted on the nose and the other at the rear of the pod-style fuselage. The stabilizers are mounted on booms that extend from the wings. The Skymaster has a retractable undercarriage that gives it that little bit of extra speed.

The combination of a tractor and a pusher engine produces a unique sound.

Aircraft help

Aircraft keys

Key Function
d Open/close cockpit door
c Open/close front cowl flaps
C Open/close rear cowl flaps
m/ Shift+M Adjust fuel mixture
n/ Shift+N Adjust speed governor (propeller pitch)

Limits

  • VNE: 198 KIAS (Never exceed speed)
  • VNO: 167 KIAS (Max. speed for normal operations)
  • VA: 140 KIAS (Design maneuvering speed)
  • VFE: 109 KIAS (Max. full flap extended speed)
  • VLE: 200 KIAS (Max. landing gear extended speed)
  • VLO: 140 KIAS (Max. landing gear extend/retract speed)
  • Stall speed, full flaps: 61 KIAS
  • Stall speed, zero flaps: 70 KIAS
  • Max. weight: 4630 lbs. (2100 kg)
  • Service ceiling (two engines): 18,000 ft
  • Ground run for takeoff: 1,000 ft
  • Ground roll for landing 700 ft

Normal procedures

The model is pretty detailed, and users can select between 5 HQ liveries
Nice view of the Skymaster cockpit at night

Startup

  • Turn ON battery and front and rear generators
  • Turn ON master avionics button (left wall panel)
  • Turn ON the avionics (NAV/COMM Radios, DME, ADF...)
  • Turn ON fuel pumps (not implemented yet)
  • Turn ON required lights and pitot heat
  • Open front and rear cowl flaps
  • Turn ON rear magnetos (mouse wheel), continue turning the knob for starter (left button)
  • Turn ON front magnetos, continue turning the knob for starter

Takeoff

  • Check open front & rear cowl flaps to avoid overheating
  • Check rich mixture and high RPM speed governor (propeller pitch)
  • Full trhottle, release brakes
  • Rotate at 60 KIAS
  • Retract gear

Cruise

The Cessna 337 Skymaster has a constant-speed propeller; so, you can increase propeller pitch to get more airspeed, but with a loss of engine RPM and power.

  • Decrease throttle to desired power
  • Decrease RPM with speed governor (propeller pitch)
  • Adjust mixture depending on flight altitude (for 5000ft or more). Check EGT for best mixture.
  • Close cowl flaps

Landing

  • Open cowl flaps
  • Increase RPM with speed governor (propeller pitch) to maximum
  • Reduce power with throttle
  • Open landing gear
  • Deploy flaps gradually under 110 KIAS
  • Touchdown at 75/60 KIAS, depending on aircraft weight

Systems

Detail of the avionics panel

The Cessna 337 still in development, but it has some suitable systems. Electrical, vacuum and fuel system are working, but they have no failure system modelled yet. Users can adjust the weight of each seat on the plane and fuel amount. Almost all buttons, knobs and levers are functional and properly animated, and all instruments are labeled for a properly identification.

About knobs, use scroll mouse for gross adjustments, and left-central buttons for fine tunning. When setting radio frequencies, the mouse scroll will adjust integral numbers, and buttons will tune decimals. Try that method with instruments, cowl flap switches, trim levers, magnetos, etc.

Avionics

The Skymaster release is provided with a working Bendix/King avionics pack, capable of full IFR/night navigation:

  • 2 KX-155 COMM/NAV Radios, attached to a pair of KI-206 VOR locators
  • KN-62A DME receiver with internal frequency hold and NAV1 remote operation
  • KR-87 ADF receiver, attached to a KI-227 ADF locator
  • KMA-24 Audio panel
  • KT-76A Transponder, with radar sweep simulation
  • KI-250 Radar altimeter, capable to mark decision height for low-visibility landings
  • Hobbs Meter
Note  A full KMA24 audio panel implementation was added in January 2017. The knob on the right of the unit switches the speaker amplifier on and off and also controls the marker beacon receiver. To hear ATIS broadcasts, either switch the comm radio output using the COMM phone switch, or use the COMM speaker switch with the knob in any position other than off. To hear marker beacon idents, the knob must be in any other position than off and one of the MKR switches selected on the panel.

Radio stack instruments are modelled according to the Bendix King pilot guides. Refer to those guides for operating instructions. [1]

Autopilot

The Cessna 337G Skymaster/Navomatic 400A autopilot has a fully working 3D panel and dialog.

ELT

The ELT (Emergency Locator Transmitter) is a device which send a message in case of aircraft crash. That message contains info about aircraft model, owner and approximate coordinates of the crashed plane, and it is made to request SAR (Search and Rescue) services. The Cessna Skymaster is the first plane equiped with a functional ELT on FlightGear.

External links