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VSKYLABS DC-3 C-47 Flying Lab Manual

VSKYLABS DC-3/C-47 Flying Lab Project

User Manual and Instructions
(under construction)

NEED TO KNOW:
DC-3/C-47 AIRCRAFT MANUAL AND POH

DC-3/C-47 Manuals:
OK...as I've said up in this page...there is too much of practical information to learn...what I'm going to do is first to set here some really practical links to useful website and resources. Take your time and get to know the DC-3/C-47...I can recommend reading information regarding the aircraft "general" systems/systems operations and deeper into flying techniques and performance/limitations.

Here is an AMAZING resource for Flight Operating Instructions and Manuals for the DC-3/C-47. It called "www.avialogs.com" and it is a "treasure" for Aviation enthusiasts. You will find these, among other useful materials:

You don't have to subscribe to read these documentation online. There is a reading window  with comfortable pages view settings (screenshot attached below):

NEED TO KNOW:
Transatlantic crossing with the DC-3/C-47

The VSKYLABS DC-3/C-47 Flying Lab mission-range performance was tested, evaluated and tuned by flying authentic routes in real-time simulation (some times with time compression, of course). It is not enough to set the engine's Specific Fuel Consumption to be "by the book", and actually create an aircraft which is using it, so it will deliver the expected outcome (range and "practical" fuel management). 

So...having a certain engine defined "by the book" will not determine the operation radius, but the "whole" aircraft, as an aerodynamic, powered, flying machine. A lot of variables are to be added to the "calculated" SFC of an engine, in order to get the aircraft to demonstrate the actual performance....

We need to taxi, burn fuel in engines run-up (even if it is done with an estimation), take off with the authentic weight and fuel, climb, cruise, fight the winds, descent, approach, land....all of these were tested as a whole "mission" during the development phase of the flight dynamics model of the VSKYLABS DC-3/C-47 Flying Lab Project.

Tuning the various variables, such as wings performance, drag, propellers performance and drag, angle of attack during each phase of flight...even the position of the trims...is a complex "act of balance", since everything is tied up together and affecting the overall performance. Since there are limitations in (every) PC-based flight dynamics simulation engine (including X-Plane), sometimes, the "blanket" for covering the various flight envelope regimes, may be too "short", and a decision is to be made: "which part do I cover, and which I don't"...

Because of that, and in order to get a DC-3/C-47 which will perform good in all flight phases, the final flight dynamics model might "host" some compromises, in some of its aspects. Good news is that the VSKYLABS DC-3/C-47 Flying Lab model is now demonstrating a very accurate performance, within the acceptable margins of realism.

To make it short, and right until I'll gather the information into a useful guide, I highly recommend reading this amazing story: http://airfactsjournal.com/2017/01/flying-beyond-doubt-epic-dc-3-journey/

NEED TO KNOW: SYSTEMS AND SYSTEMS OPERATIONS

NEED TO KNOW:
SYSTEMS AND SYSTEMS OPERATIONS

Although defined with the various systems that are needed to operate the aircraft, the VSKYLABS DC-3/C-47 is not a "Study Level" model, in terms of advanced systems algorithm simulation. For example, in order to fire up the Pratt & Whitney R-1830 Twin Wasp engines, there is no need for the complex procedure involved in the start-up procedure of the real aircraft.

This section is a short briefing that explains how to use the main systems of the VSKYLABS DC-3/C-47 aircraft. 

This briefing is not covering *all* of the VSKYLABS DC-3/C-47 systems, but only some of them. 

NEED TO KNOW: SYSTEMS AND SYSTEMS OPERATIONS

AIRCRAFT MAIN SYSTEMS

COCKPIT CONFIGURATION:
The VSKYLABS DC-3 / C-47 aircraft is featuring the cockpit configuration similar to the one that is described in the AAF Manual Pilot Training Manual for C-47 Skytrain. (Few changes existing).  




Modern GNS:
Version v2.5 is introducing dual folding GNS-530 terminals. This arrangement is letting the cockpit to stay authentic and old school, but to include a modern GNS environment for pilots who want to use it.

While folded, the terminals are set to 'off'. In addition, they offer full control over nav1,nav2,com1,com2 and separated dual display for maximum usability. Volume control knobs for com/nav on the GNS terminal are working also, so pilots who are using the GNS configuration are not required to use the upper old-school radio panel.

When folded up, they are turned off and thanks to their slim design they are blended perfectly into the upper windshield line and practically not causing any distractions. 


MIXTURE CONTROL:
The VSKYLABS DC-3/C-47 is featuring an auto-lean/auto-rich mixture settings, as it is in the real DC-3's. It eliminates the need to install a (non-authentic) EGT in the panel, and also, while in auto-lean mode, the mixture will be automatically adjusted to the peak EGT for cruising. To incorporate this feature into the mixture handles, I had to setup the operation method of the mixture handle so it will be effective also for shutting down the engines. It is very simple, as described in the instructions and the screenshot below:
  • Clicking at the "Auto Rich" zone:
    • Both engines set to "Manual Leaning".
    • Mixture control is "Normal": From 100% rich to 0% (shut off).
    • Mixture levers can be operated with the mouse (click and drag).
  • Clicking at the "Auto Lean" zone:
    • Both engines set to "Auto Lean".
    • Mixture is automatically set to peak EGT at all flight conditions.
    • Mixture levers can be operated only to "Auto Lean" or the "Shut off" positions.
    • Mixture levers can be operated with the mouse (click and drag), but only between the Auto Lean and Shutoff zones.
  • Switching between modes of operation:
    •  Simply click on the desired mode of operation zone.

AUTOPILOT:
Version 001 is incorporating A Sperry type Autopilot with the basic DC-3 configuration of Elevator (nose attitude for pitch) and Ailerons (bank angle). Maintaining heading ("Rudder") could not be setup and changed during flight (as it was in the real aircraft). Future versions will probably include the heading mode and other experimental aspects with the autopilot.

Autopilot Operation:
  1. Trimming the aircraft.
  2. Engaging the autopilot.
  3. Corrections for pitch and bank (thus heading) are made with the 'elv', 'ail' knobs.
  4. Heading ("Rudder") mode is not available in version v001 (one can using the setting knob of the upper scale as an independent heading bug). 
  5. In this workflow, it is quite easy to fly with the autopilot, even in a rapid navigation route. The aircraft is responding nicely and unless you tried to engage the autopilot while flight situation wasn't stable, it is very comfortable. Every once in a while a minor heading correction (using the bank knob) is needed. Not an annoying workload.

Autopilot Further Information:
The Sperry Autopilot which was used in the C-47 in the late 40's and 50's featured 3 knobs: ailerons "hold", rudder "hold" and pitch "hold". I wrote "hold" because the autopilot was in fact a gyro-pilot, and the axes were coupled to the relevant gyro axis (the "cage" was used for setting the gimbals).

Maintaining a desired pitch angle or bank angle using a gyro-pilot is easy to understand. I would like to put some light about the "rudder" knob, and the compass/setting scales that are related to it in the autopilot panel:

In the autopilot panel there is a compass scale window (lower scale is actual aircraft heading, and upper scale is a setting scale, biased to the "rudder" knob in the autopilot panel). The human pilot maintained a certain heading with his trimmed aircraft before engaging the autopilot. Then he used the rudder-knob to set up the upper scale to match with lower scale which presented the current aircraft heading (stable heading as the aircraft is trimmed). Then, he engaged the autopilot and the autopilot could maintain this heading with rudder control (gyroscopic attitude of the heading and not magnetic heading). So, in fact, while the autopilot could maintain a certain "heading", it could not turn into a new heading and then to maintain it.

So, heading corrections and resetting could not be achieved while flying in the real DC-3 C-47, with the use of the "scale-heading bug" in the autopilot panel...

Here is a quick link to the C-47 Sperry Autopilot control panel taken from the Skytrain manual: https://drive.google.com/open?id=0B18IAG6g43Y_a1dHeWpLNUJkdm8

TAIL WHEEL LOCK AND CONTROL:

There are TWO modes of operation:
  1. Novice (default): "Locked" is actually an "augmented lock" state. While "locked" the aircraft can be operated as a conventional tail-dragger with additional tail-wheel steering ability (not realistic, but will make taxi more easy for the novice pilots).
  2. Expert (toggle mode): "Locked" is totally locked. To enable this feature simply click on the Lock-Light-Indicator, and the letters "EX" will appear on the light itself, indicating that it is now in "Expert mode".
  3. In both modes...Tail Wheel Lock operation should be made only by using the Tail-Lock handle at the lower pedestal.

AIRSPEED INDICATOR ADJUSTABLE TAB:



WINDSHIELD WIPERS:

Use the Windshield Wipers handle to operate:


NAVIGATION AND COMMUNICATION:
Aircraft is including: 2*COMM, 2*NAV, 2*ADF, 2*DME in the overhead panel. All radios are equipped with working volume control knobs.

Aircraft is including: Radio Compass with fixed card (biased to ADF1), RMI with rotating card and NAV1/2 ADF 1/2 needles and switches, CDI+OBS, OMI markers.

FUEL SYSTEM OPERATION AND READINGS:
Fuel system is including Main L, Aux L, Main R, Aux R tanks with a cross-feed. Fuel consumption selection is only between the Left and the Right Main tanks, while the Aux tanks will start to feed in the engines when the Main tanks are empty (on each side). So, effectively and physically we have 4 tanks, all 4 can feed the engines but the selector can select Main L or Main R only (X-Plane default fuel system limitation...stretched to its its limits...). EDIT: Fuel system may be setup in the future so it will manage automatically the fuel level on each side, between the Aux and the Main...



FLAPS AND GEARS:
  1. Could be operated also by their handles (point and click).
  2. Flaps are set to be infinitely-adjustable between up/down when using keyboard or assigning a button/hardware switch.
  3. FLAPS operation by the handle itself (with the mouse) it is setup with a 3 click zones - for "up", "half" and "down" modes.
  4. GEARS operation by the handle is setup with 2 click zones - for "up" and "down".

HIDE THE YOKES:
When a full view of the instrument panel is needed, click on the aluminum plate underneath the left pilot seat, in front for the Rudder pedals:



TRIM-TABS OPERATION:
The real C-47/DC-3 Surface Control System consists of elevators, ailerons and rudder, which are made of metal frames covered with fabric. There are all-metal Trim-Tabs on the elevators, the right aileron and on the rudder.
  • Operate Trim-Tabs for elevators by using the wheel on the left side of the pedestal.
  • Operate Trim-Tabs for ailerons and rudder by using the hand cranks on the lower part of the pedestal.

Landing Gears Skis:
The VSKYLABS DC-3/C-47 Flying Lab is equipped with landing gear skis. In real life, the skis are installed for operation on snow and ice covered terrain. The skis system is an integral part of the aircraft, but can be switched on and off (default state is "off"), simply by using the ski selector handle which is installed below the side window to the left of the pilot's seat (left seat).


Activating the skis will affect the flight model physics with additional drag forces that will be induced around the skis, and as a result of the location of the skis below the CG, will induce a slight nose-down moments that will require re-trimming of the aircraft. The main wheels tires extend approximately 8 inches below the bottom surface of the skis.





Ski Take-Off:
  • The ski takeoff is similar to the normal wheel takeoff. The run may be longer depending upon surface condition. It is recommended to lower the wing flaps to 1/4 DOWN.
  • To avoid nose-over, the entire ground run should be made in a 3-point or tail low attitude. Excessive back pressure on the yoke will cause the tail wheels to dig-in and increase friction. To get the aircraft as soon as possible to the air, normally 45 inches MP is used.
  • After becoming airborne, relax back pressure immediately and continue accelerating until a safe airspeed is attained. The flaps should be retracted slowly (with short pauses) between 80 and 110 mph.
  • Note: X-Plane is not simulating true snow/ice when the aircraft is 'off-runway', and takeoff run is much longer when trying to takeoff from a point which is located off-runway (not on an X-Plane 'snow air strip').
  • Real life tip (currently not practicable in X-Plane...): Depending upon snow conditions, it may be advisable to prepare several tracks along the planned takeoff path by taxiing over the length of the run several times prior to takeoff. This procedure is assisting in shortening the takeoff run. 
Ski Landing:
  • Expect a much shorted landing slide than a normal landing. A reference point should be picked up to aid in maintaining direction.
  • It is recommended that half flaps be used.
  • All skis landing should be made tail low, and slightly above stalling speed. Immediately upon touchdown, reduce power, hold the control column full back and raise the flaps as soon as possible. 
  • When landing with low visibility and no horizon, depth perception is difficult when no visual reference points are available. Under these conditions, it is necessary to establish a constant rate of descent and attitude with the use of power and "fly on" at a slow sinking rate until contact with the surface is made in the tail low (3-point) landing attitude).
  • Under average load conditions with gear and skis down and half flaps, a descent of approximately 300 feet per minute at an airspeed of 90 to 95 mph is recommended.

COCKPIT SIDE WINDOWS OPERATION :

The VSKYLABS DC-3/C-47 Flying Lab is featuring sliding cockpit side-windows. To slide open or close, simply point and click on either one of the side windows. In X-Plane 11 version, opening the window will let the external sounds to get into the cockpit.




RAIN EFFECT:
The VSKYLABS DC-3/C-47 Flying Lab Project is featuring rain-effect. The rain effect is applied automatically every time the aircraft is sensing rainy conditions. Note that when setting rainy weather, but flying out of the rain areas, the rain effect will not have any effect.

The rain effect is visible on both sides of the windshields, and can be seen in external view.

Here are a few screenshots, demonstrating the phases of the effect, depending on flying conditions and wipers operations:



CARGO/PASSENGER MODES OPERATION:
The VSKYLABS DC-3/C-47 Flying Lab Project will feature a detailed cargo configuration in future updates. The mechanism for switching the aircraft interior from Passenger mode to Cargo mode is simple and intuitive.

All you need to do is to turn your head back (when sitting in cockpit view), point and click on the first two seats to the left (right hand side seats when looking to the nose section).

This is a Toggle-Switch mechanism, so clicking in the same area again will bring back the seats:


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