Douglas DC-3C
For
MS Flight Simulator
Aircraft Operations Manual
* * *
Introduction
The
DC-3C is an extensive modification of the Microsoft default DC-3 to make the
experience of operating and flying it more authentic. The problem with many of the simulated
aircraft in MSFS is that they are too simplistic and too perfect. This works fine for the more casual virtual
pilots but for those of us that want a deeper sense of realism, we long for
more complete and accurate systems modeling and for emergency procedures,
checklists, and operational limitations that have meaning -- because things can
(and sometimes do) go wrong in real-world airplanes.
This
manual assumes you have flown simulated DC-3's before and are familiar with the
basics. If that's not the case, it might
be better if you try the default DC-3 or another, simpler version before you
tackle this one.
The
focus of the DC-3C project is on the aircraft's systems environment rather than
the flight model. This package contains
the most realistic freeware versions of DC-3 flight dynamics I could find,
along with my personal favorite set of authentic sounds; and a generic bare
metal base texture so that if you’re interested you can easily substitute your
favorite livery or paint your own. (Full
credit goes to the hard work of the talented people whose freely given work
I've incorporated; they are listed in the Appendix A.)
Most
of my effort has gone into a set of gauges that work around and over the
default Flight Simulator implementation to provide electrical, hydraulic, oil,
fuel and anti-icing systems that behave like those in the real DC-3C. That
effort required some slight modifications to the aircraft.cfg and .AIR files;
so this DC-3C package is a complete set and the panel and gauges can't be
transported to another version without some minor work. Appendix C describes the changes I made so
that if you're familiar with FS panel design you can retrofit this gauge set to
almost any other DC-3 implementation.
The
systems modeled in this simulated DC-3C are based on the 1957 DC-3C flight
manual from QuebecAir, which is available for download on the web. Whatever that manual says about how the
various systems operate has been reproduced here with what I hope is
near-absolute fidelity. There are some
few things (for example, the real DC-3 propeller unfeathering procedure) that
no matter how hard I tried I couldn't fake or coax MSFS into allowing. I hope future versions of the simulator allow
more flexibility. All deviations from
the QuebecAir flight manual are listed in Appendix D.
If
you're not a real DC-3 pilot but have enjoyed flying simulated ones, you need
to study and understand this manual; because the experience of flying the DC-3C
is superficially similar to other versions you may be familiar with. But what's going on "behind the
scenes" may be different than anything you've experienced in the sim
world; and you must treat your DC-3C right if you expect her to return the
favor and keep you in the air. The
failure modes implemented in this airplane are far deeper and more DC-3
specific than the generic ones in FS, and serious pilot-induced errors can lead
to serious consequences while operating this airplane.
As in
the real world, when flying the DC-3C, you must accept that rarely, but
sometimes, your pre-flight checklists may uncover problems that will prevent
your flight that day; in which case you'll need to taxi back to the hanger and
call maintenance (i.e. re-start your flight).
If that level of realism frustrates you, random failures can be turned
off (as explained later in the manual) but you'll need to do that before every
flight.
Thank you for trying the DC-3C.
Please email me with your comments and suggestions at
Section I
Normal Operating Procedures
The
Douglas DC-3 isn't as complex as a Boeing 747, but it's not a Cessna 150
either. It has its own set of unique quirks and complexities. This section leads you through the typical
steps involved in operating the DC-3C properly.
Be
assured that there is nothing in the
following flight procedures that's said for pretend realism. The systems you are operating here aren't the
ones that you may be used to that are based around what's built-in to Microsoft
Flight Simulator. Every checklist item
and every warning is here to caution about a real possible situation in the
DC-3C aircraft, including some that could happen in the real world but that
simulator pilots seldom expect to ever encounter. Even light bulbs can burn out
in this airplane.
Entering the Cockpit
1.
Verify
the CART ATTACHED light is on. Normally,
as you enter the cockpit for the first time, the ground crew will have the
battery cart plugged in and supplying you with ground power. This is to charge and preserve your battery.
However, some smaller airports don't have ground power. If you aren't parked on a hard surface, the
cart won't be attached and your battery is all you have. Note:
the parking brake acts as a signal to the ground crew to connect or disconnect
the cart. There will be a delay between
the brake setting and the actual connection or disconnection. Be patient. Further note: At some small FS2004 airports, what looks like a hard
surface isn't. Don't be surprised if at a small airport no cart is connected
for you.
2.
Verify
the voltmeter on the left overhead panel is reading about 30 volts. If no ground power is available, the voltage
should be the battery voltage instead, roughly 26 volts. Any reading under 24 volts means your battery
may be in poor condition. If the reading
is under 22 volts you won’t be able to start your engines -- time to call
maintenance and replace the battery. But
battery failures are rare.
3.
Turn
on the MASTER SWITCH, located on the overhead panel.
4.
Turn
on the NAV lights on the overhead.
5.
Turn
on the PANEL LIGHTS if needed.
6.
Verify
the red oil and fuel pressure lights for both engines are ON.
7.
Verify
the red BATTERY DRAIN light is OFF if the cart is attached.
8.
Verify
the red ENGINE FIRE lights are OFF.
9.
Verify
the GEAR lights are both ON and GREEN.
10. The red DOOR light should be ON,
as the cabin attendant will usually open up the doors when the engines aren't
running and the no smoking and seat belt signs are switched off.
11. Flip up the RADIO MASTER
switch. Verify that the green TRM light
on COMM1 lights up. If you don't have
ground power, switch off any non-essential radio equipment to preserve your
battery. Turn them on later when needed. On the ground, you should only need COMM1 for
communications. You can turn on all your
radios when you've got both generators running.
This is not a worry if the CART ATTACHED light is on,
leave all your radios on (if you want) in that case.
Engine Start
1.
Turn
the SEAT BELTS and NO SMOKING signs ON.
The cabin attendant will close the door for you.
2.
Verify
the door is closed. The light should go
off.
3.
Turn
both GENERATOR switches ON.
4.
Note:
we start the right engine (#2) first.
This is traditional DC-3 practice.
Not only is that the engine we can't see from the captain's seat, but
delaying the left engine start would give a little more time for any late-arriving
passengers to board, as the door is on the left side.
5.
Set
the Right Magneto to BOTH.
6.
Set
mixtures to AUTO RICH.
7.
Set
Propellers to FULL FINE (all the way forward).
8.
Open
the throttles slightly (about 1/8 of their travel at most).
9.
Cowl
Flaps should be OPEN.
If they aren't, there's nothing we can do about it now, because we don't
have any hydraulic pressure yet. Cowl
flaps use hydraulic pressure to operate.
We won't have hydraulic pressure until we start an engine unless we use
the auxiliary pump, and we don't need to do that right now. (There may be some residual pressure in the
lines that will allow one or two changes in the cowl flaps position before it’s
bled off.)
10. Turn the right engine fuel pump
and energizer switches ON. These are
located on the right overhead panel.
11. Important:
read the next three paragraphs over carefully and understand them before you try to do them.
12. Flip the IGNITION switch (over the
magnetos) to the right. The right engine
will start turning over. Let it turn
over at least three times (to flush out any oil left in the cylinders), then:
13. Lift the right engine PRIMER
switch at one-second intervals until the engine fires. Once it fires, the ignition switch will
return to neutral for you. The amount of priming needed varies depending on how
cold the engine is. The first start on a
very cold day could take quite a few primes.
But if the engine doesn't start after about 8 or 9 primes, click the
IGNITION switch to shut off the starter and investigate: are the mixtures on
auto-rich? Magnetos set to BOTH? Fuel pump on?
Energizer on?
14. Do not prime
the engine more than once after the engine starts unless you hear it start to
die. If you hear the engine backfire,
the most probable reason is that you over-primed it. Severe over-priming of an engine before
starting it can damage it and even result in an engine fire. Be careful.
15. Once the engine is running, adjust
the throttle to idle at about 1000 RPM.
16. Turn OFF the fuel pump and
energizer switches.
Repeat
this same procedure for the left engine. Do not allow the RPMs
to exceed 1400 during this start procedure.
If you
forgot to turn on the seat belt and no smoking signs or close the door, the
cabin attendant will close it for you once both engines are running.
If the
Cowl flaps aren't open (you'll have to look out the window [or use an outside
view] to see, just like in a real DC-3), set them open now. (Cowl flap controls
are on the cowl flap control panel [the C Icon].) To set the cowl flaps open, rotate the knob
to the OPN position and wait for a few seconds, then move the knob to OFF. We normally leave the knob in the OFF
position because the cowl flaps operate from hydraulic pressure and hydraulic
leaks are something to always be alert for. The OFF setting removes pressure
from the cowl flap hydraulic line while leaving the cowl flaps at their last
setting, so if a leak occurs in that line we won't
lose precious hydraulic fluid.
Warm-up
1.
Set
throttles to about 1300 RPM. Observe the
ammeter on the right side of the overhead panel to ensure that both generators
are online. Generators go offline at under, roughly, 1200 RPM.
2.
Warm-up
the engine by waiting for the oil temperature to reach 50 degrees and the
cylinder head temperature to reach 100 degrees (the green zones). Be patient
here, this warm-up is important for the health of your engines, and their
health is vital to that of yours and your passengers!
3.
When
the engines have warmed up, release the PARKING BRAKE. The best way to do that is to tap the toe
brakes, although clicking on the brake handle will work. This signals to your ground crew that you are
ready to taxi. If it's windy, you should
keep pressure on the toe brakes to prevent inadvertent movement until the cart
is unplugged.
4.
Wait
for the ground crew to detach the battery cart.
The CART ATTACHED light will go off and you'll hear the relay switching
the main bus over to internal power. Do not taxi until the cart attached
light goes out or you'll hurt something, probably your own electrical system.
5.
Verify
that the BATTERY DRAIN light is still out.
Both ammeters should show a small drain on each generator. If the battery light isn't out, advance the
throttles slightly until the generators kick in.
6.
Switch
both generators off and observe the voltmeter.
It should drop to about 26 volts.
This is your battery charge level.
It's possible that you could have a dead or dying battery on board. You should not fly without a good battery (24
volts or over); you will need it.
7.
Switch
the right generator ON. Observe the
right ammeter level. This is the full
electrical load being pulled at this time.
This load for each generator must be under 75 amps or the breaker for
that generator will trip.
8.
Switch
the left generator ON and verify that the load is shared equally between the
two generators. Do not attempt flight
with one generator inoperative, you won't have enough power to safely operate
all the equipment you'll need. One-generator
or battery-only operation is for emergencies only and requires a reduction of
the normal in-flight electrical load.
9.
Verify
the CART ATTACHED light is off. If you
try to taxi before the cable is unplugged, you'll likely short out your
electrical system or at least damage the plug so that you can't reconnect. This is worth saying again.
10. Verify the oil temperature and
pressure gauges are in the green. DO NOT
taxi with the oil temperature under 40 or the cylinder head temperature under
100.
11. Bring up the hydraulic control
panel [the H icon] and verify that the gear and system pressure reads about
700-750 PSI. If it does not, you have a
hydraulic leak or failure and it's time to call the mechanic. All shutoff
values must be in the ON position.
12. Check the fuel levels in the tanks
and verify you have enough for your flight.
13. Get clearance and taxi to the active.
Taxiing
1.
Set
the cowl flaps to TRAIL (then OFF as usual.)
2.
Unlock
the tail wheel for taxi.
3.
Shortly
after you start moving, verify that the brakes work. The DC-3 has hydraulic brakes, and they can
fail on either or both wheels. Verify
that the hydraulic pressure doesn't drop significantly when you apply the brakes,
which would indicate a leak in the brake line.
Remember, we're not saying this just because it's true in the real DC-3
and we want to sound authentic; we're saying it because those are both failures
that can occur in this simulated DC-3C you are driving now. Every simulated pump can fail and every simulated fluid line can break and leak.
Engine Run-up
1.
Set
the parking brake ON. Note: if you have not taxied away from the ramp,
the ground crew will automatically re-connect the battery cart to your DC-3 in
about 15 to 20 seconds. If you have
taxied away, the cart is no longer available; don't expect it to be
re-connected until you land and set the parking brake at the ramp.
2.
Advance
the propellers to FULL FINE (forward).
3.
Advance
the throttles until both engines are at 2000 RPM.
4.
Check
both magnetos on both engines. Verify the
drop in RPM is no more than 65. Any greater indicates a dead magneto, meaning
you are down to one on that engine and if that fails the engine fails. Magnetos fail more often than any other
engine component, that's why there are two of them per engine.
5.
Check
carburetor heat on both engines. Verify that the carburetor air temp increases
by about 50 degrees.
6.
Retard
the propellers to full coarse, and verify that the RPM
drop is no more than 700 RPM. Any greater drop means the propeller governor is
suspect and flight should not be attempted.
7.
Advance
propellers back to FULL FINE. Verify RPM
returns to normal. Again, look for
suspicious RPM changes. The RPM should
return very near to where it was before.
8.
Press
the left-engine feathering button and verify that the RPM starts to fall. Let it fall about 200 RPM, then press the
button back in. If the RPM doesn’t fall,
it means the feathering pump has failed.
Inability to feather a failed engine in flight means you won’t be able
to maintain altitude on one engine.
Check the right-engine button in the same way.
9.
Return
the throttle back to about 1250 RPM.
10. Switch off both generators and
verify that your battery voltage is about 26 volts. Then switch both generators on again. Verify that they share the load equally.
11. Very Important! Verify that the flight
controls have full, free movement. Use an outside view to watch them move,
because in the sim you can move your joystick but that doesn't guarantee the
control surfaces are doing likewise.
It's possible that a flight control cable could be broken or hung. This is very serious. I have personally unexpectedly crashed on
takeoff while testing the DC-3C after forgetting to check the flight
controls. I'll never forget again.
Pre-Takeoff
1.
Switch
the Beacon ON.
2.
Switch
the landing light ON.
3.
Set
the trim tabs to zero or slightly up.
4.
Be
sure the flaps are UP (unless a very short field in which case one notch).
5.
Pitot
heat ON if temperature warrants.
6.
Prop
anti-ice should be ON if icing conditions are present. Potential icing conditions are temperatures
between 3 and -25 Celsius with precipitation or clouds of any kind, especially
rain. However, DO NOT attempt takeoff
with the wing de-icers on. If you suspect ice on your wings (the sim
won't show visually it but it could be there) you may cycle the wing de-icers once (turn the switch on for 15 seconds, then off)
while on the ground. You may also wish
to use carburetor heat for takeoff in icing conditions. (I have verified that the icing simulation in
FS2004 is real and it can ruin your day.
The DC-3C anti-icing and de-icing systems do work.)
7.
Turn
the Inverter switch ON. The inverter
powers the Radio-Magnetic Indicator flight instrument.
8.
Get
clearance, taxi into position.
Take-off
1.
Important: Lock the tail wheel. The DC-3 is a bit awkward on the ground and
you don't want that awkwardness to bite you on the takeoff roll. This can be critical in a crosswind
situation; more than one DC-3 has exited the runway in a non-vertical fashion
due to forgetting this detail.
2.
Advance
the propellers to FULL FORWARD.
3.
Advance
throttle to TAKEOFF POWER - 44 Hg Manifold pressure. This should be the only time you ever allow
the RPM or manifold pressure gauges above the green zones. Both will be in the yellow on the takeoff
roll.
4.
Rotate
at about 85 knots.
5.
Gear
UP as soon as positive rate of climb is established.
6.
Flaps
UP if you needed to use any (which will be rarely).
7.
Remain
in TAKEOFF POWER until airspeed reaches 105 KIAS; then retard throttles to 42
inches manifold pressure and propellers to 2500 RPM (METO power). METO Power is just on the top edge of the
green zones for both RPM and manifold pressure.
8.
Note: some DC-3 pilots prefer using
full throttles rather than the de-rated power I recommend here. Either will work satisfactorily, but I
believe that if you don't have to stress your engines a little more than is
necessary, why do it? There are valid
arguments both ways. On a short field,
or where there are obstacles, substitute full power for the 44 inches I
recommended above.
Climb
1.
Climb
in METO power until 500 ft AGL or obstacles are cleared, then
switch to normal climb power -- 36 inches of manifold pressure and 2350 RPM.
2.
Climbing
above 5000 MSL, switch mixture to AUTO-LEAN.
3.
You
will notice that as you get above 4000 MSL or so, you will have to add power to
maintain the same manifold pressure.
This is the normal effect that thinning air has on a reciprocal engine.
Cruise
1.
Cowl
flaps to CLOSED. Flying with closed cowl
flaps gives you more airspeed and you shouldn't need the extra cooling at
cruise. Always remember to move the cowl
flap control to OFF after a few seconds.
2.
Throttle
30-32 inches MP, propellers 2000 RPM.
Maximum sustained cruise power is 34 inches MP and 2100 RPM. If you are over 160 KIAS in level flight for
any period of time, you're probably running your engines too hard.
3.
Monitor
the engine instruments. Refer to the
CAUTIONS section below. Keep all the gauges "in the green" at all
times. Be alert to any unexpected fall
in fuel or oil pressure, or increase in oil or cylinder head temperature; these
are signs of potential engine trouble.
4.
Your
best indication of system abnormality is asymmetry in the gauges. A little is
normal, but any significant difference in the two engines,
or a significant unexplained rising or falling trend indicates trouble. Falling fuel, hydraulic, or oil pressure
could indicate a leak. Some leaks can be
dealt with via the shut-off values. Consult the "Emergency
Procedures" below.
In Range (Approach)
1.
Cowl
Flaps to TRAIL.
2.
One
notch of flaps if needed, but no more, when under 135 KIAS.
3.
Descend
at 20 inches MP, 2000 RPM, or less if needed to keep speed where you need it to
be.
4.
Don't
allow the top two digits of the RPM to exceed the manifold pressure by too much
until you are at or below 105 knots IAS; for example, 2100 RPM versus 15 inches
MP is a difference of six and a situation to avoid; there are many terms for
this but I call it "back loading" and it can damage your engine if
allowed to happen often.
Final
1.
Gear
DOWN. Note: Gear will lower by its own
weight even if your hydraulic pressure is low.
Cowl flaps, wing flaps, and brakes will not work without hydraulic
pressure, however.
2.
Flaps
DOWN to 1/2 at 105 KIAS; 3/4 and FULL below 97 KIAS. Flaps on the DC-3C will not lower until under
their safe airspeeds. This is a characteristic of the real DC-3C.
3.
Normal
cruise electrical loads can exceed the capacity of a single generator to handle
the load. Since generators automatically
switch offline when under 1200 RPM, this introduces the problem of generators
tripping the breakers when the engines go to idle on the flare. To prevent this from happening you have two
options. The first is to switch off the
inverter when starting on final, if the Radio Magnetic Indicator isn’t needed
(as it normally isn’t). This should
bring the load back under the 75 amps one generator can handle. The other option is to watch the RPMs when you flare to prevent them going under 1200.
4.
Speed
should be about 85 KIAS on final.
Maintain slight power until flare.
5.
Flare,
idle engine and touch down at 80 KIAS or below.
If you don't bounce you know you've nailed it. Some small bounce is pretty normal, too much
bounce and you need to work on your technique, you're probably too fast.
(Normal air pressure in the DC-3's tires is only 40 PSI, which makes them very
soft and bouncy indeed.)
Taxi to Ramp
1.
Flaps
UP.
2.
Landing
lights OFF.
3.
Beacons
OFF.
4.
Set
the parking brake when at the ramp.
5.
If
possible, wait for the cart to attach before shutting down the engines, even
through it may take a minute or two for them to roll it out to you. Often, on
quick stops where there was no time for the cart or no cart available, DC-3
pilots would shut off the left engine but leave the right one running while
passengers boarded or cargo was loaded.
The point is to preserve your battery.
If you do this, be sure to not overload the one remaining generator --
kept it below 75 amps unless the cart is attached. More details are in the Electrical section
below.
Section II
Emergency Procedures
Engine Fire in Flight
This
is probably the worst thing that can happen, so it's listed first.
1.
DETERMINE
the affected engine. Don't be in a hurry
and pick the wrong one. There are two
lights, one for each engine. Visually
you can verify by looking out the window or from an outside view. The burning
engine will be spewing black smoke and flames may be visible under the
cowlings.
2.
SHUT
DOWN the engine; turning off the magnetos, mixture, and fuel selector for it to
OFF. Bring up the Emergency control
panel and turn the three firewall shutoff values to OFF. This is to eliminate all potential fuel for
the fire.
3.
FEATHER
the propellers using the propeller feathering procedure below.
4.
SELECT
a suitable landing area and turn toward it.
Do this before
you try and put out the fire. Time is
short and precious. You will land soon.
5.
Now,
return to the emergency fire control panel and turn the fire suppression engine
selector to the burning engine. Pull the
CO2 BOTTLE #1 handle. You'll hear the
gas release. Wait 10 seconds after the
sound stops, and check the fire warning light.
If it's still lit, the fire is still burning. Try BOTTLE #2.
6.
LAND
IMMEDIATELY, regardless of whether the fire went out or not. Fires can
re-start; it may not be out completely.
If it's still burning, you have no time to waste. The consequences will
go from bad to worse as time passes.
Soon, aircraft systems may start to fail and the aileron control cable
will eventually burn through and you will "depart controlled flight"
as they say. You have between 8 and 12
minutes, maximum, to get on the ground safely with an engine on fire.
Section III
Cautions
There
are a number of "sins" you can commit while flying a DC-3, and all of
them have consequences when you're in the cockpit of this DC-3C. Some are immediate, however most are subtle
and unseen, but they add up. Too many
sins and things can add up to disaster.
Unlike a modern aircraft, the DC-3 doesn't always have safety features
to prevent many of these errors from being committed. You have to be aware of how to treat the
airplane and its engines right so that they treat you right.
Here's
how the consequences are implemented.
Each engine has a "damage count", which may or may not start
out at zero for each flight. (There are random factors involved in all this so
that things aren't the same on every flight.) Each engine also has a "fail
point" at which it is subject to failure once the damage count has reached
that level. Not every engine has the
same fail point, in fact, the code is written so that on any given flight both
engines will never have the same fail point.
One will fail before the other even if their damage counts are the
same.
Although
one or both engines may not start their damage counts at zero, both will start
far enough below the fail point to allow for a safe and uneventful flight --
provided you don't commit too many sins during the flight! But you won't ever know exactly how many
indulgences you have (it varies every time), so assume always that one sin is
too many, even though it probably isn't.
Most
sins listed below have the potential to add to the damage count. A few of these bring on immediate
trouble. Most just add to the counts. Some don't even apply to the engines, so
don't affect the counts but ruin your day in other ways.
This
is a listing of things NOT to do while flying the DC-3C, and what might happen
if you do them.
Remember,
turning random failures off doesn't turn pilot-induced errors off. If you want
to do that, fly another simulated DC-3, not this one.
The List of Sins
1.
Don't
taxi or move the aircraft while the cart is attached. You WILL break the plug, and possibly short
out the whole
electrical system.
2.
Try
to avoid starting the aircraft on its own battery without the cart
attached. The battery has limited
capacity and the starter motors will drain it all too quickly if you have
problems starting the engines. If you
have departed the ramp area, no cart will be available to you; and if your
battery can't deliver at least 22 volts you won't be able to start the
engines. (Note, the cart also will not
be attached or re-attached unless you have the parking brake on, and are also
on a concrete or asphalt surface.)
3.
Don't
taxi or run the engines at over 1500 RPM until the oil temperature is above 40
degrees and the cylinder head temperature is above 100. If you do, you risk adding to the engine
damage counter.
4.
Monitor
your electrical load. Don't allow more
than 75 amps to be drawn from any one generator. If you do, the breaker on that generator will
pop out shutting down that circuit. If
this happens, you must reduce the electrical load and reset the breaker.
5.
Don't
allow your battery to become seriously discharged, because a low battery
requires a heavy amp pull from the generators to recharge it. This is an easy way to exceed the 75 amp
limit on generator output.
6.
Do
not allow the manifold pressure up above 44 inches, except during a short
period on takeoff. Any extended time
above 44 inches in flight may add to the damage count. Much time above the red line (48) WILL add to
the damage count.
7.
Do
not allow the cylinder head temperature to get above the red line (260 degrees)
EVER. Doing so WILL add to the damage
count, and continuing to run the engine in an overheated condition will drive
up the count rapidly. The same applies to the oil
temperature. Keep the temperature gauges
in the green. Managing your cowl flaps
properly is the key to not running too hot.
8.
Do
not allow the RPMs (divided by 100) to exceed the
manifold pressure at airspeeds above 100 knots.
Doing so introduces the problem of "back loading", where the
spinning propeller drives the shaft rather than the engine. Doing this risks adding to the damage counts, and the greater the gap, and the greater the speed,
the more likelihood of damage.
How do I know the damage count?
You
don't. However, there are some
clues. Watch your instruments. If the
oil temperature on an engine starts to rise, and the oil pressure on that same
engine to fall, the engine is going to fail soon -- you can count on it. But even if you don't see any clues, that's
no guarantee that all is well. If you
hear the engine backfire, that's also never a good sign.
If the
oil pressure starts to fall without a corresponding rise in oil temperature,
it's probably the sign of an oil leak.
See "Emergency Procedures" above. Same applies to the fuel pressure or
hydraulic pressure.
What happens when the damage count
gets to the fail point?
Once
again, there are random factors involved in the calculation. There's no guarantee, you may be lucky that
day or you may not. There are four
possibilities:
1.
Nothing
happens. You dodged the bullet, this
time, but the damage count is still over the limit and one more addition to it
will roll this particular set of dice again.
2.
Nothing
happens immediately, but the oil temperature starts to rise and the oil
pressure starts to fall. The engine will
fail soon, but not quite yet.
3.
The
engine fails and stops running, with or without a loud bang. But the loud bang is not a good sign.
4.
The
engine catches fire. This may or may not
result in immediate engine failure, but it will result in the engine fire
warnings lighting up and buzzing. See
EMERGENCY PROCEDURES above. (TIP: if you want to see an engine fire and
practice fighting it, hit the primer about 20 times before starting an engine.
It'll light up for you.)
This
fail point checking occurs every time the damage counters are incremented. Therefore, even if you escape the maximum sin
count once, you're on borrowed time.
If one
engine fails, you can be sure the other one is pretty near its fail point
too. This makes one-engine flight much
more challenging. You need to be
particularly careful not to overheat the remaining engine or you'll be in a
big, heavy glider headed towards the nearest farmer's cornfield.
“Random” Failures
The
DC-3C is equipped with a realistic random failures system that's on by default
with every flight. "Random
Failures" are non-pilot-induced ones. This system has four settings:
- Rare: Failures can happen but they are rare. This is the normal mode.
- Never: Random failures won't happen (but pilot-induced ones
always can.)
- Likely: The chances of a random failure are greatly
increased.
- Certain: You will
experience failures, probably multiple ones.
The
normal default is 'rare' which is realistic.
You could fly for weeks or months without having anything go wrong. But anything can at any time, on the ground
or in the air. Checklists in the DC-3C
take on serious meaning.
You
can control this setting by clicking on the "CAUTION EMERGENCY USE
ONLY" sign on the emergency control panel.
Each click cycles through one of the four settings.
"Random
failures" in the DC-3C are not truly random. Which failures are likely or possible are
based on your situation. Some are
pre-set to occur only before you power up your DC-3C. Others happen mostly when the engines are
first stressed (run-up or takeoff).
Others can happen anytime, anywhere.
The
DC-3C failure modes go far beyond what's available in the regular Flight
Simulator scheme. There are over 64
failure points, most specific to the real DC-3C and its systems. You can experience engine failures, hydraulic
leaks, fuel leaks, electrical shorts, failed generators, failed pumps,
inoperative instruments, bad magnetos, and even snapped or frozen flight
control cables. Some things are subtle,
like battery under-volts or a leak in the alcohol tank. Others are unmistakable, like the warning
light and buzzer that signals an engine fire, and if you look out your window
you'll see the evil black smoke and licking flames from the cowlings.
But there is no failure which you
have no way of detecting or coping with.
For instance, the system won't break or freeze a control cable in flight
because in a sim that's simply unfair; you can't do anything but crash. However cable faults can happen on the ground, and if you skip checking for it before
takeoff you could find yourself on a very short and painful flight path.
Sometimes,
failures occur and the pilot isn't even aware of it. An alcohol leak on a summer day when the
deicing system isn't needed is unlikely to be noticed. But an oil leak will come to your attention,
especially if you don't see the drop in pressure until both engines seize
up. You might not notice a hydraulic
leak until most of your fluid is gone and the flaps won't work -- and you have
no brakes! The DC-3c really should have
a low hydraulic pressure warning but the real one didn't so this simulated one
doesn't either.
You
have options for dealing with any failure, but you must understand the DC-3's
systems to know what to do. In the rest
of this manual, we'll explain the workings of the DC-3C's aircraft systems, in
enough detail for you to understand them from a pilot's (not a mechanic's)
point of view.
Section IV
Aircraft Systems
Electrical System
There
are three sources for electrical power to your DC-3C:
1.
The
"battery cart" that can be connected while you are near the ramp with
the parking brake set. This will provide
up to 150 amps of power at 28 volts, more than sufficient to charge your
battery and meet all your power needs.
2.
One
generator on each engine. Each generator
can supply up to 75 amps of power. Each
generator will only provide power when its engine is running at about 1200 RPM
or above. The generators can re-charge
the battery also, but this requires amps too, and the lower the battery charge
is the more amps are drawn to recharge it.
3.
The
aircraft battery is actually two 12-volt batteries wired in series to provide a
26 volt supply. The battery alone can
provide up to 100 amps, but the higher the load, the faster the charge will
drop. As the charge drops, the battery
voltage drops. Most of the avionics in
the DC-3C require at least 18 volts to operate.
The engine start motors require 22 volts to turn over.
A
voltmeter and a dual ammeter are provided on the overhead panel to monitor the
status of the electrical system. A
warning light over the engine instruments will light up red whenever the
battery is being drained rather than charged.
The
voltmeter reads the voltage currently supplying the main bus. The DC-3C has a relay which automatically switches
the battery cart to supply the main bus when the cart is connected. When the cart is disconnected, this relay
switches power to the generators or to the battery if the generators are not
online. Here are the rules for the
voltmeter reading:
·
When
the cart is connected, the voltmeter shows the cart voltage.
·
When
the cart is not connected but either generator is online, the voltmeter shows
the generator voltage.
·
If
neither the cart nor the generators are supplying power, the voltmeter shows
the battery voltage.
The
ammeter has a needle for the left and the right engine. Each reading shows the amps being pulled from
that generator to supply the electrical needs at that moment. If the generator is not online or is
inoperative, the reading will be zero.
Each
generator can produce up to 75 amps.
Together, the two generators together produce a theoretical maximum of
150 amps. There is only a single
electrical bus in the DC-3C, which we refer to as the "main
bus". That bus is distributed to
the various devices and instruments through the main circuit breaker
panel. Appendix B contains a detailed
list of the amperage requirements for each device.
The
normal cruise load is about 80-100 amps, except when the anti-ice equipment is
switched on which raises that to 125 amps at the point the boots cycle to their
maximum extension.
In the
event of an engine or generator failure, it will be necessary to reduce the
electrical load to under 75 amps by switching off all
non-essential equipment. Often, when an engine
fails, the load placed suddenly on the remaining generator causes its breaker
to trip. In that case, you must switch
off some equipment before resetting the breaker.
In
case both generators are inoperative, it's essential to reduce power drain to the
absolute minimum to conserve battery life.
Be
careful when feathering, this operation uses an electric pump which places a
heavy drain on the supply while the feathering process is taking place.
Note:
the DC-3C electrical system is outside the MSFS one. None of the addon
software (such as FSUPIC) or tricks that prolong battery life will have any
effect on it. The battery life is
realistic and adequate but not excessive.
Fuel System
Each
engine has its own engine-driven fuel pump and fuel line, and each is
supplemented by an electric pump, which must be used to start the engine, and
which can be used in flight in case of engine pump failure.
The
DC-3C has four fuel tanks, each with a capacity of about 200 gallons. The main
tanks are named the right main and the left main. The auxiliary tanks are referred to as the
right and left rear tanks, because they are located aft of the main tanks. The quantity of fuel in these sets of tanks
will affect the DC-3C's center of gravity, so proper fuel management during
flight is important.
Each
engine has a fuel selector on its side of the throttle quadrant that selects
its fuel source. Any engine can drain
from any tank, and there is an OFF setting for each engine. Normally, the right engine should draw from
the right tanks, and the left from its side.
For
takeoff and landing, the fuel selectors should be on the main tanks, right main
for the right engine and left main for the left engine. This is because on the DC-3C the carburator vent is routed to the main tanks, and during
periods of high engine manifold pressure this helps prevent vapor lock.
During
cruise, the fuel selectors are normally set to draw from the auxiliary (rear)
tanks until they are down to about 10 gallons each, then
switched to the main tanks.
The
fuel line to each engine passes through the firewall, and there is a shutoff
valve on the emergency control panel that will shut off fuel at that
point. This valve should, of course,
normally be open but reasons to close it would be engine fire or a suspected
fuel leak.
Fuel
quantity and pressure are measured by gauges on the main panel. An unusual drop
in fuel pressure could be indicative of a malfunctioning engine fuel pump and
may call for the electric pump to be used.
A drop in pressure could also indicate a fuel leak. If use of the electric pump does not restore
pressure to normal, a leak is confirmed.
Check the fuel quantity gauge for any abnormal drop in fuel level in any
one tank. Land as soon as practical - a
fuel leak can lead to a very dangerous fire.
Important note: some MSFS aircraft have a fuel
system where all tanks are automatically drained to supply the engines. This is not true in the DC-3C. If the fuel tank you have selected runs dry,
the engine will stop, regardless of the quantity of fuel in any other tanks.
Oil System
The
DC-3C has two separate oil systems, one for each engine, each with their own
separate oil supply and pump.
Oil is
used for lubrication of the engines as well as for operation of the propeller
governors.
Oil
pressure and temperature are monitored by gauges on the main panel. Oil temperature that is too low or too high
is very detrimental to the operation of the engines, and must be monitored at
all times.
Falling
oil pressure could indicate a faulty pump or an oil leak. In any case, you
should get on the ground as quickly as possible if oil pressure cannot be
maintained.
Hydraulic System
The
DC-3C depends on its single hydraulic system for the operation of the landing
gear, trailing edge flaps, brakes, and cowl flaps.
The
hydraulic panel is the central point where the hydraulic system is monitored
and controlled. Gauges there indicate
pressure to the landing gear and in the main system. Normal pressure is about 750 PSI.
Each
engine has its own hydraulic pump, and either engine alone can power the system
with sufficient force. In the rare case
where both pumps are inoperative (say, an engine failure on one side and a pump
failure on the other) an electric auxiliary pump is provided to maintain
pressure.
Lower
than normal or gradually dropping pressure indicates a compromise in the
hydraulic system (a leak). The four
shutoff values on the hydraulic control panel allow you to close off parts of
the system to identify the source of a leak and to prevent further loss of
hydraulic fluid. If you shut off a
section that has the leak, pressure should return towards normal or at least
stop falling.
If a
leak is suspected, it must be isolated and closed off promptly, or the fluid
supply could get so low that no hydraulic services are available. The landing gear will drop by gravity, but
the cowl flaps, wing flaps, and brakes depend on hydraulic pressure to operate.
Anti-Icing System
Your
DC-3C is equipped with a full set of deicing and anti-icing systems, and if you
fly in icing conditions you'll need them.
(Contrary to some folklore, FS2004 and FSX do simulate the effects of
icing on propellers and airframes, to the point of departing controlled flight
if the conditions are severe and not dealt with.)
There
are four kinds of icing that can affect the DC-3C.
Carburetor icing (that we're all familiar with)
can happen anytime the carburetor air temp falls below zero and there's
humidity in the air. Use the carburetor
heat controls on the throttle quadrant to fix this. Nothing unusual, this has happened to every
sim pilot who flies with the realism sliders to max.
Pitot icing is when ice forms around the tiny
opening of the pitot tube that measures airspeed,
blocking it. The symptom (in FS2004,
somewhat unrealistically) is that the indicated airspeed will suddenly drop to
zero. The cure is to turn on the pitot
heat to melt the ice. In fact, anytime
temperatures are near or below freezing you should have the pitot heat switch
turned on. Temporary pitot freeze will
often occur in severe icing conditions even with the heater on before you
entered the conditions. This is a
primary indication (i.e. a warning) that propeller and airframe icing may also
be present.
Propeller icing.
In airframe icing conditions (from 5 above to 25 below (Celsius) when
flying in clouds or in precipitation) ice can form on propeller blades,
reducing their effectiveness and thereby reducing thrust and therefore
airspeed. The effect is subtle at first, but it gradually gets worse as time
goes by. An otherwise unexplained
gradual drop in airspeed could be icing even if it looks clear outside if the
temperature is near or below zero. If you ever see your pitot freeze, even for
a moment or two, then you can be sure conditions are ripe for prop and airframe
icing (this is true in FS2004, not necessarily in the real world).
The
DC-3C is equipped with a propeller anti-ice system which pumps alcohol out to
the propeller blades to prevent the formation of ice on them. You should turn on the prop anti-ice system
whenever you suspect icing conditions present to prevent ice forming. This system will also melt any ice that's
already there. Use of this system
consumes alcohol, and once the alcohol supply is consumed the anti-icing system
no longer functions. The aircraft's normal supply is 11 gallons of alcohol, and
the use rate is six quarts per hour per engine.
Airframe icing can and will occur whenever
conditions are right for prop icing. Ice
forms on the wings and all exposed surfaces (alas, it isn't visually depicted
in the sim). The effect of this ice is
to add to the gross weight of the airplane, increase the stall speed, and
gradually change the shape and aerodynamic properties of the wing. The DC-3
series aircraft handle ice loads well, but enough ice and even a DC-3 can fall
out of the sky. Airframe icing is
particularly dangerous if the pilot is unaware of it and attempts final
approach and landing at normal speeds, resulting in an unexpected stall.
The
DC-3C is equipped with a set of de-icing boots along the leading edge of both
wings. When this system is switched on,
the rubber boots are pressurized to expand and break up the ice formations. The boots operate in a cycle, where every 50
seconds they expand for a period of about 10 seconds, then contract. You should NEVER operate this de-icing system
unless you need it, and it's best to operate it intermittently rather than
continuously. Don't be alarmed when you
hear the sound of the ice striking the hull as it flies off the wings on each
expansion cycle.
APPENDIX A - CREDITS
Without
the work of many talented and hard-working designers I’d never have been able
to complete the project, as I am a poor graphics artist and not an expert on
flight dynamics and FDE design, nor am I a pilot of a real DC-3.
In no
particular order, the awards go to:
Mark Beaumont and Dave Bitzer
for their work in making the DC-3 flight dynamics much more realistic than the
default version, and for the four-tank fuel setup that works like the real
DC-3.
Norm
Hancock of DC-3 Airways for some of the bitmaps for the engine gauges.
Hans-Joerg Naegele,Wolfram
Beckert, Howard Sodja, and
Jan Visser for many of the bitmaps associated with
the flight instruments and radios, which I took from their wonderful Connie
panel.
Tom
Gibson for the idea that started this whole thing, from seeing the way he
implemented the DC-6 electrical system complete with ground cart.
Trev Morrison for
his great DC-3 sound package.
I’m
sure I’m forgetting many others.
APPENDIX B - ELECTRICAL LOAD
Breaker
Load Amps Breaker rating
1
Left engine generator - 75
2
Right engine
generator - 75
3
4
Left engine starter 15 20
5
Right engine starter 15 20
6
Left engine fuel pump 10 15
7
Right engine fuel pump 10 15
8
Left engine feather motor 20
25
9
Right engine feather motor
20
25
A
Automatic Pilot 6 10
B
Battery charging 10 -
C
COMM1 Radio 3 5
D
NAV1 Radio 3 5
F
Transponder 3 5
G
ADF Receiver 3 5
H
DME Receiver 3 5
I
COMM2 Radio 5 10
J
NAV Lights 5 10
K
Beacon 5
10
L
Landing Lights 10 15
L
Anti-icing pump 10 15
M
De-icing boots 15 20
N
Panel lights 2 5
O
Aux. Hydraulic Pump 8
10
APPENDIX C - Customizing another DC-3 for this gauge set
Got to work on this. Some notes:
Add
1513, 1518 and 1519 to the .AIR file
Fuel
tanks in the aircraft.cfg must match
gear warning horn in sound.cfg
DC3CPNL.cfg
and sounds in sound folder
APPENDIX D - Deviations from the QuebecAir DC-3C Manual
Unfeathering
does not work properly. In the real
DC-3, you unfeathered the prop first, then attempted to restart the engine. MSFS 2004 will only unfeather
as a part of the actual restart.
Gear dropping. In the real DC-3,
the gear would drop by gravity alone, and a sharp nose-up was needed to lock
the gear in place. In FS2004, the gear
locks in place automatically without the nose-up maneuver.
The
real DC-3C often had an auxiliary power unit installed in the tail, which was a
small gas powered generator. I choose
not to implement the APU on this version.
The
DC-3C used by QuebecAir had a gasoline heater than was used to heat the cabin,
with the controls in the cockpit. I
chose to not implement these heater controls (with their fire warning and fire
suppression capability) in the sim in this version.
The
DC-3C had a hand-operated
auxiliary hydraulic pump.
I couldn’t figure any logical way to make a hand-powered pump (with no
co-pilot to pump it wile you flew) so I chose to modernize the concept slightly
and provided the same functionality with an electric auxiliary pump.