B-17: Flying Fortress The Mighty Eighth Patch Version 2.0

Although there are various changes in this patch the majority of
difference is to be found in the way the simulation manages engines.
Simulation and Modelling of the engines has been made more complex and
realistic full explanations follow.

Installation

This patch will upgrade B-17 V1.1 with or without earlier Patches
installed. You can apply this patch safely to any version of B-17
below V2.0. You should not, however, install the earlier patch onto a
version of the game patched to V2.0. If in doubt, consult your Read Me
file to check the Version number of B-17 or the Volume Label of your
CD.

The patch comes with a full install shield front end. Simply
doubleclick on the B-17 Patch 2.0 icon. From there, follow the
instructions on screen to fully install the patch. The patch needs to
make changes to the AIRCRAFT.OMF B17Data.OMF files and
RiverAndRoadsDB.LMF (amongst others!) so you will lose any changes you
may have made to these files. Please be aware that you should not
overwrite the files provided by this patch with older files you may
have modified. If you wish to make any changes using the OMFMOD
utility, please make them to the new files provided!

New Difficulty Options

Note: The difficulties for Engine Management are controlled via
Realism: General Difficulty.

Low: No damage, simple modelling, no AI
Medium: No damage, full modelling, full AI
High: Full damage, full modelling, full AI.

Notes on Engine Management

When an engine is damaged it suffers from a heating penalty. Therefore
damaged engines will tend to overheat more at the same power levels.

Given that, the following points should be remembered:

Carburettor Air Filters should be turned on below 8,000 feet and off
above that. 1.5 inches of manifold pressure are lost due to use of
these. If used above 8,000 feet there is an increasing heat penalty on
the Carburettor Air Temperature.

Fuel Boosters should be on for engine start, take-off, landing, flight
below 1,000 feet and flight above 10,000 feet. If fuel pressure is
above 10 then there is a fuel usage penalty.

Open cowl flaps have a small effect on drag.

Monitoring Engine Temperatures

The best view to monitor the status of your engines from is the Pilots
Instruments View. To quickly access this you should press (To
Enter the Aircraft if outside), <3> (To select the Pilot), (To
select the Instrument View) and then (To select the right part of
the control panel).

You inlay card can be used to quickly orient yourself as to which
gauges refer to which temperatures for your convenience you can leave
your mouse pointer still on any needle to identify its gauge.

The temperature gauges have had a number added, letting you know
exactly what the gauge is reading. This can be used to get a precise
reading if the gauge itself is unclear. In addition the following
colour codes have been added by colouring the tool tip text as
follows:

Colour Temperature Status

Blue The Temperature is below desirable levels. Action should be
taken to increase the temperature

Green The Temperature is within desirable levels. No action is needed.

Amber The temperature is exceeding desirable levels, but not by a
dangerous amount as yet.

Red The Temperature is exceeding desirable levels and by a dangerous
amount. Action should be taken to decrease the temperature.

Each individual element of the engine where temperature is important
is mentioned in detail below. When action is indicated, you can find
useful information there.

In addition two types of controls have had to be changed.

Cowl Flaps needed more detail to allow players to balance Carburettor
Air Temperature properly. Cowl Flaps are now operated on a percentage
basis (tooltips will confirm) with the Left Mouse button opening them
and the Right Mouse button closing them. Of all the engine
instruments, cowl flaps alone cannot be used to hand an engine back to
the AI. This is due to their dual Left and Right mouse button
functionality. If you change the settings of a cowlflap manually, then
AI control WILL still be locked out, but you will need to right click
on any other control related to that engines performance in order to
hand the engine back to the AI Due to graphical limitations cowlflaps
set to 40% or less will appear closed and those set to 41% or more
will appear open.

Fuel Mixture

Mixture Setting Circumstances for use Effect on Heat Fuel Economy

Auto Lean Cruising at Low Hottest Best
altitudes or payloads

Auto Rich Take Off, Landing and Slight Cooling Worse
Climbing. Cruising at
high altitudes with
heavy payloads.

Emergency Rich Emergency situations Rapid Cooling Worst
where Engine Temperature
is critical

Note that Emergency Rich reduces maximum Power Output under normal
circumstances, but may increase allowable output by cooling very hot
engines.

Strategy:

Your Oil Temperature needs to be closely watched, as Cowl Flaps and
Intercoolers can do nothing to affect it. Only reducing power and
increasing airspeed and/or altitude can lower your Oil Temperature.
Times to watch particularly for high Oil Temperatures are Low Altitude
climbs, especially after take off or when carrying a heavy payload.
Always remember that a high oil temperature may force you out of
formation or risk engine damage and should be avoided.

If your Oil Temperature DOES start to rise during a climb (especially
if it rises evenly across all engines) you should try levelling off
slightly and reducing power to maintain a constant airspeed of 150mph.
Having a high airspeed will tend to increase the cooling effects on
the engine so reducing the power on a climb without in turn reducing
the climb rate will result in a bleed off of Airspeed.

The Carburettor Air Temperature reacts quickly to cooling or heating,
and tends to decrease in relation to the temperature of the air
surrounding the aircraft (which cools quickly with altitude). You
should therefore gradually move the intercoolers to the Hot (closed)
position during a climb to stop ice forming in the carburettor. The
sign to check for if icing in the carburettor is suspected is a drop
off in power output from the affected engine. If the temperature in
the carburettor is not raised to counter this then the power reduction
will accelerate. Eventually the engine will fail entirely and, once
the carburettor is completely frozen in this manner the damage will
not be correctable in flight.

Remember that the Intercoolers ALSO affect Cylinder Head Temperature,
albeit to a much lesser extent than their effects on the Carburettor
Air Temperature.

The Cylinder Head Temperature (CHT) will vary slowly and is best
controlled with the Cowl Flaps, although the intercoolers also affect
it slightly. Running the engine in Auto Rich will have a slight
cooling effect but Emergency Rich will have a dramatic cooling effect
at the cost of excessive fuel consumption and loss of power.

In emergencies diving at speeds of around 200-250MPH is a useful
tactic for reducing the engine temperatures quickly.

Oil Temperature Data

Operational Temperature Ranges
Min: +60
Max: +88
Desired: +70

Heating Influences

Power (Manifold Pressure)

Cooling Influences

Airspeed
Altitude

Rate Of Change

Very Slow

Damage

When power is high and temperature is low.
When temperature is high.

Carburettor Air Temperature Data

Operational Temperature Ranges
Min: +15
Max: +38
Desired: +20

Heating Influences

Power (Manifold Pressure)

Cooling Influences

Intercoolers
Airspeed through Intercoolers
Altitude through Intercoolers

Rate Of Change

Fast

Damage

When the temperature is low the engine's efficiency will be gradually
reduced until eventual failure. If the temperature is increased before
failure the efficiency will gradually recover.

When the temperature is high.

Cylinder Head Temperature Data

Operational Temperature Ranges:
Min: +150
Max: +205
Desired: +204

Heating Influences

Power (Manifold Pressure)

Cooling Influences

Airspeed minor effect through Intercoolers, major through Cowl Flaps
Altitude minor effect through Intercoolers, major through Cowl Flaps
Intercoolers
Cowl Flaps
Mixture Auto Rich/Emergency Rich

Rate Of Change

Slow

Damage

When the temperature is high.

Gameplay Strategies

The biggest change in gameplay from this patch regards altitude and
the way the successful commander uses it during a mission. The
following things will have to be remembered.

1. Non-critical hits to engines will reduce power output or the
ability to deal with heat with similar results, a lesser ability
to sustainably produce the power needed to loft a fully laden B-17
at 30,000 feet and 150mph.

2. The only factor that changes in your favour as the mission
progresses is the payload of your B-17. Fuel is consumed steadily
and your bomb load will hopefully be released about halfway
through the mission. The load on your engines will therefore
decrease as the mission progresses.

3. If your B-17 is forced to abort the mission because of an
inability to stay with the formation then you should immediately
jettison your bombs. This will lighten the load on your bomber,
and may make the difference between making it back and force
landing or bailing out.

4. You CAN manually force more power out of your engines. The AI will
act protectively towards your engines, and you can often squeeze a
lot more power out of your engines than it can. Only push an
engine to destruction if you have to, however watch for the black
smoke that warns of overheating to the point of damage.

5. Extreme Payloads may compromise your squadrons ability to cruise
at 30,000 feet, this is especially obvious for deep penetrations
into Germany / Austria. If you prefer this altitude for your
missions, but find your squadron formation breaking apart before
you get that high, then you should try 25,000 or even 20,000 feet
until things stabilise.

6. Utilising ANY control attached to an engine deactivates the AIs
control of that engine. As well as the normal controls you should
be aware of controls like Fuel Booster pumps, Intercooler settings
and Cowl Flaps. Remember that right clicking on any control
(except Cowl Flaps) associated with that engine will allow the AI
to take control of the engine again.

7. The AI will attempt to maintain temperatures and power outputs
within acceptable norms (given above). Once you return control
back to the AI, it will only alter your original settings in order
to stay within those norms.

8. Evasive action during flak attacks is a necessity if playing with
complex engine management. Every flak fragment that impacts an
engine reduces that engines efficiency. A great way to avoid
damage from flak is to go to the Radio Operator as soon as flak is
sighted (or a timeskip is interrupted with an attack warning) and
order a 2,000-foot change in altitude. By the time the flak is
bursting around your formation you should be far enough into your
altitude change to avoid the worst of it.