|Description||Addon to FlightGear that adds dogfighting support and AI bots|
|Developer(s)||User:Flug (since 2009),|
|Status||Under active development(04/2013)|
Bombable is an add-on to FlightGear that adds bombs, weapons, damage, fire, and explosion effects to FlightGear that work with the main aircraft, scenery, AI aircraft and other AI objects, and multiplayer aircraft objects. Bombable turns Flightgear into a combat flight simulator.
- 1 Bombable features
- 2 Downloading and using in FlightGear
- 3 List of Bombable Aircraft
- 4 How to add Bombable to a FlightGear aircraft
- 5 Related articles
- 6 Bombable video
- 7 Readme
- 8 History
- 9 Status
- 10 Versions
- 10.1 Version 4.5b (01/2014, compatible with FG 2.12.1 and earlier versions)
- 10.2 Version 4.5 (04/2013, compatible with FG 2.10)
- 10.3 Version 4.4
- 10.4 Version 4.3
- 10.5 Version 4.2
- 10.6 Version 4.0
- 10.7 Version 3.0p
- 10.8 Version 3.0o
- 10.9 Version 3.0n
- 10.10 Version 3.0m
- 10.11 Version 3.0L
- 10.12 Version 3.0k
- 10.13 Version 3.0j (private release)
- 10.14 Version 3.0i
- 10.15 Versions 3.0 through 3.0h
- 11 External links
- Multiplayer dogfighting.
- AI dogfighting and bombing scenarios, using most any FlightGear aircraft that can shoot weapons or drop bombs, against planes, ships, and vehicles that dodge, turn, attack, shoot at you, and generally act like fighter pilots would
- Shootable/bombable moving tanks, jeeps, ships, and aircraft that catch fire, burn, explode, sink, crash, etc. These work with most any FlightGear aircraft that can fire weapons.
- AI scenarios that allow you to use FlightGear aircraft for air-to-ground, air-to-sea, and air-to-air combat missions against these targets
- Explode/burn when you crash
- Exceeding aircraft limitations (excess g-forces, overspeed) adds damage to your aircraft and finally leads to shutdown/crash
Downloading and using in FlightGear
- Download Bombable on the Flightgear Forums thread for Bombable or using this direct link to the .zip file
- Instructions for installing and using Bombable are included in the Docs directory of the download file.
List of Bombable Aircraft
How to add Bombable to a FlightGear aircraft
- Howto: Dogfighting over Multiplayer with Bombable
- Dicta Boelcke rules for dogfighting by the WWI aces
FlightGear seems to have most all the pieces under the hood to make an excellent platform for simulating historical military aircraft, dogfighting and fighter plane tactics with aircraft of different eras, and bombing runs and other tactics from various historical eras, and other aircraft simulations that could depend on FlightGear's realistic, underlying flight models.
Some aircraft have implemented limited weapons, armament, and explosions. The A-10 Warthog was released, including an AI scenario for the A-10 to bomb M-1 tanks, which then exploded realistically.
The Bombable add-on was designed to put all the available FlightGear elements together as a proof of concept to see if FlightGear can be a realistic simulator for aircraft that include weapons and armament, working with AI aircraft and over Multiplayer, including:
- Realistic impact detection and damage assessment
- Damage tracking over AI and Multiplayer and communication of impacts and damage levels over Multiplayer
- AI aircraft, vehicles, and ships that can evade, attack, and generally act realistically
- Explosions, fires, and so on, upon damage and crash
Bombable was developed with the idea that in a realistic flight simulator environment, the rules and techniques of dogfighting and aerial warfare--like the World War I Dicta Boelcke, by Oswald Boelcke, one of the first great aces of the war--would naturally develop and naturally play out.
As of January 2014 (Bombable 4.5) the status is:
- Damage impact detection is the most advanced element in Bombable. It is greatly improved over FG's native impact detection system, and the framework is in place for further refinements or as a model for FG to implement more refined impact detection internally.
- Damage tracking and communication over Multiplayer works well in a very lightweight with a very low data rate. However, only a general damage percentage is tracked and communicated. Damage to different locations or systems is not simulated.
- AI aircraft behavior is controlled by a Nasal script that modifies FlightGear's AI system. This is Bombable's weakest point--in many ways the Nasal script is simply fighting the underlying AI code for control of the AI aircraft. Creating more realistic/intelligent AI fighter aircraft will require greater integration with FlightGear's AI systems. That is a problem for programmers--but for users, the AI aircraft now move, attack, and evade with reasonable realism.
- AI aircraft weapons systems are simulated through a probabilistic approach. And shown visually via FlightGear's Particle System. At this time it appears that creating and tracking AI weapon projectiles via FlightGear's submodel system, which simulates submodel dynamics and impacts precisely, is technically difficult and would have a drastic negative impact on the FlightGear framerate. Bombable follows the more promising of simulating AI weapon fire using FlightGear's particle system, which allows for visual display of numerous moving particles with little to no effect on the framerate and calculating weapons hits mathematically in a simple way that has minimal impact on framerate.
- AI aircraft move vertically – and do loops: AI aircraft now move much more realistically in the vertical direction. They do loops, dive, and all the rest. Their behavior (climb rates, dive rates, and so on) matches those of the corresponding FG aircraft. This makes for a much more realistic 3-D dogfighting experience in FlightGear.
- Proof of concept for explosions, fires, weapons damage animations, and crash animations is in place. All these elements could be refined for greater realism.
- Realistic roll rates for ai aircraft: Roll rates are one the most important factors determining the effectiveness of fighter aircraft-- aircraft that can roll faster can turn faster. Now the roll rate for AI aircraft in scenarios can be customized, and bugs in the roll & turn routines for AI aircraft have been fixed.
- Significant performance improvements: Bombable now makes much less of an impact on your framerate, and much less stuttering & slowdown at key points, like when numerous machine gun rounds are impacting.
- Relocate any scenario to your location: Have an AI scenario based in San Francisco, but want to fly in London? No problem, just hit a button in the Bombable menu and your scenario comes to you, wherever you are. Damage levels for AI aircraft and objects are re-set. It's like loading a new scenario without having to re-start FlightGear.
- Re-spawn AI aircraft & objects: After you have shot down (or been shot down by!) AI aircraft or objects in scenarios, you can instantly re-spawn them and try again. (Available in the Bombable menu.)
The last two are kind of game changers. With FG 2.12's ability to load and unload scenarios instantly and easily, and Bombable's ability to move scenarios to wherever you are, anywhere in the world, scenarios are now flexible and moveable.
Version 4.5b (01/2014, compatible with FG 2.12.1 and earlier versions)
Version 4.5b works with FG 2.12.x and has some improvements that take advantage of FG 2.12's new AI scenario handling system.
In addition, 4.5b has some improved aircraft, tweaks AI aircraft performance and realism, and fixes a few bugs.
Version 4.5 (04/2013, compatible with FG 2.10)
Flug just uploaded a new version of Bombable that is compatible with FlightGear 2.10.0--in fact, it should work with all 2.X versions of FlightGear.
Thanks to Voudoun da Vinci for helping track down some of the problems and the fixes.
Bombable is still pretty new to FG 2.10, so please let me know if you find any problems. Message in this thread is the best way.
FYI part of the package is a new, greatly improved, historically accurate (to the degree I could make it so!) JSBSim FDM for the Sopwith Camel.
The idea was to make the Camel fly like a real Camel--not just when flying safely well within the envelope like a commercial pilot, but when taking it to the edge and beyond, as real combat pilots did in WWI.
Not easy to fly--but a lot of fun to try. It's SopwithCamel-Bombable (JSBSim), included in the Bombable distribution.
Bombable is now compatible with FG 2.10 (as well as 2.8, 2.6 and earlier versions) and includes a new, far more realistic and true-to-life JSBSim flight model for the Sopwith Camel.
- The new JSBSim version of Sopwith Camel is far more realistic as a fighter aircraft, implementing nearly every documented flight characteristic of the original Camel. The new JSBSim Camel is very quirky and difficult to fly--just as the original Camel was. See separate file documenting the JSBSim flight model. To try the new Camel flight model, in FGRun select:
- Sopwith Camel 1F.1 (JSBSim, Experimental, Guns/Bombable)
- Improvements to make Bombable more compatible with FG 2.10 (as well as 2.6 and 2.8):
- Continue to refined workaround for the FG bug allowing only one particlesystem per XML file.
- Workarounds for a stricter XML parser that was adopted by FG somewhere between FG 2.4 and 2.10. Several of the aircraft XML files would not parse due to the special or foreign characters included in comments.
- Updated sound files to mono format (required by FG 2.10 3-D sound system).
- Minor updates/bugfixes to aircraft, scenarios
Version 4.4 is a complete revamping of Bombable into more of a complete, cohesive system for Multiplayer and AI dogfighting and bombing. The accuracy of all the basic functions has been improved and made more realistic, and a number of new "Bombable- compatible" aircraft have been included, from WWI fighters to modern-day jet fighters.
- Weapon hit detection greatly improved: Complete re-vamped system for detecting your weapon hits on AI or Multiplayeraircraft. It is no longer limited by FG's built-in, large "damage cylinder". It now extends the weapon's flight path within that cylinder to determine precisely how close the weapon hit on your target--allowing muchbetter modeling of hits, damage, and results.
- Damage analysis system greatly improved: In addition, the damage analysis system has been updated to calculate and use the momentum of weapons as the basis for determing damage of weapon hits. This has proven to be far more realistic and gives much better results thanthe previous ad-hoc method.
- Greatly improved damage impact animations: Previous versions of Bombable relied on FG's built-in impact animations. The result was that FG often showed the damage impact explosion when the projectile had actually made a clean miss of the aircraft. In Bombable 4.4, this problem is solved, with impact explosions being shown exactly where Bombable calculates they happen, and only when Bombable detects an actual hit with damage. So you have much tigher correspondence between what you see and whatdamage is recorded.
- The impact animations work for all types of small and large caliber guns and bombs. The system uses FG's excellent particle system to draw the gun and bomb impacts with almost not impact on framerate, and far less jerkiness than FG's usual submodel method. As a bonus, the new animations look much, much better as well, and the visual of the impact matches the actual damage of the impact quite well--that is, the visual size of a bomb explosion closely matches the actual damage area of the bomb; small caliber weapons hits show as smallerimpacts that large caliber weapons, etc.
- Your own weapons can damage you: Drop a bomb on your own aircraft or too near it? You'll see the results--damage to your aircraft. This makes bombing runs far more realistic--if you get too close to the bomb impact, you'll feel the results.
- Impact visuals, smoke, and fire shown on scenery: If you drop a bomb on a scenery or a building, you see an explosion and a long-lasting fire – just as you do when you bomb a jeep, tank, or airplane. Previously, the bombs, guns, rockets, and other armament only had an effect on AI and MP aircraft, tanks, ships, and so on. Now armament hits affect almost everything in the FlightGear world.
- Re-spawn AI aircraft: After you have shot down (or been shot down by!) AI aircraft in scenarios, you can instantly re-spawn them and try again. (Available in the Bombable menu.)
- Bombable Fokker DR.1 fixed: Fixed/update the Fokker Dr.1 aircraft. It is now the same aircraft as distributed in FG 2.4.0 but with added historically accurate guns and an aircraft help file.
- Bombable Grumman F6F Hellcat added: Added a new Bombable-compatible aircraft, the Grumman F6F Hellcat. This makes a great foil to the A6M2 Zero, as they fought against each other in WWII. (As always, mucho thanks must go to the authors of the F6F aircraft--all I've done is update the weaponry to be historically accurate and add a thin veneer of tweaks to make the aircraft completely compatible with Bombable. All credit for aircraft design, systems, FDM, and everything else goes to the original authors, in this case EmanuelBaranger and others.)
- New scenarios: New scenario to show off the F6F, one to show offthe Bombable UFO, and one to help with testing:
- Bombable A-10 Warthog added: The A-10 is the best plane to fly several scenarios and including it in the package means that it can be used to fly multiplayer bombable as well. It has several tweaks making it easier to use with the Bombable package and also improves an annoying bug where the A-10 slows FG's framerate massively after a few re-init/re-locates. (Again, all credit to the A-10 original authors--all I have done is adda few Bombable tweaks and specifics.)
- Bombable UFO added: This is mostly for testing; keys 1-9, 0, q, and w fire different weapons. A working AI version is included--so you can have dueling Bombable UFOs over Multiplayer or try the UFO dogfighting scenario (surprisingly fun!). Also a testbed scenario is included, and using the UFO with the BOMB-Kansas-City-Bombable-Testbed.xml scenario is the easiest way to test most Bombable functions, aircraft, and AI aircraft. (Based on FG's stock UFO, but with Bombable capabilitiesadded.)
- Bomb damage: Reconfigured damage impact of bombs; the bombs now act--lookand create damage--far closer to real data.
- New menu: Re-vamped Bombable menu with new/streamlined/more sensible options.
- Reset damage: In the new Bombable menu you can reset damage for main aircraft and AI aircraft and objects.
- Bombable scenarios renamed: Renamed all scenarios that come with the package with prefix "BOMB-". This should make it easier to find the scenarios and also update or remove them when necessary.
- Smaller smoke/fire option: A small fire option, used where appropriate, so that fires/explosions/damage don't always look sooverly huge.
- Unusable aircraft removed: Removed unused/unusable aircraft from the distribution. Some of these are perfectly fine for general flying, but weapons or other features don't work well with Bombable, and having them listed in the menus when they didn't really work made forconfusion.
- Scenario fixes: Some scenarios were not loading properly for some people in ver. 4.3. This might be because of inconsistencies in the case of some file and directory names. I worked on resolving thisissue, but please let me know if it is still happening.
- Scenarios renamed: Renamed all scenarios to start with "BOMB-". This should help us keep straight which scenarios work with Bombable and also troubleshoot and track down & fix problems with scenarios.
- AI weapons improved: AI weapons now malfunction when the AI aircraft, vehicle, or ship is damaged.
- Misc. updates: Updated included AI aircraft and scenarios to fit with the new impact detection system.
- For bombable aircraft designers: If you have designed aircraft to use with Bombable, you should look at the sample AI aircraft provided to see updates to the Bombable dimensions, vulnerabilities, and weapons sections. You will need to re-tool your aircraft slightly, but when finished the results will be much better.
- Bug fixes: Various small bug fixed and improvements, fixed a lot of the programs with scenarios, AI Aircraft, directories.
See the To Do file (many of which have now been done) for many more changes, updates, and improvements.
- Multiplayer dogfighting is now working in FG 2.4.0. (It broke sometime in the FG 2.X.X. series.) Use one of the MP-dogfighting- enabled planes included in the packet (Sopwith Camel-Bombable/Yasim, SPAD VII-Bombable, or FKDR1-Bombable/JSB, or A6M2-Bombable/YASim--use the versions marked as Guns/Bombable, not the default FG installs) and make sure your opponent does the same--you will both be able to shoot and damage each other, see damage reports, etc.
- Weapons on AI aircraft--which will shoot at you as you attack them--can now be placed in different locations and aimed indifferent directions.
In combat, they will shoot you if that location/direction is lined up with you. The AI B-17 Bomber included in the package will shoot at you from the rear; the M-1 tank will shoot towards the front at about a 45 degree angle, Jeep will shoot forwards and upwards,Ferries will shoot forward or backwards, etc.
The result is a far more realistic experience. Shooting bombers used to be like shooting fish in a barrel--now between the bombers shooting at you and the fighter planes coming in from high cover, you're lucky to score a few small hits and get out of therealive . . .
- The AI Weapons system was generally improved and weapon strength, direction, size, location, and effectiveness can be specified in the XML file for each AI aircraft type. (If you're creating your own Bombable-enable aircraft, just add weapons specs in the WEAPONSsection of AI aircraft; see enclosed AI/Aircraft files for examples.)
- Generally tweaked AI aircraft, attack & weapons routines, and AI scenarios for a better, more realistic experience. In particular,try:
- MarinCountyWWIIBombersWithCover.xml (fly A6M2-Bombable/YASim)
- MarinCountyCamelInvasion1-Simple.xml (fly Sopwith Camel-Bombable/YASim)
- Again worked on the problem of getting AI aircraft to climb and dive more realistically instead of sedately. The AI aircraft are farmore realistic/active in the vertical direction now.
- Bombable no longer overwrites existing aircraft or anything else in FG's installation. It will add new aircraft and a few other Bombable-specific files. All new/added aircraft have the suffix -Bombable. Bombable will overwrite-replace things from its ownprevious installation, but no other files.
Generally when flying Bombable's AI scenarios or flying over multiplayer with another person using Bombable, your best experience will be to use one of the aircraft provided (and identifiable by the -Bombable extension) or another aircraftspecifically set up to use Bombable's capabilities.
- Made numerous changes/updates/improvements related to getting Bombable working with FG 2.4.0.
- Found the FG 2.4.0 "reinit" problem in both M-1 and Jeep in AI/Aircraft & fixed
- Reconfigured the damage calculations for light weapons in the test_impact function. Result may be that it is harder/takes more hits than before to damage aircraft or objects. If it is too hard you can select both "Easy Mode" and "Super Easy Mode" together to make it quite a bit easier to both hit targets and create damage. This still needs some refinement but it is setting the groundworkfor a better, more consistent way of dealing with damage.
- Small refinements in display, damage reports, etc.
- FG 2.4.0 is doing this crazy thing where it reinitializes AI objects in scenario repeatedly and also (sometimes!) slips in non-AI objects like joystick inputs for initialization as AI/scenario objects. This results in massive slowdowns and other bizarre behavior. So I've set up checks to disallow repeated re-inits of AI objects and only allow AI and Multiplayer objects (as opposed joystick input devices, etc) to initialize themselves with Bombable. The ultimate solution here is a FG code fix, but in the meanwhilesome of the worst effects might be mitigated.
This is a beta release that works with Flightgear 2.4.0. Some AI aircraft characteristics have changed in FG 2.4.0 so there are someproblems and different behavior in the AI aircraft.
- Removed the "reinit" command in bombable.nas that made FG 2.4.0 croak.
- Removed the mp_broadcast.nas file that is no longer necessary with FG 2.4.0 (and in fact the old version included with Bombable made FG2.4.0 choke).
- FG 2.4.0 doesn't make the weight or mass of the armament available on impact (previous versions}}} did!), so a kludgy work-around wascreated.
- Numerous other tweaks and bug fixes.
- This is a bit of an alpha release and has not been as thoroughly tested with all scenarios as previous releases.
- AI aircraft are more mobile vertically: AI Aircraft dodge and chase you more vertically, diving and climbing.
- Various bugfixes
- AI aircraft shoot at and damage you: When in an AI dogfight, if you let the AI aircraft get into position they have a chance to shoot at and possibly damage you. This is working best with WWI AI Aircraft (Camel, SPAD, Fokker) as in the Marin County Camel Invasion scenarios, but it will also work with the Zero and Warthog scenarios.
- Mostly fixed menu/options save/restore bug: Some of the options still don't save/restore correctly, but most do now.
- Numerous other bugfixes/small improvements
- AI aircraft dodge and "attack" realistically: AI dogfights just became 10X as realistic, as fighter planes will turn and attack, just as fighter planes did in WWI and WWII. Try the Marin County Camel Invasion and Marin County Zero Invasion scenarios for a taste of how this works. (No weapons for AI aircraft yet--maybe in the future.)
- New scenario – B-17 bombers with fighter cover: Fly out of Marin Ranch and attack a squadron of 6 B-17 Bombers. As you do so, the fighter squadrons descend and swarm you. They don't fire at you (yet! fodder for future versions!) but they turn aggressively towards you, evade your shots, etc., just as real fighters would.
- Damaged ai aircraft crash more realistically
- Greatly improved, more realistic damage analysis: Damage assessment for guns is a lot more realistic, giving greater damage when you hit closer to the center of the object and allowing for the possibility that even small arms might strike a vital or explosive point, causing catastrophic damage. For instance, you can now damage the Nimitz or Eisenhower*--though it's still tough to sink.
- More realistic fire starting: One of the chief causes of combat aircraft damage is the fires that even small caliber weapons can cause--and fires are even more likely with heavier ammo that includes incendiary (high explosive) materials. Bombable now models that any hit may start a fire, and heavier rounds are more likely to start files. Fires progressively damage the aircraft and eventually bring it down. Beware that fires sometimes go out before completely disabling the aircraft--so monitor the enemy aircraft to make sure they do not recover and escape.
- More realistic aircraft smoke starting: Similar to fire starting, each damaging hit has the possibility to cause damage that causes the aircraft to emit a trail of smoke. The bigger/closer the hit, the more likely to cause this damage.
- Bombable preferences/settings saved and restored at startup
- Fixed excessive damage report problem: Aircraft would continually report damage even after objects received 100% damage--now fixed.
- Numerous small bugfixes
- Note: You can bomb the Nimitz/Eisenhower carriers if you have the bombable carriers add-on: http://forum.flightgear.org/viewtopic.php?f=2&t=7082
- Positive and negative G-force limits are now settable separately (most aircraft have different limits for positive vs negative G, so this adds some realism)
- Bugfixes on damage & damage report
- Every hit now registers via on-screen popup (vs previous behavior of only showing damage when it increased past multiples of 5%)
- Bugfixes on g-force damage that caused extraneous very high g forces to cause random damage
- Bugfixes in multiplayer communication, fixed problems when MP is disabled or doesn't exist
- Bugfix on bombable multiplayer unload (runtime error "listenerids") and improvement to unload routines
- Fixed Easy/Super Easy Mode malfunction (Super Easy Mode never engaged; new default mode is Easy Mode which should give same performance as previous default mode)
- Tuned damage/vulnerabilities on ferries (San Francisco Ferry Invasion scenario)
- Overspeed detection/damage
- G-force and overspeed detection optional: Switches in the Bombable menu to turn it off; turned off by default except for planes included in Bombable package.
- Vulnerabilities framework for primary aircraft: Allows max acceleration, max speed parameters to be set individually per aircraft (main aircraft) and then damage from overspeed/overacceleration is accrued when those limits are exceeded.
- Blackout/redout tunable per aircraft: Allows blackout & redout values to be set per aircraft--for instance to reflect that WWI aircraft had no pressure suits or special high-G training. This will help level the playing field and create uniformity in MP dogfighting with similar aircraft.
- G-force and overspeed limits and damage amounts tuned: For the four aircraft included in the Bombable package (A6M2 Zero, Sopwith Camel, SPAD VII, Fokker DR1) the g-force damage & overspeed damage parameters have been individually tuned and are fairly realistic.
- Fires only for appropriate damage: Overspeed & overacceleration (g-force) damage doesn't start a fire, though it will still rack up 100% damage and shut you down.
- Numerous bugfixes
- Excessive G-force damages your aircraft: Excessive g-force now adds damage to your airframe and can even make you crash. To avoid damaging your aircraft due to excessive g-force, always fly with blackout/redout turned on and avoid pulling g-forces much beyond those that make you blackout or redout.
- Zeros over marin county scenario: Marin County Zero Invasion scenario added.
Version 3.0j (private release)
- Burn/smoke on crash: Aircraft now catch fire, burn, and instantly go to 100% damage when they crash. This is broadcast via MP so others will see you burn when you crash.
- A5mw zero for dogfighting: A6M2 ready for MP dogfighting included in release.
- A6M2 Zero: Added historically accurate guns and cannons (fire with e and E) to A6M2 Zero.
- Bombable A62M Zero: Included Bombable version of the AI A6M2 Zero from Hellcat's Carrier Bombable project, but also made a few tweaks/improvements to he AI A6M2 for improved realism. See http://www.4shared.com/file/235605076/6101800f/carrier_bombable.html
- Dogfighting: Greatly improved dogfighting/multiplayer communication of damages
- Bugfix DR 1: Added keyboard firing switch to Fokker DR 1 (use the 'e' key to fire the weapons).
- Bugfixes: Many other miscellaneous bug fixes and improvements.
- Reset resets damage: In dogfighting, resetting or using the Location menu to change your location resets your damage to 0% and broadcasts that to others flying with you via multiplayer
- FlightGear 2.0 compatible: Tested and works with FG 2.0 as well as FG 1.9 and CVS versions between 1.9 and 2.0
- Bugfixes: Various small bugfixes
Versions 3.0 through 3.0h
- Bombable/shootable: Code to make objects, AI aircraft, MP aircraft bombable and shootable.
- Moving AI bombable/shootable objects: Code to allow AI aircraft, naval vessels, and surface vehicles to move (sort of) realistically and act as bombable/moving aerial targets.
- Scenarios: Bombing and dogfighting scenarios using these AI aircraft.
- Multiplayer dogfighting: Code to allow multiplayer (MP) communication of damage to aircraft, allowing multiplayer dogfighting
- Aircraft enhancements--weapons and dogfighting: Three WWI era aircraft enhanced with historically accurate weapons systems and prepared for MP dogfighting (Sopwith Camel, Fokker DR1, SPAD-VII)
- Contrails and smoke: MP aircraft capable of dogfighting, and some other MP and AI aircraft automatically have contrails and engine smoke trails. This makes it possible to locate the aircraft when doing MP dogfighting and generally adds to the realism.