Aircraft durability
From MegaTravellerWiki
This is a set of rules to alter the aircraft presented in COACC to bring them more into line with my vision of realism. I accomplish this in three ways:
- More-powerful engines and more-technological engines are more durable than smaller, less technological engines, using the Engine Durability system presented below.
- Hulls use a logarithmic progression in durability instead of a linear progression, meaning larger aircraft are considerably less durable than before while smaller aircraft have changed little. This reflects the soft skin of aircraft as opposed to the thick armour of craft and vehicles.
- Gun, unguided missile, and radar-guided missile attacks have proportional chances of hitting engines versus airframe based on their proportional size, instead of having equal odds of hitting either.
Contents |
Damage Scale of Aircraft
Aircraft are on the personal scale, meaning that each damage point applied against an aircraft corresponds exactly to damage points applied against people. Personnel on the ground may fire at aircraft in flight (albeit with very high target movement modifiers) to cause damage and are quite likely to cause severe damage with just a few shots.
Aircraft are "soft-skinned", made out of thin sheets of steel or composite alloys. They have an Armour Value of 1, meaning that they are relatively impervious to being punched or hit with flechette shrapnel, but can be easily penetrated by almost all other weapons.
Engine Durability
Under this revision, engines become more durable based on tech level and their productive output, which gives very appealing results to me. The assumption is that engines are built with some redundancy and can keep flying even when damaged slightly (for instance, airplanes in World War II often limped home with several bullets through their engine cowls), and this redundancy and integrity only improves with size and technology.
As opposed to the fixed 4/10 damage rating of each engine as given in COACC, engines instead are given "durability ratings" according to the following formula:
Engine_Rating = Tech_Level + (Thrust_Tonnage / 5, max 10) (rounded down)
Engines have ratings ranging from 5 to 23 (any aerobic engine rated above 23 is treated as 23, though 23 is the highest possible assuming the maximum tech level of 13 given in COACC). The durability rating of each engine is then referenced from the following chart:
5: 4/10 12: 18/45 19: 32/80 6: 6/15 13: 20/50 20: 34/85 7: 8/20 14: 22/55 21: 36/90 8: 10/25 15: 24/60 22: 38/95 9: 12/30 16: 26/65 23: 40/100 10: 14/35 17: 28/70 11: 16/40 18: 30/75
Example: The Mexico City (TL8) Heavy Cargo Jet on p.79 is a gigantic 200-displacement-tonne aircraft. Its 1600/4000 hull rating means that someone could fire at it with small arms for hours and fail to do any appreciable damage. However, under the standard system, it has four high-bypass turbofan engines and those engines are rated 4/10 each. It wouldn't take long for potshots to shoot down this massive behemoth. Under the revised system, these big engines produce a massive amount of thrust at 50 tonnes each, meaning that these powerful suckers (in the truest sense of the word "sucker") have a rating of {8 + (50/5)} 18. Instead of a paltry 4/10, these engines are rated at 30/75. All four engines put together have a cumulative rating of 120/300. They still pale in comparison to the sheer bulk of the aircraft, but it would take a lot more than lucky potshots to bring this gigantic plane down. (Note that the "Mexico City" Bomber on p.53 is a typo; it is properly called a "New York City" class. The "Mexico City" is a heavy cargo jet as stated above.)
Bear in mind, however, that these engines are unarmoured metal (AV 1) and can be damaged even by thrown debris, etc. Engine armour per the standard rules adds an additional 1 tonne per engine and increases the armour of the engines to which it is applied to the much-more respectable AV 8. I don't believe any of the example aircraft in COACC include this engine armour, sadly, which is part of the reason why I wrote this system in the first place.
Rotary Wing (Helo) Engine Ratings
Engine durability ratings of helicopters is calculated as follows:
Engine_Rating = Tech_Level + (Lift_Tonnes / 2) (rounded down)
Example: The three Gas Turbine engines of the Lombard (TL10) helicopter each produce a lift of 4 tonnes, multiplied by 20% by the tandem main rotor configuration to 4.8 tonnes each. Dividing the lift tonnage by two yields 2.4, so the durability rating of the engines is 12; referencing the chart above, we find that the engines are 18/45 each. The cumulative engine rating of 54/135 means that much of the helicopter's volume belongs to its engines.
COACC Engine Durabilities
The engine ratings of the standard aircraft from COACC have been produced here:
Class Ref New Ratings -------------- ------ --------------------------------- Ypres p.11 R5: 4/10 Tucson p.13 R7: 8/20 Cheyenne p.15 R7: 8/20 Laramie p.17 R13: 20/50 × 2 Reno p.19 R17: 28/70 × 2, R19: 32/80 × 3 Abilene p.21 R12: 18/45 × 2 Daytona p.23 R14: 22/55, R18: 30/75 Nuremberg p.25 R6: 6/15 Chicago p.27 R7: 8/20 Pleiku p.29 R8: 10/25 × 2 San Diego p.31 R10: 14/35 Pretoria p.35 R13: 20/50 Port Stanley p.37 R11: 16/40 Lombard p.41 R12: 18/45 Bitburg p.43 R11: 16/40 × 2 Springfield p.47 R5: 4/10 Seattle p.49 R14: 22/55 × 2 Los Angeles p.51 R11: 16/40 × 8 New York City p.53 R19: 32/80 × 4 Van Nuys p.55 R6: 6/15 Avalon p.57 R6: 6/15 Beverly Hills p.59 R8: 10/25 × 2 Anchorage p.61 R10: 14/35 × 4 Nairobi p.63 R19: 32/80 × 2 Pasadena p.65 R19: 32/80 × 2 Hartford p.71 R8: 10/25 Palm Springs p.73 R7: 8/20 An Khe p.75 R9: 12/30 Dallas p.77 R9: 12/30 Mexico City p.79 R18: 30/75 × 4 Tokyo p.81 R18: 30/75 × 4 Boise p.85 R21: 36/90 Akron p.87 R5: 4/10 × 3 Rio de Janeiro -- R5: 4/10 × 10 Calcutta p.89 R21: 36/90 × 4 Melbourne p.91 R20: 34/85 × 2, R20: 34/85 × 2
Airframe Durability
Aircraft in reality are soft-skinned; they cannot be mounted with a lot of armour plating because to do so would make them too heavy to fly. As such, the hull ratings given in COACC are sometimes rather generous. An airbus like the Tokyo (TL8) Heavy Passenger Transport should be quite durable, for sure, but a hull rating of 1600/4000 is rather favourable to say the least: a starship with the same approximate mass, like a Ship's Boat, has only a 270/675 rating when taken on the same scale (though the Ship's Boat does have considerably better armour, such that most attacks that would cause high penetration to a Tokyo would be zero penetration against a Ship's Boat).
Airframe durability is computed using the following formula:
Airframe_Durability = (Loaded_Tonnage × 4), to power of 0.8, × 1.75 (rounded down)
(Loaded tonnage includes only internal loads. External loads are not considered part of the airframe.)
The airframe durability corresponds to the Disabled rating of the airframe. To compute the Destroyed rating, simply multiply the Disabled rating by 2.5 and round down.
The formula was selected such that 4-tonne 16/40 hulls would remain the same, smaller aircraft would receive a slight boost in durability, and larger hulls would receive a considerable reduction in durability.
Airframe Armour
There are no rules given for hull armour in the standard COACC rules. The USN F4E Phantom II had enough armour plate throughout its fuselage to withstand most personal arms. Only machine guns (including the 20mm cannons found on the Russian Mikoyan-Guerevich) had the penetration necessary to inflict damage to the bird.
I assume that the airframe of any standard aircraft is AV 1, reflecting very thin sheets of steel or aluminum. This is strong enough to withstand punches, but weak enough to be damaged (slightly) by kicks, and generally not strong enough to protect against most small arms fire (which will achieve low penetration).
To represent optional airframe armour, I adopt the following rule: divide 20 by the tech level of the aircraft to determine the percentage of the aircraft's tonnage required for AV +1. For instance, a TL8 Laramie (the COACC equivalent of the Phantom II) requires 2.5% of its total mass to achieve +1 AV. To achieve +5 AV, it would require 12.5% of its total mass.
Under no circumstance can an aircraft have an Armour Value greater than 10, meaning that the maximum armour modification you can make to an aircraft is +9. At TL5, this would require {(20/5)*9} 36% of the aircraft's mass! At TL10, this would require only half that, at {(20/10)*9} 18% of the aircraft's mass. At TL13 (the technological end of aerobic-based aircraft), AV 10 requires {(20/13)*9} 13.84% of the aircraft's mass.
Only fixed wing and rotary wing aircraft can be armoured. Airships with rigid envelopes always have AV 1 for their fuselage, and airships with non-rigid envelopes always have AV 0 for their fuselage.
Airship/Dirigible Airframes
Airship ratings are computed as follows:
Airship_Disable = (Volume / 15) to power of 0.8, × 0.175 (rounded down) if Rigid envelope, Airship_Disable = Previous_Answer * 1.5 Airship_Destroy = (Volume / 6) to power of 0.8, × 0.5 (rounded down)
Note that under my revision, airships are extremely easy to disable. I maintain other rules (see the "Airship Durability" section below) surrounding their behaviour when disabled.
COACC Airframe Durabilities
For your convenience, I've calculated the hull durability ratings of all of the standard COACC aircraft here:
Class Ref Orig New -------------- ------ ----------- ----------- Ypres p.11 8/20 9/22 Tucson p.13 16/40 no change Cheyenne p.15 28/70 25/62 Laramie p.17 108/270 74/185 Reno p.19 200/500 121/302 Abilene p.21 100/250 70/175 Daytona p.23 100/250 70/175 Nuremberg p.25 24/60 22/55 Chicago p.27 28/70 25/62 Pleiku p.29 22/54* 20/50 San Diego p.31 40/100 33/82 Pretoria p.35 60/150 51/127 Port Stanley p.37 40/100 33/82 Lombard p.41 56/139 44/110 Bitburg p.43 60/100* 46/115 Springfield p.47 4/10 6/15 Seattle p.49 80/200 58/145 Los Angeles p.51 1000/2500 440/1100 New York City p.53 1000/2500* 382/955 Van Nuys p.55 6/15 7/17 Avalon p.57 6/15 7/17 Beverly Hills p.59 40/100 33/82 Anchorage p.61 420/1050 220/550 Nairobi p.63 420/1050 220/550 Pasadena p.65 420/1050 220/550 Hartford p.71 16/40 no change Palm Springs p.73 6/30* 8/20 An Khe p.75 16/40 no change Dallas p.77 8/20* 13/32 Mexico City p.79 1600/4000 640/1600 Tokyo p.81 1600/4000 640/1600 Boise p.85 40/100 33/82 Akron p.87 333/8333* 115/685 Rio de Janeiro -- 13333/33333 523/2076 Calcutta p.89 13333/33333 523/2076 Melbourne p.91 420/1050 220/550 * Indicates the original number was incorrect.
Hit Location Per Engine Size
There are several hit location charts presented here, with a dynamic scaling of engine probability and airframe probability. Total the durability of all of the engines on your aircraft and the durability of the hull on your aircraft. Then divide the hull durability by the engine durability to find the ratio of hull to engines, and compare the ratio to the following chart to determine which to-hit chart to use. Round to the nearest chart which applies; if exactly halfway between two charts, use the higher chart. If the ratio is less than 1.0 to 1, use Table One, and if the ratio is greater than 14.0 to 1, use Table Eight.
Ratio Table to Use Numeric ------------ --------------- ------------- 1.00 to 1 One 15 to 15 1.50 to 1 Two 18 to 12 2.00 to 1 Standard 20 to 10 2.75 to 1 Three 22 to 8 4.00 to 1 Four 24 to 6 5.00 to 1 Five 25 to 5 6.50 to 1 Six 26 to 4 9.00 to 1 Seven 27 to 3 14.00 to 1 Eight 28 to 2 Ratio: The number of hull points per engine point. Table to Use: The name of the table to use for all gun and radar-homing missile impacts. Numeric: The number of possible die roll permutations that will result in hull damage versus the number of possible die roll permutations that will result in engine damage (there are 36 possible permutations of two six-sided dice). These numbers were used to derive the charts and are not otherwise important.
This system is designed to work in tandem with the engine durability system presented above, but will work with the 4/10 system as well (though you should expect to be rolling on Table Eight a lot).
Once you have determined which chart to use, make a note of it next to the aircraft's UCP information card, preferably under the "Def:" section, using the statement "Table: Std", "Table: IV", etc. You will have to refer to the corresponding table every time the aircraft is impacted by weapons fire, so consider keeping a copy of the table right on the information card.
Hit Location Tables
These tables guarantee equal odds of damaging crew or electronics (approximately one in six hits will damage either crew or electronics), and give proportional chances of damaging engines or airframe according to their ratio.
== Standard Table == == Table One == == Table Two ==
Die Damage Result Die Damage Result Die Damage Result
---- ---------------- ---- ---------------- ---- ----------------
2 Engine 2 Engine 2 Engine
3 Engine 3 Engine 3 Engine
4 Engine 4 Engine 4 Airframe
5 Engine 5 Engine 5 Airframe
6 Airframe 6 Engine 6 Airframe
7 Airframe 7 Airframe 7 Airframe
8 Airframe 8 Airframe 8 Engine
9 Airframe 9 Airframe 9 Engine
10 Crew 10 Crew 10 Crew
11 Electronics 11 Electronics 11 Electronics
12 Electronics 12 Electronics 12 Electronics
== Table Three == == Table Four == == Table Five ==
Die Damage Result Die Damage Result Die Damage Result
---- ---------------- ---- ---------------- ---- ----------------
2 Engine 2 Engine 2 Airframe
3 Airframe 3 Engine 3 Airframe
4 Engine 4 Engine 4 Airframe
5 Engine 5 Airframe 5 Airframe
6 Airframe 6 Airframe 6 Engine
7 Airframe 7 Airframe 7 Airframe
8 Airframe 8 Airframe 8 Airframe
9 Airframe 9 Airframe 9 Airframe
10 Crew 10 Crew 10 Crew
11 Electronics 11 Electronics 11 Electronics
12 Electronics 12 Electronics 12 Electronics
---------------------- ---------------------- ----------------------
== Table Six == == Table Seven == == Table Eight ==
Die Damage Result Die Damage Result Die Damage Result
---- ---------------- ---- ---------------- ---- ----------------
2 Airframe 2 Airframe 2 Airframe
3 Airframe 3 Airframe 3 Engine
4 Airframe 4 Engine 4 Airframe
5 Engine 5 Airframe 5 Airframe
6 Airframe 6 Airframe 6 Airframe
7 Airframe 7 Airframe 7 Airframe
8 Airframe 8 Airframe 8 Airframe
9 Airframe 9 Airframe 9 Airframe
10 Crew 10 Crew 10 Crew
11 Electronics 11 Electronics 11 Electronics
12 Electronics 12 Electronics 12 Electronics
---------------------- ---------------------- ----------------------
Heat-Seekers
Guns and missiles are assumed to impact the enemy aircraft "wherever they can", meaning that the enemy aircraft is treated as a giant amorphous target: as long as the gunfire or missile actually collides with the enemy, it has done its work beautifully. Enough successful hits will bring down the target no matter where they hit, so attempting to hit the target is the primary goal and the location of the impacts does not matter so much.
Heat-seeking missiles are different; they seek out the power plants aboard a vehicle and do not hit "wherever they can" because they are not aware that there is anywhere else they may successfully impact. Heat seekers are thus a viable alternative to radar-guided missiles even in spite of their reduced speed and explosive potential.
When a heat-seeker impacts the target, use Table One to determine hit location, regardless of the actual proportion of engines to airframe.
Called Shots
Pilots firing their guns can attempt to make more accurate shots against an enemy aircraft, where they roll their standard to-hit task with a positive shift in difficulty and then roll a special to-hit-desired-location task with negative DMs according to the actual size of the intended location. The to-hit-desired-location task determines whether the shot is rolled randomly or whether it hits the desired location automatically. The attacker can also choose the specific system damaged. Even if the to-hit-desired-location task fails, the shot still hits: it simply doesn't hit the enemy where the shot was intended.
Example: You are a combat pilot on a balkanised world. After your warning shots fail to deter a civilian plane that is carrying embargoed goods to a hostile enemy nation nearby, you drop back to an attack position and aim specifically at the aircraft's fuselage, hoping to get it to turn and head back to land rather than risk being shot down. However, while most of your called shots impact the fuselage and the pilot wisely begins turning back for your own airspace, one of your shots goes stray and penetrates the cockpit, killing the pilot. As you watch the massive plane lurch drunkenly and begin to fall towards the ocean, you shake your head in disbelief and wonder what this will mean for your career.
The task from COACC is repeated here for clarity (with the amendment included).
| To hit an enemy aircraft in gun combat: |
| Difficult, Gunnery, Aircraft, Dexterity (confrontational). |
Referee: DM +1 if firing aircraft has radar. DM +1 if firing aircraft has heads-up display (HUD). DM +(aircraft computer level). DM +(difference in aircraft agility rating) (may be negative number). DM +1 if attacking aircraft is firing lasers. If attempting to hit a specific location, this task becomes Formidable.
|
| To hit a specific aircraft location successfully: |
| Routine, Gunnery, Aircraft, Dexterity |
Referee: Ignore Mishaps. DM +(computer level). DM +(difference in aircraft agility rating). See the "Called Shot DMs" section (below) for locational modifiers. If successful, the shot impacts the desired location and no hit location roll is made. If unsuccessful, roll for a random hit location as normal.
|
Called shots are only possible when attacking with guns. Called shots cannot be made with missiles or rockets, which travel too slowly and/or are self-guiding.
Called Shot DMs
- To hit the Airframe, no DM.
- To hit the Crew, DM -3.
- To hit the Electronics, DM -3.
- To hit the Engines, see the following chart per the ratio:
Ratio Table DM ------------ ----------- ------ 1.00 to 1 One 0 1.50 to 1 Two -1 2.00 to 1 Standard -2 2.75 to 1 Three -2 4.00 to 1 Four -3 5.00 to 1 Five -4 6.50 to 1 Six -4 9.00 to 1 Seven -4 14.00 to 1 Eight -4
Restrictions on Called Shots vs. Manoeuvring Aircraft
Called shots are not possible if the target has an agility greater than 1, has manoeuvred at all in the previous turn, and the angle-off is greater than 30 degrees. A called shot is still possible if the target does not meet all three of the above criteria. For instance, a called shot can be made from any angle against an aircraft with an agility of 1, regardless of whether the aircraft attempts to manoeuvre: it is too sluggish to avoid the enemy's aim. Likewise, a fighter plane on an intercept course at 60 degrees angle-off can still attempt to shoot the cockpit of an unaware enemy fighter plane—even though the defending plane has an agility greater than 1—because the defending plane is simply flying straight and level, unaware of the impending ambush. Finally, if an aircraft is directly aft of another aircraft, it can make called shots regardless of the target aircraft's agility or manoeuvring, since it's assumed that the pilot can correct course to keep on the enemy's "six".
The previously-mentioned Mexico City Heavy Cargo Jet has an agility of 1, meaning that it is at the mercy of other aircraft who want to shoot out its engines: even though its engines make up a tiny fraction of its actual bulk, an agile fighter jet can make short work of the engines and bring the beast to a rather messy landing.
Restrictions on Ground-to-Air Called Shots
Called shots against aircraft may only be made from another aircraft under normal circumstances. The referee is the ultimate arbiter in whether a called shot can be made in a given situation. Even if the referee decides that a vehicle or person on the ground may attempt the called shot, some rules should apply to limit vastly the effectiveness of ground-to-air gunfire and put the advantage squarely in the hands of the aircraft, where it belongs.
Specifically, a vehicle should not be able to make a called shot against an aircraft that is doing anything except straight and level flight, and the vehicle must still apply standard target movement modifiers per the aircraft's speed (a called shot is likely to be impossible against an aircraft that is moving at high speed, and most aircraft move at very high speed).
Basic Notes
On aircraft pre-dating TL8, technology is not generally sophisticated enough to allow for called shots. Bore-sighting a called shot is extraordinarily difficult. No further modification is made, but warn players that the odds of success for making a successful called shot against an equally-matched enemy fighter are slim to none.
Airship Durability
The COACC rules don't touch into the reason why anyone would use helium as a lift gas if hydrogen is cheaper and more effective, but as any junior scientist knows, helium is an inert halogen while hydrogen is an explosive gas.
Hydrogen Airships
Hydrogen-powered airships are considerably more dangerous than helium-powered airships. An incendiary attack against a hydrogen airship's envelope always causes a fire in the envelope if the envelope is penetrated by the attack. An airship that flies through a burning cloud of wreckage is unlikely to catch on fire, but a magnesium-tipped tracer from a HEAP autocannon is quite likely to pierce the envelope and set it alight.
Two other possible ignition sources against airships are lightning and crashing into live electrical lines when flying low.
Only one fire can be caused in a given turn, regardless of how many incendiary attacks are successful against the envelope during that turn.
Once a fire has been started, it must be doused using the on-board suppressant systems within the next turn. All hydrogen-powered airships are assumed to have manual fire suppressant systems (fire extinguishers) inside or within easy access of the envelope; if you're using a flammable lift gas, you're going to at least prepare for the possibility of it catching on fire.
| To douse a fire in the hydrogen envelope using normal manual suppressant systems: |
| Difficult, Lighter-than-Air Craft, End, 1 combat turn (absolute, fateful, hazardous) |
Referee: Any number of people may attempt this task simultaneously. Roll the task individually for each person attempting the task, such that anyone attempting to douse the fire can be subject to a mishap. If anyone succeeds, the fire is doused.
|
If a fire is not doused within one turn of being started, the airship immediately loses all of its remaining "disabled" hull points. The "destroyed" hull points are not affected. It will then drift as a "Disabled Hydrogen Airship", and is also treated as a "Burning Hydrogen Airship".
Disabled Hydrogen Airships
When a hydrogen airship is disabled, its lift envelope begins leaking gas at a prodigious rate. It will take 10 combat turns (1 minute) before the airship's envelope has leaked out enough to allow the airship to enter freefall. Otherwise, the airship will simply continue drifting in straight and level flight.
Burning Hydrogen Airships
As soon as a hydrogen-powered airship is disabled by fire, it is now subject to a nigh-uncontrollable fire. The airship begins to accumulate "Hindenburg Points".
On the turn that the airship is disabled by an uncontrolled fire, it accrues four Hindenburg Points.
During the turn, the crew aboard can attempt to douse the fire using the above task: each successful dousing reduces the number of Hindenburg Points by one.
At the end of any turn where the airship still has Hindenburg Points remaining, double the current number of Hindenburg Points. This reflects the exponential disaster of a burning hydrogen envelope as the fire spreads and gains intensity inside the envelope. Once the number of Hindenburg Points has been computed, subtract that percentage of the airship's normal "destroyed" hull rating from its current "destroyed" hull rating.
If the airship manages to be completely destroyed before its lift gas runs out, it becomes a plummetting fireball and crashes. See the information under "Crash-Landing a Burning Hydrogen Airship".
It is phenomenally unlikely that a crew will be able to douse a raging fire in the envelope if they do not manage to douse it on the same turn that it starts. The crew should consider abandoning ship immediately if this occurs. If they have a large crew, however, they may be able to douse the flames and crash-land the ship normally.
Example: An airship with a rating of 1333/3333 (old system) is struck by an incendiary shell. Two of the crewmen aboard attempt to douse the flames, but both fail, luckily receiving only Superficial Mishaps; however, at the end of the turn, the airship becomes disabled by fire, causing it to drop immediately to 0/3333. It accrues four Hindenburg points as a result of being disabled in that fashion. Now realising that they have a life-threatening incident, all eight crewmen aboard attempt to douse the flames (the pilot abandoning his station to attempt to save the airship): two of the crewmen receive Superficial Mishaps, three of the crewmen receive Minor Mishaps, and one of the crewmen receives a Major Mishap. The two other crewmen succeed in dousing two of the Hindenburg Points. At the end of the turn, the fire still has two Hindenburg Points, which is doubled to four Hindenburg Points, and the airship loses 4% of 3333 or 133 points, leaving it with 0/3200 hull points. The crew has gotten nowhere dousing the airship (it started and ended the turn with 4 Hindenburg Points), yet most of the crew is now injured.
During the next turn, the crewmen with Major Mishaps attempt to abandon ship and fail the to-bail-out task, receiving sufficient wounds to kill them. The remaining six crewmen attempt to fight the blaze -- one is killed directly while fighting the flames, one of the crewmen succeeds in dousing one of the Hindenburg points, and the other four receive further injuries. At the end of the turn, the airship has 3 Hindenburg Points remaining, which is doubled to 6 Hindenburg Points. 6% of 3333, or 200 points, is subtracted from the airship's current rating, leaving it with 0/3000 points. Even though the airship is nowhere near a 0/0 hull rating, the five remaining crewmen stand no chance of dousing the 6 Hindenburg Points, and are already badly injured. Wisely, the remaining crewmen grab their parachutes and abandon the airship; only three manage to escape with serious wounds and their lives...
Crash-Landing a Burning Hydrogen Airship
Crash-landing a burning hydrogen airship is guaranteed fatal, as the burning envelope will collapse onto the cabin upon impact. The only hope for crewmen and passengers is bailing out via parachute. If bailing out with no parachute, assume automatic death if altitude is greater than 10 metres, otherwise roll for a 1D6 mishap if falling <3 metres, a 2D6 mishap if falling <6 metres, or a 3D6 mishap if falling <10 metres. If particularly excusable, there are some situations where a person might survive a fall from extreme altitude, but generally they are extraordinarily rare, and player characters should strongly consider the possibility of loss of life and limb whenever they ride on a hydrogen airship so the referee doesn't have to break realism completely to save their butts!
Any hydrogen airship that crashes will cause 2D6 fires with Danger Space of (1d6)×3 upon impact. Roll 1D6 to determine the direction of scatter and roll 1D6 for the distance in multiples of 15 metres (if a fire scatters onto another, add the two fires together). Such fires will only occur if the airship crashes into a flammable location such as grassy plains, urban terrain, a forest, etc.; this is not the case if crashing onto a non-flammable starport landing pad, desert, ocean, etc. If the burning airship crashes into an ocean, roll for 3D6 Mishaps for all crewmen who were left on board. If a burning airship crashes anywhere else, all crewmen will be killed due to the conflagration, even if the airship does not spread fires beyond its impact location.
Abandoning a Burning Disabled Hydrogen Airship
See COACC p.54 for the "To eject from a damaged aircraft" task. The same task is used to reflect grabbing parachutes from the racks and jumping out the aircraft.
Bailing out from a burning, disabled hydrogen airship is considered Formidable, not just Difficult, due to the extreme heat unleashed by the burning envelope. In most cases, few people will survive bailing out of a hydrogen airship without injury.
Abandoning a Normal Airship
Abandoning an airship that is still floating and is neither plummetting nor burning is a Routine task, regardless of whether the airship is hydrogen-powered or helium-powered.
Crash-Landing a Non-Burning Hydrogen Airship
If the fires raging in the disabled airship have been doused (or if it never caught on fire in the first place), it can be soft-landed using the "Crash-Landing a Helium Airship" rules below
Helium Airships
Helium-powered airships are more expensive and less powerful than their hydrogen-powered equivalents, but if you managed to read even a fraction of the above, their advantages are clearly evident.
Disabled Helium Airships
Just like a hydrogen airship, when a helium airship is disabled its lift envelope begins leaking gas. It will take 8 combat turns (48 seconds) before the airship's envelope has leaked out enough to allow the airship to enter freefall (this is two turns less than a hydrogen envelope, due to the lessened lifting power of helium gas). Until this happens, the airship will continue flying straight and level unless its pilot attempts to make it descend.
A disabled airship cannot be turned: the two choices for manoeuvres are to maintain straight and level flight (with or without a pilot at the helm) or to descend (only possible with a pilot at the helm).
Crash-Landing a Helium Airship
Provided that it can land in the amount of time before its lift gas runs out, a helium airship can be softly put down on any relatively flat surface if the pilot can make it land there -- the airship has landed safely and there is no need to roll. However, because the airship cannot be turned, the airship must have such a surface along its line of flight. If no flat surface exists, the airship can be landed hard against an obstacle, with the pilot rolling the "To attempt a crash landing" task from COACC p.54 upon collision.
If it has been airborne for 8 turns since it was disabled (10 turns for a hydrogen airship), the airship immediately plummets like a rock and will fall 500 metres per 6-second-turn (80 m/s or 390 km/h): treat the airship as a crashing aircraft, using the "To attempt a crash landing" task upon impact. Regardless of success in this case, the airship is completely scuttled as a result of crashing.
If the airship was landed safely without plummetting, it can be repaired relatively easily by replacing or patching the lift envelope and recharging it with the appropriate gas.
Abandoning a Normal Airship
Abandoning a disabled (or even operational) airship that is still floating and is neither plummetting nor burning is a Routine task, regardless of whether the airship is hydrogen-powered or helium-powered. Aside from the modified difficulty, apply the normal "To eject from a damaged aircraft" task from COACC p.54.
Abandoning a Plummetting Helium Airship
Abandoning a plummetting helium airship means rolling the "To eject from a damaged aircraft" task as normal.
