The David light VTOL

[Lagrange]

Edits: removed Omni since you can't use mechanized battle armor according to errata.

Two discussions (Savannah swarms, and Artillery flak rules) started me thinking about little VTOLs as having a potentially significant role in ground combat.  Comments/questions/thoughts are welcome.

Little VTOLs are inherently cheap, which seems important in the context of artillery flak which effectively caps the target movement modifier for any airborne unit at +3.  (Grounded units fare no better, since they have a maximum to-hit of +4 (direct fire artillery) or +0+range (artillery cannon fired at the hex).)

Little VTOLs are also inherently fast, which makes them great at getting into the right position and of course you can apply a significant target movement modifier.  For example, these can do a 12 hex circle to impose a +5 TMM with no sideslip piloting skill required, or they can impose +7 with a straight flank movement.

The David light VTOL is designed to take maximum advantage of a small footprint.  The first of these is the simple David C.

Code: [Select]

David C (Cargo)

Mass: 5 tons
Movement Type: VTOL
Power Plant: 45 XL
Cruising Speed: 205.2 kph
Maximum Speed: 313.2 kph
Armor: Heavy Ferro-Fibrous
Armament:
Manufacturer: Unknown
     Primary Factory: Unknown
Communication System: Unknown
Targeting & Tracking System: Unknown
Introduction Year: 3145
Tech Rating/Availability: E/X-X-X-D
Cost: 134,167 C-bills

Type: David C (Cargo)
Technology Base: Inner Sphere (Standard)
Movement Type: VTOL
Tonnage: 5
Battle Value: 76

Equipment                                          Mass
Internal Structure                                  0.5
Engine                        45 XL                   1
Cruising MP: 19
Flank MP: 29
Heat Sinks:                   10                      0
Control Equipment:                                  0.5
Lift Equipment:                                     0.5
Power Amplifier:                                    0.0
Armor Factor (Heavy Ferro)    19                      1

                          Internal   Armor 
                          Structure  Value 
     Front                   1         5   
     R/L Side               1/1       5/5   
     Rear                    1         2   
     Rotor                   1         2   


Weapons
and Ammo              Location    Tonnage 
Cargo (1.5 tons)        Front        1.5   
The David C is designed to function as an ultra fast shuttle, able to ferry people or supplies supplies rapidly around a battlefield at speed in excess of 300kph.  While not a true omni, the David C can be quickly converted amongst several other variants with refit kits.  In terms of quirks, it has Modular Weapon (+1), Easy to Maintain (+1), Low profile (+2), Bad Reputation (-1), Poor performance (-3).  The refit kits come in two flavors.  A class B refit kit (usable in the field) changes the item in the front and takes about 1 hour (with the modular weapon quirk, twice as much without) to swap.  A class C refit kit (usable in a repair bay) adds a half ton of armor and take 50 minutes to install (with the modular weapon quirk, twice as much without).

The name David comes from the T variant which takes advantage of a B and a C refit requiring an hour and 50 minutes.

Code: [Select]

David T (TAG)
Cost: 207,083 C-bills
Battle Value: 106
Armor Factor (Heavy Ferro)    29                    1.5

                          Internal   Armor 
                          Structure  Value 
     Front                   1         10   
     R/L Side               1/1       6/6   
     Rear                    1         5   
     Rotor                   1         2     
Weapons
and Ammo              Location    Tonnage 
TAG                    Front        1.0     
Since TAG can connect an unbounded number of homing missiles to a target in a round, it provides a means to potentially eliminate any 'Goliath' with single hit.  It may be possible to instead mount a TAG as external ordnance, slowing the VTOL to 18/27.  The precise rules for TAG as external ordnance on a VTOL aren't exactly clear, so I opened a question.

The David E provides an ECM suite with a class B refit taking an hour.

Code: [Select]

David E (ECM)
Cost: 367,500 C-bills
Battle Value: 149
Weapons
and Ammo              Location    Tonnage 
ECM Suite               Front        1.5     
The David E has the same battlefield role as the Interdictor variant of the Savannah Master: it flies around the battlefield disrupting enemy electronic systems.  It's generally better at this role than the Interdictor, since no terrain is an obstacle.  Reading the rules carefully, an ECM bubble extends upward as long as elevations are in use and downwards to the ground or water interface.

Another obvious variant is the David P, which places an active probe in play, again requiring a class B refit.

Code: [Select]

David P (Probe)
Cost: 367,500 C-bills
Battle Value: 88
Weapons
and Ammo              Location    Tonnage 
Active Probe            Front        1.5     
Compared to other probes on other units, this one is of course extraordinarily fast and able to move over terrain obstacles.

The last unit is the David S which requires a class B and class C refit taking an hour and 50 minutes.

Code: [Select]

David S (Spotter)
Cost: 440,417 C-bills
Battle Value: 106
Armor Factor (Heavy Ferro)    29                    1.5

                          Internal   Armor 
                          Structure  Value 
     Front                   1         10   
     R/L Side               1/1       6/6   
     Rear                    1         5   
     Rotor                   1         2     
Weapons
and Ammo              Location    Tonnage 
C3 Computer             Body        1.0     
The David S is designed to provide effectively-short range for other unit(s) in a C3 network.  Obviously, it provides no firepower of it's own (other than, maybe, a carried bomb), but it can fill out a C3 network and (via an incredibly fast movement) may survive long enough for the firepower from other C3 units to hit hard.

Each of these variants can be used effectively without swarm tactics.  You could make an (ER) medium laser variant for swarms, but that seems like a lack of imagination.

[CVB]

Logical conclusion under the air defence conditions of FLAK artillery and artillery cannons, and nice design. Given the price difference between artillery units and these VTOLs and the fact that the David can start an attack run from outside max direct fire range even at cruise speed, adding a direct action version to go flak hunting would be usefull, e.g. 3x iOS SRM2 with inferno or 3x RL/10 (or 4x, if VTOLs can use RLs as XO. Maybe you could append your rules question?) Also VGLs or smoke SRMs to blind FLAK guns.

[Lagrange]

Logical conclusion under the air defence conditions of FLAK artillery and artillery cannons, and nice design. Given the price difference between artillery units and these VTOLs and the fact that the David can start an attack run from outside max direct fire range even at cruise speed, adding a direct action version to go flak hunting would be usefull, e.g. 3x iOS SRM2 with inferno or 3x RL/10 (or 4x, if VTOLs can use RLs as XO. Maybe you could append your rules question?) Also VGLs or smoke SRMs to blind FLAK guns.

Thanks.

There's a subtle constraint here w.r.t. direct attack plans: you only have space for 1 item.  Hence (for example) the T and S variants are a half ton light.  The source of this constraint is the use of HFF armor.  We could use FF armor, but that implies losing 2 armor points.  Normally, 2 armor points lost is minor, but there are not many armor points and the existing armor layout is pretty nice---you can take an AC/5 or ML to any location except rear, an AC/2 anywhere, and it might even survive a Flak hit (rotor x2+front+side or rotor+front+2*side).  I don't see a way to lose 2 armor points without compromising survivability substantially.

[Sabelkatten]

Could just use a 25 SFE. 15/25 is still plenty fast.

Thought to be really honest just slap an ERML on it, bring a dozen friends, and kill everything in a way that makes Savanna Masters jealous!

[Lagrange]

Could just use a 25 SFE. 15/25 is still plenty fast.

That's a good point. 

The drawback of 15/23 over 19/29 is about a +1 to the TMM in practice.  For example, at 19/29 you can move in a circle expending 6 MP for turns and covering 18 distance to impose a +6 TMM with only a +2 AMM.

So, you can either trade 2 armor points (HFF->FF) or a +1 to TMM (XLFE->SFE) for more space.

Thought to be really honest just slap an ERML on it, bring a dozen friends, and kill everything in a way that makes Savanna Masters jealous!

Yeah, the lack of serious stacking limits for VTOLs is particularly telling w.r.t. swarm tactics.  If you wanted to do swarms though, ditching the omni seems desirable as that pointlessly drives up cost.  You might also downgrade the armor while adding an extra half ton, and downgrade the engine to make an extra cheap swarmer. 

My expectation based on the earlier discussion is that most people don't like to deal with swarms in play, although it seems like a potent approach to force design.

[CVB]

Thanks.

There's a subtle constraint here w.r.t. direct attack plans: you only have space for 1 item.  Hence (for example) the T and S variants are a half ton light.  The source of this constraint is the use of HFF armor.  We could use FF armor, but that implies losing 2 armor points.  Normally, 2 armor points lost is minor, but there are not many armor points and the existing armor layout is pretty nice---you can take an AC/5 or ML to any location except rear, an AC/2 anywhere, and it might even survive a Flak hit (rotor x2+front+side or rotor+front+2*side).  I don't see a way to lose 2 armor points without compromising survivability substantially.

Overlooked the HFF slot requirements, sorry . So that would leave tonnage and space for a single RL/20, iOSRM4, iOLRM5 or iOSSRM2 and possibly an additional XO RL/10, if allowed by TO.

Although I tend more and more to leave minimal or no armor on very fast one shot VTOL designs and basically use them as loitering missiles. When an LT FLAK hits them, they are mostly toast anyway unless they accept severe loadout limits like the David does.
These loiter in the back outside of reach in turn N-1, cruise in from a mapsheet+ away and into the rear of an enemy unit in turn N. When I have to declare fire first I fire everything. Now the enemy can either try to kill it, but can't prevent his own damage because of simultaneous damage resolution, or ignore it, in which case I can retreat in turn N+1 (or spot for IDF from out of reach). When I declare fire last and the enemy decides to target me and has a good chance to shoot me down, I salvo everything; else I can decide to keep some shots to repeat the game in the next turn or still alpha and retreat. Drawing some shots onto my fast cheap units may still be worthwile as protection for my other units.

[Lagrange]

These loiter in the back outside of reach in turn N-1, cruise in from a mapsheet+ away and into the rear of an enemy unit in turn N. When I have to declare fire first I fire everything. Now the enemy can either try to kill it, but can't prevent his own damage because of simultaneous damage resolution, or ignore it, in which case I can retreat in turn N+1 (or spot for IDF from out of reach). When I declare fire last and the enemy decides to target me and has a good chance to shoot me down, I salvo everything; else I can decide to keep some shots to repeat the game in the next turn or still alpha and retreat. Drawing some shots onto my fast cheap units may still be worthwile as protection for my other units.

I find carried weapons 'meh' compared to TAG + offboard homing missiles since a single hit from a single missile rivals what could be carried, a single TAG can direct an unbounded number of missiles, and you can deploy several (say 2-4, not a swarm) David Ts with any of them hitting implying all missiles hit.

Are there situations where you can't effectively TAG but you can use carried weapons?

[CVB]

The years from 2835 to 3043 (extinction to rediscovery of TAG), for example? 
Yes, I know, that era would also exclude iOS launcher and necessitate prototype RLs.

[Lagrange]

The years from 2835 to 3043 (extinction to rediscovery of TAG), for example? 
Yes, I know, that era would also exclude iOS launcher and necessitate prototype RLs.

Interesting, this is pre-omni as well.

That sort of begs the question: 'How valuable is Omni?'  It's a drag on the T and S versions, since they lose a half ton of armor, and it elevates costs somewhat.  On the other hand, you get an  incredible battle armor squad transport for free and of course mission flexibility.

[CVB]

Once BA is available, Omni is worth every penny, IMHO, especially on such a fast unit (although I extremely dislike the mechanized BA rules as written, where a 500kg bomb slows me down more than 12 tons of assault BA clinging to to hull 

Edit: deleted, see Reply #13 below

[kaliban]

no game is perfect and Battletech is also not perfect. As long there is no limit of actions per turn, swarm tactics are very efficient.

A small fast and unarmored VTOL with a fusion engine and small energy weapons is the most destructive thing you can have in the game. A tiny helicopter of +/- 10 tons can carry 2-3 ML and zoom around the map with speeds above 10/15. They depend entirely on speed for defense but the BV is so low that you can play dozens against a lance of mechs in a single map or double map scenario.

You can use flak ammo, LB-Xs, dirty words, whatever but nothing you prevent the final outcome. It is just too many VTOLs flying around, firing against the rear arcs of the mechs, defending with +5 modifiers all the time and crossing the entire map every single turn.

[kaliban]

Two discussions (Savannah swarms, and Artillery flak rules) started me thinking about little VTOLs as having a potentially significant role in ground combat.  Comments/questions/thoughts are welcome.

Little VTOLs are inherently cheap, which seems important in the context of artillery flak which effectively caps the target movement modifier for any airborne unit at +3.  (Grounded units fare no better, since they have a maximum to-hit of +4 (direct fire artillery) or +0+range (artillery cannon fired at the hex).)

Little VTOLs are also inherently fast, which makes them great at getting into the right position and of course you can apply a significant target movement modifier.  For example, these can do a 12 hex circle to impose a +5 TMM with no sideslip piloting skill required, or they can impose +7 with a straight flank movement.

The David light VTOL is designed to take maximum advantage of a small footprint.  This is an omni, to take advantage of many interesting possibilities.  The first of these is the simple David C.

Code: [Select]

David C (Cargo)

Mass: 5 tons
Movement Type: VTOL
Power Plant: 45 XL
Cruising Speed: 205.2 kph
Maximum Speed: 313.2 kph
Armor: Heavy Ferro-Fibrous
Armament:
     1.5 tons of pod space
Manufacturer: Unknown
     Primary Factory: Unknown
Communication System: Unknown
Targeting & Tracking System: Unknown
Introduction Year: 3145
Tech Rating/Availability: E/X-X-X-D
Cost: 167,708 C-bills

Type: David C (Cargo)
Technology Base: Inner Sphere (Standard)
Movement Type: VTOL
Tonnage: 5
Battle Value: 76

Equipment                                          Mass
Internal Structure                                  0.5
Engine                        45 XL                   1
Cruising MP: 19
Flank MP: 29
Heat Sinks:                   10                      0
Control Equipment:                                  0.5
Lift Equipment:                                     0.5
Power Amplifier:                                    0.0
Armor Factor (Heavy Ferro)    19                      1

                          Internal   Armor 
                          Structure  Value 
     Front                   1         5   
     R/L Side               1/1       5/5   
     Rear                    1         2   
     Rotor                   1         2   

Fixed Equipment
None

Weapons
and Ammo              Location    Tonnage 
Cargo (1.5 tons)        Body        1.5     
The David C is designed to function as a battle armor deployment and support system, able to ferry a point of battle armor and supplies rapidly around a battlefield.  It can ferry over 10 tons of battle armor and equipment at speeds in excess of 300kph (if BA is organized as 6-man points).

The name David comes from the T variant.

Code: [Select]

David T (TAG)
Cost: 240,625 C-bills
Battle Value: 76
Weapons
and Ammo              Location    Tonnage 
TAG                    Front        1.0     
Since TAG can connect an unbounded number of homing missiles to a target in a round, it provides a means to potentially eliminate any 'Goliath' with single hit.  It may be possible to instead mount a TAG as external ordnance, slowing the VTOL to 18/27.  The precise rules for TAG as external ordnance on a VTOL aren't exactly clear, so I opened a question.

The David E provides an ECM suite.

Code: [Select]

David E (ECM)
Cost: 459,375 C-bills
Battle Value: 149
Weapons
and Ammo              Location    Tonnage 
ECM Suite               Body        1.5     
The David E has the same battlefield role as the Interdictor variant of the Savannah Master: it flies around the battlefield disrupting enemy electronic systems.  It's generally better at this role than the Interdictor, since no terrain is an obstacle.  Reading the rules carefully, an ECM bubble extends upward as long as elevations are in use and downwards to the ground or water interface.

Another obvious variant is the David P, which places an active probe in play.

Code: [Select]

David P (Probe)
Cost: 459,375 C-bills
Battle Value: 88
Weapons
and Ammo              Location    Tonnage 
Active Probe            Body        1.5     
Compared to other probes on other units, this one is of course extraordinarily fast and able to move over terrain obstacles.

The last unit is the David S.

Code: [Select]

David S (Spotter)
Cost: 532,292 C-bills
Battle Value: 76
Weapons
and Ammo              Location    Tonnage 
C3 Computer             Body        1.0     
The David S is designed to provide effectively-short range for other unit(s) in a C3 network.  Obviously, it provides no firepower of it's own (other than, maybe, a carried bomb), but it can fill out a C3 network and (via an incredibly fast movement) may survive long enough for the firepower from other C3 units to hit hard.

Each of these variants can be used effectively without swarm tactics.  You could make an (ER) medium laser variant for swarms, but that seems like a lack of imagination.

if you remove the armor you can lower the BV significantly, in case it matters

5 and 2 of armor or zero is the same in practical terms

[Lagrange]

Once BA is available, Omni is worth every penny, IMHO, especially on such a fast unit (although I extremely dislike the mechanized BA rules as written, where a 500kg bomb slows me down more than 12 tons of assault BA clinging to to hull 

Is there a way to mechanize Assault BA?   I thought mechanization topped out at Heavy BA?

if you remove the armor you can lower the BV significantly, in case it matters

It's a good point, but I'm thinking about designing from the viewpoint of a military.

5 and 2 of armor or zero is the same in practical terms

Is that really true?  An LB 2-X has a -3 to hit modifier out to range 9 (or 10 for clan) vs. a flying VTOL, so that +5 becomes effectively +2.   A small amount of armor seems to make the VTOLs much more robust.

[CVB]

Is there a way to mechanize Assault BA?   I thought mechanization topped out at Heavy BA?

TW (7th printing), chapter "Mechanized Battle Armor" p. 226 f., is silent on any weight class restrictions for mechanized BA.
The chapter "OTHER COMBAT WEAPONS AND EQUIPMENT", p. 228 states:

MAGNETIC CLAMPS
A battle armor unit equipped with magnetic clamps can mount
standard BattleMechs and vehicles as though the carrying units
were Omni units (see Mechanized Battle Armor, p. 227).

and
(p. 229)

Battle Claw/Heavy Battle Claw
Medium, light and PA(L)/exoskeleton humanoid battle armor
with at least one battle claw or heavy battle claw may conduct
anti-’Mech attacks; heavy, medium, light and PA(L)/exoskeleton
humanoid battle armor with at least one such claw may use
mechanized battle armor rules (see p. 227).

So it seems that assault BA with magnetic clamps can be mechanized.

However p. 227 states:

Movement Restrictions: Whether or not the battle armor is equipped with magnetic clamps, no vehicle may expend UMU, VTOL, WiGE, or Jumping MP while carrying mechanized battle armor, and no ’Mech may expend UMU MP.

(Emphasis added).

[Lagrange]

So it seems that assault BA with magnetic clamps can be mechanized.

TM page 259 says "assault-weight battle armor may not mount magnetic clamps".

However p. 227 states:  (Emphasis added).

That's a good find! Apparently it's been errataed since my version.  Not being able to carry BA at all is a significant value reduction for these little VTOLs.  Probably still worthwhile, but no longer quite so absurd.

[CVB]

TM page 259 says "assault-weight battle armor may not mount magnetic clamps".

I just love it when I have to find three chapters in two books to deduce the simple fact "assault battle armor can't be mechanized"

[Lagrange]

Yeah, it took a little bit of finding for me as well.

I updated the OP.  Given that we can't use mechanized battle armor on a VTOL, it seems we should just use the 'modular weapon' quirk on a non-omni unit to make it easy to swap between one variant and another.  This has the side effect of reducing the cost a bit.

[CVB]

Good thinking

[Daryk]

Do you have a page reference for the errata banning mechanized BA?  Does it only apply to VTOLs, or other types of vehicles as well?

[Lagrange]

Do you have a page reference for the errata banning mechanized BA?  Does it only apply to VTOLs, or other types of vehicles as well?

It's page 43 here.
No vehicle may expend UMU, VTOL, WIGE, or Jump MP, and no mech may expend UMU MP.

[Daryk]

Hmmm... it seems 'mechs can still jump.  It's also weird the -1MP applies whether the BA is under 10% of the 'mech's weight or not.

[Hellraiser]

I modified a Ferret for a campaign that looked very similar.
2 of them.   1 w/ TAG, 1 w/ C3S
Wonderful spotters.
Did the same thing w/ a pair of Savanah Masters.
The XL-45s gave them that little boost of speed to really get into locations for cover to make them "almost" unkillable.

[Lagrange]

I modified a Ferret for a campaign that looked very similar.

Ah, the connection with the Ferret is a good one, thanks.   (And good to know that it works well in practice.)