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Author Topic: Kind of lore/headcanon question. - How fast are ASF's?  (Read 4660 times)

AdmiralObvious

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #30 on: 11 January 2019, 01:24:05 »
There are maximum safe speeds for ships and ASF's at different levels of atmosphere. You might be able to get a dropship to do Mach 1 at sea level in an "earth like" planet, but the ship will probably have disintegrated before it reaches height 3 on the low altitude map at that speed. Going above those safe limits goes directly into the SI for the craft. Doesn't matter how fancy the armor is if the whole thing collapses into a fireball.

The_Caveman

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #31 on: 11 January 2019, 01:47:48 »
There are maximum safe speeds for ships and ASF's at different levels of atmosphere. You might be able to get a dropship to do Mach 1 at sea level in an "earth like" planet, but the ship will probably have disintegrated before it reaches height 3 on the low altitude map at that speed. Going above those safe limits goes directly into the SI for the craft. Doesn't matter how fancy the armor is if the whole thing collapses into a fireball.

Not quite.

Max safe speed for the "ground" row of the high altitude map, which corresponds to the play space of the low-altitude map, is 2 high-altitude/space hexes a turn, which is Mach 2-ish. On the low altitude map, maximum safe speed is twice a ship's safe thrust. There are canon aerodyne DropShips (Avenger comes to mind) that can reach moderate supersonic speeds at low altitude without risking structural damage.
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BloodRose

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #32 on: 19 March 2019, 08:24:52 »

A 'Mech or VTOL on the ground map will spend 9 MP to travel across 9 flat, simple ground hexes. A fixed wing vehicle on the low altitude map expends thrust to change velocity, so a fighter that spends 9 thrust (and thus 9 fuel) reaches a velocity of 9 and covers 9 hexes that turn.

"But wait, didn't you just say it doesn't move like ground units...?"

Hold on a second, I'm getting to it.

On turn number 2, that fighter traveling at 9 hexes per turn doesn't have to spend 9 thrust points to maintain its velocity. Instead, per p. 84 TW, they have to pay half their velocity in thrust points (round down) to maintain their current speed (if they want to). That fighter traveling at 9 hexes per turn only needs to spend 4 thrust points (and thus 4 fuel points) to continue traveling at 9 hexes per turn.

A great explanation but for one thing - 1 Velocity actually equals 16 hexes of movement. So a Mech that spends 4 movement will move 4 hexes, but a ASF or CF that expends 4 Thrust to reach Velocity 4 will move 64 hexes in that turn.
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Daryk

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #33 on: 19 March 2019, 18:41:25 »
16?  I thought map sheets were 17 hexes long...

Weirdo

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #34 on: 19 March 2019, 18:53:51 »
They are. If you're using normal movement rules, an aero hex is equivalent to one mapsheet. If you're brave enough to try the Aero Units on Ground Mapsheets rules, one point of velocity moves you sixteen ground hexes. No, the two don't match exactly.
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Daryk

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #35 on: 19 March 2019, 19:05:02 »
Ah, I see... thanks Weirdo!  :thumbsup:

BloodRose

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #36 on: 20 March 2019, 22:00:06 »
On a side note, this is why you have to either use the Radar map, an Aero map or have some abstracted turn-around system if you are not using masses of maps but want air support.
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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #37 on: 20 March 2019, 23:39:40 »
Using an aero map is so easy, I genuinely can't imagine going back to the ground map rules. Once you get to the ground map area, you can strike every turn if you want, and the only fancy flying you need to do is be able to maintain a velocity of six and be able to turn. Either direction, it doesn't matter.
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RifleMech

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #38 on: 30 March 2019, 00:27:13 »
So if I understand this right, and I probably don't, a 2/3 Prop fighter can hit mach speeds?

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #39 on: 31 March 2019, 02:05:41 »
No. Propeller-driven craft are explicitly forbidden from going that fast, on low altitude maps, at least. I think on the high-altitude map they're allowed to move one hex per turn, which might be supersonic, but it's abstracted so that they can do any movement at all up there. Same for airships.
"Thanks to Megamek, I can finally play BattleTech the way it was meant to be played--pantsless!"   -Neko Bijin
"It's just that the Hegemony had one answer to every naval problem. 'I kills it with my battleships.'" - Liam's Ghost
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RifleMech

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #40 on: 31 March 2019, 07:22:56 »
No. Propeller-driven craft are explicitly forbidden from going that fast, on low altitude maps, at least. I think on the high-altitude map they're allowed to move one hex per turn, which might be supersonic, but it's abstracted so that they can do any movement at all up there. Same for airships.

Sorry I'm still don't understand. I can understand the abstraction on the high-altitude map but how fast can props go on the low-altitude map? TechManual says they go out of control at 8+. That would be a max velocity of 7, right? But doesn't that come out to something like 1,209.6kph or Mach 1.12?  ???

Tai Dai Cultist

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #41 on: 31 March 2019, 11:14:44 »
Sorry I'm still don't understand. I can understand the abstraction on the high-altitude map but how fast can props go on the low-altitude map? TechManual says they go out of control at 8+. That would be a max velocity of 7, right? But doesn't that come out to something like 1,209.6kph or Mach 1.12?  ???

If breaking the sound barrier is an issue, just hand-waive it that in this particular world's atmosphere and/or at that particular altitude, velocity 7 works out to be just under the sound barrier.

RifleMech

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #42 on: 31 March 2019, 22:50:54 »
That'd only work for some planets though.

Thatguybil

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #43 on: 01 April 2019, 00:27:10 »
Prop planes can hit / exceed the sound barrier for short periods during steep dives.

marauder648

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #44 on: 01 April 2019, 03:44:15 »
Prop planes can hit / exceed the sound barrier for short periods during steep dives.

I've never heard of a prop plane breaking the speed of sound, but I don't doubt that its possible, if you went up as high as you could in a fast prop and dove as hard as you could.  Pulling out of that dive however...
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Daryk

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #45 on: 01 April 2019, 04:05:20 »
I believe it happened as far back as WWII, in isolated cases.

AdmiralObvious

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #46 on: 01 April 2019, 04:48:59 »
I'm fairly sure the first prop driven plane to break the sound barrier "officially" was either a Helldiver or a Bearcat, some time way after WWII.

You've got pilots from the Battle of Britain who claimed otherwise though, but nobody could prove it because nobody could actually verify the claim.

Ruger

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #47 on: 01 April 2019, 05:33:35 »
I believe it happened as far back as WWII, in isolated cases.

I've heard that too, but only in extreme dives with something like a P-51 or P-37...

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RifleMech

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #48 on: 01 April 2019, 10:11:12 »
According to wiki claims of reaching supersonic speeds were always in emergency dives and were never confirmed. It also says the fastest speed a prop plane is alleged to have reached is 690 mph (1110 km/h, Mach 0.96) in Spitfire. Almost but not quite breaking the sound barrier.

Wiki also says the record for fastest prop plane is the Tupolev Tu-114 with a maximum speed of 878 km/h (540 mph, Mach 0.73) I think that works out to Velocity 5?

I suppose modern BT prop aircraft can hover around mach speed in normal flight at sea level. I also suppose older planes can hit velocity 7 in emergencies. But would they have room to pull up and what about normal flight? 

glitterboy2098

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #49 on: 01 April 2019, 13:03:40 »
actually it is theoretically possible to go supersonic in level flight with the right engine and props, but it hasn't been actually achieved yet, mostly because it has been too expensive for small scale private industry and individuals, and big business and governments generally aren't interested.

RifleMech

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #50 on: 03 April 2019, 00:27:01 »
actually it is theoretically possible to go supersonic in level flight with the right engine and props, but it hasn't been actually achieved yet, mostly because it has been too expensive for small scale private industry and individuals, and big business and governments generally aren't interested.

So that would leave room for more advanced tech planes to hit velocity 7 while older tech planes are limited to velocity 6?

Alsadius

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #51 on: 04 April 2019, 12:15:35 »
actually it is theoretically possible to go supersonic in level flight with the right engine and props, but it hasn't been actually achieved yet, mostly because it has been too expensive for small scale private industry and individuals, and big business and governments generally aren't interested.

Given how RL prop engine designers worry about prop tips going supersonic, I'd shudder to think of what's happen if the whole plane did. It's well within the BT universe's capabilities, I'm sure, but the engines would probably have painfully short service lives even there.

I'm actually pretty impressed by this thread, tbh. Everything is worked out in ways that seem pretty logical, realistic for the setting, and still playable.

RifleMech

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #52 on: 05 April 2019, 08:12:58 »
So if I wanted to make a replica of an F-14 it'd have a max speed of 8/12 it would have a thrust rating of 4/6? Is that right or is jets have a top speed?

BloodRose

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #53 on: 16 April 2019, 10:02:02 »
So if I wanted to make a replica of an F-14 it'd have a max speed of 8/12 it would have a thrust rating of 4/6? Is that right or is jets have a top speed?
Thrust 4/6 would give it 4 regular or 6 'full burn' points to move per turn. Assuming you take off at safe and climb to ceiling then start to accelerate you will start off moving at 2 aero (32 ground) and gradually accelerate as you climb (assuming 2 levels/turn) by 1 aero (16 ground) unless you throttle back or climb faster. If you dont then you will reach 3 aero (48 ground) and stay there. Assuming you climb for 4 turns (to height 8) you will be going at speed three, then you level out. With no other altitude changes and going at full safe burn you will reach Speed 8 (128) in three turns and be able to maintain it easily, unless you climb or perform a maneuver that costs thrust.
Now, if you hit full burn once you level out you will jump straight to 6 (96) on turn one of leveling out, 10 on the second and then creep to 11 before finally hitting 12 on the fourth turn. At that point you are burning fuel rapidly though, and will lose speed on any maneuver that does not cost you at least 3 altitude.
4/6 is good enough for a "modern day" conventional fighter, but do not expect to be outrunning a later design (Although you could out punch them).
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RifleMech

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #54 on: 16 April 2019, 19:24:07 »
Thrust 4/6 would give it 4 regular or 6 'full burn' points to move per turn. Assuming you take off at safe and climb to ceiling then start to accelerate you will start off moving at 2 aero (32 ground) and gradually accelerate as you climb (assuming 2 levels/turn) by 1 aero (16 ground) unless you throttle back or climb faster. If you dont then you will reach 3 aero (48 ground) and stay there. Assuming you climb for 4 turns (to height 8) you will be going at speed three, then you level out. With no other altitude changes and going at full safe burn you will reach Speed 8 (128) in three turns and be able to maintain it easily, unless you climb or perform a maneuver that costs thrust.
Now, if you hit full burn once you level out you will jump straight to 6 (96) on turn one of leveling out, 10 on the second and then creep to 11 before finally hitting 12 on the fourth turn. At that point you are burning fuel rapidly though, and will lose speed on any maneuver that does not cost you at least 3 altitude.
4/6 is good enough for a "modern day" conventional fighter, but do not expect to be outrunning a later design (Although you could out punch them).


So that's a yes to an F-14 hitting a max velocity of 12?  And fuel usage depends on altitude with the higher you go the less you use?

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #55 on: 17 April 2019, 09:37:40 »
Bear in mind that all aero units have a top speed limit of twice their safe thrust, and exceeding this forces you to make increasingly difficult control rolls. (TW, p. 84) A hypothetical 4/6 F-14 trying to fly at velocity 12 is highly likely to tear itself apart in an incredibly short span of time.
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RifleMech

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #56 on: 18 April 2019, 10:29:22 »
Still haven't quite figured out velocity but it's good to know that there re maximums.  This thread has been quite educational. Thanks everyone!  :thumbsup:

Nebfer

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #57 on: 22 April 2019, 15:20:41 »
Bear in mind that all aero units have a top speed limit of twice their safe thrust, and exceeding this forces you to make increasingly difficult control rolls. (TW, p. 84) A hypothetical 4/6 F-14 trying to fly at velocity 12 is highly likely to tear itself apart in an incredibly short span of time.

Ignoring the fact that few Real fighters even reach 1.5Gs of straight line acceleration...

So technically modern fighters would be 2/3 or 3/5 if you want to be a bit generous, but their top speeds is would be notably higher than what the game would indicate from their thrust profiles. Even so most modern fighters rarely even go supersonic spending most of their time subsonic (IIRC many pilots could count the number of times they went supersonic on their hands in their entire careers).

Considering that most real fighters only travel around at mach 0.8 ish in comparison to B-techs notably higher cruising speeds of around mach 2ish, so B-tech fighters are on average twice as fast.

BloodRose

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #58 on: 23 April 2019, 06:04:19 »
Bear in mind that all aero units have a top speed limit of twice their safe thrust, and exceeding this forces you to make increasingly difficult control rolls. (TW, p. 84) A hypothetical 4/6 F-14 trying to fly at velocity 12 is highly likely to tear itself apart in an incredibly short span of time.
IIRC the maximum speed for atmo flight is Velocity 12, and exceeding it makes bad things happen.
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RifleMech

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Re: Kind of lore/headcanon question. - How fast are ASF's?
« Reply #59 on: 23 April 2019, 06:21:01 »
Ignoring the fact that few Real fighters even reach 1.5Gs of straight line acceleration...

So technically modern fighters would be 2/3 or 3/5 if you want to be a bit generous, but their top speeds is would be notably higher than what the game would indicate from their thrust profiles. Even so most modern fighters rarely even go supersonic spending most of their time subsonic (IIRC many pilots could count the number of times they went supersonic on their hands in their entire careers).

Considering that most real fighters only travel around at mach 0.8 ish in comparison to B-techs notably higher cruising speeds of around mach 2ish, so B-tech fighters are on average twice as fast.

Are you talking cruising speeds? I was going by the top speed listed in Wiki. If I did it right, it works out to 4/6 for the F-14. If I'm doing this right, an F-4 would be 3/5 with a max velocity of 10.  But that's if I'm doing things right. Also if I'm doing things right a P-51 will have a max 3 and a Sopwith Camel a max thrust of 1. I'm not sure what the thrust ratings would be. I'm even less sure about how one would make such vehicles in BT right now. So I'm back to being lost again.  :(

 

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