Hnd for aircraft questions

[Mgellis]

I'm working on a couple of articles for JTAS and Pyramid, and I have a technical question, so I'm polling the hive mind...

I need 4e GURPS Hnd/SR ratings for some aircraft. Most aircraft seem to be SR 3 (most helicopters are SR 2), so I'm not too worried about that, but Hnd is a bit harder to figure out.

Some canon figures...

Business jet in Basic Set: +0

P-51 Mustang (in High-Tech): +1

Cesna-type monoplanes: +1 or +2

Biplanes: +0 to +2 (the biplanes in High-Tech are all +0 but the one in the Basic Set is +2, I'm guessing it's a high-end aerobatic flyer for air shows or something)

Transport (C-47?) and flying boats (from High-Tech): -2

Blimp: -4

So, what I'm trying to figure out is...what is the general range of Hnd for modern jets and where do certain aircraft fall?

I'm guessing +1 for most combat jets, +2 for good ones (+3 for the very best, or only +2 for modern ones, with +3 for the very best mature TL 9 uber-jets?), and +0 for below average ones (I've heard the MiG-25 is not a very good dogfight, although I could be wrong about that). Any thoughts on this? Large jet bombers (B-52) and transports like the 747 are probably -2. Agile jet bombers (the B-1?) are maybe -1? Heavy fighter-bombers like the F-111 is maybe +0?

Any good sources on which planes are considered the "best" fighters, etc.?

I'm particularly interested in the major American jets (F-4, F-5, F-14, F-15, F-16, F-18) and the MiG series (15, 17, 19, 21, 23, 25, etc.) right now, but I'd be happy to discuss, ask questions on, and argue about anything from the 747 and the B-2 to the Mirage 2000 and the Eurofighter Typhoon. :)

So...how would you rate them?

Thanks.

Mark

[David L Pulver]

Originally Posted by Mgellis

I'm working on a couple of articles for JTAS and Pyramid, and I have a technical question, so I'm polling the hive mind...

Business jet in Basic Set: +0

P-51 Mustang (in High-Tech): +1

Cesna-type monoplanes: +1 or +2

Biplanes: +0 to +2 (the biplanes in High-Tech are all +0 but the one in the Basic Set is +2, I'm guessing it's a high-end aerobatic flyer for air shows or something)

Transport (C-47?) and flying boats (from High-Tech): -2

I'm particularly interested in the major American jets (F-4, F-5, F-14, F-15, F-16, F-18) and the MiG series (15, 17, 19, 21, 23, 25, etc.) right now, but I'd be happy to discuss, ask questions on, and argue about anything from the 747 and the B-2 to the Mirage 2000 and the Eurofighter Typhoon. :)

So...how would you rate them?

Mark

Handling should be construed as a fairly abstract number that reflects a general feel, and should rarely be greater than about +5.

The Handling formula I used to generate numbers assigns modifiers for the following factors:

- Stall speed (the lower the better; significant) +1-2 for old biplanes to -4 for something like an X-15.
- G-loading (maximum) - a major element; from 0 for <1G to +8 for 50G+ following semi-geometric progression
- SM (low generally better, range of about 0 to -3 for jumbo jet sized
- unstable / relaxed static stability (good) 0-1
- control system (e.g., unpowered, powered, fly-by-wire, etc.) 0-2
- control interface 0-1
- acceleration (the higher the better), again semi-geometric, -2 to +2 for most real aircraft, but can up to +4-5
- control surfaces (e.g., large tail, canard foreplanes, etc.) 0-2
- special features such as variable sweep, vectored thrust 0-1
- lighter than air (harder to control) negative

I won't give precise numbers, as VDS is still in editing and I haven't seen the final version, which
may be subject to change. But my last draf generated a value of about Hnd +3 for an F-16, one of the more agile modern fighters prior to the newer Eurocanards, F-22, etc.

My understanding, however, is that the values I assigned in BASIC SET and in the yet-to-be published VEHICLE DESIGN are certainly not official and no authors are required to comply with them - feel free to assign your own values based on your own research!

[Jerron]

Cessna-type monoplanes: +1 or +2
With a P51 at +1? Are you kidding? Even the complex, high performance Cessna monoplanes just about equal the P51. Maybe.

Biplanes: +0 to +2 (the biplanes in High-Tech are all +0 but the one in the Basic Set is +2, I'm guessing it's a high-end aerobatic flyer for air shows or something)
Oh yeah, that'd have to be one of them, especially if you don't have Cessnas as +2.

Transport (C-47?) and flying boats (from High-Tech): -2
[/QUOTE]

So if a P51 and a Flying boat (which is actually a specific aircraft) have a range between them of only 4 points, this scale is very tight. I'd say low end jets, the worst of the fighters- not the 12 passenger business ones- would have +2. This would be something like civilian single seaters or old 1950's jets. Any modern, halfway decent fighter jet would get +3. (They can still fly circles around a Pitts, it's just the Pitts is slow enough to do an actual show that can be seen, and most guys doing those shows are completely insane. Because a Navy flier won't do those things, doesn't mean his plane can't.) The best of the best might go as high as +4, but that would be the rarest, and top, bonus. Something like the Blue Angels who take their planes to the limit, maintenance and everything included - a regular plane of the same type might still be +3.

[Mgellis]

Originally Posted by David L Pulver

Handling should be construed as a fairly abstract number that reflects a general feel, and should rarely be greater than about +5.

The Handling formula I used to generate numbers assigns modifiers for the following factors:

- Stall speed (the lower the better; significant) +1-2 for old biplanes to -4 for something like an X-15.
- G-loading (maximum) - a major element; from 0 for <1G to +8 for 50G+ following semi-geometric progression
- SM (low generally better, range of about 0 to -3 for jumbo jet sized
- unstable / relaxed static stability (good) 0-1
- control system (e.g., unpowered, powered, fly-by-wire, etc.) 0-2
- control interface 0-1
- acceleration (the higher the better), again semi-geometric, -2 to +2 for most real aircraft, but can up to +4-5
- control surfaces (e.g., large tail, canard foreplanes, etc.) 0-2
- special features such as variable sweep, vectored thrust 0-1
- lighter than air (harder to control) negative

I won't give precise numbers, as VDS is still in editing and I haven't seen the final version, which
may be subject to change. But my last draf generated a value of about Hnd +3 for an F-16, one of the more agile modern fighters prior to the newer Eurocanards, F-22, etc.

My understanding, however, is that the values I assigned in BASIC SET and in the yet-to-be published VEHICLE DESIGN are certainly not official and no authors are required to comply with them - feel free to assign your own values based on your own research!

This is quite helpful. Thank you. If an F-16 is +3, that gives me a baseline to work with. This is what I'm thinking right now...

+6: Nightwing (from Ultra-Tech)
+4: F-22, Eurofighter
+3: F-16, Su-35, Su-27, MiG-29, Rafael
+2: Helicopters, F-15, F-14, AV-8, A-4, F-18, MiG-21, Mirage 2000
+1: P-51, F-86, F-4, A-6, F-5, Su-24, MiG-15, MiG-23, Mirage 5, Kfir
+0: MiG-25, F-111, A-10, Business jet
-1: B-1, Tu-22M, C-130, 707
-2: C-47, B-2, B-52, 747
-3: ???
-4: Blimp

How does this look? Thoughts? Comments? Arguments?

Mark

[Kizara]

Originally Posted by Mgellis

I'm working on a couple of articles for JTAS and Pyramid, and I have a technical question, so I'm polling the hive mind...

Sorry, but only in this community would you see something like this.

I just love how involved the authors/editors of GURPS products are in the forums, it gives a new meaning to the concept of 'product support'.


As for your Hnd system, I'm not familiar with all the naunces involved, but I would say you have a very tight scale there and it may be useful to loosen it up a bit to allow for more diversity between planes. To allow for smaller differences.

[nick012000]

I suppose you could probably build them with Spaceships. Just don't give them any sort of spacecraft engine; make them Aerodynamic, Winged, and give them Jet Engines (possibly more than one system of Jet Engines, depending on how big they are and how heavy the engines are).

Then stat them out as appropriate. Fighters are probably SM +5 or +6.

[Mgellis]

Originally Posted by nick012000

I suppose you could probably build them with Spaceships. Just don't give them any sort of spacecraft engine; make them Aerodynamic, Winged, and give them Jet Engines (possibly more than one system of Jet Engines, depending on how big they are and how heavy the engines are).

Then stat them out as appropriate. Fighters are probably SM +5 or +6.

Spaceships actually gives a rough match to what David Pulver suggested earlier. A SM+5, 30-ton craft, with wings, at TL 7-8, and thrust of a few gees, would have a Hnd rating of 3. So assuming that modern jets are mostly in the +2 to +4 (+0 to +2 for earlier jets, light bombers, etc.) range isn't so crazy.

Now all I need to do is figure out if I'm giving the right ratings for specific aircraft. For example, should the MiG-21 be +2? I've heard it was one of the most agile jets of its time (so was the MiG-15, but a totally subsonic jet probably only deserves a +1 on Hnd), a real pain for pilots in F-4s, but matched by later jets like the F-18 and outclassed by jets like the F-16.

Mark

[Anaraxes]

The F-4 is kind of a brick. It's not so much of a virtue for a Mig-21 to be able to outturn it. The Mig has a delta wing, which is fast and gives a good rate of climb, but usually bad for sustained maneuverability. (They "bleed energy".) It was fast, and it was light, so it had agility and good instantaneous turning, though it couldn't keep it up. I think it was a problem for F-4s more in the sheer dissimilarity of the two than anything else.

IMO it doesn't really rank with the other +2 aircraft on your list. It seems a little unfair to put it at +1 with the Mig-15 or P-51, but then you've got the F-5 and Kfir there, and there's limited granularity available. That also puts it on par with the F-4, which is probably reasonable given that it's a "classic" matchup. If either plane in a famous duelling pair were really vastly better than the other, they probably wouldn't be known as a famous duelling pair.

[David L Pulver]

Originally Posted by Mgellis

This is quite helpful. Thank you. If an F-16 is +3, that gives me a baseline to work with. This is what I'm thinking right now...

+6: Nightwing (from Ultra-Tech)
+4: F-22, Eurofighter
+3: F-16, Su-35, Su-27, MiG-29, Rafael
+2: Helicopters, F-15, F-14, AV-8, A-4, F-18, MiG-21, Mirage 2000
+1: P-51, F-86, F-4, A-6, F-5, Su-24, MiG-15, MiG-23, Mirage 5, Kfir
+0: MiG-25, F-111, A-10, Business jet
-1: B-1, Tu-22M, C-130, 707
-2: C-47, B-2, B-52, 747
-3: ???
-4: Blimp

How does this look? Thoughts? Comments? Arguments?
Mark

A more detailed analysis suggests that the F-16 et al would be at least +4 and maybe +5 in a "clean" fighter configuration; I was looking at late models with full air-ground load for the +3. In addition, the system gives the same modifier for boosted and FBW controls; the main difference is the latter boosts stability rating as well. This suggests to me that you might get:


+5: F-22, Eurofighter (at least in clean condition)
+4: F-15, F-16, Rafael, Grippen, Su-27, F-35 (maybe), Mirage 2000, all in fairly clean conditions. If you're generous, put MiG-29 here. If you're a Eurofighter skeptic, put it here as well.
+3: F/A-18, a nice MiG-21, clean late-model F-4 with slatted wings, any of the above with full air-ground load
+2: Mirage III/5/Kfir, basic or laden F-4, clean F-104, the above with full air-ground etc.
etc. Basically, I'd open the top up a bit.
A B-52 is probably -2. I hear the B-2 flies quite well, though, maybe better than the B-52.

Helicopters vary depending on whether the rotor technology is old or new. Something like Lynx or Apache iis a heck of lot more agile then an old Huey or Hind as the rotors aren't able to take the strain of more than a G or 2.

The F-4 and F-104 kind of depends: at certain speed and altitude regimes they have better acceleration than a Mig-21 - they were vertical fighters with good climb rate but not so good turn rate. The fairly abstract maneuver handling values tend to have certain break points that push numbers up or down.

A nice online site for combat aircraft discussion:
http://www.vectorsite.net/indexav.html

[Jerron]

Originally Posted by Kizara

I just love how involved the authors/editors of GURPS products are in the forums, it gives a new meaning to the concept of 'product support'.

Ditto. Thank you, Mr. Pulver, please feel free to totally negate my ideas anytime. That's one of the reasons I love GURPS, and used to love Hero. (I still don't know how I didn't notice you posted at the same time I was drafting my reply.) Games like this are interactive, and to be interactive with the people who actually write them brings it to a whole new level. Too bad the whole idea makes it impossible for you to have an assistant answer the questions, so we could get more responses, maybe.

One thing I didn't even think of is the full load you mentioned above. It does make a big difference in handling, and I can see +4 going down to +3, since +4 is actually a pretty generous bonus. How much do you suppose it would affect lower Hnd craft? I really have no experience with aircraft with external loads, but can guess it would be a big difference based on how little input is needed for flaps to have a big effect. Granted, one is made for disturbing the flight, and the other is made to not disturb the flight as much as feasible. I have a guess that as tight as the categories are, it won't change the Hnd except in extreme circumstances (like the +4, or hanging everything available including the kitchen sink off the plane). I can see a -4 blimp carrying a building (if it could lift it of course) and still only being -4, while the F4 seems to be on the edge of the +2/+3 envelope and is specifically mentioned as going down a point when laden. (African or European F4? :P)

Anyhow, without the verbosity, I guess I was asking if there is (or will be) a rule about lowering Hnd when loaded? Externally specifically, since I don't believe internally would matter much.