Talk:Craft

OK! Well past time to theorize on the capabilities of X-Com's air force. The Interceptor, the fastest thing humans can build in X-Com's 1998, has a maximum speed of "2100".

EDIT: The very intelligent Dumas has cleared up my confusion over the "nautical mile", which is the unit of distance a "knot" measures. A vessel traveling at 1 knot along a meridian, covers one sixtieth of a degree geographic latitude in one hour - that is, one nautical mile per hour. A nautical mile is 1,852 meters, 1.150779 English miles, or 6,076.1155 feet.

In dry air with a temperature of 21 °C (70 °F) the speed of sound is 1230 kilometers per hour, 770 miles per hour or 1130 feet per second. Thus, Mach 1 is roughly 669 knots.

Thus, in knots, the Mach numbers of your craft in X-Com: UFO Defense would be;

Craft	Speed(knots)	Speed(Mach)
Skyranger	760	1.1
Interceptor	2100	3.1
Lightning	3100	4.4
Firestorm	4200	6.3
Avenger	5400	8.1

UFO	Speed(knots)	Speed(Mach)
Small Scout	2200	3.1
Medium Scout	2400	3.6
Large Scout	2700	3.9
Supply Ship	3200	4.6
Abductor	4000	6
Harvester	4300	6.4
Terror Ship	4800	7.2
Battleship	5000	7.4

Half my original totals. Hideously inflated indeed. But still the kind of thing I want to see in the next "alien invasion" blockbuster. Though those "Dual Pulse Detonation Engines" still make me wonder - those are supposed to be hypersonic. --Kalaong 13:58 29 March 2008

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Tempting as it is to say you know nothing about anything, I'm just going to say that you have a hideously inflated idea of how fast these craft should be. The [Blackbird] was pretty much designed purely for speed at very high altitude (80000 feet in round numbers). At that altitude,the speed of sound is much much lower than at sea level (Density and temperature effects) and its absolute speed was around 1900 knots.

Since the knot or nautical mile is rather longer than a statute or land mile, a speed expressed in knots is 'lower' than that speed expressed in mph. The speed of sound is closer to 669 knots than 2100. So even taking the Interceptor's listed speed as being in knots, it is faster than the Blackbird and the Skyranger is supersonic.

In any case, if we want to get away from the game's arbitrary units, the best method is to time various craft as they fly between two given points separated by a well-known distance. Say, crossing the USA from east to west at given latitude.--Dumas 20:34, 28 March 2008 (PDT)

I get all of my numbers from Wikipedia. But the description of nautical miles seems to have thrown me - not just a different unit of measure, but also a different unit being measured. And what do you mean "hideously" inflated? There's maybe one X-Com base per continent, yet interceptors chase UFOs clear across the planet. Hypersonic speeds seem to be the best way to define that kind of maneuvering - at the very least. Anyway, keep talking. Constructive criticism is why I started this discussion - I'm just a geek punching keys, and I wanted to visualize the kind of craziness these dogfights would be. --Kalaong 0:16, 29 March 2008 (EST)

The nautical mile is defined as 1852 meters, or one minute of latitude along any meridian (neglecting the funky shape of the Earth). A statute mile is somewhere around 1600 meters. For reference, moving at 2100 knots gets you about 35 degrees of latitude an hour flying north/south, which is rather more than a third of the distance from either pole to the equator.

You seem to be conflating speed and range. Sure, interceptors can go halfway around the Earth, but how quickly are they doing it? Unless we time a few of the buggers, this is just going in circles. The Skyranger takes hours to get anywhere and even the Avenger takes a while to get from, say, somewhere in China to Indonesia.

Edit: Just timed a couple short flights. A Firestorm takes one hour and fifteen minutes of game time to fly from Equator to Pole (I have a base in Africa that's close to the Equator). An Avenger makes the trip in one hour. 90 degrees of latitude (Equator to Pole) is 5400 knots, so I think that taking the craft speeds as being listed in knots is correct.--Dumas 23:02, 28 March 2008 (PDT)

Better if you make a separate page discussing the real-life issues regarding X-COM's craft than to be adding/changing measure units to the craft's pages. Since the original game does not mention anything regarding which measure applies, extrapolating into reality should be kept separately, otherwise you're adding things to the original game. And my 2c for this discussion: Dumas's in game observations regarding the equator to pole travel time pretty much resolve the issue of which measure should be used. The fun thing is to try to figure out why X-COM would use subsonic interceptors. Several points could be made: dogfighting takes place at subsonic speeds, supersonic burns a lot of fuel (decreasing range), etc. Hobbes 07:18, 29 March 2008 (PDT)

Dumas, now that you've explained the concept of a "nautical mile", I just realized that using knots to define craft speed allows them to be mapped right onto the Geoscape, so it makes even more sense. Equator to pole in an hour - passenger jets take fifteen to get from LA to Hong Kong! I still think some mach numbers would be neat though - everyone has a good mental image of superjets trailing sonic booms. Hobbes, I've linked this page to the Realistic Equivalents page. And as for dogfights taking place at supersonic speeds? I direct you to the book "Speed is Life, More is Better" By John M. Scanlan. --Kalaong 13:19 29 March 2008

I mentioned dogfights, not air to air combat in general. Quoting from the Wikipedia's article: (...)Superiority in a dog fight can depend on a pilot's experience and skill, and the agility of his fighter when flown at minimum air speeds approaching loss of control (causing a danger of stalling)(...)Dogfights are generally contests fought at low airspeeds, while maintaining enough energy for violent acrobatic maneuvering, as pilots attempt to remain within air speeds with a maximum turn rate and minimum turn radius: the so-called "corner speed" that often lies between 300 and 400 knots, depending on conditions(...) Interceptors and UFOs don't actually engage in actual 'dogfights' since they simply fire at a distance in the game but my mention to it was merely a hypothesis to justify why the Interceptors are slow (i.e. they were designed with an emphasis on maneuvering rather than speed because it was previously thought that most air to air combat regarding UFOs would consist of dogfights, but operations revealed otherwise - a classic case of expectations by planners not corresponding to reality. Hobbes 12:15, 29 March 2008 (PDT)