Aircraft Take Off Speeds

[Atgxtg]

Hey,

Does anybody know where I can find a good list (or table) of aircraft take-off/stall speeds? I'm working out some stuff for Vehicles and want to make sure that my results are in the right ballpark.

For instance, I've got the F-104G at empty take-off weight with a take-off speed or about MOVE 293, 264 kph, 73 m/s, 154 mph, 241 ft/sec. It looks good, but I don't know if it is in anyway accurate. Or, at least accurate enough for RPG design purposes.

[rust]

I tried to find something, but without success. It seems that the fact that

the take-off speed depends on the actual weight of the aircraft (fuel, car-

go, weapons, passengers ...) makes people reluctant to give a specific ge-

neral value that could be entered into a list.

It could well be that you will have to look at the individual aircraft's flight

manuals (those of older aircraft are often on the internet) to find reliable

data.

As for the F-104, there are several websites that offer the flight manual,

some for money and others free.

This is one of the free ones - but I do not know whether the download is

indeed legal:

http://myfiles-express.com/search.php?search=f%20104%20flight%20manual

Edited December 11, 2009 by rust

[Atgxtg]

My results are about the same. I have found some values (including the take-off speed for the F104G of 196 mph, so my calculation was a bit low) but had hoped to get a bunch at once so I could test out my math.

I'm trying to simplify some of the real world formulas for aircraft to get something simple enough to be usable for RPG aircraft design, yet maintain some degree of accuracy.

Aircraft are proving to be the most difficult of the vehicles to provide design rules for, as they don't have any real constants. The major pain being that an aircraft's performance varies by altitude, so determining top speed is a real pain. It is quite possible that even though one plane has a higher top speed than another, if could be slower at a particular attitude.

[Rurik]

Hey,

Does anybody know where I can find a good list (or table) of aircraft take-off/stall speeds? I'm working out some stuff for Vehicles and want to make sure that my results are in the right ballpark.

For instance, I've got the F-104G at empty take-off weight with a take-off speed or about MOVE 293, 264 kph, 73 m/s, 154 mph, 241 ft/sec. It looks good, but I don't know if it is in anyway accurate. Or, at least accurate enough for RPG design purposes.

Wikipedia lists a takeoff speed for the F-104 but not a couple of other jets I looked up. Here is what they said:

Takeoff speeds were in the region of 219 mph (352 km/h), with the pilot needing to swiftly raise the landing gear to avoid exceeding the limit speed of 299 mph (481 km/h). Climb and cruise performance were outstanding; unusually, a "slow" light illuminated on the instrument panel at around Mach 2 to indicate that the engine compressor was nearing its limiting temperature and the pilot needed to throttle back. Returning to the circuit, the downwind leg could be flown at 242 mph (389 km/h) with "land" flap selected, while long flat final approaches were typically flown at speeds around 207 mph (333 km/h) depending on the weight of fuel remaining. High engine power had to be maintained on the final approach to ensure adequate airflow for the BLC system; consequently pilots were warned not to cut the throttle until the aircraft was actually on the ground. A drag chute and effective brakes shortened the Starfighter's landing roll

There blurb on Takeoff Speeds talks about air density, weight and the like, so there will be some variance. Loadout is important. On only a mildly related subject I recently read an interesting tidbit about the F-14:though it could be equipped with 6 AIM-54 Pheonix missles it in practice never was because it was too heavy to land with all Six missles - it would have to fire or drop missles if so outfitted so usually only carried 2. Funny that Harpoon II never took this into account - I'd always put six AIM-54's on my F-14's.

[vagabond]

Hey,

Does anybody know where I can find a good list (or table) of aircraft take-off/stall speeds? I'm working out some stuff for Vehicles and want to make sure that my results are in the right ballpark.

For instance, I've got the F-104G at empty take-off weight with a take-off speed or about MOVE 293, 264 kph, 73 m/s, 154 mph, 241 ft/sec. It looks good, but I don't know if it is in anyway accurate. Or, at least accurate enough for RPG design purposes.

All I could find was 190-210 kph takeoff speed. I also found a stall speed of

196-216 mph elsewhere. I've also seen 200 knots. I'd go with 200 knots

due to the source:

1979 | 3214 | Flight Archive

The Flightglobal archives pull from various magazines of the era.

Ian

[Atgxtg]

Thanks Rurik (oh, and thank you too, rust)

Stuff like load outs, I can factor for fairly easily. I've got some of the formulas for that. For example, the take off speed changes in proportion to the square root of the change in mass. So if you make an aircraft twice as heavy (by adding more fuel and weapons), you increase the take-off/stall speed by 41.4%.

Jets that are going into Air-to-air combat are often only given a partial weapon load and only half a tank of fuel because of the effects of increased mass and increased drag.

More mass means less acceleration, and a higher stall speed (equals less maneuverability).

More drag means slower aircraft, more power used to maintain thrust for lift (equals slower. less maneuverable and more fuel consumed)

Aircraft are a real pain from a game design viewpoint. For example, turning rate is dependent on speed (the square of the speed). This is true for other types of vehicles, but as aircraft tend to go much faster than other vehicles the effect is more pronounced.

This means that while a F-22 can pull more Gs than a Piper Cub, the Cub can probably out turn (make a tighter turn) the F-22. In many cases the Piper Cub may even be able to turn around faster than the F-22. Traveling at, say 5 times the speed means a turning radius 25 times as large. Even being able to pull 3 times the G force still leads to a turn radius over 8 times as big. That is one reason why aircraft don't really fight at top speed.

In game terns, I'm thinking of giving a penalty to piloting rolls based on the current speed.

Edited December 11, 2009 by Atgxtg

[threedeesix]

I don't know if this will help, but here is a website dealing with airliner take off speeds. May help with the big stuff.

Aerospaceweb.org | Ask Us - Airliner Takeoff Speeds

Rod

PS - It just looks like hieroglyphs to me.

[Rurik]

Thanks Rurik (oh, and thank you too, rust)

Stuff like load outs, I can factor for fairly easily. I've got some of the formulas for that. For example, the take off speed changes in proportion to the square root of the change in mass. So if you make an aircraft twice as heavy (by adding more fuel and weapons), you increase the take-off/stall speed by 41.4%.

Jets that are going into Air-to-air combat are often only given a partial weapon load and only half a tank of fuel because of the effects of increased mass and increased drag.

More mass means less acceleration, and a higher stall speed (equals less maneuverability).

More drag means slower aircraft, more power used to maintain thrust for lift (equals slower. less maneuverable and more fuel consumed)

Aircraft are a real pain from a game design viewpoint. For example, turning rate is dependent on speed (the square of the speed). This is true for other types of vehicles, but as aircraft tend to go much faster than other vehicles the effect is more pronounced.

This means that while a F-22 can pull more Gs than a Piper Cub, the Cub can probably out turn (make a tighter turn) the F-22. In many cases the Piper Cub may even be able to turn around faster than the F-22. Traveling at, say 5 times the speed means a turning radius 25 times as large. Even being able to pull 3 times the G force still leads to a turn radius over 8 times as big. That is one reason why aircraft don't really fight at top speed.

In game terns, I'm thinking of giving a penalty to piloting rolls based on the current speed.

The F-22 (and F-35) have a thrust vectoring ability where they can re-direct their trhust to assist in turning, making them able to turn much better than an aircraft without thrust vectoring. I'm pretty sure the designers put that in there just to mess up your formulas. A cub may still out turn an F-22, but the F-22 can easily outurn a similiar aircraft at similiar speed without that technology.

[Atgxtg]

The F-22 (and F-35) have a thrust vectoring ability where they can re-direct their trhust to assist in turning, making them able to turn much better than an aircraft without thrust vectoring. I'm pretty sure the designers put that in there just to mess up your formulas. A cub may still out turn an F-22, but the F-22 can easily outurn a similiar aircraft at similiar speed without that technology.

I'm aware of thrust vectoring. I'm already factoring it in thanks to the Harrier.

As for the F-22 easily outurning a similar aricraft at a similar speed-well usually. THere are a few planes that could give it some trouble, including the plane that is replacing, the F-15. The Eagle has a better power to weight ratio.

The actually turning circle (without thrust vectoring) is based on the turn angle and the speed of the aircraft. So at any given speed all planes turn at the same rate.

Where it varies is that:

1) Not all planes loose the same amount of speed/energy while turning

2) Not all planes stall (depart controlled flight) at the same speed

3) Not all planes generate the same amount of thrust to counter the loss in speed and lift.

4) Not all planes can take the same amount of stress (G-forces).

Now as for RPG purposes, (the reason why I'm going into this) lets say you got a PC flying in said Piper Cub somewhere in Arizona, when some bad guys show up in said F-22 to try and shoot the PC out of the sky. Realizing that his Cub is not match for the Raptor (and unarmed), the PC wisely decides to fly into a nearby canyon (say the Grand Canyon) for cover. If the F-22 pilot decides to follow and it turns into a chase in the canyons, the slower moving Cub will have an advantage.

The same sort of thing would apply to cars trying to navigate a turn on the expressway. A car going 40 mph will find the turn much easier than one going 140 mph.

[Al.]

The F-22 (and F-35) have a thrust vectoring ability

F-35 doesn't have TVC in that way.

The STOVL version (to be ordered by RN, RAF, USMC and possibly Italian and Spanish airarms) is able to rotate its aft nozzle through 90 degrees to give it a vertical take off capability (coupled with a lift fan ahead of amidships which is kind of like an enclosed and internal set of helicopter rotarblades to balance thrust moments). This is not to increase pitch or yaw in flight (or roll which it couldn't anyway as the F35 has only one jet exhaust and so could not divert thrust on one side only to generate roll).

F22 (and X31 and several Russian jets) have thrust which can be vectored in flight to provide additional maneuverability.

Harrier (in different flavours) CAN redirect thrust in flight. Although its only really the USMC who have explored this or documented it as a standard tactic.

Why has F35 not got VIFFing capability? Why haven't current versions of Eurofighter? Or Rafaele or Gripen? Especially as airshow performers look so bloody impressive when using TVC?

Partly the cost and mass overheads of installing and partly as the clever thrust-vectoring manouveres also bring their own problems (like running out of airspeed and energy at exactly the wrong time). Having said that Eurojet are making noises about retrofitting Eurofighters engines with TVC so they must think that they have

a) solved the mass issues

lost sales to Russian jets due to a lack of TVC on Eurofighter

Now that that can of worms is opened.

How are you getting on with BRP rules for EW?

Current rules for Guided munitions and ECM are not only brief to the point of missing upon blinking but also don't make sense taken together.

Of course if you manage to model ECM, ECCM, ESM, AESAs et al then you'll probably have a knock of the door late one night from your local national intelligence agency..............

Al

[Atgxtg]

How are you getting on with BRP rules for EW?

Current rules for Guided munitions and ECM are not only brief to the point of missing upon blinking but also don't make sense taken together.

Of course if you manage to model ECM, ECCM, ESM, AESAs et al then you'll probably have a knock of the door late one night from your local national intelligence agency..............

First off, I'm not certain how they are being handled (if at in) in the new Modern Equipment Catalog.

What I'm thing of for EQW is along these lines:

-For ECM/ECCM, My initial idea is to give each a STR rating and use the resistance table.

-A second idea would be to use some sort of EW skill% and have the system used give a modifier to the operator's skill roll (probably a bit less accurate, but better for an RPG standpoint as it makes the characters more important than their gear). Rolls would still be opposed.

-For thinks like using ECM to stop missiles, it would roll opposed to the missile operator (or against the missile if it were self-guided).

-For ESM, I would either give a bonus to craft with such support, or maybe even substitute their bonus with that of the support craft. I'd have to see how the numbers work out first.

-Additionally, I would probably need to differentiate between active and passive scanning, and provide a modifier to detection for active scanning.

AESAs would give a much lower modifier than active scanning.

-Stealth would provide a modifier to avoid detection.

-As far as modeling the real world goes, I do have a few sources, including some board games that should help me is setting up some benchmark figures. I doubt it will be accurate enough to worry anyone , but hopefully will be good enough to satisfy gamers.

From a design standing, I haven't done a lot yet with EW, as I haven't quite got the chase rules modified yet for air combat, nor the aircraft design system. I can write up stats for real aircraft okay, but want people to be able to create their own designs and get reasonably decent results.

Since aircraft work in 3 vectors, and their performance characteristics chance with altitude, it's been a bit tricky. I've got some formulas that work, but they are what aeronautical engineering students use. I'm working on seeing how much of it I can factor or "throw" out and still get an acceptable result. For example if I do most of the calculations at sea level, 20C, I can turn the pressure variable into a constant and combine it with other factors.

What I think I will eventually need to do is come up with a few different formulas for aircraft by type (light prop, commercial jet, jumbo jet, military jet, etc.). That way I can rely on the similarities between similar types of craft, and treat most of the variables as constants.

[Atgxtg]

All I could find was 190-210 kph takeoff speed. I also found a stall speed of

196-216 mph elsewhere. I've also seen 200 knots. I'd go with 200 knots

due to the source:

1979 | 3214 | Flight Archive

The Flightglobal archives pull from various magazines of the era.

Ian

Thanks for the info. I'm going over the document. I think I know why you see an range in the take-off/landing speed. There are actually a range of speeds that are used. One is the speed at which a pilot could get the craft off the ground, another is the speed where he should, another is a speed where he is committed and cannot safely abort, and so on. All those speeds are within about 15% of each other. There might also be a slight difference between military values and civilian ones.

Fortunately, for RPG purposes, any of the above are probably "good enough."

I don't know if this will help, but here is a website dealing with airliner take off speeds. May help with the big stuff.

Aerospaceweb.org | Ask Us - Airliner Takeoff Speeds

Rod

PS - It just looks like hieroglyphs to me.

Thank you, too. It looks like it should be very helpful. That formula for stall speed is just what I need.

As for the hieroyglpyhs, many can be ignored for our purposes. For instance, we really don't need to worry about when the nosewheel leaves the ground (Vr).

The lift formals aren't quite so bad. It just that they don't explain what everything is, since they assume that if you are reading the page, you probably know a little something about aeronautics.

To try and put it simply, the formals are based on the idea that in order for an aircraft to fly, it's wings must produce enough lifting force to counteract the weight of the plane. and "hold it" in the air. Moving faster, increasing the size of the wing, or increasing the airpressure all result in the wing producing greater lift.

Once you work out how much lift is needed, you can determine how much power is required to get that lift, and any excess power can be used to maneuver the plane.

What makes it a pain is that most (if not all) of the factors involved vary (including engine performance).