Wait....seriously!!!???!!! The HUD doesn't show airspeed????

[Oldfox]

@Oldfox. I don't know. Maybe it was to put the reference in the middle of the windscreen. There was no combining glass, the symbology was projected on the windscreen itself.

 

Wasn't designed for primary flight information far better than anything else at the time. That rapidly changed. Took forever for the USN to upgrade it. Too busy spending money on ships that we really didn't need.

 

Mmmmm. So basically that would mean the position of the pitch ladder vs the horizon line would actually move if we have our head higher/lower?

 

Thus needing to turn that knob depending on how we are seated so it gets roughly to 0 on the horizon?

 

Maybe spent to much time on modern aircraft but being falling from the sky with the 0° pitch ladder perfectly on the speed vector is pretty strange at first :D

[shagrat]

Mmmmm. So basically that would mean the position of the pitch ladder vs the horizon line would actually move if we have our head higher/lower?

 

Thus needing to turn that knob depending on how we are seated so it gets roughly to 0 on the horizon?

 

Maybe spent to much time on modern aircraft but being falling from the sky with the 0° pitch ladder perfectly on the speed vector is pretty strange at first :D

Ye shall not use the HUD as flight instrument! The velocity vector is just a help for landings.

Use calibrated Altimeter, Vertical Velocity Indicator and Attitude Indicator as primary flying instruments. ;)

[sLYFa]

@ 30,000 ft, while the Mach number is always 0.6 M

Certainly not, mach 0.6 at 30000ft will be about 200kts, thats well below corner speed.

Whenever you want to judge the lift capability of your wings you must use IAS. Mach and TAS are misleading at altitude.

[Victory205]

Mmmmm. So basically that would mean the position of the pitch ladder vs the horizon line would actually move if we have our head higher/lower?

 

Thus needing to turn that knob depending on how we are seated so it gets roughly to 0 on the horizon?

 

Maybe spent to much time on modern aircraft but being falling from the sky with the 0° pitch ladder perfectly on the speed vector is pretty strange at first :D

 

No, no, there was no parallax! :) It just placed the aircraft reference symbol in the geometric center of the windscreen. The guy that approved it at Grumman is probably dead.

 

I mentioned early in my involvement to the HB guys that you had to stick your face close to the glare shield to see the edges of the symbology. Sitting normally, the edges were masked. The videos you see are taken by a camera much closer than the pilots eye and are deceiving.

 

We actually have it easier in the sim than in the aircraft.

[shagrat]

Certainly not, mach 0.6 at 30000ft will be about 200kts, thats well below corner speed.

Whenever you want to judge the lift capability of your wings you must use IAS. Mach and TAS are misleading at altitude.

If you say so... but to my knowledge the cornerspeed is the 0.6 M and at 30k ft that translates to 200 KIAS. At 10k ft like in the diagram it still would be 0.6 M and translates to 325 KIAS and at MSL it would likely be 350ish KIAS, but still Mach 0.6...

EDIT: the performance diagram shows the turnrate/turn diameter at a certain altitude (air temperature/pressure), not the lift factor of the wings...

Edited March 20, 2019 by shagrat

[Victory205]

Certainly not, mach 0.6 at 30000ft will be about 200kts, thats well below corner speed.

Whenever you want to judge the lift capability of your wings you must use IAS. Mach and TAS are misleading at altitude.

 

He's right. IAS is essentially Q, which is what the airframe feels for lift generation. Slightly oversimplified of course.

[Oldfox]

No, no, there was no parallax! :) It just placed the aircraft reference symbol in the geometric center of the windscreen. The guy that approved it at Grumman is probably dead.

 

I mentioned early in my involvement to the HB guys that you had to stick your face close to the glare shield to see the edges of the symbology. Sitting normally, the edges were masked. The videos you see are taken by a camera much closer than the pilots eye and are deceiving.

 

We actually have it easier in the sim than in the aircraft.

 

Omg, what a great idea :doh:

 

Well thanks for your answer!! I guess realism needs us to forget about using that shitty HUD :D

[dawgie79]

Only thing I miss on the HUD on the Tomcat is a velocity vector/flight path marker. In T/O and Landing HUD mode there's too much information since I'm already used to glance at the gauges in that thing.

[shagrat]

He's right. IAS is essentially Q, which is what the airframe feels for lift generation. Slightly oversimplified of course.

Now, I am confused. I thought Mach is taking air pressure / temperature into account? So what defines the performance? A combination of IAS at a specific altitude (remembering half a dozen "speedsettings" or Mach number?

[Delta59R]

Now, I am confused. I thought Mach is taking air pressure / temperature into account? So what defines the performance? A combination of IAS at a specific altitude (remembering half a dozen "speedsettings" or Mach number?

I think of it like mach gives you true ground speed and IAS give you true lift info

[Tirak]

A-4E-C pilots be like:

 

[A101Wayz]

I really enjoy the authenticity of the F-14. Heatblur did an amazing job at making it look and sound as if we are sitting in the cockpit of a supersonic fighter. But there are things that just can't be modeled in a sim... You can't make it feel like you're in the cockpit. You can't feel the G-Forces as you accelerate, decelerate, climb or dive. You can't feel the minute pressure changes. With that in mind, I'd be all for a user selectable option that could put a digital readout of KIAS somewhere near the HUD... Not necessarily a part of the HUD display.

[Tirak]

I really enjoy the authenticity of the F-14. Heatblur did an amazing job at making it look and sound as if we are sitting in the cockpit of a supersonic fighter. But there are things that just can't be modeled in a sim... You can't make it feel like you're in the cockpit. You can't feel the G-Forces as you accelerate, decelerate, climb or dive. You can't feel the minute pressure changes. With that in mind, I'd be all for a user selectable option that could put a digital readout of KIAS somewhere near the HUD... Not necessarily a part of the HUD display.

 

There is a game mode for most modules. Not sure about the F-14, but you could go play one of those if you'd like.

[shagrat]

I really enjoy the authenticity of the F-14. Heatblur did an amazing job at making it look and sound as if we are sitting in the cockpit of a supersonic fighter. But there are things that just can't be modeled in a sim... You can't make it feel like you're in the cockpit. You can't feel the G-Forces as you accelerate, decelerate, climb or dive. You can't feel the minute pressure changes. With that in mind, I'd be all for a user selectable option that could put a digital readout of KIAS somewhere near the HUD... Not necessarily a part of the HUD display.

There has been an option to allow/show the status in Cockpit view if I remember correct, but that is nowhere near the HUD.

[sLYFa]

Now, I am confused. I thought Mach is taking air pressure / temperature into account? So what defines the performance? A combination of IAS at a specific altitude (remembering half a dozen "speedsettings" or Mach number?

 

The speed of sound is (ideally) a function of temperature only. It decreases as you get higher where the air gets colder. Your mach number is simply telling you how fast you are relative to the current speed of sound (which changes with temperature).

The mach number is intersing for anything related to compressibilty effects, i.e. wingsweep, engine ramp and wave drag.

However, the lift/drag charecteristics of you aircraft are largely determined by your indicated airspeed. This is a fictional speed that is based on Q (i.e. the dynamic pressure density*v^2/2). That Q is the aerodynamical force acting on your wing and translates nicely into lift and drag forces regardless of pressure/temperature (of course in idealised airfol theory, which does perform reasonably well in the subsonic range). It is therefore KIAS that you want to monitor to obtain the desired lift/drag ratio.

When you get to high altitude, you will need more TAS to obtain the same IAS as you would at sea level, since the air gets thinner, and you will eventually end up in the transsonic region, where the above assumptions do not hold true anymore and compressibilty correction need to be applied. This is why corner KIAS will also vary with altitude.

[grunf]

Jester should call out the speed. When asked, he would say current speed, and continuously report every x50 and x00 kt (e.g. current speed 327kt... 350... 400...) until we ask him to stop.

[shagrat]

The speed of sound is (ideally) a function of temperature only. It decreases as you get higher where the air gets colder. Your mach number is simply telling you how fast you are relative to the current speed of sound (which changes with temperature).

The mach number is intersing for anything related to compressibilty effects, i.e. wingsweep, engine ramp and wave drag.

However, the lift/drag charecteristics of you aircraft are largely determined by your indicated airspeed. This is a fictional speed that is based on Q (i.e. the dynamic pressure density*v^2/2). That Q is the aerodynamical force acting on your wing and translates nicely into lift and drag forces regardless of pressure/temperature (of course in idealised airfol theory, which does perform reasonably well in the subsonic range). It is therefore KIAS that you want to monitor to obtain the desired lift/drag ratio.

When you get to high altitude, you will need more TAS to obtain the same IAS as you would at sea level, since the air gets thinner, and you will eventually end up in the transsonic region, where the above assumptions do not hold true anymore and compressibilty correction need to be applied. This is why corner KIAS will also vary with altitude.

Ok, did know most of that. So basically you need to know cornerspeed (performance based on altitude and KIAS), so a value of 325 KIAS@10,000 ft corrected by e.g. 5 kts for every 5,000 ft, until you get near transonic speed? Or am I still missing something?

[Exorcet]

Just FYI, the F2 view info bar with Altitude, speed, etc can be enabled in F1 view.

[fmedges]

Or maybe you can just go play ace combat...

[Top Jockey]

Or maybe you can just go play ace combat...

 

Easy... we are all Goodfellas here, see the image at the top of previous page.

[birdstrike]

i like the fact, that the f-14 is in fact mostly a plane with analoge gauges tbh...gives it character.

[Delta59R]

I took the F14 up to 35k and did mach 2.0, looked and the map speed it was at ~1150. Calculated for temp it would have to be -70F... burr, is that correct?

Edit: The above was a map temp set at -12.5c, I tested again with a map temp set at 38c and mach 2.0 at 35k was at about ~1200 map speed.

Edited March 20, 2019 by Delta59R

[sLYFa]

Ok, did know most of that. So basically you need to know cornerspeed (performance based on altitude and KIAS), so a value of 325 KIAS@10,000 ft corrected by e.g. 5 kts for every 5,000 ft, until you get near transonic speed? Or am I still missing something?

something like that.

Here are the corner speeds assuming a 5.5G limit and a figher loadout (4SW+4SP)

 

5000ft

M 0.45 260 KIAS

 

10000ft

M 0.52 290 KIAS

 

15000ft

M 0.59 295 KIAS

 

30000ft

M 1.0 340 KIAS

 

As you can see both numbers increase significantly, but especially mach number at high altitudes.

[Thor_HUN]

The original HUD:

 

 

[Victory205]

Now, I am confused. I thought Mach is taking air pressure / temperature into account? So what defines the performance? A combination of IAS at a specific altitude (remembering half a dozen "speedsettings" or Mach number?

 

Mach number is nothing more than a ratio of an object's actual dynamic pressure related to the speed of sound at a particular air density. Speed of sound varies primarily with temperature, so it really doesn't tell you precisely what you need for maneuvering per se. .7 Mach at SL is a lot more maneuvering energy than .7 Mach at 50,000 feet.

 

Go sample this, you have a simulator in your hands. Report back at the difference in G capability in those two situations.

Edited March 20, 2019 by Victory205