Mustangs

[Scorpio_L]

Whats up with these P51D Mustangs???

I haven't seen 350mph let a lone 427mph. In fact, damn thing doesn't get over 250mph level flight and 10k ft.

 

[AEthelraedUnraed]

12 minutes ago, Scorpio_L said:

Whats up with these P51D Mustangs???

I haven't seen 350mph let a lone 427mph. In fact, damn thing doesn't get over 250mph level flight and 10k ft.

I'm sure you'll find many people here eager to help you, but don't blame it on the Mustang If you cannot get it past 250mph at 10000ft, that's a human error on your side. The in-game Mustang is more than capable of going well past that.

 

Did you check RPM and mixture? Sure you don't have flaps or gear deployed?

[DD_Arthur]

TAS 

IAS

?

[Toots_LeGuerre]

I've seen 520 mph on the deck after a dive many times.

And have yet to lose inner LG doors.

[BlitzPig_EL]

Scorpio_L,  do you understand the difference between Indicated Air Speed and True Air Speed?  If you are new to flight simulations, or aviation in general this can be a difficult concept to grasp, because it doesn't work like a speedometer on a land vehicle.  Google is your friend here.  Look it up.  The Mustang is one of the fastest aircraft in the sim.  Earlier this afternoon I was online with my friends and I was well below 8000 ft, in a P51D with 150 octane fuel, and bomb racks on.  I was at 2500rpm, running 54 inches of boost, which is just at the top of "continuous" engine mode, and I was indicating 325mph and was still slightly accelerating before I had to set up for landing. 

[ShamrockOneFive]

As others have said... you're seeing the difference between true and indicated airspeed.

 

There are multiple examples of what it is and how to calculate it here:

https://www.boldmethod.com/learn-to-fly/aerodynamics/why-true-airspeed-increases-with-altitude/

[Jaegermeister]

4 hours ago, Scorpio_L said:

Whats up with these P51D Mustangs???

I haven't seen 350mph let a lone 427mph. In fact, damn thing doesn't get over 250mph level flight and 10k ft.

 

 

I have trouble staying in formation between 3,000 and 10,000 feet and 240 mph IAS in the Mustang without reducing throttle and RPM below standard cruise settings of 2700 rpm @ 46" MP.

 

With the same cruise settings, I was seeing speed in excess of 400 mph IAS in a dive as would be the case on a bomb or strafing run

 

 

Just so you can see I didn't rip the wings off or something,,, still over 400 IAS

 

 

 

Edited March 28, 2022 by Jaegermeister

[AEthelraedUnraed]

I'm not so sure the issue is IAS/TAS conversion. The way I read it (...doesn't get over 250mph level flight and 10k ft) is the speed doesn't get above 250mph at any altitude and the altitude doesn't get above 10k ft. Even if the OP means "250mph level flight at 10k ft", this is 300mph-ish TAS, still much lower than the mustang is capable of. 

 

Anyhow, whatever the problem here is, it's not with the mustang

[Jaegermeister]

Just for grins I had to see what speed the Mustang does at 10,000 feet at normal combat power (15 minute max) in level flight... 

 

 

The answer is roughly 340 to 350 mph IAS. That was April on the Rheinland map with 50% fuel. I will let those who care to do the math convert that to true airspeed with the chart Shamrock was so kind to link. 

 

Perhaps @Scorpio_L does not have prop RPM adjusted correctly?

 

 

 

Edited March 28, 2022 by Jaegermeister

[357th_KW]

As a rule of thumb you can use 2% per 1000ft.  So at 10,000ft you would multiply IAS by 1.2, which gives about 410mph in the example above. 

[69th_Mobile_BBQ]

On 3/27/2022 at 10:15 PM, Jaegermeister said:

Just for grins I had to see what speed the Mustang does at 10,000 feet at normal combat power (15 minute max) in level flight... 

 

 

The answer is roughly 340 to 350 mph IAS. That was April on the Rheinland map with 50% fuel. I will let those who care to do the math convert that to true airspeed with the chart Shamrock was so kind to link. 

 

Perhaps @Scorpio_L does not have prop RPM adjusted correctly?

 

 

 

 

Is all that side slip (with the 'ball' far to the left like that) just a momentary thing or are you flying it like that all the time?

 

 

One thing that is spot-on with this video is that the Mustang requires alot of attention to trimming the plane properly.  Notice how he also explains that when not doing 'direct' maneuvers, prioritizing trimming over stick input is essential.   

I've found another video that shows GoPro in-cockpit footage with pilot explanations of settings.  The settings he calls for are a good bit lower than the in-game but, there are things unknown such as whether or not the motor is original or a modern re-creation, what variant of the "D" is being flown (we have the D-15, his might be a later model) and what the fuel load / takeoff weight is - as it's probably much lighter than if it was combat-loaded.  

 

[Rjel]

As mentioned, trimming out the P-51 is essential to fly and shoot properly. I put my rudder and elevator trim tab controls on my hat switch. It’s made flying the Mustang a breeze. With enough altitude, the elevator tabs will pull the nose of the Mustang out of near terminal velocity dive without shedding a wing or elevator. 

[Jaegermeister]

5 hours ago, 69th_Mobile_BBQ said:

 

Is all that side slip (with the 'ball' far to the left like that) just a momentary thing or are you flying it like that all the time?

 

I jumped in a QMB mission and obviously forgot to trim the rudder.... Thanks for the link to the videos though. 

 

You guys are right, I probably could have gotten a bit more speed out of it if it was trimmed properly,

 

[Youtch]

7 hours ago, 69th_Mobile_BBQ said:

One thing that is spot-on with this video is that the Mustang requires alot of attention to trimming the plane properly.  Notice how he also explains that when not doing 'direct' maneuvers, prioritizing trimming over stick input is essential.   

Very interesting video. Thanks for sharing.

[Art-J]

11 hours ago, 69th_Mobile_BBQ said:

I've found another video that shows GoPro in-cockpit footage with pilot explanations of settings.  The settings he calls for are a good bit lower than the in-game but, there are things unknown such as whether or not the motor is original or a modern re-creation, what variant of the "D" is being flown (we have the D-15, his might be a later model) and what the fuel load / takeoff weight is - as it's probably much lighter than if it was combat-loaded.  

 

Kermit Weeks is rich enough to own and fly numerous originals :D. Although to be honest all flying warbirds nowadays have more percentage of modern material than original in them anyway. They wouldn't have been signed off as airworthy otherwise.

 

There's nothing unusual in his power and trim settings - they're according to wartime manuals. One has to remember that warbird owners nowadays pretty much never go above max continuous power settings to extend precious engines life for as long as possible (Reno racers are the only exception for obvious reasons). He also has to comply with legal limits while VFR flying above his property (max 10 000 ft and 250 kts), so there's no place for higher power either.

 

The plane is block -30, other info here:

http://www.warbirdregistry.org/p51registry/p51-4511507.html

 

It certainly is lighter than wartime standards, with rear tank, original radios and navaids removed (armament too, presumably), piggyback seat inserted - usual config for restored Mustangs.

Edited March 29, 2022 by Art-J

[Hoss]

On 3/27/2022 at 2:26 PM, Scorpio_L said:

Whats up with these P51D Mustangs???

I haven't seen 350mph let a lone 427mph. In fact, damn thing doesn't get over 250mph level flight and 10k ft.

 

 

Is that TAS, or IAS? It's pretty much the same in the "Other Sim". Take it off automatic and see if you can make it go faster. 

 

Cheers!

[Livai]

• the thinner the air in other words the higher the plane flies, the faster it has to move through the air to receive the required lift (greater TAS).

The Mustang need to fly faster to keep flying. How fast depends on engine efficiency the higher you fly...........

[DD_Arthur]

22 hours ago, Livai said:

• the thinner the air in other words the higher the plane flies, the faster it has to move through the air to receive the required lift (greater TAS).

The Mustang need to fly faster to keep flying. How fast depends on engine efficiency the higher you fly...........

 

Wut!??

[Asgar]

22 hours ago, Livai said:

• the thinner the air in other words the higher the plane flies, the faster it has to move through the air to receive the required lift (greater TAS).

The Mustang need to fly faster to keep flying. How fast depends on engine efficiency the higher you fly...........

No

[BlitzPig_EL]

Wow, just wow.

 

The higher you go the the less accurate the ASI becomes because of the lower air pressure in the pitot tube system which powers the air speed indicator in the cockpit.  Barometric pressure also affects the altimeter, which is why you adjust your altimeter to the pressure at the field you are landing at.

 

Then there is pitot tube position error, which is a whole different can of worms.

Edited March 31, 2022 by BlitzPig_EL

[fogpipe]

Closing the oil rad will give you an extra 10 or so kph on the deck according to a youtube video i watched.

On 3/29/2022 at 2:51 AM, 69th_Mobile_BBQ said:

 

 

 

Il2 has taught me that cockpit glass is scratched, spotted, smudged and reflective enough to impair visibility, is this real?

Edited March 31, 2022 by fogpipe

[Livai]

4 hours ago, Asgar said:

No

 

Technically, yes, if the Mustang flies higher than the altitude it was designed, it will be difficult to keep the plane in the air.

 

[Asgar]

3 minutes ago, Livai said:

 

Technically, yes, if the Mustang flies higher than the altitude it was designed, it will be difficult to keep the plane in the air.

 

No, he says how fast you have to fly depends on engine efficiency... but how fast you have to be depends on AoA and aerodynamics of the plane  

Edited March 31, 2022 by Asgar

[Livai]

On 3/31/2022 at 7:41 PM, Asgar said:

No, he says how fast you have to fly depends on engine efficiency... but how fast you have to be depends on AoA and aerodynamics of the plane  

 

-> increasing airspeed or increasing AoA

 

Luckily are our planes so clean smooth that we don't need to worry about aerodynamics.  Already some couple of insects brings the aerodynamics out of balance same as every little unevennesses in the surface.

 

[Cpt_Siddy]

awww, new people are so adorable :D 

[Avimimus]

On 3/31/2022 at 1:39 PM, Livai said:

Technically, yes, if the Mustang flies higher than the altitude it was designed, it will be difficult to keep the plane in the air.

 

Generally, also, the ability to sustain an angle-of-attack without entering a high-speed stall / tip-stall decreases at higher altitudes. Almost all aircraft can turn less sharply but also fly faster.

 

Interestingly, the British V bombers with their huge wings could safely out-turn Soviet Interceptors at high-altitudes when they were introduced and there was a 'gap' of several years where they were basically uninterceptable as a result.

 

The original Il-2 (Il-2 1946) now has its flight model fixed at high altitudes - so I'd recommend trying out the Ta-152H against the B-29 etc. It is a different experience!

 

4 hours ago, Cpt_Siddy said:

awww, new people are so adorable ?

 

I still remember looking at the airspeed numbers in the original Il-2 when I was ~14 years old and thinking 'that can't be right'?

 

There is a big transition from learning a single number from a book and understanding what real world performance is like - and the fact that top speeds happen at different altitudes for different aircraft etc. Or what the real ranges are for air-to-air missiles (dependent on launch speed, atmospheric density, seeker constraints and atmospheric impacts on the seeker etc.)

Edited April 8, 2022 by Avimimus