P51 issue

[N345SD_Bear]

~S~

I am from Joint-Ops Virtual flight school, we have held classes as far back as in CFS1 and for the last 8 or so years IL2 and have now started classes in DCS with the P51.. a plane i love flying.

As a part of the class we try to do a profile on the plane starting at 500ft and going up every 5000ft there after leveling out and gaining top speed in IAS and converting to TAS, going up to service ceiling. Well some in the class have gotten to 39,000ft+.. very good.. but some of us including myself struggle to get past 15,000ft.

Personally, i climb slow maintaining a high airspeed 250 mph + at 46mp and 2700 rpm. Around 13,000ft mp drops to about 42 till the supercharger kicks in around 16,000ft.

Thats where it dies off for me.. i immediately return the mp to 46 after supercharger engages, rad and oil temps are good the whole time, faster you go the cooler the engine is.... so there i struggle at 15,000ft and get stall speeds below 100 mph... and cant seem to get it higher... take off conditions fuel at 67% and no ammo.

 

Anyone know what were doing wrong???

:pilotfly:

 

~S~ Bear

Edited June 16, 2014 by N345SD_Bear

[Bounder]

Hi Bear, I've uploaded a short video to youtube of me climbing past the 15,000ft point and above that you can look at, maybe it will help. It's only just gone up and should be available in 720p. The video starts with me at ~6,500ft and I cut it short at ~18,000ft, a little after the supercharger comes on, for a quick upload to youtube but can upload a full length video if you are struggling.

 

I try to maintain roughly a 2000ft/min climb rate and my speed starts around 200mph IAS drops to around 160mph IAS by ~11,000ft which I maintain thereafter. Not sure if this is the proper method (e.g. best sustained rate of climb) but I climbed up ok and reached 33,000ft before the Mustang started to struggle a bit. Like you I try to maintain 46MP and 2700rpms in the climb. I didn't check the % fuel load but you can see at 7 second mark I have ~75 gallons in both left and right tanks (the video starts a couple of minutes into the flight). Both radiators are kept on automatic for the entire flight, carburettor air control to ram air and normal (i.e. not hot air). I set and constantly adjusted my trim (rudder, aileron, and elevator) throughout the climb and am pretty much flying hands off. Obviously setting trim and keeping the ball centred will help in the climb. I'd double check your settings and maybe speak to the guys in your class that are able to climb up to 36,000ft.

 

 

Bounder.

Edited June 16, 2014 by Bounder

[Art-J]

Bear, are You sure you're not trying to maintain your climb rate a bit too high all the time? There's no way a Mustang on 46 in / 2700 RPM would slow down to 100 mph unless one points it too steep in the sky. 2000 fpm or higher, suggested by Bounder, sounds good for low-to medium altitudes and You do it easily with climb engine settings and 180-200 mph indicated, but when flying waaay up there, getting slowly down to 1000 fpm will be necessary to maintain any climb whatsoever.

 

Do You use a free TF-51 or the full version? The reason I ask this is - one of the tutorial missions installed with P-51D (the crosscountry navigation one) includes getting her up to 30 000 ft. The virtual fly-through gates positioned in the sky not only show you the required course, but also give you a basic idea of maximum climb angle you can achieve at certain altitudes. I did this mission for the first time yesterday and got to 30k almost without any problems, so You should be able to do it as well.

[N345SD_Bear]

I flew this from take off with 67% fuel and with 100%.. my climb is between 500 and 1000 fpm maintaining a high airspeed, all is ok until that crucial altitude of 13,000ft or so to 15,000ft.. even after the supercharger is engaged same as in your video sir i return to 46mp.. and in level flight i cannot get above 140 to 150 mph..

I've done this over a dozen times with the same results... as in your video i cannot maintain a climb like you did and hold that speed of 170mph+

Feels like im dragging a brick behind me compared to what i see... i do have a purchased P51 that i use

[Magician]

Are you carrying bombs, rockets, or tanks?

 

I was freaking out about how the Antonov's were flying away from me in the Red Rover mission until I noticed I was carrying the friggin tanks. Changed the loadout in the ME and now I have to "put on the brakes" and do S turns so I don't overtake them so fast.

 

I also seem to have a bit of problem climbing and keeping up with the Doras when they climb away from me, but I think that is probably because I'm starting out too slow. Have to revise and devise a new method of pursuit when they do that. It just takes forever before they stop climbing and I catch up to their altitude.... then I can start closing and get a shot. But it seems so unsporting, after they finish their climb they just fly straight and level like a sitting duck. even after I start hitting them.

[Tucano_uy]

If you weren't an experienced pilot, I would say "check your gear and flaps are up" and "check the ball and stick are centered".

 

Best thing would be to share a track.

[lesnyborsuk]

I flew this from take off with 67% fuel and with 100%.. my climb is between 500 and 1000 fpm maintaining a high airspeed

 

Maybe your airspeed is just too high?

According to this http://www.bluethunderairracing.com/the-plane/specifications/ best rate of climb speed (Vy) for P51D is 170mph. This is at sea level. This speed decreases with altitude. Meaning that if your speed is above your Vy you will gain altitude slower.

 

Ie. for C152 Vy at sea level is 67 knots. But at 10000ft it is around 61 knots (if I remember correctly).

Edited June 17, 2014 by lesnyborsuk

[N345SD_Bear]

Ok... heres my deduction....from what I've seen my plane doesn't seem to have the power others do... i cannot climb with the same power settings and rate of climb others do... from approximately 12,000 ft and up my engine suffers greatly.

I have tried this numerous times with the same result, changing load-out doesn't seem to matter much... i can fly holding level flight at 15,000 ft and top speed is 150 mph max !

Yes i trim properly and rate of climb/airspeed has been good.. trying different things airspeed 250 mph + rate of climb less than 1000 fpm to 170 mph, 2000 fpm.

Nothing changes... any ideas??

 

~S~ Bear

[Art-J]

Fudged install? Or incorrectly patched to latest version? 150 mph at level flight at 46" of MAP sounds absolutely ridiculous. That shouldn't happen no matter what loadout you carry or how badly trimmed the airplane is. Something is very "off" here. I would use repair DCS option, and I that doesn't do anything good, posting a replay here of one of these failed flights might be helpful.

Edited June 17, 2014 by Art-J

[NineLine]

Ok... heres my deduction....from what I've seen my plane doesn't seem to have the power others do... i cannot climb with the same power settings and rate of climb others do... from approximately 12,000 ft and up my engine suffers greatly.

I have tried this numerous times with the same result, changing load-out doesn't seem to matter much... i can fly holding level flight at 15,000 ft and top speed is 150 mph max !

Yes i trim properly and rate of climb/airspeed has been good.. trying different things airspeed 250 mph + rate of climb less than 1000 fpm to 170 mph, 2000 fpm.

Nothing changes... any ideas??

 

~S~ Bear

 

Post a track. Someone can look and see if there is something going on.

[Sabre-TLA]

Check the weather conditions?

 

Air temp, winds, etc could have an effect on performance.

[N345SD_Bear]

Ok... how do i access the "repair option" and how do you record a track?

[N345SD_Bear]

Can i do a reinstall without loosing my plane purchase??

[NineLine]

Ok... how do i access the "repair option" and how do you record a track?

 

At the end of your flight, in the mission debrief you can click "Save Track"

[NineLine]

Also you might try using "RCtrl - Enter" - Controls indicator while in flight to make sure you are getting everything out of your controls...

[N345SD_Bear]

Ill do this flight tonight when im off work.. 2am my time, i appreciate all your help, after i have recorded the track where can i access it and how do i get it to you for review.. i lived in Surrey for 12 yrs before moving back home to Kelowna Sith..

[NineLine]

You can attach it to your message here, and someone will look at it. It will be saved in the Tracks folder in Saved Games/DCS/.

 

I was born in Kelowna :)

[N345SD_Bear]

No way ... small world eh .. i grew up in Glenmore.. folks still live there.. i graded KSS in 78... yea im old.. lol.

Ill post that track tonight sir .. and Thanks for everything your doing to help... everyone!

~S~ Bear

[Tucano_uy]

Bear, any chance are you flying with filtered air instead of ram air selected? I don't believe the decrease should be that critical but lacking better explanations...

 

Other thing, (and don't hate me, but when troubleshooting one shouldn't discard any possibility no matter how silly it may sound), when you say you climb to 13000 feet, are you actually reading from the altimeter, or any of the external views? Is it possible that you have metric units selected in options and your altitude is actually 13000 metres?

[N345SD_Bear]

!3,000 meters = 42650.9 feet.. i dont think so buddy .. lol.. ram air is selected

[Tucano_uy]

Well, I don't have any problem to maintain level flight at 37000 feet and 180-ish MPH with the default 68% fuel load. The behavior that you describe only happens to me above that altitude, around 11300 meters.

[N345SD_Bear]

how do i attach a file here?

[N345SD_Bear]

try this

https://app.box.com/s/mt4kz9eatw8eytqda7db

[Tucano_uy]

how do i attach a file here?

 

At the bottom of the page, click on "Go Advanced", there you need to click on the clip symbol to attach a file. There is a size limit for the files.

 

EDIT: I got your track now.

Edited June 18, 2014 by Tucano_uy

[Tucano_uy]

I saw your track and everything seems to be in order but indeed it seems that the plane loses steam at some point.

 

From your track:

 

It may be that you let the speed to decrease quite a lot, then the angle of attack increases, the drag increases and from there, all the way to the stall.

 

I took control of your track at about 10k feet and tried to keep the speed around 210 mph with slightly better results, focusing in maintaining the IAS rather than any rate of climb.

 

 

EDIT: I THINK I GOT IT!!! You left the mixture control on EMERGENCY:FULL RICH. It should be on the intermediate RUN position. The engine is lacking oxygen!

Edited June 18, 2014 by Tucano_uy