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Bert Pieke

First impressions

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1 hour ago, onduty said:

1. AndiKunzi wrote " Fuel flow on an injected engine is just not changing with altitude". It is not correct, normaly aspirated, fuel injected engines do require leaning with altitude! 

Hello Tamas,

as already described:
On normally aspirated, injected engines you set climb power for MP, RPM and FF, then you have to advance throttle with altitude to keep climb MP. You won't need to adjust the mixture. This is done by the fuel metering unit. MP is adjusted each 1,000 ft to maintain the same until reaching about 8000 ft or. Fuel flow is remaining the same. Even on power falling to less than climb power with throttle wide open after passing 8,000 ft, the mixture will stay fairly correct on normally aspirated, injected engines.

May be you are refering to carburetor engines. That is a different story not covered here. (At MSL, well at the rich side, anyhow; leaning in climb and for take-off at high density altitudes.)

If you have any other opinion, please let us know the type of aircraft you are refering to and the page of the POH / AFM. I can confirm that you are wrong for the normally aspirated versions of the Piper Arrow, Cessna 210 and Cessna 310 (and I‘m pretty sure also for the TB10 and Piper Cherokee Six, IIRC). According to the AFM / POH of all those aircraft, you don't lean in climb once you have set climb power (which, as already mentioned, requires to touch all 3 / 6 controls). You do lean for cruise again once having reached cruise altitude. You may lean in climb above 10,000 ft when power is less then 70 % and CHTs are OK, but that is not referrd to as climb power anymore. 

Edited by AndiKunzi
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3 hours ago, onduty said:

But, with some "miracle" some developers could solve these "inherent problems" and provide us with accurate engine behaviour and physics: A2A C-182, PMDG j41,

Majestic Q400 and the good old DA Piper Cheyenne and with some limitations the F1 B200. That's why I'm reluctant and highly sceptical  to accept the theory of FSX/P3D inherent/unavoidable coding problems emphasized by some developers.

They accomplish this by not using the engine simulation that is part of FSX/P3D and instead using their own simulation and feed the result back into the flight simulator. This has benefits (a better simulation of the engine) and drawbacks (it is not in the sim, and therefore causes problems or extra work when interfacing with other software pieces, e.g. external avionics, that only know how to interact with the sim).

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Dear Andi,

Interesting discussion. I am affraid that we are speaking of two different things. Here is an extarct from a Beech B58 FOM (IO-550-C) normally aspirated engine, normal procedures:

 "MANUALLY LEAN TO THE FOLLOWING FUEL FLOW SCHEDULE

            FUEL FLOW SCHEDULE

  FULL THROTTLE AND 2700 RPM

          SL                 26.6 GPH

        2000                25.9 GPH

        4000                24.3 GPH

       8000                 21.8 GPH

     14000                 19.1 GPH"

You may notice that these values are for FULL THROTTLE (which you will obtain very soon during climb) and than the FF will DECREASE as you are leaning/climbing and definately not constant.

With a turborcharged engine you can forget those mixture levers until you reach critical altitude. (About FL200 in a C421 if my memory serves me well, it was about 25 years ago when I had the

opportunity to fly her).

All in all, I think this discussion leads us far away from this topic, but the problem remains: the engine behaviour of the Alabeo 421 is far from RW and we still badly need a good piston twin simulation.

Cheers,

Tamas

 

 

 

        

 

 

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Tamas Kovacsics

 

"Fun and satisfaction both in real world and sim aviation"

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Hello Tamas,

the Baron G58 is using full throttle climb - usually, you do reduce MP for climb power.

To maintain the fuel flow schedule with altitude, the POH says „maintain fuel flow at cyan marker“. That does not mean that you‘ll have to lean with altitude. If you have to lean or to enrichen the mixture or have to do nothing is a question of the set-up of the fuel metering unit.

All injected aircraft engines I am aware of do have a fuel metering unit. Input is manifold pressure and mixture position. Metered fuel flow is about proprtional to manifold pressure. This is necessary to obtain FAA or EASA certification. Otherwise, if advancing throttle out of recommended lean mixture in cruise and fuel flow would stay the same, the engine would lose power and finally quit. Or if you would go to idle on approach the engine would be flooded and quit. Mixtures are full rich on landing. Even carburetor engines do adjust fuel flow with manifold pressure, but do not fully compensate for MP.

In the example of the G58 using full throttle climb, at 10,000 ft you do have 70 % of the full throttle manifold pressure compared to MSL. Thus, the fuel metering unit of the IO-550 will reduce fuel flow from 26.6 GPH to roughly about 19 GPH. The characteristics can be adjusted. Ask an IA or mechanic. Thus, it is not clear if you have to lean to stay within the fuel flow schedule or you would have to enrichen. I haven‘t flown the G58, but I guess you basically don‘t need to touch the mixtures in climb at all, at least not in the way of significantly leaning each 2000 ft. For carburetor engines though, that is necessary.

Edited by AndiKunzi

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8 hours ago, RobertBernardK said:

Hi AndiKunzi, its great to have a real point of view about the golden eagle, from  a real pilot like me and some here, 

Do you can apply in the 421C those modifications that you have done in the 404, and share with us ?? At least the behavior on the same engine in the 404 will be in the 421, and that can get better the plane ! 

 

Thanks in advance

Robert Bernard

Hi Robert,

I‘m thinking about that. I‘d like to help the community.

On the other hand, there are professional simulators for piston twins based on FSX - and flight schools using them might be interested either.

The asymmetric thrust with a windmilling prop on a powerful twin is an eye opener.

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Just now, AndiKunzi said:

Hi Robert,

I‘m thinking about that. I‘d like to help the community.

On the other hand, there are professional simulators for piston twins based on FSX - and flight schools using them might be interested either.

The asymmetric thrust with a windmilling prop on a powerful twin is an eye opener.

Thanks for your response, so we count on you, for some help, some modification, some trick, to make this wonderful plane in a more powerful plataform of Cessna for training and fun purpose, 

So far Alabeo have a stable and well finished plataform, for me, best Cessna twin for FS. 

Redgards

Robert Bernard 

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Since the .air file is protected by copyright, I‘d only be able to provide the modified tables for download and each user would have to copy those tables in the .air file using one of the available tools for modifications of .air files.

For the aircraft.cfg, that‘s more easy.

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22 minutes ago, AndiKunzi said:

Since the .air file is protected by copyright, I‘d only be able to provide the modified tables for download and each user would have to copy those tables in the .air file using one of the available tools for modifications of .air files.

For the aircraft.cfg, that‘s more easy.

You can ask Carenado/Alabeo if they will allow you to distribute an updated airfile when you've got it done.. In the past they have allowed this, or even taken over the distribution task as an optional patch.


Bert

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Hi AndiKunzi,

Being a C421 owner, would you be so kind to validate this soundset, specifically the sound inside the cockpit?
https://secure.simmarket.com/arezone-soundstudios-cessna-421c-golden-eagle-iii-hq-soundset-fsx-p3d.phtml

Thanks in advance 😊

Egbert Drenth

 


Location: Vleuten, The Netherlands, 15.7dme EHAM
System: P3D V4 - 80386 DX2 - 4MB RAM - 3dfx Voodoo5 - Windows 3.11

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Hello Egbert,

I am no sound expert at all. The sounds seem to be a good shot. During take-off and landing I do wear headsets for improved communications wit ATC. I pay attention to engine and system noises, that's why I can't tell you too much about the wind noises.

What I can tell you: engine sound levels decrease significantly when reducing to climb power and wind noise is also much lower once the cabin gets pressurized to 1.0 psi and above.

The Cessna 421C is the least noisy propeller aircraft in general aviation due to the reduction gear and its solid 5.0 psi cabin.

 

Edited by AndiKunzi

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9 hours ago, AndiKunzi said:

Since the .air file is protected by copyright, I‘d only be able to provide the modified tables for download and each user would have to copy those tables in the .air file using one of the available tools for modifications of .air files.

For the aircraft.cfg, that‘s more easy.

You can bring here the values or tables for the .air, and the mod for the aircraft, its easy too, 

Either way, 

Best redgars and thanks for you help !!!! Long live Golden Eagle

Robert Bernard

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10 hours ago, Egbert Drenth said:

I have been burned a bit by sound sets for the C337: The Oovee sound set was far too quiet and sometimes the engine sound stops, but I got a refund for it, so no big deal. The ArezOne sound set had the problem the at the front and rear engine sounds came from the left and right side. But some of the other sounds were quite nice so I mixed and matched them with the original Carenado sounds to get something I really like.

But I'm interested in opinions on the C421C sound set, too.

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14 minutes ago, ThomasAH said:

I have been burned a bit by sound sets for the C337: The Oovee sound set was far too quiet and sometimes the engine sound stops, but I got a refund for it, so no big deal. The ArezOne sound set had the problem the at the front and rear engine sounds came from the left and right side. But some of the other sounds were quite nice so I mixed and matched them with the original Carenado sounds to get something I really like.

But I'm interested in opinions on the C421C sound set, too.

Me also. I really loved Digital Aviation's approach with their Cheyenne. They had two soundsets: 1) no headset and 2) ANR headset. ANR sound sets are just more realistic in my opinion. So, I'd like to find an alternative sound set or modify the current sounds to model ANR.

If anyone finds one or modifies their own, please let us know. 

🙂

Edited by rightseat

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Hi Andi,

I really appreciate and accept your educated answers I still have some doubts/ arguments but I do not want to strech the limits of this forum.

Just one small and final, (I promise guys!) addition. Here is a part from the B58 POH, systems description:

"On serials TH-1472 thru TH-1840, not in compliance with Raytheon

Aircraft S.B. 28-3052, the IO-550-C engines are

equipped with altitude compensating engine driven fuel pumps.

These pumps automatically lean or enrich engine fuel mixture

as the airplane changes altitudes. Leaner engine mixtures can

be set by pulling the mixture levers aft from the full rich position

while maintaining the EGT within limits.

On serials TH-1841 and After, and prior airplanes in compliance

with Raytheon Aircraft S.B. 28-3052, the IO-550-C engines are

equipped with engine driven fuel pumps that require manual

leaning."

Therefore, I think that this automatic feature is specific to certain fuel injection systems on selected airframes.

Andi, you raised my interest again in the Alabeo C421 with a  modified air or cfg file whatever it is in FSX. I envy your computer skills!

It would be great to see a roughly correct engine behaviour (FF,EGT, RPM,MP relationship.)

By that, this would be a completely new product. So, I will follow this forum closely for developments... and hope.

In the meantime, Alabeo came out with V1.1 which at least features an independently working FD system.

All the best,

 

Tamas


Tamas Kovacsics

 

"Fun and satisfaction both in real world and sim aviation"

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