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domm

DC8 Operations

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DC8 Operations

Two remarks: The reverses work without the pneumatic pressure (pressure manifold indicator zero psi) , which is abnormal.

:D

When starting­­: The fuel flow debits with the fuel valve on off, when the starter  is actuated ??? :wacko:

page 54 Auxiliary start. I read:

"Auxiliary starts used compressed air from a main gear oleo. This system was found to cause corrosion in the strut and the system was removed from all DC-8s"

This is true, but the DC8F,  and some 50/55 passenger version was equipped with 2 high pressure air bottle installed in the right wheel well, air  ducted to a small combustor attached to the #3 eng., ( Methanol  reserve in #3 pylon) So this auxiliary function was operative.

 In the conbustor kerosene was mixed with the air and ignited. The exhaust gasses were then supplied to the #3 Eng starter to turn it & fire up #3 engine.

Once again this was a last ditch arrangement for when there wasn't an air start truck was available

It was intended to be used at remote airports with few facilities and was used only to get one engine started on the ground. Once one engine was running there was electrical power and cross-bleed air to start the remaining engines.

On some aircraft there was also an air compressor to inflate the air bottles

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19 hours ago, domm said:

The reverses work without the pneumatic pressure (pressure manifold indicator zero psi) , which is abnormal.

 

The reversers are actuated by bleed air directly from the engine and not from the pneumatic manifold.  Manifold air does operate the emergency thrust brake retractor system, but this is not modeled. 

 

19 hours ago, domm said:

When starting­­: The fuel flow debits with the fuel valve on off, when the starter  is actuated ???

 

This is not a behaviour that I coded. It appears to be simply how the FSX starter system works.  I could inhibit the movement of the fuel flow gauges (it's on my list) until the fuel is turned on, but fuel will still be consumed. 

 

19 hours ago, domm said:

This is true, but the DC8F,  and some 50/55 passenger version was equipped with 2 high pressure air bottle installed in the right wheel well, air  ducted to a small combustor attached to the #3 eng., ( Methanol  reserve in #3 pylon) So this auxiliary function was operative.

 

An auxiliary start system may have been implemented on some aircraft, but I have no information available to simulate it.  My manuals only describe the original system that was taken out of all DC-8s.

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6 hours ago, Michael2 said:

 

The reversers are actuated by bleed air directly from the engine and not from the pneumatic manifold.  Manifold air does operate the emergency thrust brake retractor system, but this is not modeled. 

 

 

On your DC-8 reverser work even with the engines stopped, (OFF..not running)  and this is False.   You can try... And anyway, as soon as a motor runs there is pneumatic pressure indicated on the  pressure manifold indicator.

I am retired pilot, and I started my career on DC-8 in the French Air Force, and after at UTA. DC-8 50/55F/70serie So I know this aircraft very well. ( From the moment my memory is still good)
And all the DC-8 series, 50F in  the French Air Force and the all F versions from UTA, had the auxiliary star  on the #3 engine by combustor.

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4 hours ago, domm said:

On your DC-8 reverser work even with the engines stopped, (OFF..not running)  and this is False.   You can try... And anyway, as soon as a motor runs there is pneumatic pressure indicated on the  pressure manifold indicator.

 

 

I am retired pilot, and I started my career on DC-8 in the French Air Force, and after at UTA. DC-8 50/55F/70serie So I know this aircraft very well. ( From the moment my memory is still good)
And all the DC-8 series, 50F in  the French Air Force and the all F versions from UTA, had the auxiliary star  on the #3 engine by combustor.

 

I agree that the reversers should not move when the engines are off. I overlooked this and will correct it when the cargo version is released. 

 

I'm happy to have the benefit of your experience if you wish to help improve the aircraft.  I can show some pressure in the manifold even with the switches off after an engine start, but I need to know how much.  You can send me a personal message if you wish. 

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3 hours ago, Michael2 said:

I'm happy to have the benefit of your experience if you wish to help improve the aircraft.  I can show some pressure in the manifold even with the switches off after an engine start, but I need to know how much.  You can send me a personal message if you wish. 

Hi,
I will tell you my opinion. The cockpit is perfectly represented, well done, and that brings me back 50 years. So your plane is fine, even with this problem of textures.:cheers_s:

My pleasure is to learn flying aircraft to young people around me.

I finished my career on 767-300 at Air France

.As soon as I have time I will try this DC 8, and inform you about possible problems. If ever, I can remember. I do not have any more documentation and I have thrown away a few years ago the Operations Manual and the checklists and procedures.

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Hello Michael2

First quick test

First off all...Fuel management.

It's a pity because: The DC-8 had the most advanced fuel management system, in the 50s, and you could run an engine from any source 

Crossfeed not simulated, so all fuel fill valves sw are useless

The crossfeed does not work, as well as engine fire shut-off

transfer fuel from one tank to another impossible.

Fuel in tank Alt 3 =0 and boost pump Alt 3 ON we have 15 psi ?? (see attached jipg)

Fuel in tank Alt 2 =0 and boost pump Alt 2 ON we have 0 psi that is OK

 

Do you send information by personal message?
Have you noticed that I'm at -8 in red, so a bad one  (
and I do n't care about that) .

I'd love to help you, but why should I help Aerosoft, who does not even bother to answer me? So if you do not mind, I'll give my comments through the forum.
Good Day  to You
regards

Fuel_1.jpg

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On 11/11/2018 at 6:02 AM, domm said:

Crossfeed not simulated, so all fuel fill valves sw are useless

 

It's correct that crossfeeds are not simulated. The focus of the simulation is on normal operations -- failures are not simulated. You are unlikely to need the crossfeeds except in response to a failure.  Secondly, in FSX, the VC has reached as many mouse click spots as can be added without causing graphics corruption.  I could add crossfeeds in P3D v.4x, but not in FSX.  Fuel transfers from the centre tanks and between alt and main tanks are simulated and thus the fuel fill valve switches are not "useless".  A former DC-8 flight engineer participated in beta testing and pronounced the fuel panel "fully functional" except for crossfeeding.

 

There should not of course be any fuel pressure for engine three in your screenshot and I thank you for pointing out the error.  This will be corrected in the next release. 

 

You can pass information by PM or in the forum as you wish -- it makes no difference to me. 

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9 hours ago, Michael2 said:

 

 Fuel transfers from the centre tanks and between alt and main tanks are simulated and thus the fuel fill valve switches are not "useless".  A former DC-8 flight engineer participated in beta testing and pronounced the fuel panel "fully functional" except for crossfeeding.

 

 

You are unlikely to need the crossfeeds except in response to a failure.

Not only, in the real aircraft if you want to make a Run-up operating an engine from other than its own system,  or a long flight on 3 engines, you must need, the crossfeed in crossfeed position.

Your flight engine who participated in the beta test, is a funny man.

**************************************

NO the fuel panel is not "fully functional"

The crossfeeding is ESSENTIALl to operate, for example, 3 engines with one inoperative engine, and to use the unused fuel of the tank corresponding to this engine.

I already ended up finishing a flight on 3 engines, and for that we need crossfeed and fill valve

 

If the operation of the cross feed is not simulated, then the fill valve is useless.


The ramp below the fill valve switches is the manifold, which is pressurized only during refueling and transfer from tank to tank.


Try to make a transfer, and give me the result.

 

I tried the operation superficially, what you need to know is that not much is simulated.
for example the pneumatic crossfeed.

Takeoff warning should be with # 1 and #3, not just on the #1

Run-up on engine 3 with zero fuel in the main 3..see jpg

 

But this your DC-8 has no faults, so everything is good

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Run-up #3.jpg

Fuel_2.jpg

Fuel_3.jpg

Fuel_4.jpg

Fuel from Aux.jpg

Fuel_1b.jpg

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Understand You are a retired DC-8 Frighter pilot with lot of experience....But try to understand that focus of the simulation is on normal operation with no failures and that includes NOT 3-eng flight or crossfeeed operation..

DC-8 system is very complex and the best solution must be a syntetic F/E for relief..........

There is 15 PSI from all tanks with fuel zero (panel.gif) and the reversers open with engines on but remember this flightsim and not real aircraft so the best is to operate it the normal way and have fun flying this fine Aircraft ..I myself flies the Scanair DC-8 on short legs in Northern EU max 2 HRS flight time....

"Your flight engine who participated in the beta test, is a funny man" is no good english but is very "funny" to read..... thanks... looking forward next post

 

panel.gif

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2 hours ago, domm said:

The crossfeeding is ESSENTIALl to operate, for example, 3 engines with one inoperative engine

 

Flight with an inoperative engine is not a part  of "normal operations" as AAC47 has stated above. 

 

The examples you give where crossfeeding is needed all involve failures (which will not happen in the simulation) with the one exception of running only a single engine for a significant time after starting.  To avoid the need for subsequent crossfeeding -- don't do that. 

 

I have also already stated that in FSX there is a limit to how many controls can be animated. They can't all be simulated.  

 

2 hours ago, domm said:

But this your DC-8 has no faults, so everything is good

 

I believe you know I have never made such a statement.  I agreed with you that the reversers should not be animated when the engine doesn't run, that there should not be fuel pressure on empty tanks and that I should inhibit movement of the fuel fuel gauges during startup before the fuel is turned on and that I would correct these behaviours.  So what exactly is your problem? 

 

 

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1 hour ago, AAC47 said:

"Your flight engine who participated in the beta test, is a funny man" is no good english but is very "funny" to read..... thanks... looking forward next post

 

 

Thank you for your comment.  (Frighter and pax for DC-8, pax only for DC'10, and 767)

Sorry for my English, it's not my language, I speak better than I write it,
on the other hand I speak 4 languages, but all with a problem for writing.
(except for French)

And you???


I know I wanted this DC-8 at Aerosoft store, to bring me 50 years back. and I understand that it's only for fun.

And I understand that focus of the simulation for this DC-8 is on no failures.

To have something very close to reality, with failures possible, you have to pay more and go to PMDG>>>Random failures, programmed failures, and the best..... Service based failures, that is based to mechanical reliability that closely approximates the mechanical reliability of the airplane in normal service operation

I'm going to stop criticizing this DC-8, but if the developer wants info, then by PM, I would certainly answer him.

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14 minutes ago, Michael2 said:

So what exactly is your problem?  

 

 

I have no problem, I was wrong, I thought I had something closer to reality, that's all.
But I will stop there.

the flight compartment is perfect.

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Domm, you are more than welcome to bring to my attention things that are not simulated correctly if you choose to do so. I am working right now to correct the items you have noted (aside from crossfeeding). I just don't want or need the sarcasm or personal remarks.

 

But bear in mind that there are some systems or parts of systems that cannot be simulated due to limitations in FSX and also the amount of time I can reasonably put into the product. I have already gone way past the amount of work than could be justified from a purely commercial point of view.  PMDG for the most part only simulates modern aircraft that appeal to a much bigger market. I would think at least ten times as big, maybe a lot more. They can afford to put many more hours into their products.  A DC-8, no matter how well done, will never produce enough revenue to justify the labour that goes into a PMDG aircraft.  I am sure their DC-6 is excellent, but it was essentially subsidized by their other products or made as an investment in learning to make content for X-Plane.

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Michael, If I can tell you some things about the DC-8, I'll do it with pleasure.  (Post in PM)

Best Regards

Domm

 

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Merci Domm,

 

Je parle un peu de français, mais pas beaucoup, et pas bien.  Mes enfants vont à l'école en français mais ils refusent de le parler chez nous, donc je n'ai pas l'occasion de l'utiliser.

 

I think I am breaking the forum rules now, so I will revert to English. I have corrected the fuel pressure, reverser and fuel flow during start issues and these fixes will be included in with the cargo version free upgrade, which is almost complete. 

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Can You send a picture of F/E panel for -70 series.  Cabin Compressors...? APU....? Can You describe main difference to erlier versions...?

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8 hours ago, AAC47 said:

Can You send a picture of F/E panel for -70 series.  Cabin Compressors...? APU....? Can You describe main difference to erlier versions...?

I do not have a photo of F/E  panel, just one from Airliner

I never flew on DC-8 series 70, but on DC-8 55 in air force and UTA  62 at UTA and I went directly to DC-10.
The 2 70 was in the French Air Force.
1 APU in the front cargo. 2 packs adn not freon compressors, and like the 62 that 8 fuel tanks
. That it, for me..sorry

fe-panel.jpg

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3 hours ago, Michael2 said:

Also connected the take off warning to throttle #3 as well as #1.

:excellenttext_s:

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Thanks for the picture of DC-8-70 panel ....It is almost similar to -62 and -63 panels.......

Question: Was the Cab. Compressors OFF or ON in T/O in the DC-8 you flew........In -60/-62  they were OFF and was started when airborne.........

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On 11/16/2018 at 4:23 PM, AAC47 said:

Thanks for the picture of DC-8-70 panel ....It is almost similar to -62 and -63 panels.......

Question: Was the Cab. Compressors OFF or ON in T/O in the DC-8 you flew........In -60/-62  they were OFF and was started when airborne.........

All cabin conpressor 50/60 series Off for takeoff and landing,

" maxi of two cab compressors on at max or reduced takeoff power

  it depends on the length, and the altitude of the runway, and the outside temperature"

BUT: Normal procedure=T/C off for takeoff and before landing

At 400/500 feet of obstacle clearance altitude, whichever is higher, the first T/C ON the second at 1000 feet

After climb sw on remaining two TC's

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