Confusion Over Cargo Weight Of DC-4s. C-54s, and Carvairs

[Aharon]

Shalom and greetings all my pals,

I am totally perplexed by pound weight of cargo load of DC-4s and Carvairs in both freeware CalClassics and payware Flight Replicas model bases.

According to real world Buffalo Airways website, their DC-4 can carry 20,000 pounds of cargo load.

In the payware model base, I tried to take off using both DC-4 and Carvair with 50 percent fuel load using full cargo load of 9,500 lbs as seen on this figure below which failed to climb after shaky take off and crashed on ground.

max_number_of_stations = 6
station_load.0 = 950, 10, 0, 1
station_load.1 = 2500, 2, 0, 1
station_load.2 = 2500, 1, 0, 1
station_load.3 = 2500, -2, 0, 1
station_load.4 = 1000, 5, 0, -1
station_load.5 = 1000, -10, 0, -1

I was forced to slash cargo load by half from 9500 lbs to 4750 lbs and reduce fuel load from 50 percent to 40 percent which barely got my payware plane into air, climbed very very slowly, and cruised at too slow speed 160 kt.

By contrast, for years years years I have NO problem flying CalClassics DC-4s and C-54s cruising at 200 kt using 8,200 lbs of cargo load and 50 percent fuel load as seen on the cargo load data beloe

max_number_of_stations=2 ;loaded symmetrically v CoG
station_load.0=800,0,0,0 ;4 crew + bags
station_load.1=7400,0,0,0 ;max cargo payload with max fuel
station_load.2=800,0,0,0 ; cargo


My questions are: why are both freeware and payware DC-4s/C-54s as well as payware Carvairs have top cargo load of 9,500 lbs for payware addon and 8,200 lbs for freeware add on when the real world Buffalo Airways say their DC-4 can carry 20,000 lbs in full cargo load?https://storage.proboards.com/forum/images/smiley/huh.png? And why are DC-4s/C-54s/Carvairs in the payware model base cannot go above 160 kt in speed when in real life the maximum should be 220 kts and cruising should be 190 kt?https://storage.proboards.com/forum/images/smiley/huh.png??

And why do CalClassics DC-4s have normal climb while the payware counterpart has painful slow climb??

Am I doing something wrong??

By the way, Carvairs in real life can carry 19,000 lbs of cargo load yet I could not climb with 9,000 lbs of cargo load which is set as maximum cargo load for payware add on!!

Regards,

Aharon

[Mike71]

Are you using FSX or P3D version?? My P3D4 version has an ASI calibrated in mph vice KIAS. That is a 15% difference in what you use if flying KIAS (which I always prefer). Example: 140 KIAS is about 160 mph indicated

C-54 and DC-4 production airplanes have weight and engine combinations that are all over the map. In addition there are many approved mods throughout their life, and military specs were higher than authorized by FAA certification in many cases.


You likely know that cargo capacity is governed by max ZFW minus empty operating weight. The specifics in the FAA cert are a little obscure in their data - ZFW was not a very concrete parameter in the days that these planes were designed.

If you REALLY want to get tired of reading, look at the FAA certification data "AIRCRAFT SPECIFICATION NO. A-762" -at the back is information pertinent to all models. You can find it here: https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/MainFrame?OpenFrameset

This will give you some insight. I think the FR model is roughly based on the C-54B - they are not very specific.


Of course this does not answer your question regarding the performance in your sim - that is a different matter.

[nagpaw]

Hi, Aharon! Can you give us some more information? Specifically, we'd need...

1) What was the aircraft's takeoff weight in each situation?

2) What takeoff flap setting did you use?

3) What takeoff, METO, and climb power settings did you use in each aircraft?

When an operator like Buffalo talks about their aircraft's "maximum payload," they're usually telling you the Maximum Zero Fuel Weight (MZFW) minus the Basic Operating Weight (BOW). An airplane can only carry "stuff" up to the aircraft's MZFW. All weight above that must be fuel. Does that mean the aircraft can always operate at MZFW? No, since the MZFW is a structural weight only, and doesn't consider takeoff and climb performance or fuel requirements.

For example, the SAA Museum lists their DC-4's MZFW as 60,700 pounds. For our purposes let's assume that's a standard weight across all your DC-4s. With a payload of 20,000 pounds, that would make the BOW 40,700 pounds. The Flight Replicas model uses 40,000 pounds, and if you're using the JBK v3.0 freeware version, the BOW is 43,176 pounds. Both those weights are believable based on the facts available.

[Mike71]

Agree, nagpaw.

wrt ZFW, some airplanes, and especially some of these WWII/later long range props, had ZFW's that varied considerably based on fuel tank installation and tank loading - just to confuse the issue. The FR model I have is set up as an 8-tank version. I pick some representative max weight (73,000 lbs) and station load values from various real life sites and FAA data, then mod the aircraft.cfg file to reflect what I choose. You have to be careful regarding cg position and engine version max power when doing this, however.

Also realize that the fuel and payload values in the aircraft.cfg file do not have to add up to max ramp or max takeoff weight - they often exceed max weight. The FS pilot has to adjust the loading to stay within limits. This is typical of real life as well.

[Aharon]

Thanks all for very kind answers


Are you using FSX or P3D version??

I am using FSX Deluxe with SP1 and SP2


Hi, Aharon! Can you give us some more information? Specifically, we'd need...

1) What was the aircraft's takeoff weight in each situation?

2) What takeoff flap setting did you use?

3) What takeoff, METO, and climb power settings did you use in each aircraft?

Answer for first question is that I have to make another flight to get you answer. Sorry about that

Answer for second question is flap one in hope you are not going to scream that I am using wrong flap setting I do not want to use flap two for fear of slowing down the plane during take off run, take off, and climb however I use 2.5 percent trim setting

Answer for third question is that the answer is same as first answer to first question. Sorry about that.




Also realize that the fuel and payload values in the aircraft.cfg file do not have to add up to max ramp or max takeoff weight - they often exceed max weight. The FS pilot has to adjust the loading to stay within limits. This is typical of real life as well.

I am aware of that which is why I used 50 percent fuel load and full cargo load of 9,500 pounds (to recreate flight carrying maximum number of cars) on Carviar. That did not work for me as it crashed few seconds after take off and climb. So I reduced to 40 percent fuel load and cut the cargo payload to half to 4,750 lb which is NOT realistic because Carvair can carry more cars than 4,750 lbs and that barely barely got me into air with painful slow climb while not allowing me to go above 160 kt speed during cruising speed.

What about 160 kt cruising speed? Is that realistic?? Or wrong?? I used full throttle power (100 percent) yet it would not go above 160 kts.

This got me baffled because I looked at history of all past Buffalo Airways flights by DC-4 carrying MUCH heavy load of cargo for much longer flights than I did as seen example below:

load of 8,000 lb generator for 400 nautical miles flight

load of 12,000 lb oil rig equipment for 200 nautical mile flight

load of 19,900 lb drum barrels of crude oil for 200 nautical mile flight

Am I doing something wrong??

Regards,

Aharon

[nagpaw]

Answer for second question is flap one in hope you are not going to scream that I am using wrong flap setting I do not want to use flap two for fear of slowing down the plane during take off run, take off, and climb however I use 2.5 percent trim setting


You'll never get any screaming from me, my friend! I'm here to socialize and learn from others :angel:

Your understanding is correct. Takeoff flap settings are indeed a tradeoff: lower settings increase the takeoff roll but increase climb performance, while the opposite is true for higher settings. The only thing I would suggest is verifying the actual flap indication. The first "notch" of flaps in one model may be ten degrees while it's only 5 degrees in the other model. Make certain you're comparing apples and oranges.

I'm assuming you're only seeing an indicated airspeed of 160 knots. What manifold pressure and propeller RPM are you seeing with "full throttle" in cruise? It's beginning to sound more like a problem with your setup than with your technique. Lemme jump into the FR Carvair on my end and come up with some numbers for comparison. Be right back...



...and I'm back!

So here's what I did. I loaded my Carvair up at KTNT with standard weather (15 degrees C, altimeter 29.92" HG). I put 350 gallons in the Left, Left Aux, Right, and Right Aux tanks (an approximate 50% fuel load) and loaded 9,500 pounds of "stuff," yielding a takeoff weight of approximately 58,600 pounds. I set the flaps to 10 degrees (the first "notch"), the cowl flaps at 50%, and enabled auto mixture. Takeoff power was 50" MP and 2,700 RPM. She flew off just fine and climbed at 155 knots/180 mph indicated and 1,000 feet per minute to 2,000 feet MSL with a climb power setting of 38" MP and 2,550 RPM (the top of the MP green band and upper end of the first red RPM arc), 50% cowl flaps, and the landing gear up.

I leveled at 2,000 feet MSL with 30" MP and 2,200 RPM and closed the cowl flaps. She's rumbling along at 186 knots/214 mph indicated, or 193 knots/225 mph true airspeed. Keep in mind that those power settings I mention are merely "approximate" numbers I made up from experience, and not the real airplane numbers. Your mileage may vary, but only slightly.

Also note that the FR Carvair's airspeed indicator displays miles per hour instead of knots. Remember that for most purposes ------> mph x 0.86 = knots.

Try that yourself in the FR Carvair and let us know what you discover. The things to really check are the power settings you're able to achieve and the proper weights and configurations (flaps, cowl flaps, landing gear).

Again, it sounds to me like a software or hardware issue on your end, which may require reinstalling the DC-4 package. Unfortunately, software issues are where my expertise ends.

[Aharon]

You'll never get any screaming from me, my friend! I'm here to socialize and learn from others :angel: Your understanding is correct.

Thanks




Also note that the FR Carvair's airspeed indicator displays miles per hour instead of knots. .

wait wait wait it is in mph, not kt?????????? Since when any aircraft has automobile style mph gauge in cockpit??



I'm assuming you're only seeing a indicated airspeed of 160 knots. What manifold pressure and propeller RPM are you seeing with "full throttle" in cruise?

What I saw in the speed gauge is 160 BEFORE you told me it is in miles per hour, not knot

And as for manifold pressure and propeller RPM, I am too embarrassed to admit it is in red color above operating limits because I was trying to get to 190 kt cruising speed although I do not think it caused my plane to crash. However, it meant full throttle at 100 percent instead of customary 75 percent for any old iron planes. I tried 75 percent during cruising and speed just dropped to dangerous level so I increased to 100 percent,



So here's what I did. I loaded my Carvair up at KTNT with standard weather (15 degrees C, altimeter 29.92" HG). I put 350 gallons in the Left, Left Aux, Right, and Right Aux tanks (an approximate 50% fuel load) and loaded 9,500 pounds of "stuff," yielding a takeoff weight of approximately 58,600 pounds. I set the flaps to 10 degrees (the first "notch"), the cowl flaps at 50%, and enabled auto mixture. .

Me too with exactly same load except cowl flaps on engines were at 100 percent since it is summer weather. Is this wrong??



She flew off just fine and climbed at 155 knots/180 mph indicated and 1,000 feet per minute to 2,000 feet MSL with a climb power setting of 38" MP and 2,550 RPM (the top of the MP green band and upper end of the first red RPM arc), 50% cowl flaps, and the landing gear up. I leveled at 2,000 feet MSL with 30" MP and 2,200 RPM and closed the cowl flaps. She's rumbling along at 186 knots/214 mph indicated, or 193 knots/225 mph true airspeed.

ARRGHHHHHH you are lucky!!!!!!!!!!! Thanks for your extremely kindness to take time from your busy schedule to test the Carvair plane based on same load settings as mine (except cowl flaps). Surprised me that your flight was success and mine was not (crashed onto ground few seconds after take off) Still baffled how you managed that!!! Something wrong with me.

Regards,

Aharon

[MrZippy]

Aharon,

Shortly after wheels up, be sure to get your Prop RPMs down into the green zone. If you don't, this may happen....as shown with the MJahn C-47 V2 :redfire:

81280

[Mike71]

--- wait wait wait it is in mph, not kt?????????? Since when any aircraft has automobile style mph gauge in cockpit?? --

AharonLOTS of planes have ASI's in mph. I hate it, but it is reality. Many military and civilian planes used mph before and during WWII. Today many civil airplanes have ASIs with dual scales. It likely was a result of trying to make novitiate pilots comfortable in flying and not being confused about "knots".

[srgalahad]

An ASI in MPH? Certainly. Until after WWII that would have been common all over and probably the majority - almost all US-built a/c would be so. ASI's usually show whether Kts or MPH clearly on the face.

A few things to ponder... let's start with the data. Have you referred to the Performance Charts supplied by FR? They are located in the \SimObjects\C-54B folder.

Always check RPM & MP on the takeoff roll to be sure you really are producing the expected power.
First tab shows 20* flap T/O speed @60,000# as 90KTS (105 MPH). Flaps 10 might be slightly higher due to less lift available. Next, you cannot, in the DC-4 just pull into a climb from take-off. As soon as positive rate of climb, Gear UP, but don't increase AOA. Let speed build to about 115Kts before raising flap -in steps. This might mean no more than 1-200 ft/min climb rate initially. Yeah, the trees can look big. Also, in summer (>15*C) performance will degrade.

So, if you now get up to speed and are climbing, reduce power as shown in the charts (Max T/O 2700/50" power is limited to 5 minutes).

A couple of thoughts about following the Buffalo 'missions' you reference. They were likely flown in winter - well below std. temp. The ones you list above (2-400nm) are probably never above 5000' asl and it's highly probable that were flown VFR so fuel load could be reduced. An hour and a bit out, same back and 45 min. reserve would cut the fuel load to around 1200 US Gal. (30%) Joe was adamant that engines never be abused so it's likely that the numbers used would be from the 'long range' part of the table or higher (Intermediate) out/low back (remember this would be at lighter weight.) -I know this because I heard him explain it to a rookie co-pilot -thru my office window 3 floors above and 200 ft away with words I can't quote in this forum. :listening_headphone

The Carvair (when used as a shuttle across the channel) would have been similar. Speed was not the first metric to be chased. Fuel consumption and reliability were far more important, so it might be reasonable to look at 170-180 KIAS cruise. As well, the hops were short (350 nm or less) so fuel could be reduced with services available at each end. (Southend to Strasbourg - 325 nm - 2:20 on the schedule - average 141 kts) http://timetableimages.com/ttimages/complete/cab62/cab62-4.jpg

Back to the climb for a moment. I rode jumpseat on a (close to) max weight DC-6 trip of about 1000 nm on a hot summer day. 25nm after t/o we were thru 1000 ft, and at 100 nm thru 3500 ft.

Be gentle. Crew chiefs can be nasty when annoyed.

[Aharon]

Thanks all for very kind words and very kind suggestions.

I think the problem with my Carvair from the failed first flight resulting into crash seconds after take off and from unimpressive but completed second flight with bizarre 160 kt OR 160 mph reading in speedometer gauge during cruising at 7000 ft is that I might have made TWO mistakes.

The two mistakes are that I should have set cowl flaps at 50 or 25 percent instead of 100 percent and that I started climb too soon after take off when I was supposed to take off and level off at 200 fpm after take off to gain plenty of speed before starting normal climb.

Maybe those 2 mistakes might have played role in the crash during first flight???

Maybe the third reason for the crash is that settings in FSX.cfg is set to false in automixture in realism paragraph even though I did the job set proper automixture in Carvair???

Apart from trying to figure out why I crashed in the first flight and unimpressive but completed second flight, there is problem of Carvair having inability to go above 160 kt speed.

Is the speedometer gauge really in KNOTS or MIlES PER HOUR????

Going to make third Carvair flight soon trying to recreate strange success of flight flown by Nagpaw who managed to achieve normal 190 kt cruising speed at full cargo load or is it 190 mph in gauge???

ARRGGHHHHh

Regards,

Aharon

[Aharon]

LOTS of planes have ASI's in mph. I hate it, but it is reality.

Me too I think speedometer gauge should be in knots and mach

Regards,

Aharon

[Aharon]

Aharon,

Shortly after wheels up, be sure to get your Prop RPMs down into the green zone. If you don't, this may happen....as shown with the MJahn C-47 V2 :redfire:

Famous Mr Zippy,

I know what you mean and I always use 75 percent throttle power and 75 percent propeller throttle in Jahn DC-3/C-47 version THREE, not two but Flight Replicas does not have built in failure in the DC-4 package therefore it is not reason for crash in first flight. Besides, the crash just happened seconds after take off not during climb.

Regards,

Aharon

[nagpaw]

The two mistakes are that I should have set cowl flaps at 50 or 25 percent instead of 100 percent and that I started climb too soon after take off when I was supposed to take off and level off at 200 fpm after take off to gain plenty of speed before starting normal climb.

Maybe those 2 mistakes might have played role in the crash during first flight???

Maybe the third reason for the crash is that settings in FSX.cfg is set to false in automixture in realism paragraph even though I did the job set proper automixture in Carvair???

Normally the cowl flaps would make a difference, as they create quite a bit of drag. But after some further research, it appears that the FR DC-4/Carvair flight models don't account for cowl flap drag. So that probably didn't make a difference on your failed flights. Climbing before you've gained sufficient airspeed certainly could have, especially if you were using the incorrect airspeed scale.

I use the automixture with the FR DC-4 and Carvair just to make certain I'm getting the appropriate power. I know it's not perfect, but there's really no other way to adequately lean the engines manually.



Is the speedometer gauge really in KNOTS or MIlES PER HOUR????

Going to make third Carvair flight soon trying to recreate strange success of flight flown by Nagpaw who managed to achieve normal 190 kt cruising speed at full cargo load or is it 190 mph in gauge???

ARRGGHHHHh

Yup, it's in miles per hour. If you press <SHIFT+Z> to bring the information bar up at the top of the screen you can read the airspeed in knots. Fly with both for little while and you'll be able to easily figure out the appropriate airspeeds in miles per hour by comparing the two indications.

Also, I'd recommend using the published power settings. For each phase of flight, you'll have a range of manifold pressures and RPM to use. The documentation includes some general power settings, but you'll find exact settings in the outstanding flight planning charts included with the package. They're in your "SimObjects/Airplanes/Douglas C-54B/2. PERFORMANCE CHARTS folder. The cruise charts are titled, for example, "Cruise 50-45." The two numbers indicate the aircraft weight in thousands of pounds (i.e. 50,000 to 45,000 pounds). Make certain you're using the correct chart for your weight. There's a note at the bottom of each chart on converting the numbers for use with the Carvair.

Also note that the charts give airspeed in TRUE airspeed. When you read a book or website about airplane performance specifications, the cruise speeds given are almost always TRUE airspeed, not INDICATED. As a rough guide, for any given indicated airspeed, true airspeed increases by about 2% per one thousand feet of altitude gain. If you're not familiar, here's a quick and dirty way to find your true airspeed, in this example for an indicated airspeed of 160 knots at 7,000 feet...

1) Note the indicated airspeed in KNOTS from the <SHIFT+Z> data block at the top of your screen (160)

2) Multiply that speed by 0.02 (160 x 0.02 = 3.2)

3) Multiply the result by your altitude in thousands of feet (3.2 x 7 = 22.4)

4) Add the result to your indicated airspeed in knots (160 + 22.4 = 182.4 knots)

5) The result is your true airspeed in KNOTS.

6) <OPTIONAL> Divide by 0.86 to find your true airspeed in MILES PER HOUR (182.4 / 0.86 = 212 mph)

There's a formula to convert the other way, but I won't muddy the waters just yet :untroubled:

Whoops! I have to head to work for a few days, but I'll try and check your progress along the way. I know it's frustrating, but I think you're getting there! :encouragement:

[Motormouse]

And while you're pondering all that check out
international standard atmosphere, and realise that all gauges are baseline calibrated to it so any variation above or below isa will affect what is seen on gauge,

Ttfn

Pete

[srgalahad]

Alas,f you lift off at barely stall speed, already producing max. power, it is unlikely that you will get above stall. Given that our controllers are rarely precise enough to make 1* pitch changes all you will get is a period of mushing along on the edge of the stall until you encounter a solid object. Always. This isn't just a FS thing either as accident databases will prove. Moving on...

Following published tables is always a good idea, but yes, the right units must be applied. Knowing the conversions is essential and takes time and practice.
As far as manual leaning is concerned, it's difficult if the model does not have things like EGT gauges. However, there is a simple solution: Herve Sors' Advanced Flight Simulator Data (AFSD) (https://www.aero.sors.fr/designer_pilot_utilities1.html) is a small program that displays all the data from the sim (by category). Run it, check the "Fuel" table, looking at F/A Ratio as you approach max. power on takeoff (or during runup, if you do one of those) and adjust the mixture. Then check it every couple of thousand feet in the climb and adjust, tweak at cruise and repeat on descent. The Target is .08333 which is what FSX thinks is optimum.
AFSD's tables also show precise, real-time IAS + TAS + CAS and, if selected, will give an updated stall speed as fuel/weight is lost. I use it constantly when testing new models and in those odd situations like max. range flights to squeeze every mile out of the fuel.

As far as getting a sim aircraft to match "book" or brochure or Wiki data, I always work on the premise that it (FSX) is a$49 bit of software, trying to read/display another $49 bit of software, both of which were written on a budget and within time constraints: Close is good - but your mileage may vary.

[Aharon]

Thanks all again for kind explanations and for useful hyperlinks

Nagpaw,

I had one failed Carvair flight, NOT failed flights The second was success BUT totally unimpressive to me.

Will make third Carvair flight soon and will let all of you know about the results. I suspect that I had been flying too many DC-4 flights enough to fail to realize that Carvair does NOT necessarily have same performances as DC-4/C-54 especially when the former has 747 style hump! That might account for my failed first Carvair flight thinking that Carvair should have same performance as DC4/C-54

Regards,

Aharon

[Aharon]

OKAY OKAY OKAY

With self corrections such as setting cowl flaps at 50 percent instead of 100 and level off immediately at 200 fpm to build up speed after take off instead of immediate climb have solved the problem and everything was successful using 50 percent fuel load, 10,000 lb payload, and 600 lb, not 900 lb crew load.

HOWEVER, it fails to solve one problem which is SPEED.

Carvair will not go above 155 kt (I added my own gauge in kt reading) or 180 mph in Carvair cockpit speedometer gauge reading. Carvair is supposed to have top speed of 220 kt and cruising speed of 190 kt. Because of extremely too slow speed, I could not reach my desired 9,000 ft and had to settle for 5,000 ft cruising altitude because climb was very very painful slow at much lower 130 kt speed.

What can I do to correct the speed problem?? I tried to reduce propeller control throttle to 73 percent to make sure the rpm gauge stays on top of green just below red to test my theory that this will help increase speed if engines are more happy but that reduced cruising speed from 155kt to 150 kt.

Regards,

Aharon

[Mike71]

Is 220 KIAS a never exceed or max operating speed? Vne is typically achieved in a descent, not achievable in level flight at full max continuous power. Vno is often a stability degradation / gust factor issue. I will see what I can find out.

One way to cheat is modify the aircraft.cfg file: the line power_scalar = 1 in 10% increments to see what happens

[Ascua]

Hi all, this thread just made me curious, been flying the JBK C-54 a lot lately. lets see if my numbers help.

The aircraft was loaded with 800 + 7400 + 800 for a total 9000 lb
for the flight Southend - Strasburg, I loaded 965 gals of fuel (flight + 1 hour reserve), that gave me a take off weight of 57969lb
I use RealEngine 1.4 to set up limits and monitor the engines and importantly to maintain "auto rich" (8.5%) and "auto lean" (7%) mixture.
Weather was real +6C, wind 049/10 on take off and QNH 29.68

For the take off, flaps 10 and full throttle (50", 2700 RPM) was used up to 200ft then wheels up and reduction to 38", 2500 RPM and flaps up. like that she would happily climb at 140/150 KIAS at 500 fpm, temps in the green with 30% cowl flaps to selected cruise altitude of 8000 ft.

Once at 8000 feet, I left everything as per climb and let accelerate, it finished at 197 KIAS, that given the conditions were 220 KTAS, then reduction to 31", 2050 RPM and "auto lean" which gave 156 KIAS, equivalent to 175 KTAS and all temperatures in the green.

Temperature , pression and weather were obviously changing along the way but the performance was stable.

The only thing I tweaked in this plane is reducing the cruise lift scalar to 0.9 as it had a tendency to fly nose down from 160 KIAS on
I got the numbers to fly it from a real manual downloaded from internet.

Hope it helps

[Aharon]

Is 220 KIAS a never exceed or max operating speed?

Good morning Mike,

Please please please remember I am NOT NOT kind of crazy flight simmer who likes to fly at top speed in most unrealistic manner. According to various info, 220 kt is max operating speed and 180-190 kt is cruising speed at 10,000 ft.

I always believe in recreation of real world realistic flights in most realism manner.

You got to remember there are TWO kinds of realistic cruising speeds for DC-4s, C-54s, and Carvairs. The cruising speed for those planes when brand new and in regular daily service during 1950s are MUCH higher than cruising speeds of Buffalo or any airline DC-4s/C-54s at present 21st century era. Buffalo or any airline would fly those planes at much lower speeds in 21st century than what planes would normally fly in era 1950s. In other words, flying at 155kt would be normal cruising speed for Buffalo Airways DC-4s/C-54s in 21st century but NOT normal for American Airlines or Pan Am DC-4 which could do at higher but normal cruising speed of 180-190kt in 1950s.

So I am setting speed BASED on which year any of those aircrafts flew in the past to recreate most realistic realism of historic flights so I would be flying Carvairs in era 1960s at normal cruising speed of 180-190 kt which is the speed I am unable to recreate in most realistic manner. If it was Buffalo Airways DC-4/C-54, that would be perfect slower speed at 155kt (I think Buffalo Airways picks 145kt) and I would not be asking around here for help to solve the problem.



I will see what I can find out.

Would appreciate that



One way to cheat is modify the aircraft.cfg file: the line power_scalar = 1 in 10% increments to see what happens

I am definitely not going to tinker with aircraft.cfg or otherwise I would invalidate warranty and lose tech support from Flight Replicas. The only exception is me adding to the DC-4 package my speedometer gauge in kt reading because I always use kt, not mph when flying.

Regards,

Aharon

[Aharon]

Hi all, this thread just made me curious, been flying the JBK C-54 a lot lately. I got the numbers to fly it from a real manual downloaded from internet.

Cool and thanks for doing test flight. However I have feeling that Carvairs have FAR MUCH different flying performances and dynamics than DC-4s/C-54 due to the fact that the former has massive hump and the latter does not have. I think the hump can affect the air flow. That is unless foremost aviation experts tell me it is NOT true that massive hump on Carvair can affect air flow.

And care to tell us where you found real manual from the internet, please?

Regards,

Aharon

[Ascua]

Certainly, there you go, it is for a C-54G

https://ww2aircraft.net/forum/attachments/c-54g-r5d-2-flight-operating-instructions-pdf.610177/

Also, but not so informative

https://www.filefactory.com/file/42t4d0c7smnh/Douglas_DC-4%20OM.pdf

Saludos

[Aharon]

Thanks, Asgua for the cool hyperlinks!!

After finishing three Flight Replicas Carvair flights thanks to great help, corrections, and suggestions by everybody here at SOH forums, I am NOW ready to make first flight with Flight Replicas DC-4 to see what flying dynamics and speed look like!!

The first DC-4 flight will be loaded with 35 percent fuel, 600 lb crew, and heavier 12,000 lb of cargo load to recreate historic flight between CYZF and CYHY by Buffalo Airways DC-4 doing emergency last minute Christmas gifts and food load supply from CYZF to CYHY. I hope to be able to reach 9,000 ft cruising altitude!

Regards,

Aharon

[nagpaw]

Aharon,

I'm back! Reading some more into the thread, I want to make certain that we're talking about the same numbers. Most of the specifications I find for the Carvair say she cruises at about 180 knots at 10,000 feet. That 180 knots is very likely True Airspeed (TAS), not Indicated (IAS). At 10,000 feet, a TAS of 180 knots would be about 150 knots IAS, or 174 miles per hour on the airspeed gauge. Is that the speed you're getting, and how much power is required to hold that?

[Aharon]

I want to make certain that we're talking about the same numbers. ?

Good morning Nagpaw,

I always use IAS speed in kt reading. And I use IAS kt speed info on DC-4 from sources in the vast world of internet. I installed into DC-4 package my speedometer gauge that gives me IAS kt speed reading and pressing ctl-Z in FSX to produce informative readings in red font which confirms accuracy of IAS kt speed reading from the custom made speedometer gauge.

Also, many DC-4 manual books offer speed charts in both mph and IAS speed which I get info from.


At 10,000 feet, a TAS of 180 knots would be about 150 knots IAS, or 174 miles per hour on the airspeed gauge. Is that the speed you're getting, and how much power is required to hold that?

After finishing three successful Flight Replicas Carvair flights with too low speed, yesterday I made first Flight Replicas DC-4 flight which unfortunately produced same speed result as Carvair.

I set 35 percent fuel, 600 lb crew, and heavier 12,000 lb of cargo loads into DC-4 to recreate historic flight between CYZF and CYHY by Buffalo Airways DC-4 doing emergency last minute Christmas gifts and food load supply from CYZF to CYHY with hope to be able to reach 10,000 ft cruising altitude!

So far, I could not make to 10,000ft and had to settle for 6,000 ft because the climb was painfully too slow at 200 fpm climb rate. I could not do 500 fpm or 1,000 fpm climb because that made the speed too dangerously low which forced me to settle for 200 fpm climb rate to maintain stable speed.

I wound up cruising at 6,000 ft at the IAS speed of 161 kt, 185 miles per hour, and 170 kn ground speed (stated by GPS) This might be realistic for Buffalo Airways DC-4s in present time (I know Buffalo Airways prefer 145-150 kt cruising IAS speed for DC-4) but too low for commercial airlines such as Pan Am or Delta or so on in era 1950s.

As for how much power I used, I used full throttle power and full propeller control throttle and full mixture. Yes yes yes it is too unrealistic but that is only way I can maintain acceptable speed even though it is too low.

Also flying first DC-4 flight produced new interesting problem. Whenever I clicked anti-ice or deice switches for wings and engines, it worked fine BUT BUT whenever I clicked two deice pitot tube switches, it always caused FSX freeze with the error message seen below so I was forced to fly the DC-4 flight in freezing below temperature weather without use of deice pitot tube switches.

Regards,

Aharon

Error message seen below whenever I tried to click on two deice pitot tube switches:

Faulting application name: fsx.exe, version: 10.0.61472.0, time stamp: 0x475e17d3
Faulting module name: ai_player.dll, version: 10.0.61472.0, time stamp: 0x475e180c
Exception code: 0xc0000005
Fault offset: 0x00036419
Faulting process id: 0x2cd0
Faulting application start time: 0x01d6fe574bb67304
Faulting application path: D:\Microsoft Flight Simulator X\fsx.exe
Faulting module path: D:\Microsoft Flight Simulator X\ai_player.dll
Report Id: 17864985-a648-4fbf-894e-ffa1d373d59e
Faulting package full name:
Faulting package-relative application ID:

[nagpaw]

Yikes! I'm no software expert, but that really sounds like a software problem to me :biggrin-new: Have you tried reinstalling the FR DC-4 package?

[Aharon]

Yikes! I'm no software expert, but that really sounds like a software problem to me :biggrin-new: Have you tried reinstalling the FR DC-4 package?

Well it is least of my problems and I am flying DC-4 package fine without use of pitot tubes. I am going to try trick how to activate pitot tubes without touching the switches by assigning/ using keyboard button command to that to see if that works without freezing up FSX.

What I need is to solve the too low speed problem.

If the DC-4 package is designed based on Buffalo Airways DC-4s in present era, I would understand and accept or agree to its realism of too low speed. But I do not think DC-4 package is designed in mind for Buffalo Airways DC-4s flying in 21st century.

Regards,

Aharon

[Aharon]

Just watched NWT ICE PIlOTS episode where they did many many emergency Christmas gift and food airlift flights from CYHY Hay River to CYZF Yellowknife due to the fact that ferries were closed because of frozen lake.

DC-4 was loaded with 20,000 lbs of emergency supplies per each of many shuttle flights.

Makes me wonder if Flight Replicas DC-4 can do that?? Fuel must have been set at very little 20 percent full for 120 nautical mile trip to be able to carry 20,000 lbs of cargo per flight.

Regards,

Aharon

[Aharon]

I know this because I heard him explain it to a rookie co-pilot -thru my office window 3 floors above and 200 ft away with words I can't quote in this forum. :listening_headphone

Srgalahad,

Sorry to bother you but if you work three floors above Buffalo Airways offices, maybe you can see Buffalo airways DC-4 pilots such as Justine Smile and ask them what is their preferred climb rate for their DC-4s because I am having hard time believing that Flight Replicas DC-4s can do only 200 or 300 fpm climb rate while maintaining stable speed and I can manage to reach only 5,000 ft instead of my desired 10,000 ft.

Thanks,

Aharon

[Mike71]

The FR model aircraft.cfg file shows a max weight of 73000 lbs, an empty weight of 43000 lbs and 1450hp engines. This approximates a military C-54G or production DC-4 according to FAA cert documents. The weight limit is based on integral wing tanks (vice strap down tanks in the forward fuselage as used in early C-54s), and fuel dump valves.

My Navy C-54G performance figures say that at sea level standard day after takeoff, 140 mph / 120 KIAS climb at 73000 lbs standard day at 33" MAP and 2300 RPM the plane can climb at 770 fpm.

Early USAF C-54 pilot manuals make a broad statement that C-54s can carry 20,000 lbs of cargo - of course that did not necessarily carry over to FAA certification for civil conversion of military aircraft.

Apparently Buffalo Airways "DC-4"s were a mixed bag of converted military versions - C-54A (https://en.wikipedia.org/wiki/Douglas_C-54_Skymaster#C-54A), C-54E (https://en.wikipedia.org/wiki/Douglas_C-54_Skymaster#C-54E), C-54G (https://en.wikipedia.org/wiki/Douglas_C-54_Skymaster#C-54G)s. Each had different weight restrictions for civil ops, as well as a wide range of P&W / Wright engines varying from 1350 or 1450 HP at full takeoff ratings.

Anyway, testing my P3D FR DC-4 I agree, climb sucks. I am going to fiddle with the power_scalar = 1 to get better climb, check cruise perf etc to see what I can do.

[Aharon]

Apparently Buffalo Airways "DC-4"s were a mixed bag of converted military versions C-54A (https://en.wikipedia.org/wiki/Douglas_C-54_Skymaster#C-54A), C-54E (https://en.wikipedia.org/wiki/Douglas_C-54_Skymaster#C-54E), C-54G (https://en.wikipedia.org/wiki/Douglas_C-54_Skymaster#C-54G)s. Each had different weight restrictions for civil ops, as well as a wide range of P&W / Wright engines varying from 1350 or 1450 HP at full takeoff ratings.

OH DARN you mean the painters painted Buffalo Airways liveries on wrong model bases?? Repainters assign Buffalo Airways liveries to RSD model base. Should I move the liveries to C-54A or C-54B unless you tell me it will not make difference and you tell me that C-54A and C-54B have same climb rate problem as DC-4 and Carvairs?

BTW, thanks for letting me know about specific model bases for Buffalo Airways DC-4 fleet.


My Navy C-54G performance figures say that at sea level standard day after takeoff, 140 mph / 120 KIAS climb at 73000 lbs standard day at 33" MAP and 2300 RPM the plane can climb at 770 fpm.

Early USAF C-54 pilot manuals make a broad statement that C-54s can carry 20,000 lbs of cargo - of course that did not necessarily carry over to FAA certification for civil conversion of military aircraft.

That would be perfect and that sounds perfect for Buffalo Airways planes.



Anyway, testing my P3D FR DC-4 I agree, climb sucks. I am going to fiddle with the power_scalar = 1 to get better climb, check cruise perf etc to see what I can do.

That would be much much much gratefully appreciated as I always look forward to recreate more historic flights of Carvairs carrying many cars and Buffalo Airways planes carrying up to 20,000 lbs of cargo load.

Thanks for your kindness.

Regards,

Aharon

[Mike71]

Your "RSD" - you meant R5D - model is apparently based on the Navy R5D-5 or USAF C-54G with a MGW of 73000 lbs and 1450 hp engines. Buffalo had at least 2 C-54Gs involved in accidents. How many others I do not know. I assume your repaints would be correct as is for the R5D.

[Aharon]

Your "RSD" - you meant R5D - model is apparently based on the Navy R5D-5 or USAF C-54G with a MGW of 73000 lbs and 1450 hp engines. Buffalo had at least 2 C-54Gs involved in accidents. How many others I do not know. I assume your repaints would be correct as is for the R5D.

Thanks for confirming correct placement of Buffalo Airways onto R5D model base.

BTW, I am curious to see if the R5D model base with Buffalo Airways livery also known as C-54G can carry 20,000 lb cargo load with minimum fuel plus emergency fuel reserve enough for 150 nautical mile trip from CYHY to CYZF for recreation of famous emergency Christmas cargo airlift can take off and climb to 10,000 ft.

Regards,

Aharon

P.S. I do not know why my sentences are in shade.

[Aharon]

I am told by Carvair experts that a Carvair carried an average of 5 cars and 20 passengers per flight. Although I have no idea how many pounds are five cars but we can deduce that the total weight of 20 passengers without luggages is 3,800 pounds based on average weight of 190 pounds per passenger.

Should be interesting to see if I can recreate load of 5 cars and 20 passengers in Carvair flight.

Regards,

Aharon

[Mike71]

----

BTW, I am curious to see if the R5D model base with Buffalo Airways livery also known as C-54G can carry 20,000 lb cargo load with minimum fuel plus emergency fuel reserve enough for 150 nautical mile trip from CYHY to CYZF for recreation of famous emergency Christmas cargo airlift can take off and climb to 10,000 ft. ---

I have been doing some more review of data and testing. An R5D-5 / C-54G with 1450hp engines can have many variances due to how they were converted for civil use. I have modified my aircraft.cfg file to make a representative aircraft that has a representative climb rate. This is based on three authoritative though somewhat incoherent documents I have, including FAA cert data, NAVY/USAF handbook and a TRANSAIR DC-4 manual excerpt as follows:

A quick point: the FR models include 2-speed superchargers in order mostly for use in military versions. HOWEVER - civil models normally had been modified to have only a slightly better, single speed supercharger so obviously no blower speed shifting required at altitude.. For my purposes here these figures refer to Low Blower settings, flaps & gear up, cowl flaps as required.

Empty weight: 40700 lbs (realistically about 42000 with full interior, stripped out as a freight dog interior here)
Max weight: 73000 lbs (as is per FR)
Max Zero Fuel weight: 60700 lbs (FAA option: equates to 20,000 lbs max payload INCLUDING PILOTS!))
Max Fuel capacity: 21384 lbs (as is per FR)
Max Landing Weight: 63,500 lbs (FAA option)

Max fuel at max cargo capacity: 12,300 lbs
Max cargo at max fuel capacity: 10,916 lbs
Max landing fuel at max cargo (max zero fuel weight): 2800 lbs


Modified power scalar: 1.125 vice 1.0


At 73000 lbs TO weight, plane can climb at ~ 140 mph / 800 fpm at 2550 RPM and 42" MAP (roughly METO power, referred to as max continuous in older certification process )


~ 140 mph / 500 fpm at 2300 RPM and 34" MAP (referred to as normal climb or optional climb in manuals)


A quick check at 5000 MSL, 72400 lbs GW 33" MAP/2000 RPM shows a TAS of about 206 KTAS/237 mph.(Indicated (values are 193 KIAS / 222mph)


Fuel consumption at these settings are at 2100 pph / 350 gal per hour fuel flow. This is pretty close to the data FR has in their EXCEL spread sheet.


Obviously, with a full payload of 20,000 lbs and 12300 lbs of fuel, you could fly for about 41/2 hrs and land with 1 hr of fuel - about 900 nautical miles no wind.


Obviously you could do better by getting up to 9,000 or 10,000 MSL depending on direction and wind because your TAS would increase by another 10% or so.

BY THE WAY - you MUST constantly increase throttle to hold desired manifold pressure as you climb - it drops about 1" per 1000 ft if you don't. Make sure you do that!
In addition, do NOT get slow in a climb. This type of plane, with such a low climb rate, builds up induced drag rapidly and loses the ability to quickly regain speed and climb rate, requiring a level off or even slight descent to get re-established..

[Mike71]

I am told by Carvair experts that a Carvair carried an average of 5 cars and 20 passengers per flight. Although I have no idea how many pounds are five cars but we can deduce that the total weight of 20 passengers without luggages is 3,800 pounds based on average weight of 190 pounds per passenger.

Should be interesting to see if I can recreate load of 5 cars and 20 passengers in Carvair flight.

Regards,

Aharon
For US averages, Minivans, Small SUVs, Small Pick-Ups average about 4000 lbs empty (3200 - 4500 lb spread)

[Motormouse]

For US averages, Minivans, Small SUVs, Small Pick-Ups average about 4000 lbs empty (3200 - 4500 lb spread)As the Carstairs operated UK to Europe air ferry routes, average European cars of the period were about 1 tonne in weight, things like rolls Royce would go to 2.5 tonneTtfnPete

[Aharon]

I have been doing some more review of data and testing.

That is much appreciated in most grateful manner and I do look forward to complete modifications or revisions when you have chance to finish testing and reviewing.



At 73000 lbs TO weight, plane can climb at ~ 140 mph / 800 fpm at 2550 RPM and 42" MAP (roughly METO power, referred to as max continuous in older certification process)~ 140 mph / 500 fpm at 2300 RPM and 34" MAP (referred to as normal climb or optional climb in manuals)

I wish I can do that and the real world 500 to 800 fpm climb rate sounds realistic for all model bases in your Flight Replicas DC-4 package



A quick check at 5000 MSL, 72400 lbs GW 33" MAP/2000 RPM shows a TAS of about 206 KTAS/237 mph.(Indicated (values are 193 KIAS / 222mph)

That sounds realistic for all DC-4 variants serving as brand new planes in airlines in era 1950s and that sounds realistic for all Carvair planes in their prime time in era 1960s. Buffalo Airways planes are of course at far much lower speed in present era preferring 155 to 145 KIAS cruising speed.



Obviously, with a full payload of 20,000 lbs and 12300 lbs of fuel, you could fly for about 4 1/2 hrs and land with 1 hr of fuel - about 900 nautical miles no wind.Obviously you could do better by getting up to 9,000 or 10,000 MSL depending on direction and wind because your TAS would increase by another 10% or so.

Whoa I wish I can do that. I thought 20,000 lb cargo load of Buffalo Airways plane is suitable for short hop flights, not for non stop 4 hour flight with one extra hour left of fuel after landing!


In addition, do NOT get slow in a climb. This type of plane, with such a low climb rate, builds up induced drag rapidly and loses the ability to quickly regain speed and climb rate, requiring a level off or even slight descent to get re-established..

If I can figure out how to do that!!!Hopefully your modifications will help me to do that.

Many many thanks for your hard work in testing, modifications, and reviewing. looking forward to your finished revisions.

With humblest thanks and much appreication,

Aharon

Motormouse,

Thanks for your information on average weight of each of European cars

Mike,

Thanks for your information on average weight of each of American cars.

Regards,

Aharon

[srgalahad]

This is a flight in a STOCK FR C-54G/R5D (with the addition of the CF-IQM paint).

CYHY departing Rwy 31, to CYZF landing Rwy 33 this morning. Wx is Active Sky

Base weight + 600# crew, 20000# load + 6369# fuel. = 66,356.9 lbs at takeoff.
Take off Max power, 0 flap, gear up thru 100 agl.
Once gear up and airspeed above 150 mph, reduced to 35" / 2350 rpm and set autopilot for 7000 ft and 800 fpm
Speed reduces from 155KIAS to approx 140 KIAS at 4000 so climb was reduced to 600 fpm
Power not increased to maintain 35" in this short climb
Level at 7000, power set to 30" /2150 rpm and once speed stabilizes - 185 KIAS (200 KTAS)
Fuel for the leg: 1218 # + taxi or enough for about 5 hrs.

The data log of the flight is attached. (Just stretch it wide once you open the .txt file so you can see the columns.) Data collected from the sim via Duenna (Johannes Mueller and Eamonn Watson).

So, yes it's possible to achieve close to "book" numbers and loads.
Also, if you are trying to recreate Buffalo flights, there is NO need to go for higher altitudes in the DC-3 or DC-4. The Minimum Enroute Altitude on V321 between HY & ZF is 3000' (I don't have the latest IFR chart) so the northbound leg could be filed at 3000 but more likely 5 or 7 and no higher. Why bother on such a short leg? I used 7000 just for the test and the temps. were low, but if there was no weather, I'd likely use 5000.

BTW, I can't help you with current data for Buffalo any more than what you can find online. I left Yellowknife in 1996.

[PeteHam]

I've been searching for suitable new textures for this classic workhorse.

I'm mainly looking for Alaskan and Canadian cargo textures and I note that you've added .... (with the addition of the CF-IQM paint).

Would you be so kind as to point me in the right direction for these textures please.

Thanks,

Pete

[Aharon]

This is a flight in a STOCK FR C-54G/R5D (with the addition of the CF-IQM paint).

Thank you for your kindness in sparing time from your busy schedule to make testing flight.



Take off Max power, 0 flap, gear up thru 100 agl.

Are you saying that you took off with max power and zero flap or are you saying that you retracted flap and gear at 100 AGl?



Base weight + 600# crew, 20000# load + 6369# fuel. = 66,356.9 lbs at takeoff.
reduced to 35" / 2350 rpm and set autopilot for 7000 ft and 800 fpm
Speed reduces from 155KIAS to approx 140 KIAS at 4000 so climb was reduced to 600 fpm

Level at 7000, power set to 30" /2150 rpm and once speed stabilizes - 185 KIAS (200 KTAS)

I wish I could achieved those figures!! Maybe it works for you because you used R5D model base and I used DC-4 and Carvair model bases unless somebody tells me model bases do not make difference.

Did you make that flight test before Mike made modifications to aircraft.cfg or after he made modifications and gave the revision to you to test?


Also, if you are trying to recreate Buffalo flights, there is NO need to go for higher altitudes in the DC-3 or DC-4. The Minimum Enroute Altitude on V321 between HY & ZF is 3000' so the northbound leg could be filed at 3000 but more likely 5 or 7 and no higher..

Strange I thought Buffalo Airways always uses 9,000 to 10,000 ft for CYHY to CYZF and back routes. I remember from seeing NWT ICE PIlOTS episodes.

Once again, thanks for your very kind assistance and for your flight testing.

Maybe I should test R5D model base to see if I can do the same thing you did unless Mike tells me that all model bases in the Flight Replicas DC-4 package have same aircraft.cfg. However, I think DC-4 and Carvairs should do better in performance to match real world operations.


Regards,

Aharon

[Aharon]

After finishing few flights abroad FR Carvairs and FR DC-4s, I am going this week make a testing flight using R5D model base (C-54G) to see if I can replicate amazing successful flight that Srgalahad did as seen below. Hope it will work for me!!! Willl let all of you know the results

Regards,

Aharon




Base weight + 600 lbs crew, 20000 lbs load + 6369 lbs fuel. = 66,356.9 lbs at takeoff.
reduced to 35" / 2350 rpm and set autopilot for 7000 ft and 800 fpm
Speed reduces from 155KIAS to approx 140 KIAS at 4000 so climb was reduced to 600 fpm
Level at 7000, power set to 30" /2150 rpm and once speed stabilizes - 185 KIAS (200 KTAS)

[Aharon]

Originally Posted by srgalahad http://www.sim-outhouse.com/sohforums/images/buttons/viewpost-right.png (http://www.sim-outhouse.com/sohforums/showthread.php?p=1253258#post1253258) Base weight + 600 lbs crew, 20000 lbs load + 6369 lbs fuel. = 66,356.9 lbs at takeoff.
reduced to 35" / 2350 rpm and set autopilot for 7000 ft and 800 fpm
Speed reduces from 155KIAS to approx 140 KIAS at 4000 so climb was reduced to 600 fpm
Level at 7000, power set to 30" /2150 rpm and once speed stabilizes - 185 KIAS (200 KTAS)

Okay okay I finally got to test R5D model base with Buffalo Airways repaint and loaded it up with same weight load factors as stated by Srgalahad seen above in his quotation EXCEPT I set the crew as 400 lb, not 600 lb unless I wanted to hire sumo wrestlers or football linebackers as pilots.

I regret that I am unable to recreate the climb rate and speed successes of Srgalahad.

For my flight from CYHY to CYZF, the R5D plane was unable to sustain 800 fpm at 155 KIAS speed and I was forced to use 200 fpm in order to maintain stable 130 KAIS speed. If I use 400 or 500 fpm, the speed would go down to 120 KIAS speed. I gave up climb at 3,000 ft and built up speed to 145 KIAS to resume climb to 5,000 ft which reduced the speed to 130 KIAS although I prefered 7,000 ft to 10,000 ft cruising altitude which is not going to happen for me.

And the cruise speed after reaching and leveling at 5,000 climbed to top speed of 154 KIAS or 170 mph with full throttle power which fell short of 185 KIAS speed that Srgalahad enjoyed cruising in his same plane. Also 154 KIAS speed at full throttle power is not realistic as full throttle power is supposed to produce top speed of 200 KIAS or 75 percent throttle power is supposed to produce 185 KIAS or much much reduced throttle power is supposed to produce 145 KAIS speed for Buffalo Airways planes.

I am okay with 154 KIAS as it is realistic speed for Buffalo Airways planes which usually cruise at 140 KIAS but but but top speed of 154 KIAS is not realistic for R5D model or DC-4 model or Carvair model as in real life, I am sure those planes in their hayhey glory days as brand new planes cruised at much higher speed especially air force C-54s!!!!

Either I am doing something wrong or aircraft.cfg in all model bases need to be modified If I was in real US air force with my climb and speed performance, I do not think I would be successful for Berlin Airlift missions and air force generals would likely to scream at me for lousy climb and speed performance.

Can anybody help me in solving the mystery of climb rate, climb speed, and cruising speed, please? Carvair is kind of fun to fly. So R5D with Buffalo Airways is too. And I do not want to give up and do not want to put the plane in permanent hangar storage.

Thanks,

Aharon

[expat]

Sorry if I missed it being addressed above, but are you using manual mixture settings and leaning the mixture accordingly?

[Aharon]

Sorry if I missed it being addressed above, but are you using manual mixture settings and leaning the mixture accordingly?

Expat,

No need to apologize. I am using 100 percent fuel mixture switches (4) unless somebody tells me that this causes low KIAS speed and I should reduce mixture to increase KIAS speed??????? If so, how many percent mixture?

Regards,

Aharon

[expat]

If you are not using the "auto mixture" setting, you will find particularly with old propliners a substantial power loss/increase by adjusting the mixture, along with MAP and prop pitch/rpm throughout the flight profile. I do have the FR C-47 but don't recall how mixture sensitive it is vs the Calclasssics DC's and Connnies which are quite so. Others here can elaborate more expertly I am sure.

[Ascua]

Hi all
In real life it is a fact that you have to lean the mixture as you go higher to maintain the best possible fuel-to-air ratio in the pistons and therefore the bigger explosion (hence power), there are a number of other factors , but lets not muddle at this point.

If you allow for auto mixture in FSX (there is a tick box for that in the realism settings) it might be possible to see the difference, otherwise, I found a gauge that does that in the Cal-Classic forum:
https://calclassic.proboards.com/thread/7825/fs9-fsx-automixture-gauge

Or you could also use "Real engine 1.4", which you can find here:
https://www.sim-outhouse.com/sohforums/showthread.php/71359-FS2004-FSX-RealEngine-Aircraft-Limitations-v1-4-zip

Hope it helps

Saludos

[srgalahad]

You asked before and I don't think I answered. In my sim the FR model is installed as downloaded. No mods, no tweaks. I can see no reason within the model that there should be any difference on a different computer. Having said that, there are numerous things that can make a difference: calibration of controllers can limit how the sim is controlled (full-forward may not be full throttle for example); loading of the a/c -weight and balance affect trim and attitude affects drag; I don't know if FR included drag for the cowl flaps but I have seen models that do to the tune of 5 kts or so. As discussed above, if you are using manual mixture it's essential to have it set correctly. (My flights were with sim Auto-mixture enabled)

That's why I recommend (while testing) that you use AFSD to be able to monitor the various parameters accurately as you go. Again, power and IAS will drop with increased altitude so do your testing at/near sea level to start and (with AFSD) monitor/record TRUE airspeed - once you get close to the 'published' numbers, try higher altitudes but remember that power and IAS will drop as you fly at higher altitudes - check the TAS.
One particular thought - why try to climb at 155 Kts (178 Mph!)? that is an exceptionally high airspeed . Older aircraft generally climbed at much lower IAS than their cruise/max speeds (see below)

I was able to find an Operating Manual for Resort Airlines DC-4B ( appears modified from Chicago & Southern manual). The charts are a bit difficult to read (older photocopies) but you can glean a lot if you squint and interpret. It also has comprehensive checklists and training hints that fill in more details.
Here are data pulled from the pertinent sections:


Weight: MTO 70,000# MLW 61,000#

Wright Cyclone R1820-C9HD 6.8:1 (Fuel 100/130)

Ratings:
T/O 1425 HP 51.5" MP 2700rpm SL 5 min.
Normal 1275 HP 46.5"MP 2500 rpm SL
Normal 1275 HP 45.5" MP 2500rpm @3500 ft
Take off flaps 15*

Page 21/22 of the .pdf
"Performance data shown... based on the following speeds:
Climb speed: Flaps up (Max continuous power) 138 MPH (that's 120 Kts IAS)
other data listed for engine inoperative

Page 34------------
True Indicated Airspeed 138MPH
Gear up, Flaps retracted Max. Continuous power

Reading from chart:
SL 73,000# 950 fpm -- 2000ft 925 fpm --- 4000ft 900 fpm --- 5000ft 825 fpm

Page 61:
..."it is possible to create a stall condition by raising the flaps at airspeeds below those necessary to maintain flight for reduced flap extension."
-----------------------------------------------------------------------------------------------------
Note: with a high-drag airframe like this even small deviations from the above speeds/attitudes can have surprising (and negative) effects on performance. Speed takes quite a while to recover if lost.

https://aviationarchives.blogspot.com/2016/07/douglas-dc-4-operating-manual.html
A copy of the Douglas DC-4 (C-54B-DC) Operating Manual from Resort Airlines, dated April 15, 1951. Credit: Irfan S. Hokan Collection Click here to download manual in PDF form (12.3 Megs) (https://www.filefactory.com/file/42t4d0c7smnh/Douglas_DC-4%20OM.pdf)

[Aharon]

Expat, Ascua, and Srgalahad,

Thanks all for your kind words and answers.


\"Performance data shown... based on the following speeds: Climb speed: Flaps up (Max continuous power) 138 MPH (that's 120 Kts IAS)

120kt KIAS is NORMAl speed for climb?? I thought it is very abnormal as I had been averaging 130kt KIAS during climb at 200 fpm!!!!! If I tried 400 fpm or 800 fpm, it would dip down to 120kt KIAS which made me afraid that the plane would crash! Is 120kt KIAS normal for climb speed???

Flight Replicas has informed me that it is NOT my fault or NOT my flying skills. Flight Replicas said it is fault of FSX Deluxe with SP1 and SP2 because DC-4 is designed for FSX Acceleration or FSX Steam or FSX Gold. And DC-4 does not work well in FSX Deluxe with SP1 and SP2.

I might disagree with Flight Replicas because FSX Deluxe with SP1 and SP2 is same as FSX Acceleration and I think it is MY fault because I might have been using WRONG level settings for propeller control, mixture, throttle, power, and fuel even though I managed to successfully complete the flights.

Can anybody show me screenshots of cockpit panel showing precise settings at percentage (70 percent or 80 percent or so as indicated by window bubbles when mouse is hoveringover levels) of fuel, mixture, and throttle levels in middle of cruising flight action so that I can study to see what I did wrong during my successful flights although slower KIAS speed. I think I am not supposed to set mixture level at 100 percent during flights.

If Srgalahad can do this performance indicated below, then I should be able to do too!!


srgalahad Base weight + 600 lbs crew, 20000 lbs load + 6369 lbs fuel. = 66,356.9 lbs at takeoff.
reduced to 35" / 2350 rpm and set autopilot for 7000 ft and 800 fpm
Speed reduces from 155KIAS to approx 140 KIAS at 4000 so climb was reduced to 600 fpm
Level at 7000, power set to 30" /2150 rpm and once speed stabilizes - 185 KIAS (200 KTAS)

Regards,

Aharon

[Aharon]

Okkkayyyyyyyyyyyyyyyyyyyyyyy

Made another testing flight abroad R5D!!!

Had it climb after take off and flew it using different methods which was to reduce propeller control levels to 70 percent and reduce the mixture levels to 70 percent.

That improved the climb speed from 130 kt to 140 kt, improved the climb rate from 200 fpm to 400 fpm, and improved the cruising speed from 154 kt KIAS to 166 kt KIAS.

But that falls short of 180 kt KIAS cruising speed and 800 fpm climb rate.

Mmmmmmmm what else should I do to get to 180 kt KIAS cruising speed and 800 fpm climb rate??

Regards,

Aharon

[marijn]

Hi Aharon,

Why are you talking about percentages? I have this plane as well and it flies by the number.
I always use the manual and follow the given procedures:

Take-off: 50"manifold / full prop / mixture auto rich (85%)

when possible reduced to 40" / 2550 RPM and climbing at 500 fpm

Climb: 35" / 2350 RPM / mixture auto rich

Cruise: 30" / 2250 RPM / mixture auto lean

Good luck,

Marijn

[Ascua]

Hi Aaron, I do not know if you did it already but just in case...

When you are flying this sort of aircraft, it is important to get them in the correct attitude (angle of attack, AoA) to get the less drag and the best speed.

Basically, when you get to the desired altitude, do NOT reduce the engine settings, let the aircraft accelerate on its own, then, once the maximum speed is attained (or the target cruise speed is well exceeded), reduce the engine settings to cruise.

The aircraft then will decelerate on its own and keep the best attitude and speed for those settings.

This is so because as you climb you have a higher AoA than at cruise and you fly slower, which creates some drag. By accelerating you reduced the AOA and the drag induced by this will reduce and then as you reduce your settings it will slowly increase to the correct values on its own.

In another words, at cruise settings you may not have enough power to counteract the drag caused by the AoA, so go past that point and then reduce so when everything stabilizes you are in the optimal (ish) position. :peaceful:

The explanation is a bit more complex than that, but if you haven't give it a try and tell us.

Saludos

[marijn]

Hi Aharon,

The above method and flying to 500 ft ABOVE your assigned altitude, set RPM and manifold pressure to cruise and decent to your assigned altitude will give the same result and a correct AOA.
(but all of this is also described in the manual of course).

brgds,

Marijn

[Aharon]

Thanks all for kind explanations Much appreciated

Regards,

Aharon