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

[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 OM.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 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 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.

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, C-54E, C-54Gs. 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, C-54E, C-54Gs. 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.