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

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  1. #1

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

    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?? 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???

    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

  2. #2
    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_G...e?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.
    Last edited by Mike71; February 3rd, 2021 at 14:14.

  3. #3
    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.
    America never stopped being great.

  4. #4
    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.

  5. #5
    Thanks all for very kind answers

    Quote Originally Posted by Mike71 View Post
    Are you using FSX or P3D version??
    I am using FSX Deluxe with SP1 and SP2

    Quote Originally Posted by nagpaw View Post
    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.

    Quote Originally Posted by Mike71 View Post

    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

  6. #6
    Quote Originally Posted by Aharon View Post
    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

    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.
    Last edited by nagpaw; February 4th, 2021 at 10:42. Reason: Added test flight data.
    America never stopped being great.

  7. #7
    Quote Originally Posted by nagpaw View Post
    You'll never get any screaming from me, my friend! I'm here to socialize and learn from others Your understanding is correct.
    Thanks

    Quote Originally Posted by nagpaw View Post

    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??


    Quote Originally Posted by nagpaw View Post
    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,


    Quote Originally Posted by nagpaw View Post
    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??


    Quote Originally Posted by nagpaw View Post
    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

  8. #8
    Quote Originally Posted by Aharon View Post
    --- wait wait wait it is in mph, not kt?????????? Since when any aircraft has automobile style mph gauge in cockpit?? --

    Aharon
    LOTS 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".

  9. #9
    Charter Member 2017 srgalahad's Avatar
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    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.

    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/...62/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.

    "To some the sky is the limit. To others it is home" anon.
    “Anyone who has never made a mistake has never tried anything new.” -Albert Einstein


  10. #10
    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.

  11. #11
    Quote Originally Posted by Mike71 View Post
    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.

    Quote Originally Posted by Mike71 View Post
    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.


    Quote Originally Posted by Mike71 View Post
    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

  12. #12
    SOH-CM-2021 MrZippy's Avatar
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    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

    Click image for larger version. 

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  13. #13
    Quote Originally Posted by MrZippy View Post
    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
    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

  14. #14
    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.

  15. #15
    Quote Originally Posted by Mike71 View Post
    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 mode
    l 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.

  16. #16
    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

  17. #17
    Quote Originally Posted by Aharon View Post
    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)

  18. #18
    Quote Originally Posted by Aharon View Post
    ----

    BTW, I am curious to see if the R5D mode
    l 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..
    Last edited by Mike71; February 19th, 2021 at 12:00.

  19. #19
    Quote Originally Posted by Mike71 View Post
    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.


    Quote Originally Posted by Mike71 View Post
    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


    Quote Originally Posted by Mike71 View Post
    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.


    Quote Originally Posted by Mike71 View Post
    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!

    Quote Originally Posted by Mike71 View Post
    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

  20. #20
    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

  21. #21
    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
    Born to Fly

  22. #22
    Quote Originally Posted by Ascua View Post
    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

  23. #23
    Certainly, there you go, it is for a C-54G

    https://ww2aircraft.net/forum/attach...ns-pdf.610177/

    Also, but not so informative

    https://www.filefactory.com/file/42t..._DC-4%20OM.pdf

    Saludos
    Born to Fly

  24. #24
    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

  25. #25
    Quote Originally Posted by Mike71 View Post
    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.


    Quote Originally Posted by Mike71 View Post
    I will see what I can find out.
    Would appreciate that


    Quote Originally Posted by Mike71 View Post
    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

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