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tgibson

confusion reigning...

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Hi there.I am confused...again. I'm flying Jens Kristensen's DC-4 across to Honolulu and it seems to be flying tail down,so I assume I'm going too slow.The red bar shows 154 kias, the GPS shows 187 gs (is that still knots?) and the tool-tip on the airspeed indicator shows 197 knots!!My reason for asking is that the DC-6 flies nose down when you are going too fast and I've been waiting for the DC-4 to do the same(!) so I can throttle back.I've even put all the bags under the captain and it's still the same tail down attitude.Any advice appreciated,Thanks,Andy

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Greetings Andy,No need to be confused. Just take it one step at a time.First make sure that you are scrolling through the on screen handling notes step by step through the flight. Press F10 and select the lowest icon to get the handling notes into the kneeboard.Scroll down to the normal cruise setting where you will see;***********************************Normal Cruise (c 720hp x 4):COWL FLAPS = CLOSEDMAP = 33 RPM = 2000Check CHT < 230CPlan 1450 PPH****************************If I assume that you are westbound to PHNL then in nil wind conditions, given that the DC-4 is unpressurised, you will normally choose to cruise at 12,000 feet.Just after you reach top of climb your weight will be around 72,000lbs and your drag will be about 165 KIAS. Your velocity will be about 197 KTAS and your ground speed would be 197 minus any headwind vector. All in knots.Your pitch will be about plus one degree at that high weight.Once you are down to half fuel your weight will have reduced 14% to 62,000lbs and your induced drag will reduce by about the same amount. Your velocity will be a few percent higher and will be just over 200 KTAS, (at constant power). Now you are 10,000lbs lighter the aircraft will be flying in a near level pitch since it was designed to do that with normal cruise power applied at mid cruise weight at design cruise altitude. Obviously it will take 10000/1450 = 7 hours from top of climb to reach mid cruise weight and level pitch. Did you wait seven hours?With no headwind that is the point at which you should scroll the handling notes down to the long range cruise section immediately below.****************************Long Range Cruise (c 600hp x 4):COWL FLAPS = CLOSEDMAP reduce to sustain zero pitchRPM = 2050Check CHT < 230CPlan 1200 PPH**************************** For the rest of the flight you intend to micro manage MAP to restrain fuel burn since you appear to be attempting a very long range flight for a DC-4. The above represents perfect operation and delivers the design payload v range curve with zero pilot error. Since you are only reaching 154 KIAS you either;1) have too little thrust because you failed to apply 33/2000 or2) you have too much drag because you have the aircraft in the wrong configuration or3) you failed to apply automixture or 4) most likely of all you failed to create an adequate 4D flight plan and are cruising at an inappropriate altitude. Did you retract the gear and the wing flaps?Did you remember to close the cowl flaps at top of climb?Did you remember to select automixture in the realism screen before operating an aircraft with R-2000 engines?It sounds as though you have enough experience to have remembered all the above.In which case the reason that you are excessively nose up and too slow is simply that you are too high. If you do not exceed 12000 feet you will achieve a higher velocity using normal cruise power because Pratt and Whitney recommended normal cruise power is matched to the fact that this aircraft has an unpressurised cabin. 12000 feet is design cruise altitude for the DC-4 and normal cruise power matches that certification circumstance.The on screen handling notes for the DC-4 begin;************************************Douglas DC-4 Pilot's Handling Notes ************************************SUMMARY.This DC-4 has four 1200hp Pratt & Whitney R-2000-11M2 Twin Wasp engines which are carburetted and highly supercharged. 1450hp is available for take off. The high speed blower provides 1100hp up to 15,000 feet. The constant speed propellers can be feathered. Automixture should be selected from the realism screen.WARNING - These engines suffer from harmonic vibration. Avoid use in the rpm ranges 1550 to 1800 and 2310 to 2510.This aicraft is not pressurised. With passengers aboard operation above 12,000 feet should be restricted to 30 minutes per flight. For long haul military cargo flights with crew on oxygen normal C-54G cruise was at FL140.************************************If you were cargo hauling in a MATS C-54G under military operating criteria instead of reducing MAP around mid flight you would step climb to 14,000 feet and don your oxygen mask. You have enough oxygen to supply the crew for the entire flight, but not enough for a cabin full of fare paying passengers some of whom may be ill or elderly and frail.The means by which you may judge current operational ceiling are explained in more detail in the Propliner Tutorial available from the Tutorials section of www.calclassic.com. I think you have understood its content, but in this case you must bear in mind the fact that your cabin is unpressurised and you may need to spend some or all of any long haul flight below operational ceiling.Finally remember that moving payload has absolutely no bearing on the angle of attack that a wing must develop to sustain the weight of any aircraft. The position of payload can never affect aircraft pitch in flight. Payload position (CoG) only alters the elevator trim setting required to sustain any particular IAS. If as the captain you allow the loadmaster to load the aircraft badly the consequence is additional trim drag to sustain the required pitch and never a different pitch. You may be suffering excess trim drag due to your confusion concerning the possibility of payload position altering flight pitch. The reason that you seek zero pitch is to minimise cruise drag, including trim drag. In a propliner trim will normally be neutral at normal cruise power, at design cruise altitude, at mid cruise weight, but only if the aircraft was loaded correctly so that CoG is neutral.FS9 really is a flight simulator and it is demonstrating very nicely the cumulative effect of all pilot errors perpetrated. You are losing 6.7% of the velocity available from the calorific value of the fuel burned and therefore 6.7% of the available range. On an internal flight this might lead to an interview with your training captain but on a flight to PHNL the cumulative errors might prove fatal.Having said that don't beat yourself up because you missed the optimum 4D flight plan payload v range profile by less than 7%. Most FS users don't get anywhere near that close to achieving the theoretically available payload v range curve of the aircraft they are flying. You have already understood most of what you need to know.The above assumes nil wind. Elementary strategies for dealing with headwinds are also explained in the Propliner Tutorial.

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FS Aviator, many thanks for your superb advice. I downloaded your propliner tutorial a while ago and find that very informative, but hard going for a tyro! and it's something to keep re-reading to gradually get more out of it, and gain some understanding of these magnificent airplanes and the way they flew.I was in fact committing a whole range of errors(quite possibly most of them- although the landing gear was up and the cowl flaps closed) on my way to Honolulu!! and it's debatable whether we would have got there at the altitude I was-- 15,000ft--with any passengers still with us. As it turned out the wind changed suddenly and put the airplane in what I thought was a terminal stall and dive, but it recovered at 7000 ft and is now flying beautifully at a more level attitude and higher speed and I'm going to stay at that level until all the pax are brought out from under the seats and settled down again. My 1st Officer has opened his eyes again and we will continue our journey.Many thanks again, I'm going to print your reply and add it to the tutorial.Andy.ps. In all honesty I will admit the cowl flaps were closed because I hadn't opened them.

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FS Aviator,I just want to post about your Propliner Tutorial. To my way of thinking it is the most extraordinary manual I have come across, a fully thought through technical manual, and yet able to be read by those of us who are not necessarily technically minded, and a manual that gets to the heart of the craft of flying as well.Thank you.Andy

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Could you provide theLinks for that tutorial and for this DC4 please.Much appreciated.Thanks.Manny

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Hi Manny, go to www.calclassic.comand enjoy everything there. You will see 'tutorials' listed on the left. The dc-4 is there as well, although I'm not sure you can d/l the original from there- the dc-6 and others certainly. Check in the Avsim library for Jens Kristensen for the dc-4 models and other repaintsAndy.

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I've always been more of a DC-6 pilot, flew it to Japan once from Seattle, but I should fly the DC-4 some. Anyway did you make it to Hawaii? Or did you run out of fuel and have to ditch in the N. Pac? That water is a little cool this time of year, even at that latitude...Rhett

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Mace, hi there.. oh ye of little faith.. I am posting a screenshot of the airplane as we wend our way over the Pacific. All the passengers are now recovered somewhat and FS Aviators advice means the airplane is acting as it should and still have 88% fuel for about 65% of the trip, so it might be okay!http://forums.avsim.net/user_files/142014.jpgAlt:10000ftkias:167gs:230rpm:2000map:1.4psi ?It is a really enjoyable airplane and I've added a couple of instruments to make it simplerhttp://forums.avsim.net/user_files/142015.jpgthe wind drift gauge is by Glen Copeland and is very useful on a flight over water!The dc-6 and dc-4 are just great models !Andy, without a wet suit.

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Sounds good. Now you know it is sacriledge to fly a classic prop with a GPS, you do know that, don't you? :)You may not need a wetsuit, but you will need a lightning rod...Rhett

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Hi. I read somewhere that it was okay to use the gps as a navigator as it were:-roll and so do input the flight plan and follow that, but I may change to the earlier times Driftmeter from Dave Bitzer and that would make things more interesting! Especially as we'd never find the airport we were supposed to be landing at:( Andy.

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Yeah, you can use the gps, I was just giving you trouble... :)Oceanic navigating like they did back then is fun to me...You can download a sextant here at AVSIM, that supposedly lets you nav by the stars. I have never tried that though.I once read about how they used to navigate across oceans back then, say 1940's and 50's. Seems like they used some high-freq radio beacons, similar to NDB's. Also they used LORAN I believe. And inertial navigation systems were first tested in WW2 but I am not sure if any civilian DC-4's got that.Another technique pilots used during WW2 in the Pacific to find tiny islands was to use dead reckoning, and then once they flew to their end point, if the island was not in view, they flew a "box" pattern of progressively larger squares around that central point. The idea being that they would eventually see the island as they flew this box pattern. (or they would run out of gas)One time in FS I dead reckoned a DC-6B from the Galapagos to Easter Island, and, amazingly, I was only off by about 15 nm. That was using real weather too...all I had to go on was an upper air forecast. That was the best I have done. More often I have had to fly around a little at the destination point to find the island...or run out of fuel...Rhett

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Hi.The gps is the radio operator, even if there's only two in the crew! My best hope for ded. reckoning flights over large bodies of water would be an amphibious DC-6 if I were the pilot and I'm sure my co-pilot would insist on it before getting in the airplane!I tried the driftmeter out, but at night you can't see the surface of the sea to take a reading of the drift so I think I'll stick with the wind drift gauge from Glen Copeland for now. How many crew did the DC-6 and -4 carry? just 2?Good luck over the wet bits,Andy.

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I think the -4 and -6 had at least 3 crew; pilot, co-pilot, and flight engineer. You might want to ask that question over at Tom Gibson's Classic airliner forum though. He or someone else there will know for sure.Rhett

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Hi,Glad you're all enjoying flying the classic propliners!The DC-4 had a crew of 2 to 4. Two on domestic flights, and 4 on overwater (add a radio operator and a navigator). No flight engineer on the DC-4. They usually carried an engineer on USAF C-54's, but he usually didn't actually operate the engines, he was more of a fixit guy. They added a flight engineer to the crew of the DC-6 and later Douglas aircraft - he sat facing forward between the pilots, and used the pilot's throttles and gauges - the DC's didn't have a separate flight engineer's panel like the Connies did.Another technique for finding an island was to use the "known error" method. You would calculate the possible error in your course, and put it all to one side of the island. So you would purposely miss the island - but you knew in which direction you missed it. So when you reached the point at which you expected the island to appear, you turned 90 degrees in the direction opposite of the known error and waited for the island to appear. Essentially this eliminated half of the box when flying the technique described above.Hope this helps,--Tom GibsonCal Classic Propliner Page: http://www.calclassic.comFreeflight Design Shop: http://www.freeflightdesign.comDrop by! ___x_x_(")_x_x___

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