fish4life wrote:gianthammer wrote:fish4life wrote:Shouldn't a C-46 be able to maintain altitude on one engine?
This Post is speculation taking into consideration one persons knowledge and experience with this aircraft Type;
At or close to Max Gross Wt (Considering the Routing YZF-YVQ), Unfeathered Prop not producing full Power, possibility of being in icing conditions.
I would say no, you would be in a constant 100-300'/min decent
The crew did a great job salvaging this situation
Explain to me why these are still legal then? Is it not time to retire the old girls, when everything else this size has to make accelerate stop distances and have guaranteed engine out climbs how are these allowed to operate?
The following may give you an idea as to why the C46 is still being used:
FLYING THE C-46
Flying the C-46 … First Impression (by Jeff Ethell)
(Note: Jeff Ethell came to Camarillo CA in Feb 1997 to fly the CAF So Calif Wing Curtiss C-46 “China Doll”. Immediately after the flight, he gave the following commentary.)
The C-46 was a big surprise to me. After you fly the DC-3, B-25, and other aircraft considered to be “heavy twins”, you appreciate that anyone who flew WWII airplanes probably had to be 18 years old and a weight lifter, because the airplanes are so heavy on the controls. It’s not unusual for the B-17 or B-25 to have 100 pounds of control pressure to deal with. Particularly if you lose an engine, you end up wrestling the airplane to the limits of your strength. There’s nothing to help you other than muscle power and maybe differential engine power.
It probably wasn’t so bad in WWII because those guys were young and fresh out of Cadets. But to those of us who fly them now, they’re heavy airplanes. Even though everyone told me that I’d enjoy how the C-46 felt, I was still surprised. From my perspective it was immediately pleasant. The controls never got heavy. The whole time we were flying, even in slow flight and with one engine out, the airplane was very nice to handle. I was surprised at how light an airplane its size was on the controls.
The C-46 was a pre-WWII design, intended to be a pressurized high altitude airliner. It never got there because WWII came along, and it never got its chance to do what it was designed for. But it was available for the massive transportation problem that came with WWII, when we had to move enormous amounts of material, and originally had no Transport Arm to speak of.
Airplanes were inducted into the military. The DC-3 was simply painted green, the seats taken out, and deemed ready to fly as the C-47. There were no self-sealing tanks, no armor plate, no help at all. WWII films taken over Arnheim, and D-Day, show that when a C-47 was hit it became a massive ball of flame. The plane went down immediately. There was no way out; everyone died. It’s a terrible thing to watch.
The DC-4 became the C-54 the same way. In fact, United Airlines bought ten of them, but when Pearl Harbor happened they were told “No Delivery”. Again, they were painted green and off they went into the Army Air Forces.
Fortunately the C-46 came along, and it had the power to out-perform even those airplanes with four engines. The C-54 out-performed the C-46 to some extent over the Hump, but Hump pilots told me the C-46 was THE airplane you could overload, climb to 20,000 ft (which was mandatory for the first time), go through terrible weather, get to the other side, off-load the equipment and come back. The C-47 couldn’t come anywhere close to that. Hump losses were high. We lost well over 700 airplanes, mostly due to weather, while ferrying 650,000 tons of critical war supplies to forces in China. During the peak month of July 1945, there was an average of 1.3 flights across the Hump every minute!
Having flown the C-46 now, I can see what they’re talking about. It’s a four-engine airplane with two engines! It doesn’t need the other two engines because it has two large R-2800s. Everything else had the smaller R-2000s, 1830s, or 1820s. The intention was to give the customer (it turned out to be the Army) a high performance airplane that didn’t over-tax the pilot, could be loaded to its limits and would fly … even on one engine.
That was a revolution in the air-transport world. Quite frankly, WWII was a revolution all the way through. It probably advanced airline flying by 10 years because the airline pilot who came out of WWII knew what carburetor icing was, understood the problems of having to go through very tough weather fronts, etc. The C-46 was probably the only airplane until 1944 that could deal with these problems to some degree.
The C-46 comes off the ground like a shot. Of course we were flying it light, but even so, it was off the ground quick and was immediately responsive. Differential engine power was wonderful. There’s lots of power in the throttles. You have large engines out there and a move on the throttles gives an immediate response. You don’t have that in airplanes of lower horsepower. I didn’t fly the C-46 in a cross-wind, so I didn’t experience some of the things that could get a pilot in trouble. But it was wonderful throughout the regime I flew.
This pre-WWII airplane was ahead of its day, and held its own throughout the war. Without it there probably wouldn’t have been the airlift operation we had; the “Hump” wouldn’t have existed. It’s certainly a great airplane, and a wonderful piece of history to keep flying. The CAF flies the only two C-46s that are displayed to the public (“China Doll” and “Tinker Belle”). Another 20 or so are still working in Alaska, Canada, and Central America.
More About Flying the C-46 (by John Deakin)
(Note: John Deakin flew C-46s for Air America in SE Asia)
The one thing the C-46 is really famous for is lousy directional control on the takeoff and landing roll. Its rudder is extremely ineffective at low speeds on the runway, even after the tail is up on takeoff. Even under ideal conditions with the wind right down the runway, or with no wind at all, the airplane might suddenly, for no reason whatsoever, head for the side of the runway rather briskly. If you slam in full rudder to stop it, that rudder is totally ineffective. The only solution is to yank back the opposite throttle to stop the nose. And when the nose starts back, you have to get the throttle back up again to get the beast under control. That particular quirk has bitten more potential C-46 pilots than anything else.
The C-47 doesn’t have the same problem. The rudder area on the C-46 is about 30 percent of the vertical surface area, leaving about 70 percent for the vertical stabilizer. The C-47 is reversed, giving it better directional control than the C-46 at low speeds.
Also, the C-46 is a very fat airplane, so when it’s moving down the runway the fat fuselage blocks a lot of airflow over the vertical surfaces. The small rudder doesn’t get much airflow, which limits its effectiveness. The C-47 has a much narrower fuselage, which allows more air to flow over the vertical surfaces, and it has a larger rudder to boot.
You can easily taxi a C-47 at moderate speed, 10 knots or so, and have rudder control with the free swiveling tail wheel. The C-46 rudder has absolutely no noticeable effect when taxiing.
The C-46 has monstrous ailerons, consequently the adverse yaw effect is much greater than on other airplanes. The result is that if you roll the wheel to the left for a left bank, the nose actually goes to the right if you don’t apply a fair amount of rudder to resist it. In most airplanes on a crosswind takeoff, you use the ailerons into the wind to help a little bit. With the C-46 it’s absolutely crucial to use the aileron very heavily to roll it into the wind.
It’s quite comical to watch when a jet pilot gets into this airplane and doesn’t instinctively use the rudder. They’re not used to not using the rudder at all, because most of the jet transports have dampers and other mechanisms that let you keep your feet on the floor when your’re hand-flying them.
The airplane does a job that no other airplane can do even today. A perfect example is the Everts operation out of Fairbanks AK. They haul 12000-15000 lbs of gasoline and other liquid fuels in 55 gal barrels into and out of 2500 ft gravel strips day after day … an astonishing feat. I’d love to try that for two weeks and really get sharp with the airplane again. Five C-46s fly for Everts, and they’re restoring one or two more.
The C-46 has big, fat, soft, low pressure tires, so it operates well off rough, soft, mud, or grass strips. Its footprint is fairly light for a huge airplane. At the time it was built it was the largest twin-engine airplane ever made. It’s bigger than the B-17 and B-24 in all dimensions except that the B-24 has a 2 foot longer wingspan:
AIRPLANE HEIGHT WING SPAN (FT) LENGTH (FT)
C-46 21.7 108.1 76.3
B-17 19.1 103.7 74.7
B-24 18.0 110.0 67.2
The rudder throw, i.e., the distance the rudder pedals move, is the greatest on any airplane I’ve ever seen. It’s quite difficult to set your seat so you can get full rudder on one pedal and get your other leg out of the way of the control yoke. There’s a real trick to it.
I hesitate to say it performs well on one engine, because these days we’re spoiled by jets and other high performance airplanes, where the loss of one engine is a no-brainer … it’s just a little unbalanced thrust. You have better performance on one engine with any of the modern twins than on both engines with the C-46. Nevertheless, for its era, the C-46 had remarkably good performance on two engines, and pretty good performance on one engine.
It has enough rudder control to handle an engine out, but you have to get it all in there. You have to be aggressive with it. It’s got sufficient power on the remaining engine to get around the pattern even with the max gross weight of 48000 lbs on a fairly warm day.
The airplane can do a good three-point landing on short fields. Most people who fly large airplanes are stunned when they see the airspeed indicator sitting at 60-65 kts and it hasn’t stalled yet. You make the landing approach at 65 kts, fairly steep, in fact scary steep, and at the bottom when you approach the runway, you yank the power off and haul the nose up and it squats down on three wheels, and you’re so slow with so much flap out it slows down very quickly. That’s how you get it onto short, rough fields. There aren’t many other airplanes that can do that.
In Vietnam we’d go into short, miserable strips surrounded by unfriendly people who enjoyed shooting at airplanes. We’d make a very tight descending spiral with a 45 deg bank turn at 65-70 kts, and make a real tight final turn. Just as the wings rolled level, we’d touch it down at a full stall and slam on the brakes and get it stopped before running off the far end. Only a C-46 will do that with a huge load. The C-47 is good at this also, but can haul only half the weight the C-46 does. A tail wheel airplane is definitely superior to a tricycle gear plane for getting into a short, unimproved strip, and the C-46 really excels at it.
In most airplanes, especially the larger ones, there’s a considerable delay between moving a control in the cockpit and having something happen out on the wing, particularly with the throttles or props. With the C-46 you just pop a little throttle on it and you get instant power response. You wouldn’t think the big prop would speed up that fast, or that the engine could respond so quickly. When the airplane suddenly veers into one of it’s wild excursions, you just pop a little power to it and you get instant response. The most effective directional control on the airplane is differential power. It’ll get you out of trouble quicker than any thing else.
I never flew the airplane under icing conditions, but its reputation is excellent for fighting ice. It was used heavily on the DEW Line, where it flew in miserable Arctic conditions, and of course across the Hump where its bad-weather exploits are legendary. I flew C-46s mostly in SE Asia, where the only ice was in our scotch.
It has a good range with regular tanks, which hold 1400 gals. That will take it 10 hrs easily, and if you really go into fuel conservation, you can get 12-13 hrs flight-time out of that much fuel. It will do 150 kts at low power settings and perhaps 125-135 gals/hr. It you really push it, it’ll go up to 180 kts at maybe 180 gal/hr. Figure roughly 1 kt per gal per hr, which makes fuel planning fairly simple. At 150 kts, the range is 1500 to 2000 miles … it depends on how slowly you fly and the load on board.
For a WWII era aircraft of its size and type, the C-46 is pretty fast. Even though it looks fat, it’s a streamlined airplane. It has a red-line speed of about 230 kts, whereas the “Gooney Bird” is well below 200 kts. At airshows it’s impressive to dive down the last 500 ft at full power and go roaring along the runway at red-line speed! Everybody’s impressed by how the big, fat, clumsy airplane can really move along.
The C-46 is a stiff wing airplane. Most airplanes are designed with lots of flex in the wing to absorb the turbulence. In theory the wing on this airplane is built like a bridge, and is actually designed not to flex. Don Downie (former Hump pilot and co-author with Jeff Ethell of “Flying the Hump”) said “Even in the most violent turbulence, it was impossible to see any flexing of this rigid wing structure. By comparison, the C-47 had a very flexible wing designed to bend under loads. Many times from the cockpit of the C-47, you could see the engine nacelle flex downward as the wing tip flexed upward, much to the consternation of those of us accustomed to the brick-house rigidity of the C-46.”
http://www.cafsocal.com/our-aircrafts/o ... -the-c-46/
