Sound of Wright vs Pratt Whitney (Super Constellation vs. DC4)
Ok, this one will bring tears to the vintage flyers amoung you with memories and a soft spot for pistons ...
As I mentioned in an other thread I grew up in the flight approach path of BOG El Dorado. To say that the sound of a Super Constellation flying over head was distrinctive is an under statement when comparied to the sound of a DC4 or even a DC6. Also to see the Super Constellation at fly over at night with all four exhaust stacks on fire ... My father once said that the difference was due to the Wright engines on the Connie having synchronised firing making for a more uniform and smoother sound. Not sure about the DC7 which also had Wrights. I wish I could remember the sound of the Stratocruiser's P&W Wasp Mayor corn cobs whether they were synchronised and if they therefore sounded similar to the Connie. Something tells me the were but ... I could also easily tell between a Curtis Commando ( C46) and a DC3 without stepping outside to look. |
b377 -
Ok, this one will bring tears to the vintage flyers amoung you with memories and a soft spot for pistons ... Tears is right! Only time I get to hear those sounds now is on my Flight Sim. Of course the Connie had different engines: R-3350 w/o PRTs and R-3350 w/PRTs. Different sounds. But, you mentioned the Supers and they all had the 3350s with PRTs. The "fire" had a lot to do with mixture settings. All the DC-7s had the 3350s with PRTs. But exhaust stack design has a lot to do with the sound as well. The Convair 340s (R-2800s) with augmenter tubes sounded different from the DC-6s with the same engine. The R-4360s (corn cobs) were something else! As to the C-46 vs the DC-3; again two different engines. Ahh.....the good ol' days. |
Big radial engines.
Not sure if every one knows, (I only discovered recently) that the model number is the capacity of the cylinders in cubic inches. Wonderful sound. There's a DC-6 flying in the UK still. |
The PRT's mute the exhaust of the R-3350 on the L1049, as distinct from the "pure" exhaust of other round engines.
Now, for a great note, you can't beat the augmented exhaust of the R-2000 on the DHC-4 Caribou!!:D G'day ;) |
Feather #3 -
The PRT's mute the exhaust of the R-3350 on the L1049 |
Turbo Compound
Four rows of seven with a turbo supercharger that pumped the intakes and drove the crankshaft through an impellor, gear thing. The flame(s) were invariably white, and provoked interesting reactions from some pax.
"Sound" does it insufficient justice. |
The Wright 3350 was two rows of nine. I've flown them.
Stephan Wilkinson |
Not only two rows of nine, but the ones with PRTs had THREE turbo blowers.
Four rows of seven relates to the 4360s. |
Turbo blowers?
For those who do not know, a PRT is a Power Recovery Turbine and it is not a "blower". The three PRT's are driven by exhaust gasses and used the power generated to increase horsepower. Vertical shafts driving onto the crankshaft via bevel gearing transmitted the added power. In at least one instance I know of, in about February 1959, an uncontained PRT failure started a fire which brought down a RAAF P2-V5 Neptune, with the loss of 10 crew, when the wing spar burnt through. The wing failed on finals to the short grass runway at RAAF Richmond, the aircraft impacting into the eastern bank of the Hawkesbury River a couple of miles short of the airfield. It was not a pretty sight.
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an uncontained PRT failure started a fire... When the PRT failed, it would initially torch out the exhaust stack, big time, and would be noticed by an approximate 20 BMEP decrease on the affected engine. Shutdown, right now. The CurtisWright turbocompound engine was a paragon of efficiency, but somewhat unreliable in service. |
PRT
Ok that was something I did not know that the PRT was partly responsible for the different sound, which sounds very plausible indeed.
Two things outstanding: - What about synchronised firing of all cylinders in the four Wright engines on the L1049 vs. free running P&W on DC4/6? - Can any one elucidate on the sound of the corn cobs? These did not have a PRT but super chargers and 27 pistons each. Do the C97s still flying sound like the old Stratocruiser? I was once told that the sweet, tuneful, friendly sound of the DC3 was in part due to shape & inner structure of the wings (resonance) ... |
B-377 N1039v
b377 - yessir...
xxx R-4360 on the B-377 (C-97) were same engine/same power, sounded same. My ear cannot recall the thunder of the 3500 hp these made. 28 cylinders, 56 spark plugs per engine... My mother took me from Brussels to London early 1950s, a PanAm B-377. I recall playing with a model toy plane, on the stairs to the bar in the tail. Got a "diploma" signed by the captain, aircraft was N1029V. xxx Van Nuys, early 1970s... American Jet (Alan Paulson's facility). There was an old Guppy stored there, I went inside... to cockpit... Sat in the captain seat, some old instruments were left. And there was a N registry small plastic plate on the pilot panel... N1029V...! Took my Swiss army knife, and yanked-it... incredible souvenir. Sadly, when I moved to Argentina 1993, lost a lot of my memorabilia... xxx :8 Happy contrails |
Golly BelArg !
Ditto BOAC Strat, March 1958 NY - LDN then BOAC Strat, April 1958 LDN- Kingston ( to connect Avianca L-1049 service to Barranquilla) My mother sent me to rescue my father from bar lounge below after a few too many G&Ts . I recall ( at 4.3 years old) looking up thru lounge window at horizontal stabiliser which seemed miles above. Alas got no souvenirs only a post card that said BOAC Stratocruiser Speed Bird RMA Cordilia. Landed Heathrow North Terminal - now Terminal 3 I think. To think that not a single B377 was preserved !! |
27 cylinders
b337 Don't mean to be picky, but the "corn cob" engine had 4 rows of seven = 28 cylinders. Propellers have a bigger influence on the sound you hear than many people appreciate. That said, the sound of a Pratt & Whitney R-4360 Wasp Major at full chat sure is unique.
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Whilst I don't get to play with the big round engines, I do get a lot of pleasure from the Wasp Junior (P & W R985). If the sound of a single 985 flying over a few feet above me on a still day in open water is anything to go by the tone of the multi row engines must be incredible.
Whilst radials may not be as reliable as turbines, listening and feeling the regular beat is very reassuring offshore. |
:)Thanks Old Fella
7 x 4 = my slide rule is past it Corn cobs must have been very smooth engines with such number of pistons reciprocating .. all 112 of them. I really regret not having a museum worthy Stratocuiser to behold in persona - a fallen queen, a Lady with a Past or what ever as explained by EK Gann in this Flying Circus but nevertheless the most unique airplane that ever flew. |
That said, the sound of a Pratt & Whitney R-4360 Wasp Major at full chat sure is unique. Any of you guys flying a C97? Remember to tell me if bringing one to the UK. Any one ever recorded a C97 on CD? |
Powerplants
I guess I'm fortunet as I flew the L1049H,DC6B/DC7C in airline service along with the C97 while in the Calif. ANG. Each of these aircraft had their own unique personality and unfortunely the R4360 and the R3350 both left something to be desired regarding reliability. Of the three, the R2800 was cerainly the most dependable powerplant. At the end of the Vetnam war, the Air Force would not let the C97 into the various air bases within Vietnam simply because they would breakdown and take up valuable ramp space that was needed for the C141 and C130. We would off load in Guam and they would put the cargo on either a 141 or 130 for the in country leg.
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Spooky
How did the C97 sound compare with the other planes you flew? L1049,DC6/7 etc |
Reliability R-2800 vs. R-3350
When I joined PanAm, had a lot of captains ex-377, DC-6/7 drivers.
So, had a lot of questions to them. xxx "Captain Joe, how do you recognize a DC-6 from a DC-7...?" "On the ground, I know, 3 blades versus 4 blades... but...?" And the answer was... "Son, if a plane is landing with one feathered, must be a DC-7..." xxx :} Happy contrails |
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