Firelock76I did a bit of research on that prop-jet powered Republic fighter. It was the XF-84H, called, and not affectionately, the "Thundershriek!" Apparantly the noise level didn't just make people nauseous, it let to some seizures and nervous breakdowns! AND it could be heard as far as 25 miles away!
The Thunderscreech was an interesting aircraft, as was the somewhat less deflicted XF88B (the latter engineers were smart enough to keep the propeller stopped and feathered on the ground!). The idea was to run a substantial portion of the propeller blades supersonic all the time, in the case of the 84H, on the ground with the engine at idle. This meant that the blades were shedding shockwaves outward at considerable intensity. This is not noise, it is the same cause as sonic boom, or the thing that killed the Discovery crew. As a 'fun' aside, the shock directly affected peristalsis in the large intestine leading to 'soiled underwear'...
Now, in a sense, this was the T1 of the aircraft world, because when supersonic props worked correctly both the speed and range of the aircraft increased dramatically. Someone pointed out that the effective HP equivalent of the thrust for the regular Thunderjet was about 11,000 vs. 5800 to 7500 shp for the same speed; the expected range of the turboshaft version was about 2000 miles unrefueled, which is astounding. (Of course the aircraft had terrible stability problems, had an emergency landing almost every time, and didn't come within over 100 kt of its design speed ...but the promise was, and still is, there for supersonic propellers)
Apparently the Navy was testing a contrarotating version of the outfit at the time 'research was suspended' - whether this would have fixed some of the stability problem is probably less important than the continuation of the noise ... which might be reduced somewhat with modern bladetip designs (like those seen on the Airbus A400) but NOT the profiles then thought appropriate for a propjet fighter. (It should not be surprising that the Tu-95 Bear, which was a faster aircraft than the 84H, was extremely loud in the air, again predominantly due to shock noise from the props)
As a somewhat amusing aside: A later high-performance aircraft with high nominal fuel efficiency was the original follow-on to the SR71, with the pulse detonation wave engines running at about 30Hz, apparently just as loud albeit at lower frequency than the shocktrains from the Screech. Note that that aircraft went nowhere, either, but the promise of good fuel efficiency at reasonably high Mach continues to be explored...
And could that man dress! I saw a picture of "Mistearl" on the deck of an ocean liner in about 1930. Derby hat, spats, striped trousers with creases so sharp you could shave with them! He had style and that's a fact!
Harley Earl! The man most responsible for the complete change in American auto body styling from 1929 to 1939. What a guy.
I did a bit of research on that prop-jet powered Republic fighter. It was the XF-84H, called, and not affectionately, the "Thundershriek!" Apparantly the noise level didn't just make people nauseous, it let to some siezures and nervous breakdowns! AND it could be heard as far as 25 miles away!
Wow. No wonder they dropped it.
Leo_AmesThe Airbus is counter-rotating. The pair of propellers on each wing turn in opposite directions to counter the effect of torque, instead of the typical arrangement where they all turn in the same direction.
There's much more to it. Google "down between engines" to see some of the aerodynamic reasoning. Here is a PDF with some background that describes advantages when an engine goes out.
A few things for what it's worth. I used to work with a guy who retired from the Air Force as a sergeant. His outfit was inspected by Brigadier General Stewart in Viet Nam.
There is an old man in Petrolia, Ontario which is near Sarnia who owns a 1967 Bristol car, an aluminum-bodied coupe with a Chrysler 318 and Torqueflight. It's a project but it's solid. He said he grew up in Bristol and remembered the Brabazon on it's test flights. He said he'd take about $8,000.00 for the car but it needs a lot of work.
The Lockheed P-38 was a major influence on General Motors styling in the late 1940s. Where do you think those stubby fins on a 49 Cadillac come from, as well as the air scoops below the headlights on a 49 Oldsmobile? Harley Earl was the head of styling and he knew his stuff! If you know anything about old cars, you'd know he designed the 1927 LaSalle, the first car ever styled as an entire entity and what a beautiful machine it is!
Yes, I'm a train, car, airplane and ship nut. Like DM said about anything that moves.
If my knowledge of aviation history is accurate, the Lightning indeed was the first major example of counter-rotating props.
Edit: Wikipedia says that the Wright Flyer had such an arrangement. So I suppose that one has to take the honor, although it can hardly be said to have popularized it.
The novelty with the P-38, if Wikipedia is accurate, is that the counter-rotation was reversed so that the top of the propeller arc was moving outwards, away from each other. This seems to have aided stability, especially when firing its weapons.
I always assumed that two propellers on the same axis turning in opposite directions were referred to as "counter-rotating." No matter, I get your drift.
As I recall, the first time a twin engine design with props turning in opposite directions was on the Lockheed P-38. Early models had both engines turning in the same directions but that lead to severe torque and controllability problems.
Don't make the mistake of confusing contra-rotating with counter-rotating. They're two different types of arrangements.
The Airbus is counter-rotating. The pair of propellers on each wing turn in opposite directions to counter the effect of torque, instead of the typical arrangement where they all turn in the same direction.
Also has a novel setup that allows the engines to be identical across all installations, with only the gearbox to the propeller being different. That's why this typically hasn't been done in large multi-engine installations since traditionally, they'd of needed clockwise and counter-clockwise engines. The complication and added expense thus has usually discouraged this despite the performance advantages.
Contra-rotating is like what the Tu-95 Bear is equipped with, where two propellers are paired on the same shaft and rotate in opposite directions of each other.
Just watched the video of the A400M. I was VERY impressed with the short take-off roll, impressed with how fast it stopped, and VERY, VERY impressed with that Immelmann Turn the pilot performed with a bird that big!
Those are state-of-the-art multi-blade propellers, but they don't appear to be of the counter-rotating type. They do seem to have a reverse feature which I assume is to aid in short-field stops.
Looks like a pretty versatile machine, to me at least.
http://www.damninteresting.com/the-plane-that-flew-too-soon/
C&NW, CA&E, MILW, CGW and IC fan
Maybe memory fills in gaps?
I have seen nothing about any technical problems with the Brabazon. Other sites suggest that the yuuuge lightweight structure showed fatigue cracking whereas the above site suggests the cracks were in engine mounts and amendable to correction with proper reinforcement.
Everything I have seen is that the failure of the plane was in marketing -- there were no customers.
It was marketed as carrying small numbers of passengers at slow speeds with adequate amenities to make the journey "civilized." I think there is an analogy there to long-distance passenger trains. I have brought this up earlier on the Passenger Trains Forum with respect to the design trade between a fast mode where people tolerate being crammed in for short durations vs a slow mode that lets you "get up and walk around", but providing that walk-around space costs fuel and other expenses.
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
No surprise there's a lot of aviation fans here. As the late, lamented David P. Morgan once said "Big things that move are a lot more interesting than big things that don't!"
I lucked into a fine condition copy of Morgan's "The Mohawk That Refused To Abdicate" a few months back. It was hard to miss at the train show, what with that loud, garish, oh-so-Seventies dust jacket, but as they say "Don't judge a book by it's cover!" Good Lord, that man could write!
A bit more on the Brabazon. I'll admit it's been 20-plus years since I read the article about it in "Aviation History" ( I think) magazine so my memory could be faulty on this, but as I recall there were actually TWO engines for each of the propellers that were connected through a complicated transmission system, hence the "bugs" that couldn't be worked out. The whole thing was over-engineered when a simpler approach would have been better. Again, I could be remembering wrong so if someone wants to correct me on this I won't be offended.
The B-36 by comparison had direct-drive from the recip engines to the props.
I would agree with that, too. I've also met a few railfans who are fans of large vessels. I am not in that category (yet) but I do have some interest in large ships.
NorthWest Good to see that many others here are aviation fans!
Good to see that many others here are aviation fans!
My experience has been that there is a sizable overlap between the two fields. In my case, it couldn't be helped since I grew up about two blocks from three main lines (South Shore, CWI & NKP) and right under the southeast approach to Midway Airport (DC-7's, Super G's, Viscounts, etc.)
The main problem with the A400M is the cost; Airbus will be hard pressed to make a profit selling them due to budget overruns in development. While they have cut into Boeing's C-17 market, being cheaper, they do not have equal performance. They are intended to replace the C-130s but are larger, leaving open a market for a smaller transport aircraft.
The crash was caused by the fuel trimming software creating a fuel imbalance that cause engines to fail and the plane to bank, IIRC.
The new European Airbus A400M military transport uses counter-rotating turboprops. Seems to have many problems, however. One crashed on test flight in May.
I remember going with my family to Sydney Kingsford Smith Airport in the evening during the late 1950s to see our neighbour (the Engineer Officer of the Royal Navy's Fourth Submarine Squadron) who had been recalled to the UK, depart on a Bristol Britannia. I think that this was the first air farewell, although I remember farewelling people on Orient and P&O liners earlier.
A lasting memory is the noise of the compressed air starter for the Bristol Proteus turboprops as the four engines fired up. The air starter on a Century 636 sounded vaguely similar...
The designer of the Proteus apparently said they were aiming to build the most economical aero engine in the world, regardless of size and weight. he then said "we acheived the size and weight..."
The engine arrangement on the Brabazon (and the Saunders Roe Princess flying boat) was similar to that on the Convair B-36, except that they used tractor propellers rather than pusher propellers. I guess the nuclear deterrent and its priority meant that more effort could be spared to make it work on the B-36....
M636C
Haven't had the privilege to see Fifi in the air yet, but happily, B-17's and B-24's get to this neck of the woods from time to time thanks to the Collings Foundation.
Years ago, a group in Geneseo was flying a B-17 (Fuddy Duddy was its name), a Catalina, and a B-25 around the Northeast like that group and the Confederate Air Force do.
Wonder if they're still around or where these planes ended up if they're not. Hope the Flying Fortress isn't the one that had to make an emergency landing in a muddy field that prevented firefighters from getting their equipment in to save her a while back. :(
Firelock76Did you know the Republic Aircraft tried a turboprop fighter in the 50's? The noise level from that one, I believe a variant of the F-107, was so bad that even with ear protection ground crews got nauseous.
You're talking about the XF-84, a variant of the F-84F (A pre "Century" series fighter-bomber).
The Allison T-40, a comparable engine to the contra-rotating turboprops on the Bear, was used in other models, too. The Convair R3Y Tradewind was the only turboprop flying boat to enter US Navy service, albeit in small numbers due to the program soon being cancelled due to the unreliable engines and the shift away from flying boats.
Lots of one-off prototypes as well, like several vertical take-off experiments and the XF-84.
I haven't heard it personally, but I understand the noise of a TU-95 is absolutely horrendous! Supposedly even US submarines can track that airplane when submerged. Not that the "Bear" isn't a good airplane, but wow!
Did you know the Republic Aircraft tried a turboprop fighter in the 50's? The noise level from that one, I believe a variant of the F-107, was so bad that even with ear protection ground crews got nauseous. It was dropped without regrets.
The trouble with the Brabazon was trying to build a jumbo airplane with '40s materials and piston engines. By the time they got it done, the future had gone to faster aircraft, most notably the Comet.
I for one would have been interested to see a Brabazon engined with the Tu-95's NK-12s -- including the multiple-speed gearboxes -- and the later version of the propellers. Wouldn't have cut down on the noise much, might not have increased the speed enough, but it would have allowed the 'lap of luxury' last-bastion-of-the-Empire stuff to be preserved...
If memory serves, by looking at that photo of the Brabazon you can see what the trouble with the aircraft was, that very unconventional engines-buried-in-the-wings combined with counter-rotating propellers. The Bristol engineers just couldn't get the bugs out of it.
The Britannia as I understand was pretty darn good.
Bristol Brabizon
Bristol Britannia (derived from the Brabizon)
CSSHEGEWISCH I've been trying to remember the title of that movie, which I saw on television when I was about 10 or 11. I do remember that the plane (model name "Reindeer") looked like a Viscount with some extra parts.
I've been trying to remember the title of that movie, which I saw on television when I was about 10 or 11. I do remember that the plane (model name "Reindeer") looked like a Viscount with some extra parts.
The wikipedia entry is:
https://en.wikipedia.org/wiki/No_Highway_in_the_Sky#
The British release used the book title, but it was called "No Highway in the Sky" in the USA. The aircraft is illustrated by a movie frame grab. I think the "Reindeer" name was derived from the multiple vertical tails.
Having read the book, I think the Bristol Brabazon was the aircraft Shute had in mind when he wrote the book. There was a reference in the book that the tailplane had a greater span than a WWII fighter aircraft wingspan...
Honegger wrote Pacific 231 in 1923
The locomotive in the film clip 231 E 24, was the fourth Chapelon Pacific built new in 1936, originally NORD 3.1194. 3.1171 to 3.1190 (231 E 1-20) were rebuilt in 1934/35 from Paris Orleans 3520 class built as early as 1909.
Apart from the double chimney as the poppet valves, the external appearance of the P-O Pacifics was generally similar to the rebuilds, dating right back to the smaller wheeled 4500 type, the first Pacific in Europe in 1907. Many ETAT Pacifics, similar apart from a round top firebox to the 3520s, were built for a number of French systems (including the P-O).
The PLM had numerous locomotives of a different design, and the Nord had two native designs with narrow fireboxes before adopting the Chapelon rebuilds.
But it is likely that Honegger had a locomotive that looked like 231 E 24 in mind when he wrote the piece....
Firelock76 CSSHEGEWISCH Why would anybody want to see something as ugly as a B-24?? Disclaimer, Dad flew with the 306th Bomb Group in 1944. I would! And have! OK, a B-24 isn't as good looking as a B-17, it couldn't take the punishment a '17 could, it was more difficult to fly than a '17, but by God a lot of history was made by the B-24 and a lot of good men served on 'em. I'll visit a B-24 any time one come to town. By the way, the late Jimmy Stewart flew B-24's.
CSSHEGEWISCH Why would anybody want to see something as ugly as a B-24?? Disclaimer, Dad flew with the 306th Bomb Group in 1944.
Why would anybody want to see something as ugly as a B-24?? Disclaimer, Dad flew with the 306th Bomb Group in 1944.
I would! And have! OK, a B-24 isn't as good looking as a B-17, it couldn't take the punishment a '17 could, it was more difficult to fly than a '17, but by God a lot of history was made by the B-24 and a lot of good men served on 'em.
I'll visit a B-24 any time one come to town.
By the way, the late Jimmy Stewart flew B-24's.
One of the major problems with the B-24 was the combination of high wing and sealed fuel tanks rather than the bladders used in most aircraft, which resulted in fuel leaks that made their way into the fuselage after relatively minor damage.
Jimmy Stewart appeared in the film "No Highway" based on the book by Neville Shute (Conway) as a research scientist working on airliner structural failures who found himself on an airliner that was likely to fail during the current flight.
At an intermediate stop he retracts the undercarriage on the hardstand after failing to convince the flight crew of the problem.
A friend was concerned that Jimmy Stewart (not surprisingly) appeared more familiar with the controls than his character was supposed to be...
After repairs, the aircraft taxies out for takeoff and the tailplane falls off....
Interestingly, the book, written in 1949, predicted the failures of (and the official responses to) the De Havilland Comet years later.
And achieved the rank of Brigadier General in the Air Force Reserve.
2 years ago I was in New York City walking down the west side and what flies down the Hudson? The B-17G from the Yankee air museum in Ypsilanti, Michigan, which, by the way was where B-24s were built by Henry Ford in the Willow Run plant. What sweet music it made! My old man was a dorsal gunner on a B-29, completed his training but the war ended before he could see combat.
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