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Canoes On The Convair CV-990  
User currently offlineDeskPilot From Australia, joined Apr 2004, 767 posts, RR: 0
Posted (9 years 11 months 3 weeks 4 days 18 hours ago) and read 2765 times:

I assume that the canoes located on top of the wing hid/streamlined the flap extension mechanism. Correct ?


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Photo © Bob Garrard



Anyone know why Convair chose to place this on top of the wing ? Was this a benefit to the "ramp rats" in that there was less items to hit your head on under the wing ?

Are there any other types that used this approach ?


By the way, is there anyone on board who knows how to fly a plane?
15 replies: All unread, jump to last
 
User currently offlineL-188 From United States of America, joined Jul 1999, 29795 posts, RR: 58
Reply 1, posted (9 years 11 months 3 weeks 4 days 17 hours ago) and read 2752 times:

The Germans did a lot of work on those surfaces during WWII, I want to say they called the Kurchmann Carrots but don't hold me to that.


OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
User currently offlineOPNLguy From , joined Dec 1969, posts, RR:
Reply 2, posted (9 years 11 months 3 weeks 4 days 17 hours ago) and read 2739 times:

That aircraft was slightly before my time, but I seem to recall reading somewhere that the 990 was so fast, they had to put these things on the winds to dissipate the shock waves, or for some other related aerodynamic purpose. (Someone correct me if my recollection is faulty). I believe they also held fuel...

User currently offlineDeskPilot From Australia, joined Apr 2004, 767 posts, RR: 0
Reply 3, posted (9 years 11 months 3 weeks 4 days 17 hours ago) and read 2728 times:

Some history of its demise. Note the lack of range ("..was unable to fly across the USA with a full payload..")

"...The CV-990, originaly developed as the CV660 but re-numbered
for sales promotion purposes, was flewn for the first time on
January 1961, the intercontinental version being known as the
Coronado.

Continual development problems delayed deliveries. Trials revealed
the need for modifications, including the addition of Krueger-
type flaps on the leading edge between the fuselage and inner pylons
to increase elevator effectiveness. The outer pylons were shortened
by moving the engines back some 720 mm (29 in.), to eradicate excessive
vibration, but when flight trail were resumed on April 20, 1961,
serious drag manifest itself, and it was discovered that the CV990
was unable to meet its speed 990 km/h (620 m.p.h.) maximum crusing and
range guarantees, and was unable to fly across the USA with a full payload.

The CV-990 differs from the CV-880 in having a longer fuselage, greater
wing chord and area, more fuel and anti-shock bodies on the wing
trailing edge.

The Convair CV-990 was ordered by Swissair, Scandinavian Airlines
System SAS, Real Aerovias/Varig and American Airlines. Several
air-carriers had both the CV-880 and CV-990 in their fleets but due
to ecconomical reasons they were later faded.

Spantax SA, a Spanish Charter Company became a major operator of the
Convair CV990A Coronado...."





By the way, is there anyone on board who knows how to fly a plane?
User currently offlineLorm From United States of America, joined Jun 2004, 409 posts, RR: 1
Reply 4, posted (9 years 11 months 3 weeks 4 days 17 hours ago) and read 2715 times:

These bumps or canoes were also known as Whitcomb bumps ,which reduced the intensity and drag of shockwaves.


Brick Windows
User currently offlineOPNLguy From , joined Dec 1969, posts, RR:
Reply 5, posted (9 years 11 months 3 weeks 4 days 17 hours ago) and read 2710 times:

Also see:

http://encyclopedia.thefreedictionary.com/Convair%20990


User currently offlineJetMechMD80 From United States of America, joined Jul 2004, 380 posts, RR: 7
Reply 6, posted (9 years 11 months 3 weeks 4 days 11 hours ago) and read 2635 times:

They were called anti-shock bodies, and they also held fuel in them.


"I get along great with nobody"~ Billy Idol
User currently offlineLorm From United States of America, joined Jun 2004, 409 posts, RR: 1
Reply 7, posted (9 years 11 months 3 weeks 4 days 11 hours ago) and read 2630 times:

I am really not sure where the Whitcomb designation fits in, (designer?) but yes the 990 was tested up to mach .98

NM.... http://www.fact-index.com/w/wh/whitcomb_area_rule.html

Yes lazy, ready to sleep! Eat your heart out, all you need to know on Whitcomb bumps.

[Edited 2004-09-02 12:34:24]


Brick Windows
User currently offlineFBU 4EVER! From Norway, joined Jan 2001, 998 posts, RR: 7
Reply 8, posted (9 years 11 months 3 weeks 4 days 10 hours ago) and read 2622 times:

These "Küchemann Carrots" were a 1950's solution to high speed/compressibility problems and they first appeared on the British Handley Page Victor bomber.
The Soviets also designed bombers with this feature.In these cases the carrots also functioned as wheel wells.



"Luck and superstition wins all the time"!
User currently offlineQantasA332 From Australia, joined Dec 2003, 1500 posts, RR: 26
Reply 9, posted (9 years 11 months 3 weeks 4 days 10 hours ago) and read 2621 times:

(Richard) Whitcomb was a NASA/NACA engineer who did a lot of work in many different areas of aerodynamics and aircraft design. Some of his most well-known contributions to modern aircraft design are the winglet and the aforementioned area rule -related developments, to name just two. He was quite an excellent engineer...

Cheers,
QantasA332


User currently offlineBroke From United States of America, joined Apr 2002, 1322 posts, RR: 3
Reply 10, posted (9 years 11 months 3 weeks 3 days 8 hours ago) and read 2514 times:

The fairings on the trailing edge of the 990's wing are called Whitcomb Shock Bodies. They are intended improve the transonic drag of the airplane and are a form of area rule. As a note, the Shock Bodies on the 990 predate those on the Victor, as they were added to the Victor after production of the airplane was finished.
The Victor is the only airplane that I know off that employs a crescent wing shape. If you look are the wing from above, you would see that the wing sweep decreases as you go further out on the wing. A compromise to get a higher critical Mach number and have reasonable approach and take off speeds.


User currently offlineMr Spaceman From Canada, joined Mar 2001, 2787 posts, RR: 9
Reply 11, posted (9 years 11 months 3 weeks 3 days 3 hours ago) and read 2486 times:

Hi guys.

Here's a photo that shows a red fuel cap (I guess that's what it is Big grin) on one of the Convair CV-990-30-6's Whitcomb Shock Bodies.


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Photo © Charles Falk



Here's a nice aerial view of a Coronado .....


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Photo © Markus Herzig



Here's a Convair 990-30-5.


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Photo © Johan Ljungdahl



Here's the Handley Page Victor K.2 with it's anti-shock bodies visible.


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Photo © Simon Thomas
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Photo © Tom Everitt



Regarding fuel, I always liked the "Slipper Tanks" on the De Havilland DH-106 Comet 4C. They make the jet airliner look FAST!


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Photo © Eduard Marmet




Chris  Smile



"Just a minute while I re-invent myself"
User currently offlineBa97 From Canada, joined Apr 2004, 377 posts, RR: 0
Reply 12, posted (9 years 11 months 3 weeks 1 day 19 hours ago) and read 2379 times:

Are the slipper tanks basically extra wing fuel tanks? If so, I throw a question out- How come other planes do not do it for greater range? I suspect storing fuel inside is easier than outside on a wing and having a ground crew trained to put on/take off tanks is expensive...did I just answer my question?


there is economy class, business class, first class...then Concorde..pure class
User currently offlinePrebennorholm From Denmark, joined Mar 2000, 6421 posts, RR: 54
Reply 13, posted (9 years 11 months 2 weeks 4 days 23 hours ago) and read 2297 times:

Ba97, the DH-106 went through a tremendous development as more powerful engines became available. While the Comet 1 could hardly match the performance of a small RJ today, then the Comot 4 became a much heavier and much more capable plane.

Still the wing didn't change all that much. Fuel capacity became a limiting factor. Most dramatic wing change was a substantially changed leading edge profile to improve take-off performance - introduced on the Comet 3 if I remember correctly.

In order to just be able to cross the pond with reduced payload a minimum change Comet 4C version was produced with those slipper tanks.

The Comet 4C would have been a better plane without those slipper tanks. But that would have cost a lot of money and time for redesigning the wing. That could have been feasible if the Comet at that time - the late fifties - had been looking into a bright future. But more modern designs were already being tested or were well advanced on the drawing board.

And about the Whitcomb bodies: Already in the 70'es the airline companies discovered that they don't sell Mach numbers to their passengers. They sell travel at competitive prices.

That effectively ended the "speed rush". Speed settled down at M=0.80 to 0.84, and slightly slower on short haul.

That is more obvious today than even before as the airlines let the passengers stand for hours in check-in queues to be able to save two bucks on handling costs (especially the LCCs). And get away with it.



Always keep your number of landings equal to your number of take-offs, Preben Norholm
User currently offlineSlamClick From United States of America, joined Nov 2003, 10062 posts, RR: 68
Reply 14, posted (9 years 11 months 2 weeks 4 days 19 hours ago) and read 2268 times:

Bear something in mind guys. It is my observation that life in the jet routes moved at about M .76 in the 1980's and at about M .80 now. So if you build a plane that will fly at point nine eight it will just get stuck in traffic.

Add to this, my company blocks flights at about ten minutes longer than it actually takes to fly them on a good day. What is the point of going faster?

I have a really nice fast sports car and I feel that I personally own the mountain roads between here and the ocean. It is true until I come up behind a motor home or a Volvo. Same principle for fast airplanes. Okay if there are only a few. Not good when there are more than a few, but not enough to raise the bar.

BTW Why do they bother putting rearview mirrors on Volvos?



Happiness is not seeing another trite Ste. Maarten photo all week long.
User currently offlineAloges From Germany, joined Jan 2006, 8702 posts, RR: 43
Reply 15, posted (9 years 11 months 2 weeks 2 days 1 hour ago) and read 2200 times:

Thanks for the replies, folks! I read through them, and they're much appreciated - you learn a thing or two on this website every day! Big grin

"BTW Why do they bother putting rearview mirrors on Volvos?"

So the driver can see the poor mad guy crawling behind him and laugh his you-know-what off?  Big grin



Walk together, talk together all ye peoples of the earth. Then, and only then, shall ye have peace.
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