After the Arrow

OMG, the ogival-wing Arrow is beautiful. Breed a CF-105 with a Concorde - lovely !

Both the airframe and the wing started out as lines on paper drawn by this man, Jim Floyd. Small world.

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I`d hate to be a killjoy but I am struggling to think of many production fighters that had major structural modifications like are being proposed here for the Arrow. The Tornado ADV was stretched from the IDS but that`s about it I think. Sure there have been wing kinks and slats, bulged bellies for extra fuel, lumps and bumps for electronics and the odd canard foreplane but everything else has been incorporated within the basic design as frozen back when production started. I struggle to think the Arrow with be the plane to buck this trend, indeed if it needs this sort of radical redesign then it would have to be considerd a failure.
 
I`d hate to be a killjoy but I am struggling to think of many production fighters that had major structural modifications like are being proposed here for the Arrow. The Tornado ADV was stretched from the IDS but that`s about it I think. Sure there have been wing kinks and slats, bulged bellies for extra fuel, lumps and bumps for electronics and the odd canard foreplane but everything else has been incorporated within the basic design as frozen back when production started. I struggle to think the Arrow with be the plane to buck this trend, indeed if it needs this sort of radical redesign then it would have to be considerd a failure.

I hate being a killjoy too. When an aircraft design proves to be something special, it's natural to extrapolate the good properties into broader function using the age-old cut-and-paste technique. The FSW S-37 and stealth T-50 required some fresh lines drawn.

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Wieghts

The Arrow as a very narrow GAP btw it's empty weight and it's maximum take off weight, the MTOW being only a bit over 40% higher than empty weigh. That's low for an interceptor. The F106 has 60%, the MiG25 over 100%. unless the aircraft could get very efficient engines, that would be a serious drawback.
The Arrow would need to be able to lift more weight to be really useful.
 

MacCaulay

Banned
The Arrow as a very narrow GAP btw it's empty weight and it's maximum take off weight, the MTOW being only a bit over 40% higher than empty weigh. That's low for an interceptor. The F106 has 60%, the MiG25 over 100%. unless the aircraft could get very efficient engines, that would be a serious drawback.
The Arrow would need to be able to lift more weight to be really useful.

They did have efficient engines: http://en.wikipedia.org/wiki/Orenda_Iroquois

The Iroquois was so good the French were thinking very seriously about buying Canadian for the engines on their Mirages.


The design of the Arrow was so freaking ahead of it's time, there wasn't even a testbed wind-tunnel in existance in the entire country to test it. They had to go to America to do it.
 

Ming777

Monthly Donor
Was that with the J-75s, because it could be been a bit better with the Iroquois Engines that never got a chance to take off.
 
Yes

Those number are for the MkI. Would the MkIII be able to lift more weigh or was it a structural limitation? It would always need to lift more fuel for long range anything. If it's stuck at 9ton of payload, four 500kg bombs would leave only 7tons for fuel. I find it strange that the MiG could lift so much more, allowing the recce versions to carry a huge centreline tank (5280litres) plus internal fuel...
 
Was that with the J-75s, because it could be been a bit better with the Iroquois Engines that never got a chance to take off.

The J75-version Arrow had a thrust of 12,500 lbf on full military power, 23,500 lbf on full afterburners. The PS.13 Iroquois made 19,250 lbf of full military power (a 54% increase) and 30,000 lbf on full afterburners (a 28% increase). Both of those would have made a big, big difference in the aircraft's performance. I don't imagine something with the Arrow's very low wing loading (its wing load is little more than half that of the CF-18 at max load) and powerful engines that more payload would be a difficulty.
 
But

An F106 with just one J75 lifts 6 tons. An equally efficient design with two should lift 12 tons, not just 9. Could it be that the MTOW as given for the MkI reflects the lack of external stores? In that case the low weigh would only mean there was nowhere to hang more stuff. If it's structural, it is the Arrow's major weakness.
 
There was genuine concern in the company that the Arrow would be ordered with P&W engines if performance was deemed adequately outstanding. This is why maximum speed figures were never sought, at least publicly. The MTOW given for the Mk1 would not have allowed full fuel and weapons, but the number seems to have been picked arbitrarily. There was a higher MTOW specified for the Mk2, but I would have to look it up. This number would accommodate the two additional fuel tanks specified for installation outboard the maingear. The Mk1 was the variant to prove the aerodynamics of the airframe, and the published figures were not as meaningful as they might be regarding the proposed but cancelled Mk2 with Iroquois. The maximum speed, range, weapons load, and MTOW of Mk2 will forever remain undetermined and open to conjecture, but the design team, who had credentials, certainly weren't worried about the final product being able to perform it's forseeable mission profiles. It was only politicians who worried about having too many large taxpayers in Malton. One could wonder what would have happened if Crawford Gordon had been a diplomat.
 
I buy that...

But I would have bought the Arrow too so you're preaching to the choir on this one. Going public with conservative figures must have seemed smar at the time, but made press support for the aircraft more difficult. I'll use a guesstimate of 12 tons usable load for the MkI and up that to 16 for late versions. That would allow patrol interceptor duties, and is more in line with the later MiG25.
 
I hate being a killjoy too. When an aircraft design proves to be something special, it's natural to extrapolate the good properties into broader function using the age-old cut-and-paste technique. The FSW S-37 and stealth T-50 required some fresh lines drawn.

The SU27/30/34 is an extreme version of what I mentioned. The Su 27 got cannards on it`s LERX and a stepped canopy on a bulged back to become the Su 30, and the SU 30 got its bulged forward fuselage widended to become the Su 34. All the while the wings and other fight surfaces and fuselage have remained constant. Even this extreme example may be the exception which proves the rule.
 
The SU27/30/34 is an extreme version of what I mentioned. The Su 27 got cannards on it`s LERX and a stepped canopy on a bulged back to become the Su 30, and the SU 30 got its bulged forward fuselage widended to become the Su 34. All the while the wings and other fight surfaces and fuselage have remained constant. Even this extreme example may be the exception which proves the rule.

The MiG-21 was another aircraft which achieved some cut-and-paste treatment. There isn't a good photo of the ground attack version of the Analog with lateral intakes on a completely redesigned forward fuselage. When I worked at DeHavilland Canada, there were 3 active models, 2 in production, and all were cut-and-paste of previous production to a large extent.

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The MiG-21 was another aircraft which achieved some cut-and-paste treatment. <snip>

So did the MiG-19. It's original version is quite different to the Q-5 which the Chinese are still using as a ground attack aircraft. Some of the more important changes are: solid nose and redesigned air intakes; the addition of an internal weapons bay; new wings; and a stretched area-ruled fuselage.

I don't know how relevant this is to a discussion of altering the Arrow's airframe, but there seems to be some precedent for these sorts of modifications. Perhaps the Eastern bloc were more willing to consider that sort of approach?
 
So did the MiG-19. It's original version is quite different to the Q-5 which the Chinese are still using as a ground attack aircraft. Some of the more important changes are: solid nose and redesigned air intakes; the addition of an internal weapons bay; new wings; and a stretched area-ruled fuselage.

I don't know how relevant this is to a discussion of altering the Arrow's airframe, but there seems to be some precedent for these sorts of modifications. Perhaps the Eastern bloc were more willing to consider that sort of approach?

On closer examination the forward fuselage, the part that can be detached from the main fuselage gets altered regularly enough; the F4D got stretched into the F4E, the Mirage IIIC into the IIIE, the Tornado IDS into the ADV, the Su30 into the Su34. However this is more or less built-in to fighters at the design stage, this is how the RAAF and RCAF managed to buy brand new Hornet centre barrels and replace the time-expired centre barrels on their Hornet fleets.

Behind this main attachment point, where the engines are mounted and flying surfaces are attached to the main fuselage, does not get altered in production aircraft. Parts get scabbed on, but these major structures don`t get stretched etc.
 
On closer examination the forward fuselage, the part that can be detached from the main fuselage gets altered regularly enough; the F4D got stretched into the F4E, the Mirage IIIC into the IIIE, the Tornado IDS into the ADV, the Su30 into the Su34. However this is more or less built-in to fighters at the design stage, this is how the RAAF and RCAF managed to buy brand new Hornet centre barrels and replace the time-expired centre barrels on their Hornet fleets.

Behind this main attachment point, where the engines are mounted and flying surfaces are attached to the main fuselage, does not get altered in production aircraft. Parts get scabbed on, but these major structures don`t get stretched etc.

Not since Kawanishi N1K-1J/2J, anyway. And not without calling it a different name.
 
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