Soviet fighters and 4.12

Originally Posted by Pursuivant

I thought that it translated as "fillet" (i.e., thin strip of material just ahead of the tailplane used to improve stability for bubble canopy planes), like was added to the P-51D-20.

When I think of a "razorback" aircraft I think of a plane like the P-47C or P-47D-10 which had a "greenhouse" (or "lantern") canopy and a very narrow rear fuselage. Arguably, the P-40 had a similar appearance.

Yeah, early P-47's were called razorbacks ... because of the rather sharp edged spine behind the canopy. Bubble canopy equipped P-47's, therefore, weren't razorbacks, just jugs. Planes in general before bubble canopies were the norm so (in the west, anyway) there really wasn't so much a a need to distinguish them from the bubble canopied version as much as identifying the new bubble version itself as something new and different.

Bubble canopies typically hurt directional stability a bit because of the turbulence (and, in the Mustang, additional canopy height) behind them but not much more, really, than going to a larger prop, let's say from a three blade propeller to a four blade, as when Mustang went from Allison to Merlin. The Mustang, having had both mods, drove work in improving directional stability although the Brits had started work on that issue earlier after testing their first (non bubble) four blade Merlin versions (some interesting test parts there).

[ElAurens]

The bubble top P51s were also slower than the "razorback" original design as well.

[1984]

Originally Posted by Pursuivant

So, if I've got my Russian aircraft terminology right:

No Gargrot = "razorback" or high rear fuselage faired into a "greenhouse" ("lantern") canopy.

yes, high rear fuselage it's not fairing="gargrot" and, apparently, high rear fuselage can be called on english as "razorback"...

but, apparently, english "razorback" can mean lot of things without accounting for type design ie it's like i called - wrong, in fact, just for simplicity - all planes with bubble tops "without gagrot"...

Gargrot = cut-down rear fuselage with "bubble" canopy set on top of the fuselage or partially faired into it.

For example, Yak-7 = No Gargrot, but Yak-3 = Gargrot.

gargrot it's only fairing of main constructions, can be low (yak-1b or 3) or high ("yak-1 1941" or "yak-7 1941") ie you no quite understood and for better understanding 2 quotes on russian (sorry, and you just can find similar description on english) - description of fuselage of yak-1 ie apparently of all yaks and description of fuselage of la-5 with high rear part...

yak-1 -

Основной частью фюзеляжа является сварной металлический каркас, составляющий одно целое с моторамой, выполненный в виде пространственной фермы из труб СЗОХГСА диаметром от 20 до 50 мм. Главными элементами каркаса являются четыре лонжерона, связанные 10 рамами.

Для придания фюзеляжу обтекаемой формы сверху и снизу фермы установлены гаргроты.

Верхний гаргрот, являющийся продолжением фонаря кабины, обшит бакелитовой фанерой... Нижний гаргрот обшит полотном по стрингерам и крепится к фюзеляжу на болтах.

la-5 -

Фюзеляж состоял из металлической передней фермы и деревянного монокока, выполненного за одно целое с килем. Его каркас состоял из четырех лонжеронов и 15 шпангоутов. Фюзеляж наглухо скреплен с центропланом четырьмя стальными узлами. Кабина пилота закрыта сдвижным фонарем, стопорящимся в открытом и закрытом положениях. На шпангоуте за спинкой пилота установлена броня толщиной 8,5 мм.

Do you know what the word "gargrot" means literally?

all time i thought what it's not russian word, french or something like this, but fast search not gives clear answer... maybe, it's frech "grotte" ie cave or cavity ie place after canopy... + something like... "garçon"?...

and, in total, of course it's all only my opinion, how i understood all these things...

[Pursuivant]

Originally Posted by 1984

gargrot it's only fairing of main constructions, can be low (yak-1b or 3) or high ("yak-1 1941" or "yak-7 1941")

Sorry to be stupid. Let me try again.

Is this a plane with a gargrot?

http://www.airwar.ru/image/idop/fww2/yak1/yak1-c6.jpg

Is this a plane without a gargrot?

http://www.airwar.ru/image/idop/fww2/yak1/yak1-c2.jpg

Or, does Gargrot have anything to do with the shape of the canopy at all?

Further search makes me wonder if the word doesn't refer to the construction of the cockpit or to an access panel.

Originally Posted by 1984

all time i thought what it's not russian word, french or something like this, but fast search not gives clear answer... maybe, it's frech "grotte" ie cave or cavity ie place after canopy... + something like... "garçon"?...

I can believe that the word is of French origin, since there are lots of borrowed French words in Russian, but I don't think it's related to the word garçon. It might relate to "grotte" - which is French for "cave" (пещера - if Google Translate is right).

[1984]

Originally Posted by Pursuivant

Sorry to be stupid. Let me try again.

no problem... i think, mainly, it's my convoluted explanations of not specialist and my strange english...

Is this a plane with a gargrot?

http://www.airwar.ru/image/idop/fww2/yak1/yak1-c6.jpg

gargrot - it's fairing of main constructions of yak (it's carcass + mount for engine + longerons, if i'm not mistaken), and of canopy of any type too... like flesh it's just fairing of skeleton and skull of man... ie, fairing can be high how here for yak-1 in 1941-1942...

Is this a plane without a gargrot?

http://www.airwar.ru/image/idop/fww2/yak1/yak1-c2.jpg

or low, how for yak-1b and similar models with "bubble top"...

Or, does Gargrot have anything to do with the shape of the canopy at all?

gagrot there always, it's for good aerodynamic form and covers entrails of aircraft, but form depends on form of canopy of cabine ie bubble top or not...

Further search makes me wonder if the word doesn't refer to the construction of the cockpit or to an access panel.

gargrot it's and fairing of canopy and of constructions, and panel which covers what in plane, but not panel for access of crew, ie like skin and flesh, and remember, yak have 2 gargrots - upper gagrot, behind cabine and canopy, and lower gargrot, in other places other "things" if i'm not mistaken...

and in fact, for better understanding, just need to find descriptions of type of fuselage, of yak and for example of bf 109...

and find about "monocoque" etc on english...

I can believe that the word is of French origin, since there are lots of borrowed French words in Russian, but I don't think it's related to the word garçon. It might relate to "grotte" - which is French for "cave" (пещера - if Google Translate is right).

yes, пещера - ie for us cabine with canopy of yak, then, "пещера=cave=grotte" in carcass with various filling which covered with "gargrot", which do and aerodynamically normal form too...

garcon it's joke - just first word with "gar"...

[1984]

Originally Posted by Pursuivant

...

apparently, if whole my theory not mistake, i think what found second word - "haut" ie high ie высокий + on russian often h reading as г (-аргрот) - haut grotte ie after cabine with canopy high fairing of fuselage...

[Pursuivant]

Originally Posted by zipper

Bubble canopies typically hurt directional stability a bit because of the turbulence

Don't you mean torque? As I understood it if you've got the prop spinning one way, the rest of the airplane wants to go the other way and the height of the fuselage and the tailplane helps counteract that.

I could believe turbulence is a factor, though, since a bubble canopy might create a small vortex just behind the bubble, which might cause buffeting of the elevators and horizontal portions of the tail.