F-84 Thunderjet canopy question

[Shay]

I've had question for sometime regarding the straight-wing F-84's canopy.

Throughout the 2nd World War we saw a progression in fighter design towards better visibility. Most fighter types at, or shortly after the beginning of the war were designed with a multi-peice (birdcage) canopy design. Off the top of my head, the P-51, P-47, Corsair and even the P-40 all eventually evolved to a low rear deck fuselage combined with a one peice teardrop plexiglass canopy.

Ok Picture time:

P-51 before,


And after design changes,


The Mighty P-47 before,


And after,



The Corsair before,


And after,


And last but not least the P-40 before,


And after,



These just a few examples of this particular facet of wartime design evolution.

And brings me to my point. All these aircraft designs moved to a design which allowed a pilot more improved visibility by removing obstructions and allowing a 360 degree veiwing radius.

So why does it seem with regards to the Thunderjet programme that at some point they went backwards.

From the outset the P-84 was designed with a one peice teardrop canopy with no framework or obstructions. Subsequent production models were produced with this same canopy until the G model. According to JB website:

Perhaps the most distinctive feature of the F-84G was the introduction of a multi-framed, reinforced canopy which replaced the clear unframed canopy of earlier versions. However, the presence of a reinforced canopy on a Thunderjet was not always a reliable indicator of its being a G-model, since this type of canopy was fitted retroactively to many earlier F-84s.

Obivously Republic and the USAF felt this new framed canopy was superior to the clear one due to the fact that they retro-fitted them to earlier models.

So my question is why? What was the reason behind the decision to move to this type of canopy which appears to have less field of view over it's predicessor?

XP-84


XP-84A


F-84C,


F-84E,


F-84G,




Retro-Fitment to earlier models:










Any thoughts as to why?

Shay
______________
Semper Fortis

[JBoyle]

I've always wondered it myself.

A GUESS...to increase strength?

[gregv]

Possibly anything to do with having to eject through the canopy?

Just a thought.

greg v.

[Larry Kraus]

I read somewhere that the F-84 canopy had to be reinforced due to a number of failures.Pressurization was relatively new to production fighter aircraft at the time.A similar problem cropped up in other aircraft of the period.The prototype of the AJ Savage had a bubble canopy that was changed to a multiple pane unit in production models,for example.

Yes my extensive F84 books says pressuration was the reasoning for bracing struts in the canopy framework.

Doesnt explain the F-86 tho does it? Same time frame etc but full blown canopy... or F80 but then the F80 was rather small...

[K5DH]

I've always like those straight-winged F-84s for some unknown reason. There's just something attractive about them.

More photos, please. . .