Why were most early WW2 fighters designed with limited rear visibility?

[Shortround6]

I was on Greg's Airplanes earlier today and he said that bubble-top P-47Ds were about 500 lbs heavier than the razorback Ds. Any truth to that?

According to AHT the P-47D-25 (first production version with bubble canopy, there were earlier prototypes/test rigs) the P-47D-25 through 40 had
New engine version on some.
The bubble canopy.
larger main internal fuel tank (by 65 gallons)(about 90lb increase in the weight of the tank)
revised cockpit switches
stronger belly shackles
Extra oxygen bottles
Dorsal fin (-27 and later)
Dive flaps (-30 and later)
Under wing rocket provisions (-35 and later)

and that is just the changes from the D-20 to the D-25 and later. There were a bunch of changes from the earlier Ds to the -20s. like the extra 118lbs (?) for the paddle blade prop. or the addition of the under wing pylons.

I would say that the later Ds with bubble tops could easily have weighed 500lb more. However, how much of that increase in weight is because of the bubble canopy is certainly subject to question as so much other stuff was added.

 

[SaparotRob]

…. There were a bunch of changes from the earlier Ds to the -20s. like the extra 118lbs (?) for the paddle blade prop.…

Was there a more official name for the paddle blade prop? That just doesn't seem to have a proper "governtmentese procurement requirement" tone to it.

 

[Thumpalumpacus]

According to AHT the P-47D-25 (first production version with bubble canopy, there were earlier prototypes/test rigs) the P-47D-25 through 40 had
New engine version on some.
The bubble canopy.
larger main internal fuel tank (by 65 gallons)(about 90lb increase in the weight of the tank)
revised cockpit switches
stronger belly shackles
Extra oxygen bottles
Dorsal fin (-27 and later)
Dive flaps (-30 and later)
Under wing rocket provisions (-35 and later)

and that is just the changes from the D-20 to the D-25 and later. There were a bunch of changes from the earlier Ds to the -20s. like the extra 118lbs (?) for the paddle blade prop. or the addition of the under wing pylons.

I would say that the later Ds with bubble tops could easily have weighed 500lb more. However, how much of that increase in weight is because of the bubble canopy is certainly subject to question as so much other stuff was added.

Stuff like this is why I asked here.

 

[Thumpalumpacus]

Was there a more official name for the paddle blade prop? That just doesn't seem to have a proper "governtmentese procurement requirement" tone to it.

Mk 29 Oar, Broad Chord, High Speed.

 

[MiTasol]

Was there a more official name for the paddle blade prop? That just doesn't seem to have a proper "governtmentese procurement requirement" tone to it.

Darned good question. In 60+ years in the industry I have always known the two types of blades as needle and paddle and never even questioned what the official names are.

 

[SaparotRob]

Mk 29 Oar, Broad Chord, High Speed, 1 each.

Fixed it.

 

[Geoffrey Sinclair]

The USAAF version list says changes from the P-47D-23 to the D-25 were Bubble Canopy and flat front windshield, enlarged main fuel tank, 30 gallon water tank, water pump adapter, increased oxygen supply, deletions of provisions for contractor equipment RC-96, type E-15 turbo tachometer to replace type E-13, AN-5773-1 engine gage unit to replace type B-7. Roger Freeman gives the D-23-RE as 9,900 pounds empty, 14,000 pounds gross, the D-25RE as 10,000 and 14,600 pounds.

Looking at the Lancaster fuel tank weight I use 1 pound per imperial gallon capacity as a rule of thumb but of course as we know for a cube 1 unit of volume requires 6 units of area, five units of volume requires 22 units of area and so on.

 

[buffnut453]

Mk 29 Oar, Broad Chord, High Speed.

Is that a propeller or a lady of ill repute?