Bf109 - why no bubble canopy ?

[cimmex]

The Germans fitted the cockpit framing with two blanks 20 mm cartridhes that coiuld be fired to push the canopy to jettison it for bailout.

Sorry, there was only one cartridge for jettison the hood at the Fw 190.
cimmex

 

[GregP]

Thanks Cimmex. Can I assume it was located at the top center, or was it located at the bottom near the rail on one side? I have never seen the cartridge location shown on a cutaway and the description I read was 20+ years ago.

 

[cimmex]

Found a pic
cimmex

 

[bobbysocks]

I douht a rear view mirror will do much good in a heavily vibrating machine

If an aircraft is in the rear view mirror then he is right behind you and got you. The wingman system was designed so he is looking after your 6. Maybe the 109 was accidently continued so real efforts to improve were never planned.

a lot of mustang pilots had rear view mirrors. had they been a waste of time i doubt they would have left them on.

 

[GregP]

Thanks Cimmex. Can I assume the cartridge is #15?

 

[FLYBOYJ]

a lot of mustang pilots had rear view mirrors. had they been a waste of time i doubt they would have left them on.

Depends who you talk to - some liked them, some put them on then removed them.

http://www.ww2aircraft.net/forum/technical/rear-view-mirrors-fighters-1315.html#post66041

 

[Milosh]

There were several other aircraft that also could not open their cockpits in flight, including the Fw 190. The Germans fitted the cockpit framing with two blanks 20 mm cartridhes that coiuld be fired to push the canopy to jettison it for bailout.

The 20mm blank was used to break the 'suction' that held the canopy in place even after the jettison lever had been engaged.

The 20mm is located between #11 and #16.

 

[Aozora]

Thanks Cimmex. Can I assume the cartridge is #15?

Looks more like #14 which fired into the base of 16; from memory an MG 151 cartridge was used?

 

[alejandro_]

I have read the whole discussion. I haven't been able to find much information on this subject. Some captured Messerschmitt documents can be found at the NA at Kew, but no comment is made on bubble canopy. In other forums I read that Willy Messerschmitt did try a few but nothing came out of it. I can think of a few reasons:

- There was a fuel tank behind pilot. If bubble canopy is added it has to be trimmed, reducing an already low fuel capacity. You could make up by installing a modified fuel tank, or adding new ones, but then you can have issues with CoG.
- Time, which Germany did not have.
- Effects in directional stability. P-51C/D needed some modifications after bubble canopy was installed.

Finally, I had a look at Stepanets' book on Yakovlev fighter aircraft. He was a designer for the company in WW2 and provides many details on the fighter development. He does comment on the Yak-1 with improved visibility but it did not seem to be very complicated.

 

[zoomar]

Germans had all-round vision canopies since the He 112, but these - as well as later canopies on the Me 262 and Me 309 were not true bubbles. They were framed with the center section hinged for pilot access. Was the entirely clear view canopy on the Fw 190 V1 or early Fw 187 true bubbles in manufacture? Actually, is the bubble canopy really that much better than a clear-view canopy merged into a built up rear fuselage? It's worth noting that the final Lavochkin piston engined fighters reverted from an all-round vision canopy in the La-5 and 7 series to a canopy tailored to a raised upper fueslage, probably with no better all-round visibility sported by the Bf 109K. Of for that matter, the He 100 that followed the He 112 abandoned the all-round clear vision cockpit.

 

[stona]

The fundamental problem for the Bf 109 hood was that it hinged rather than sliding. It was a simple task to fit a blown hood to a Spitfire, not so a Bf 109.
Cheers
Steve

 

[spicmart]

Until the E-model the 109 sported another kind of canopy than the later versions.
Why did they change it? Which canopy had more room?
It appears to me that the earlier ones roomy.

 

[paradoxguy]

A tangential question--why did Messerschmitt persist with hinged canopies that opened to one side or the back with their fighters and zestorers, even the Me 410 and Me 262? Did hinged canopies have an inherent functional advantage over sliding ones, or were they just simpler to manufacture?

 

[GregP]

Hi Steve,

That's simple ... change the hinges to slides. No big deal. If you're going to modify it anyway, make it easier on yourself.

 

[GrauGeist]

Until the E-model the 109 sported another kind of canopy than the later versions.
Why did they change it? Which canopy had more room?
It appears to me that the earlier ones roomy.

The cockpit of the Bf109 was always cramped and on the border of being claustrophobic.

 

[GregP]

I can tell you from experience that if you're in it face first working on the lower firewall ... it is VERY claustrophobic and also tough to get out of! I needed help from two guys.

We were attaching new landing gear brackets and it was quite unconfortable being upside down trying to tighten the nylocks.

 

[stona]

Hi Steve,

That's simple ... change the hinges to slides. No big deal. If you're going to modify it anyway, make it easier on yourself.

But again that's not as easy to do as to write! It could be done of course. I don't know what modifications would be required to the fuselage/sills, apart from the obvious runners. You'd have to alter the rear section, at least to move the radio mast. It would be a lot simpler than developing a low back

There doesn't seem to have been any will, either at the manufacturer or the RLM to make such changes.

As someone has pointed out Messerschmitt persisted with hinging hoods on several types. Maybe that's just the way their canopy guys did it. Some allied types had some odd means of access too....."car door" Typhoon springs to mind.

Cheers

Steve

 

[Rufus123]

I know these numbers would be impossible to come up with but I wonder how many planes and pilots were lost due to lack of visibility?

 

[stona]

I know these numbers would be impossible to come up with but I wonder how many planes and pilots were lost due to lack of visibility?

No way of knowing, but a substantial percentage of pilots were shot down by an assailant who they never saw, for one reason or another.

Steve

 

[Shortround6]

Nobody knows and there is no way to find out, but it obviously was enough of a problem that many fighters were converted to have better reward vision and many/most new ones had canopies offering good reward vision. Exceptions usually being the "interceptors" which were tasked with making one or two firing passes at bombers ( early 1950s jets) and NOT engaging in fighter to fighter combat.