Sonerai 1 bubble canopy

[Lakr95]

Has anybody ever built a Sonerai with a bubble canopy? Did a quick scotch and it looks pretty good. Would there be any concerned over the fuselage strength? How much strength would be lost from lowering the turtledeck?

 

[soneraifred]

The turtledeck structure is normally not considered when determining the strength of the fuselage. So, you can change it without affecting the load carrying capability of the fuselage. A bubble canopy was installed on a Sonerai IIL several years ago, and as far as I know it flew well.

 

[tls258]

Take a look: http://users.lmi.net/~ryoung/Sonerai/bubble.htm

I emailed Neil about his bird (the top one in the link). Here was his response:

"I simply used the standard canopy and didn't cut the end off. The frame and hinge was also standard with the exception of making the rear bow lower to match the lowered turtle deck. Also I reclined the seat and moved the rudder peddles forward. This got me to sit lower in the airplane. Raising the turtle deck screws up the airflow across the rudder/fin and I think it ruins the look of the airplane."

 

[Lakr95]

Take a look: http://users.lmi.net/~ryoung/Sonerai/bubble.htm

I emailed Neil about his bird (the top one in the link). Here was his response:

"I simply used the standard canopy and didn't cut the end off. The frame and hinge was also standard with the exception of making the rear bow lower to match the lowered turtle deck. Also I reclined the seat and moved the rudder peddles forward. This got me to sit lower in the airplane. Raising the turtle deck screws up the airflow across the rudder/fin and I think it ruins the look of the airplane."

That looks great with the rv3 canopy.

 

[John B]

It's not an Rv 3 canopy. It is a Sonerai canopy without the rear cut off. An RV 3 canopy is shaped different at the rear.

 

[Flyguyeddy]

Neil sidder’s plane is about 45 minutes from me and in non-flying state. Had a nose over in some beans i guess and its in bad shape.

 

[patmc]

without turtle deck you loose roll over protection

 

[Elviar]

If speed is what you're going for, the razorback P-51C was faster than the bubble canopy P-51D. They traded a little speed for better visibility, so I've heard.

 

[tls258]

P-51C

Appears that the D was a tad faster that the first B and C. About as fast as you might jog, if that makes any real difference at 25,000 ft and 437 mph, as you are flipping around and trying to kill the adversary pilots and avoid being killed by a ME-262 or such. Basically the same speeds considering variations in individual aircraft. What was more important to the pilots was the much better visibility the bubble canopy provided. https://www.mustangsmustangs.net/p-51/specifications/

Model	P-51B/C-1	P-51B/C	P-51D/K
Maximum Speed	430 @ 25k	439 @ 25k	437 @ 25k
Cruise Speed	325 @ 10k	325 @ 10k	325 @ 10k
Climb to 20,000 Feet	7.00	6.90	7.30
Service Ceiling	41500	41900	41900
Combat Range (no d.t.)	755	1180	1155
... speed/Altitude	290 @ 20k	294 @ 20k	294 @ 20k
Range w/ drop tanks	1450	1900	2055
... spped/Altitude	290 @ 20k	294 @ 20k	280 @ 20k

 

[Elviar]

There's published data to the contrary, but as you pointed out, the differences are small. My point was that there is little to be gained by eliminating the turtle deck.

 

[John B]

If you do away with the turtledeck you basically do away with baggage, or at least reduce its size. Also, I don't know about anyone else, but my shoulders are above the longerons, so to get close to proper shoulder harness angles you need a turtledeck to prevent spinal compression in the event of an accident. With a bubble canopy I see no way to get the shoulder harness attach above the shoulders.

 

[jeff naul]

Neil lives just a few miles from me, I'll send him a text about this thread and let him chime in.

 

[Neil1]

Got a message from Jeff just a while ago and decided to sign in.
I never had any negative impact from lowering the T-deck. in fact, I think it let the fin do it's job better as there was less blanking as occurs with any raising of the back of the fuselage. Also I think most people thought it looked great. I did recline the back seat by moving the bottom forward and also moving the rudder pedals forward. I had plenty of room for baggage to go to Lakeland in 87. Completed in 1984.

 

[Neil1]

Here's a few more notes; The T-deck was lowered to the same height as the instrument panel. Still plenty high to raise the shoulder harness attachments. A roll over structure added between the seats. This was perhaps the most useful thing of all as it was the perfect grab handle to use when getting in or out. A single leaf tail spring and Maule tail wheel was installed after landing on a couple of grass strips that weren't so great. I set the king pin angle about 10 to 15 degrees forward at the top. This resulted in what had to be the easiest tailwheel airplane to control on the ground I have ever been in. Steered with springs, not a rod. You could actually take your feet off the rudder pedals on roll out.

 

[squirrely dan]

Make sure you put in some sort of roll over protection if you make that mod. It’s how Charlie Hilliard died.

 

[Flyguyeddy]

Got a message from Jeff just a while ago and decided to sign in.
I never had any negative impact from lowering the T-deck. in fact, I think it let the fin do it's job better as there was less blanking as occurs with any raising of the back of the fuselage. Also I think most people thought it looked great. I did recline the back seat by moving the bottom forward and also moving the rudder pedals forward. I had plenty of room for baggage to go to Lakeland in 87. Completed in 1984.View attachment 15336

Another photo to add to my collection!

 

[Aviacs]

If the subject airplane is a 1, I have a never-used RV3 canopy & frame listed in the classifieds. (old listing).
Fair price to someone who can pick it up in person at or near KELM.

smt