Why don't all fighter jets have bubble canopies?

Question

If you look at the cockpit on the F-16 it has really good visibility and nothing on it, but if you look at the F-14 or the F-18, or anything else like the F-4 Phantom they have like metal bars in the front and its not all glass/canopy. Why don't all planes have clear/bubble canopies? and if you know what are the metal things or whatever is on the canopy/glass called?

****UPDATE: i am sorry for the misunderstanding. i thought bubble cockpits to be more like the single seater f-16, where there is nothing on the cockpit window. if you look at the f-18 (any version) there is a metal bar in it on the front where there might be some mirrors or something. But doesnt that get in the way of precious visibility? Why isnt it just clear?

Answer 1

I'd say that every detail of every plane(like the cockpit) is important to the aerodynamics and performance of it, so even though it may be such a small change as that, it does actually matter- part of the reason is that technology is changing all the time.

Answer 2

Typically, those frames are called "canopy rails". The largest reason most fighters are designed without bubble canopies is cost and ease of manufacture. Bubble canopies like the f-16's are made of single-piece polymers that are difficult to manufacture and require much more expensive materials than earlier aircraft. Making several smaller pieces joined by rails is easier, as it requires less complex shapes to mold and less costly because with multiple pieces, you can use materials that are less durable and usually less costly. This is possible because the smaller a piece of material is, the stronger it is in most situations. Bubble canopies have largely become standard in fighter aircraft due to further development of the necessary manufacturing techniques. For example, look at the SAAB JAS-39 Gripen or the Dassualt Rafale. However, it is still common to put a rail in front, because this allows for a stronger frontal structure to protect against bird strikes and small arms. Making a full one-piece canopy that is durable enough is still fairly difficult.

Answer 3

Specifically on the F-4 and F-14, you'll notice the different sections are actually different materials, hence the reason for the canopy frame. It holds those pieces together. On those two aircraft, the front of the canopy is actually a flat piece of bullet proof glass to help the pilots survive ground fire during ground support operations

Answer 4

well newer planes have better hud(head up display) and radars so why do they need a clear canopies. just take flying an aircraft in bad weather, the pilots relies much on technology then visual. so , there...

Answer 5

Because bubbles can be popped, 'specially when you're flying real fast :P

Answer 6

As everything in an airplane, the canopy too is a compromise. You can have a good visibility at the cost of mechanical strength or vice versa.

The F-16 bubble canopy has good visibility without the front bows, but it is of uniform thickness all the way. This means the same mechanical strength throughout. The trouble is when it comes to ejection it is too thick to blast through, you will have to blow off the entire canopy before ejection. The "two-piece" canopies have the front made of thick polycarbonate designed to survive birdstrikes, but thinner top section for easier ejection.

The F-16 style is a good compromise and no wonder it is adapted in the F-22.

I am not quite sure, but I think that the metal things are called bows.