Guys,
Perhaps I can help here. I was on the F-35 programme when a number of design decisions were being finalised and also worked closely with the cockpit and escape system teams.
I have to gently disagree with some posts here. Happy to discuss, I'm just trying to present the facts as best I know them.
First, the F-35 was planned from the outset to use LO as an integral part of the overall design - LO wasn't added to compensate for any performance characteristics. A one piece canopy certainly helped with the LO signature, as it got rid of a straight line joint - but it also reduced weight. LM/GD had many years of one piece canopy experience with F-16 as well as F-22, and didn't see it as a big deal.
The front of the canopy isn't 'bird proof', but is much more bird strike resistant than legacy US canopies, mainly as a result of more stringent UK requirements. The front part initially had an additional internal shell bonded to the outer shell, this may have subsequently changed. The rest of the canopy's thickness was driven by normal design constraints including external and internal loads.
The front hinge design was driven by a number of factors. Commonality certainly played a part, as identified by LO. There was also a desire to get the best opening for entry, and the forward hinge provided better clearance around the seat. It also gave better access to the avionics items located behind the seat, and it also made seat removed much easier. The F-35B's lift fan also made an aft hinge design problematic. As ever, any design choice is driven by many factors, not just one.
It's also quite true that the F-35B's flight envelope ruled out jettison of an aft hinged canopy as an escape option, the same logic that drove the initial development of MDC canopy shattering for the Harrier. Commonality meant that the escape system had to go across all three variants. LO meant that the legacy MDC patterns (wavy lines) had to be replaced by a single central line (as per the Gripen). (I hope that answers Fod's observation). No-one said it was going to be easy....
Getting the big canopy shards away from the seat was a challenge, especially at the lower speeds of F-35B transition, as well as at F-35C carrier ops speeds. The seat is required to handle an exceptionally wide range of weights, and also achieve a very low installed weight. (That weight was further trimmed after the weight problems of 2004 - it's now a very light seat indeed). Oh, and they were required to meet some very tough requirements for seat maintenance. MB's efforts were well regarded by all the programme partners as well as the customers. Sometimes, aircraft design is just plain hard.
The helmet has been an ongoing saga for some years, with VSI struggling to achieve weight targets that were probably over optimistic at the outset. The decision a couple of years ago to look at the BAES helmet as an option certainly spurred VSI to some rapid improvements, but the aircraft was always going to have a US sourced helmet, driven by Congressional politics.
It's a 'big hat', driven by an explicit customer requirement for an HMD. That's presented challenges since day one, and I recall that it was being handled as a significant programme risk. Things weren't helped by high level decisions to reduce the number of track ejection tests. These had to be reinstated at a later date. As I've often posted, people can make decisions that later don't work. It doesn't mean that they are bad or stupid people.
To be clear, I'm not trying to 'defend the programme'. But I do try to present the complexity of a real programme, and reassure some readers that the F-35 team has lots of clever and dedicated engineers doing their damnedest to deliver a world beating aircraft to the front line. I think they'll succeed. Others don't. That's fine - free forum and all that.
Best regards as ever to all those working hard to get the aircrew into the aircraft and back out in one piece.
Engines
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