Monday, April 1, 2013

How not to develop a military aircraft

Interesting quote:

A major blow to the JSF manufacturing concept, leading to an increase in production costs, was the abandonment of “quick-mate joints.” The idea was to attach interlocking parts to individual components that would make the final assembly of the fuselage, wings, and engine easy, like snapping and soldering jigsaw puzzle pieces. But the interfaces drove the weight up by about 1,000 pounds, so a traditional, time-consuming joining system was adopted. All three F-35 variants lost their quick-mate joints to preserve production commonality.

This from 2003: (Bob Cox, Team Seeks Weight Loss for F-35 Joint Strike Fighter, Fort Worth Star-Telegram, June 19, 2003). Tom Burbage, Lockheed Martin's director of the Joint Strike Fighter Program stated at the time.: "That was the trade-off we had to make to get the weight down." That article mentions the removal of the quick-mate joints.

Based on that, I read the 2004 SWAT as 2700lbs of weight reduction in the design. With 2000lbs. of that being going from a 2x 2000lb air to ground munitions for the F-35B to the original JSF 2x 1000lb internal air to ground munitions.

2003: Quick-mate joints go away (think lego blocks), for another 1000lbs.

Total: F-35B--3700lbs.

And later weigh creeped up depending on the variant. And of course a previous post where Burbage mentions poor weight assumptions in the design. You know, things like weapons bays and such.

2003 and 2004 killed variant commonality which at one time whas hyped as much as 80pc.

Now:


(click on image to make larger)

1 comment:

Doug Allen said...

So they "saved" 2000lbs simply by reducing the bombload to 2x1000lb bombs instead 2x2000lb bombs? Isn't that cheating? By that logic, I can save money on groceries by skipping lunch everyday.

It also makes me wonder if there will be problems cramming future weapons into that bomb bay.