8.4 tons fuel, 2.8 tons ordnance in both (with external carriage if necessary) -- 0.82 (F-35) vs 0.83 (EF)

The loads are identical in all of the above cases, making it a perfectly fair and suitable comparison. The ONLY thing biased about it is that, for simplicity sake, I did not add tank weight and pylon weight to the Typhoon's numbers in the last case even though these are undoubtedly present.

No fuel, no ordnance in both -- 1.54 (F-35) vs 1.67 (EF)
4.7 tons fuel, no ordnance in both -- 1.12 (F-35) vs 1.17 (EF)
8.4 tons fuel, 2.8 tons ordnance in both (with external carriage if necessary) -- 0.82 (F-35) vs 0.83 (EF)

What is less suitable is comparing an F-35 with 8.4 tons of fuel and a Typhoon with 4.7 tons of gas -- their respective internal fuel load. That is an unequal load; you can put only 4.7 tons of gas in an F-35 if you want.

In any case I do not see that F-35 as being overweight even if they did not reach the unrealistically ambitious goal of a 12 tons empty weight target. As it currently stands, the F-35 has roughly the same thrust to air frame weight ratio as a Rafale. Pretty darn impressive considering the tremendous enveloped volume compared to the willowy Rafale.

Hot off the press from DefenceNews

http://www.defensenews.com/story.php?F=3334533&C=europe

These additional costs are significant. Check my calculations, but for the UK alone it appears that the additional charges will add over $35 million to the cost per jet (232 as total procurement number).

These additional charges could have profound implications to the long term development of the Typhoon and will undoubtedly effect F-35 procurement (if the report is accurate).

I think this comparison is not really suitable. 6.5 t payload for Typhoon and 2.8 t payload for F-35 to make a point there is no huge difference in TWR isn't valid. Take compareable loads.

What is less suitable is comparing an F-35 with 8.4 tons of fuel and a Typhoon with 4.7 tons of gas -- their respective internal fuel load. That is an unequal load; you can put only 4.7 tons of gas in an F-35 if you want.

But then the Typhoon enjoys a larger combat radius, so that comparison is not fair either.

Well the Typhoon has a fuel load of about 4.95 t just for info.

The F-35 is not fully developed now and when you look at the trend it will probably further growth in weight before it enters service, but we'll see.

Realistically, the Typhoon will have to carry external fuel on most missions so the comparison in this case is valid. To counter, one would have to come up with scenarios in which a large internal fuel capacity would be a disadvantage (virtually every design decision involves tradeoffs).

If we factor in the drag that three 1500-liter external tanks (what the Typhoon would need in order to carry that much fuel) would add, the fact that the F-35 would carry at least a portion of the ordnance (whatever the 2.8 tonnes represents) internally, and that two engines generally burn fuel at a faster rate than one (all else being equal), I doubt that the Typhoon could fly farther on the same amount of fuel, despite weighing a couple of tonnes less structurally.

and that two engines generally burn fuel at a faster rate than one

Weight growth in a fighter is almost entirely due to adding new systems to the airplane., not structural weight. Take the F-16 for example, it's structural weight from Block 1 through Block 30 increased very little, even as thousnds of pounds of new systems were added. The structure had sufficient margin to accomodate the weight.

Finally for Block 40, the new system weight growth was such that the structure had to be up graded significantly, with added structural weight.

The point is, the F-35 weight growth depends almost entirely on what new systems are added.

If weight becomes excessive, your guess that maximum g loads could be compromised really doesn't help. Reducing max g contributes very little tp extending structural life on an airplane, because the great majority of the damage is done by thousands of repeated lower level g excursions, not a few max g peaks.

Well a concrete example would be better than throwing in numbers which might be more or less misleading.

Well that depends on the fuel consumption, when the SFC is similar the F-135 will burn a similar amount of fuel as it provides even more thrust than both EJ200 in their current form.

Perhaps the F-22 was always supposed to have a 43000 lb empty weight (or whatever it really is now), but I recall seeing several smaller (but always increasing) numbers published during the FSD phase, as well as reports of needing to change to heavier materials for their properties (e.g. greater heat resistance/conductivity) or generally strengthening certain parts of the airframe to handle unexpectedly high loads measured in flight.

Was there any estimated reduction in airframe life that was deemed acceptable in the interim as the weight gradually grew?

Have the engineers gotten all the flight test data they require yet? Would it make a difference at this point? (these are not rhetorical questions--I just know very little about aerospace engineering)

Point taken about maximum g, but the general idea I was trying to get across was that it's possible that potential compromises to flight performance due to structural limitations may be more acceptable for the F-35 than, say, for the F-22.

That said, if I'm off-base about the F-22's development, then I was deceived by media propaganda, and I gladly take back everything I've said in this thread regarding airframe weight.