I just watched one of the show on Modern Marvel and the USAF said that F-117s are having totally 80's technologies except for modern avonics and
fiber opic system that only can improve and make it flies better. They said that the exterior of the jet is more expensive to take care of than to
work with F-22. Isn't that something to
? Its not so new jet anymore.
As I recall, the first F-117 FSD aircraft flew in early May or June 1981. The Have Blue back in late '77 or the beginning of '78. While the whole
precursor Senior Trend effort was authorized way back in 1973 or 74. The entire blackjet was a hodgepodge of 'borrowed' systems from the F-15 and
16 and A-10 efforts which were then 'state of the art' and thus considered non-developmental engineering source items by which ADP saved engineering
time and effort.
Though it has since undergone two major and one minor upgrades, it would therefore be more accurate to say that the jet is in fact based on 1970s
For comparison with the civil world where the only thing that matters is passenger count, M&R and gas figures, if you bought a 727 in 1981, wouldn't
you consider it dated technology today?
I can say that B-2 structures are made up of pure composite and very few metals like titanium and aluminium are only made up of connect the wings
blend into the body. USAF said that it is the most strongest and long-lasting aircraft in their inventory. There is a but and its nightmare for
maintence crews to do their jobs on that aircraft. The composites are very delicate to take care of. Still, its beautiful aircraft!
Modern composites are not really any more vulnerable to damage than metal structures though they are harder to repair once 'dinged'. The reality
being that _strategic stealth_ is what makes the B-2 such a bear to maintain because it's flight profile and endurance forces it into some extreme
conditions (refuels in the mid-20s right in the hear of the storm belt, transits in the high 40-50s, waaaaay up high in the UV saturated
Add to this the overall size, complex airfoil LE shape, and the former use of tape'n'butter style LO sealing (like drywall mud and seal tape) and
you have a very vulnerable, agitated, airframe that is hard to take care of because it requires 100% signature control measures to be monitored and
maintained at all times between extended flight intervals (albeit over a limited number of sorties).
AHFM and other tricks along with sheer experience on the ariframe are helping but the aircraft is still very much a pimped and primped prima donna.
Of greater concern is the fact that composites _are_ a nightmare to build as well with major shrinkage and uneven curing always a problem while their
internal structures are not always amenable to remote (X-Ray, Ultra Sound or Radar) mapping for imperfections which leads to a lot of early production
wasteage as you do destructive tear downs to get the cuts and the autoclave and the finishing processes down pat.
In fact, Northrop engineered an aluminum wing backup for the Batarang because they didn't believe the composite one would work.
Nor are 'all composite' vs. 'hybrid' designs an easy-out option because imbedding metal pieces into composite spars and frames often causes
differential thermal activation (inside and out, the pin or bolt acting as a heat sink) during cure and even when done right is effectively a
structural void inside the composite which WILL apply load stresses that don't transfer across to the whole structure evenly.
Which makes any area around a metal/composite join altogether more fatigue prone.
Indeed, one of the things which destroyed the ATA effort was the USAFs refusal to play ball with the Squids in handing over their composite
engineering experiences so GD/McD had to choose between engineering for LO, engineering for weight and engineering for structural design issues with a
budget that was barely adequate for any one of the three.