Forum: General F-35 Forum

Stephane Trimble over at Flight Global just wrote another fine article on the F-35 program. I thought I would share.....

IN FOCUS: F-35 concurrency reaches turning point

http://www.flightglobal.com/news/articles/in-focus-f-35-concurrency-reaches-turning-point-366056/

F-16.net Sponsor

Fair enough but 'wind buffeting' had me giggling: "... Some issues, such as wind buffeting, are described as a major risk, but the report then acknowledged that so far it is no worse than on other fighters...." Wot? It can't stand outside in da wind? Very Happy

I s'pose that depends upon one's altitude and attitude at the time buffeting sets in. A technical measure perhaps applicable is 'pucker factor' should deck or terra loom close at hand.

Speaking of "buffeting", it seems to be a very common problem on most jet fighters with twin vertical tails. In fact NASA was working on the problem on the F-18. See the nine page report:

CONTRIBUTIONS TO ACTIVE BUFFETING ALLEVIATION PROGRAMS BY THE NASA LANGLEY RESEARCH CENTER

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20040086836_2004091398.pdf

Just skimming the report, the quick fix for the F-35 might be some thing similar to the McDonnell Douglas designed "Exoskin".

Ask Eagle guys about buffet. Ask old hard wing F-4 guys about buffet. Ask AV-8B pilots about buffet.

Until it becomes dimensional/quantified and compared for reference to other jets, this issue is a red herring.

Last edited by spazsinbad on Dec 17, 2011 - 11:01 PM; edited 1 time in total

Ask an A-4 pilot about buffeting when the leading edge slats came out in a turn under G force. Ask about when one came out and one did not. Very Happy

[A-4 slats were held in place by 'wind' when 'wind' decreased gravity dropped them down.] Very Happy

spazsinbad wrote:

Ask an A-4 pilot about buffeting when the leading edge slats came out in a turn under G force. Ask about when one came out and one did not. Very Happy

[A-4 slats were held in place by 'wind' when 'wind' dexreased gravity dropped them down.] Very Happy

BTDT

Rats. Senator McCain isn't returning my phone calls re the A-4.

fixed by fences and other hardware attached to jet USUALLY... We don't wnat that on LO jets. Seen any F-18's lately?

Quote:

In any previous fighter programme, these issues may not have received such high-level scrutiny. But no other fighter programme has faced the cost of modifying hundreds of production fighters as flight tests reveal new problems over an 11-year period. Even if the changes are relatively minor, the cumulative cost to make the changes could be prohibitive.

I have to agree that it will be along time before the services forget this and it will be an even longer time before they agree to concurrent test and production again. Still, in the early days, it wasn't unusual for an aircraft to go though models A-E before production stabilized and that was over only a few years.

I wonder if you could take a whole new approach though. Maybe categorize testing by design impact. Engine and structure receive full life testing before production begins, since those have the biggest cost impact to fix later. Virtually everything else is easily replaced or modified, so they can be tested and produced concurrently.