Hmm..., where to begin?  I will just start at the end, and work my way forward from the beginning.

The end:
Yesterday I was sitting at my desk when the phone rang.  It was someone from the Navy, asking if I could recommend a good entomologist.

The Stuff Before the End:

By the end of January the raisin testing had settled down to a smooth routine.  The chemists' testing proved that the coating which had been damaged so badly by bugs was improperly cured.  The step from the chemistry lab to the production line has some subtle traps, and we had fallen in to one of them.  However, when properly cured, the new coating was practically immune to raisins.  Testing continued, but was not very interesting.  A new test lab worker took over the day to day stuff.  I only needed to keep the gun in working order (the speed trap needed rebuilding.) and, of course, demonstrate the test for visitors.

Despite the popularity of my procedure, I was still not sure just how good a simulation it was.  Raisin damage and bug damage look similar to the naked eye.  However, under my low power, low priced microscope differences appear.  The company called in a few experts.

The middle-men between my company and the military guys are from the University of Dayton.  Among other things, U of D does a lot of military aircraft research.  One of the guys there offered to do an analysis of the bug strikes with their high powered, high priced analytical equipment.  I sent off a few raisin-hit window pieces and some bug-hit window pieces for them to look over.  We still were not sure just how much of the damage was impact/abrasion related and how much was chemical attack, and hoped they could shed some light on the subject.

Dayton's preliminary results said that there was still bug stuck to the windshield, even after cleaning and polishing, but they were taking their time deciding about the physical vs. chemical question.  That there would be bug remains remaining seemed odd to me, so I went looking for a way to check their results.  How does one meet or exceed the capabilities of a major university research department on short notice and a shoe string budget? It's easy, if your mind is twisted enough.

I put on my thinking cap and decided that what I needed was some way to increase the contrast between the window's protective coating and any persistent bug remains.  A solution was obvious once I thought about it in those terms.  I opened up my Edmund Scientific catalog and ordered a $30 set of microscope specimen staining dyes.  These are the same dies that your high school biology teacher told you make the nerve cells blue even though they are really not that color in living tissue.

My dies arrived after a week or two, but I was busy with other stuff and so did not get around to using them for a few days.  When I was informed that our Military customers were coming for a visit I did my analysis right away.  I had bug and raisin hits on two types of coatings for comparison.  One was the coating that did badly.  The other was an earlier coating that suffered less bug damage but was rejected for other reasons.  (A flight test window with this early coating had just been returned, and it had a few bug hits.)  I applied my low tech dyes to the specimens.  Lo and behold, it worked.  Suddenly bug bits were staring me in the face from both flight tested coatings, but no grape jelly remained on my raisin hits.  Furthermore, all the damage on the early coating was still bug plastered, while only one quarter of the damaged area on the new coating was covered.  I had duplicated Dayton's data, but it was the end of the day so I headed home with the score tied.  Dayton 1, Edmund Scientific 1.

The next morning the Navy guys arrived.  I went to work on my project right away, while they reviewed those unimportant details of the test program like finances and delivery and contracts.  I found that with soap and water I could remove the residue.  The early coating was left unmarked after the bug guts were gone, but the new coating looked pretty much the same.  This despite the fact that the early coating was vulnerable to raisin damage.  Hmm...  But there was no time to think through the implications just then, as two Lieutenant Colonels walked into the lab to see my apparatus.

I have had mixed experience with military people.  They all seem to like getting things done, but do not have the same approach.  On one program there is a guy who makes up his mind and then goes looking for the best facts to confirm his conclusion.  Information which disagrees is suspect, and must be reiterated several times.  I have little use for this type.  These two were another, much more interesting type.  Very intense, very focused.  The guy in charge knows what he wants; a bird proof F-18 windshield.  He struck me as very intelligent, but not necessarily concerned with the technical issues.  I think he worried more about people.  He looked for the person who knew best what they were talking about in any given group and gave that person his full attention.  For bug impact testing, that happened to be me.

I went through my usual spiel.  This is the windshield returned from flight testing.  Notice the bug damage.  To duplicate it I tried high speed crickets, but they did not work.  So I went looking for something that was more resilient than a cricket, but not bouncy like rubber, and would fit in my gun...  I explained about raisins and showed him the box of raisin bran sitting on the counter.  I pointed out the raisin marks on the windshield, ready for comparison to the bug marks.  Then I showed him the good new coating as compared to the improperly cured new coating on the test windshield.  The explanation is always fun to give, but the audience made it more interesting than usual.  The Lieutenant Colonel was listening to what I said very carefully.  He was ignoring the crowd of technical engineers and sales engineers and management types standing around.  I think he was not just considering whether raisins make a good test, but whether the engineer working on the problem knew what he was talking about and could solve it.

Last of all I demonstrated the gun itself.  It is sort of a kludgey looking device, mounted on plywood and having more wiring than it really needs.  It looks like something that should have odd uses.  I had it set up to fire down the lab table as a small square sample of coating, with a sheet metal backstop.  I selected a promising looking raisin and loaded up the gun.  I put on my eye protection, explaining that sometimes raisin bits would fly back out from the backstop.  (It is true, but I wore it more to give them a sense of anticipation than for safety.)  Then I pushed the button.  CLANG!  A sheet metal backstop makes a gratifying bang when hit with a five hundred mile per hour raisin.  The military people liked it.  They wanted to see it again.

I summed up our current findings by saying that we were still not sure whether the damage was due to physical impact or chemical attack, but that if it was physical impact we had it beat.  Proof positive was that the old coating survived bugs but not raisins, and the new coating now survived raisins.  To guide any new testing we would need actual flight test data. Whether he put his faith in my science or just me I do not know, but he agreed with my conclusion.  He turned to the crowd of other engineers and said they would go with more flight testing.

Which brings us back to my phone call.

The Navy guy on the phone was responsible for the flight testing of our well cured window.  He needed to know if the bugs would be swarming in the next couple weeks, and so was looking for the entomologist I had contacted in Florida.  I gave him the name and number.  Now I am just waiting to hear how the window does through regular channels.  (Or, at the very least, as regular as any of my channels ever are.)