|
|
Re Metric Military;
I'm not sure how declaring the military "metric" simplifies things much:
On the ground, things come in anything you can think of, and some things you never heard of, depending on where you are doing business and who you buy it from (what does it say on the label?) 20mm, 30mm, .50 cal and 40mm are all good, though the 40mm launcher on the M-203 hurts your shoulder after awhile, depending on the round you use; and a good helping of 8-inch or 2000 pounders can really turn a bad situation around.
If you get a call for an airstrike, it could come in km or sm, either way you convert it into nm to fly there, then back into feet (decimal, not inches), lat-long and degrees (also in decimals) to put a weapon solution on it, though for CAS you might need to keep the metric equivalents handy for talking to the ground guys, depending on who they are. If your customer is an artillery guy, you'll get milliradians with your meters. Altitude is in feet most places not ICAO, which is moot when you hit the flight levels--give me a number, I can't tell by looking out the window either way (doesn't US ATC give distance in sm?)
Don't go head-to-head with a bad guy inside 9,000 ft, you'll hit him, though how you spot 9,000 when it occupies roughly the same second as 3 sm and zero is a personal matter I suppose. If I recall correctly, bombs fall and burst in meters and psi, and penetrate via fps. Radars give range in nm, altitude in feet, while things like gating can still show up in sm. Guns and rockets are in meters and fps, missiles are in feet and mach (or is it the other way around?) Release altitude is in feet: baro / MSL or AGL / radar depending on weapon type, fusing etc, though that doesn't mean the slant-range won't be in meters, and the canopy correction factor for the HUD is in diopters.
On your way there don't forget to be true if not magnetic, either way where does your device of choice switch to great circle--and we still keep that sextant handy when we get too far from land, if there is room for it in the cockpit. Fuel in pounds, speed in mach number or knots, OAT in Celsius for fuel flow calcs; your choice of ground, indicated, calibrated or true to get things over into nm, which are the numbers the strike package uses when flying tactically who cares anyway since that doesn't include winds aloft which inertial or GPS can only reads cumulative or instantaneous and weatherpersons (Fahrenheit and millibars) are as reliable and truthful as lawyers. So for fuel, just give me a number, preferably in minutes at my current (indicated) airspeed, relative to the target / nearest suitable runway as I go along: though lingering a few seconds too long in AB (that's re-heat over in metric, zone five in swabby) converts everything into chapter and verse (Psalms work well).
D. Garrett
Todd Bartrim wrote:
Hi John;
Ok, I didn’t realize you were referring to matching your US odometer to distances up here. Not a problem up here as every vehicle sold in Canada since 1977 has the odometer in Km. And from wheat to steam and everything in between, it drove everybody from farmers to engineers nuts at first. I was 10 when it was switched and wasn’t impressed at the time as I was having enough trouble learning the 3 “R”s, but it turns out to have benefitted me as I can easily use both systems without the need for mental conversion (except temp, never did care for the Fahrenheit thing), but my Dad who all along has embraced the metric system still mentally converts (even though he is loathe to admit it), while my much younger brother has never really known anything but metric. I can tell you that many things are much simpler to calculate using metric. Steam tables are one of the nastiest examples I can think off. Not something many people ever have to deal with, but a good example of how much simpler and strait forward that metric can make something.
While I still have memories of dreading the changeover, in hindsight it was really all that painful and it will benefit future generations. Dave, correct me if I’m wrong but I believe the US military has changed over or are in the process of it now? So while you naturally want to resist it, if not your kids, then your grandkids will benefit from a change while they’re young enough to adapt easily.
I’m tempted to answer some of the other e-mails regarding economic benefits etc. but I really can’t see what continuing this discussion has to do with rotary engines in airplanes, so I’ve decided to leave it at this.
Now if wasn’t currently -29C here (that’s -20F for you SAE types) or if I’d gotten my shop heated before winter, then maybe I’d actually be working on my plane and have something more relevant to talk about!
Todd (resistance is futile… you will be assimilated J)
*From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] *On Behalf Of *John Downing
*Sent:* Monday, November 27, 2006 6:20 AM
*To:* Rotary motors in aircraft
*Subject:* [FlyRotary] Re: Metric
Todd; When you leave Michigan and travel east towards Niagara Falls, you pass through the rural farm land all laid out in mile square sections. The signs are in km and the odometer is in miles and all the distances need conversion. I didn't think it was broke, but they changed it. When you look at the bushels of wheat per acre, it really gets more involved, hectoliters per hectare??, that change must have driven allot of ole farmers nuts. Just my casual observation from the farm. JohnD
----- Original Message -----
*From:* Todd Bartrim <mailto:bartrim@gmail.com>
*To:* Rotary motors in aircraft <mailto:flyrotary@lancaironline.net>
*Sent:* Monday, November 27, 2006 12:25 AM
*Subject:* [FlyRotary] Re: Metric
I have seen this in Canada and none of the distances match
anything you see.
I don’t get this? Care to elaborate?
Todd (matching distances everywhere I look)
|
|