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-   -   Knots or MPH?? That Is The Question (https://vansairforce.net/community/showthread.php?t=81947)

MauiLvrs 01-29-2012 12:19 AM

Quote:

Originally Posted by Geico266 (Post 622850)
[b] Most pilots uses statue miles to a destination when traveling they usually don't use nautical miles.

EVERYONE we fly with uses nautical miles ... because that is what is on all the charts.
Where would one get charts with statue miles? AAA:eek:

trackdom 01-29-2012 12:31 AM

You have no idea how hard it is for an English guy to admit that anything invented in France is better..:)

I do love this forum!

rvmills 01-29-2012 02:01 AM

So Larry, just how many buckets of popcorn have you enjoyed since stirring this pot up, eh! ;)

And "nobody cares about how fast a ship goes"?...I dunno, how fast the carrier was going made a fair bit of difference in the "quality" of the air behind it (more natural wind = less burble), so we cared how fast it was going! (We also cared how fast it was going when it was headed into port! :cool:)

Hey Mike, all those Class B, C, D, Mode C, etc rings and things on charts (and yes, in GPSs too)...what kinda miles are those in...hmmmm ;)

So there are a lotta knots out there...the only ones I don't like are the ones that get in my headset cord...pesky dern things! :rolleyes:

MPH sounds good to U.S. race fans (500 MPH Unlimiteds and 400 MPH Sports does sound pretty cool, ya gotta admit)...and it sounds good to U.S. airline passengers (they'll get there faster...and happier...at 500-600 MPH...yessir!). If you're quick, or do it 6-10 times a day (outbound and inbound...AMHIK), you can convert KTS to MPH on the fly, just like C to F temps, which we also have to do, since C is on the paperwork, but is still a mystery to most folks here (and as Bob Ax said...we were going to be converted by 1975!

If you really want to brag, state top speed in MPH, and stall speed in KTS, then you win on both ends! Don't screw it up though! ;)

And have you guys forgotten? Girls like knotty boys...so what are ya thinkin'!?! :D

Cheers,
Bob

Sig600 01-29-2012 02:06 AM

He lives!!!

jsharkey 01-29-2012 05:37 AM

Quote:

Originally Posted by frankh (Post 622932)
RV's are fast enough to use Knots and get respectable numbers..well OK, not the RV12...:)

The serious answer is one talks to ATC continuosly while flying IFR, speed comes up quite often (either cus there is a Cessna put put in front of you or a jet behind you) and your better off using the same language.

As an engineer that is fluent in both metric and Imperial units, I have to say the metric system is by far the best.

You have no idea how hard it is for an English guy to admit that anything invented in France is better..:)

The American (Imperial?) system is an engineering pain and a mistake waiting to happen for anything involving mass because it uses the same units for mass and weight or force.

Jim Sharkey

Geico266 01-29-2012 05:55 AM

Quote:

Originally Posted by rvmills (Post 623022)
So Larry, just how many buckets of popcorn have you enjoyed since stirring this pot up, eh! ;)

And "nobody cares about how fast a ship goes"?...I dunno, how fast the carrier was going made a fair bit of difference in the "quality" of the air behind it (more natural wind = less burble), so we cared how fast it was going! (We also cared how fast it was going when it was headed into port! :cool:)

Hey Mike, all those Class B, C, D, Mode C, etc rings and things on charts (and yes, in GPSs too)...what kinda miles are those in...hmmmm ;)

So there are a lotta knots out there...the only ones I don't like are the ones that get in my headset cord...pesky dern things! :rolleyes:

MPH sounds good to U.S. race fans (500 MPH Unlimiteds and 400 MPH Sports does sound pretty cool, ya gotta admit)...and it sounds good to U.S. airline passengers (they'll get there faster...and happier...at 500-600 MPH...yessir!). If you're quick, or do it 6-10 times a day (outbound and inbound...AMHIK), you can convert KTS to MPH on the fly, just like C to F temps, which we also have to do, since C is on the paperwork, but is still a mystery to most folks here (and as Bob Ax said...we were going to be converted by 1975!

If you really want to brag, state top speed in MPH, and stall speed in KTS, then you win on both ends! Don't screw it up though! ;)

And have you guys forgotten? Girls like knotty boys...so what are ya thinkin'!?! :D

Cheers,
Bob


It's January, cold, windy, a little "cabin fever" setting in. This is what happens when there is no build in the shop.

" No one cares how fast a ship goes!" Did I really say that? :o. I was in the Navy, yes we cared. :D

We have been debating this for some time in another group and it spilled over into this one as an after thought. Just having some fun.

Vlad 01-29-2012 06:00 AM

Quote:

Originally Posted by Geico266 (Post 623052)
I am just having some fun. It's January, cold, windy, a little "cabin fever" setting in. " No one cares how fast a ship goes!" Did I really say that? :o


Your fun was taken seriously by the majority of VAFers. How come nobody uses metrics? I heard one favoring Mach but the unit was not in the poll. :D

DanH 01-29-2012 06:13 AM

Hey, we decided this issue years ago, right here on VAF. Everyone was happy with the Mock System.

100 mph = Mock 1....cocktail party bragging rights for RV-12 owners.

200 mph = Mock 2....routine for the rest of us, although -9 owners really should fix their static system leak.

300 mph = Mock 3....used by a small group of Rocketeers, or the airport liar.

ccsmith51 01-29-2012 06:23 AM

A question...
 
All the reasons for using knots are valid. However, I use MPH because that is what every plane I have piloted since I started flying in 1968 has the ASI in MPH. I was instructed in MPH. I don't fly IFR, and the guys I fly with use MPH.

Does anyone know why, if knots is the standard for aviation (charts, ATC, ect.), it seems virtually all civilian aircraft made in the last 50 years have ASI's in MPH? It seems like the manufacturers should have used knots, but they didn't. Or would that be an option when the plane was manufactured and the buyers selected MPH?

Peterk 01-29-2012 06:27 AM

Klik
 
Quote:

Originally Posted by Vlad (Post 623054)
Your fun was taken seriously by the majority of VAFers. How come nobody uses metrics? I heard one favoring Mach but the unit was not in the poll. :D

Vlad! Everything on VAF is taken seriously...Larry saw a Saturday Night Live opportunity and took it. Proud of you Larry! Of course everyone is right because the airplane doesn't care and soon they will all be flying without pilots anyway (we just get in the way). And yes, the metric system is used in the states by the US Army...just ask any grunt what a klik is...and always has been.

Pete

Greg Arehart 01-29-2012 06:33 AM

To me a pace (having used it a fair bit in the field to estimate distance) is R-L-R, thus 1000 5-foot paces is pretty close to a mile.

Quote:

Originally Posted by gasman (Post 622977)
The average 6 foot tall male has about a 3 foot stride. In the example of a mile equal to a thousand Roman paces, their stride had to be 5' 3" long!! And YES.... that would require some very tall legs.

BTW......... How did the 201 Mooney get it's name?


Peterk 01-29-2012 06:49 AM

Quote:

Originally Posted by DanH (Post 623056)
Hey, we decided this issue years ago, right here on VAF. Everyone was happy with the Mock System.

100 mph = Mock 1....cocktail party bragging rights for RV-12 owners.

200 mph = Mock 2....routine for the rest of us, although -9 owners really should fix their static system leak.

300 mph = Mock 3....used by a small group of Rocketeers, or the airport liar.

Dan,

don't forget the GAPHO system!

04 gph = GAPHO 1...cocktail party bragging rights for RV-12 owners

14 gph = GAPHO 2...routine for the rest of you

lbs/hr = GAPHO 3...used by a small group of Rocketeers.


(just having fun of course...not necessary to brag about gph at stall speeds)

Pete

Jerry Fischer 01-29-2012 06:56 AM

Knots...
 
You got a problem with that? See Above avatar from an 'ol carrier sailor in Naval Aviation...nuff sed...:cool:

Geico266 01-29-2012 07:39 AM

Quote:

Originally Posted by Jerry Fischer (Post 623068)
You got a problem with that? See Above avatar from an 'ol carrier sailor in Naval Aviation...nuff sed...:cool:

Old carrier sailor? When I was in the Navy we still used oars. ;)

Real sailors deploy on destroyers BTW. We measured distance in strokes per hour. :D








;)

skylor 01-29-2012 09:19 AM

Quote:

Originally Posted by hydroguy2 (Post 622948)
I use Knots...but today I needed to do some bragging. So before work I took a short flight over the ice fisherman at the Annual Perch Derby. Zipped by them at 150agl(offset 350') doing 205MPH just to show them what 200mph looks like. At the end I pulled into a ~3000fpm climb.

Life is good at 178kts, but 205mph makes a better fishing story.

I'm surprised you would post such a thing in a public forum, potentially monitored by the Feds.

L.Adamson 01-29-2012 09:32 AM

Quote:

Originally Posted by skylor (Post 623105)
I'm surprised you would post such a thing in a public forum, potentially monitored by the Feds.



150agl(offset 350')= 500'. That's legal, isn't it?

dmaib 01-29-2012 09:33 AM

Quote:

Originally Posted by ccsmith51 (Post 623059)
All the reasons for using knots are valid. However, I use MPH because that is what every plane I have piloted since I started flying in 1968 has the ASI in MPH. I was instructed in MPH. I don't fly IFR, and the guys I fly with use MPH.

Does anyone know why, if knots is the standard for aviation (charts, ATC, ect.), it seems virtually all civilian aircraft made in the last 50 years have ASI's in MPH? It seems like the manufacturers should have used knots, but they didn't. Or would that be an option when the plane was manufactured and the buyers selected MPH?

I suspect that civilian airplanes had their speed in mph because the marketing whiz's thought faster speeds sold more airplanes. Somebody in an earlier post in this thread mentioned that it would be impossible to certify an airplane using mph, now. All the airplanes that were certified using mph probably still have a valid type certificate that used mph. Just a guess on my part.

Knots are the standard. (FAA, ICAO, etc) However, I think there are some countries that use metric routinely.

L.Adamson 01-29-2012 09:35 AM

Quote:

Originally Posted by skylor (Post 623105)
I'm surprised you would post such a thing in a public forum, potentially monitored by the Feds.



150agl(offset 350')= 500'. That's legal, isn't it?

Looked it up, to be sure

(c) Over other than congested areas. An altitude of 500 feet above the surface, except over open water or sparsely populated areas. In those cases, the aircraft may not be operated closer than 500 feet to any person, vessel, vehicle, or structure.

Mike S 01-29-2012 09:44 AM

Quote:

Originally Posted by rvmills (Post 623022)
So Larry, just how many buckets of popcorn have you enjoyed since stirring this pot up, eh!
Cheers,
Bob


WenEng 01-29-2012 09:57 AM

Check your math Larry.....
 
So you are flying 350 ft laterally away from the fishermen and you are 150 ft above the ice. Thats a right triangle. The ''hypontenuse of that triangle is 381 ft. (Square root of (350 squared plus 150 squared). I'm no aviation expert, but I think 500 feet requirement is a straight line measurement.
I think you would have to be 476 feet laterally to the side of people at 150 ft to equal 500 straight line.
My guess is you are wagging the lateral distance and if you checked it closely you would see that you were indeed farther away than you estimate:). But thats just my humble opinion....

skylor 01-29-2012 10:10 AM

Pythagorean Theorem
 
Quote:

Originally Posted by L.Adamson (Post 623112)
150agl(offset 350')= 500'. That's legal, isn't it?

Better brush up on the Pythagorean Theorem...A^2+B^2=C^2....the distance was only 380 feet.

frankh 01-29-2012 10:12 AM

Quote:

Originally Posted by Peterk (Post 623065)
Dan,

don't forget the GAPHO system!

04 gph = GAPHO 1...cocktail party bragging rights for RV-12 owners

14 gph = GAPHO 2...routine for the rest of you

lbs/hr = GAPHO 3...used by a small group of Rocketeers.


(just having fun of course...not necessary to brag about gph at stall speeds)

Pete

14 gph?... ..try 7 GPH at 160knots or 184mph..But thats really 7.5GPH when burning autofuel with 10% ethanol.

24.5 mpg..I can lve with that..:)

Frankh.RV-7a

PerfTech 01-29-2012 10:17 AM

I Use Both!!
 
....I Use Both! And must admit, I am most comfortable with MPH. I wish this were the standard for aircraft as that measure is what we are accustomed to using in this country. We will most likely soon be using whatever the Chinese mandate?:rolleyes: Since knots are considered the standard for aviation throughout the world, I find it odd that Vans, (being the only aircraft of any real importance) elected to publish all performance specifications and sales information in MPH exclusively. Few people that have RVs have their panel, GPS, airspeed indicator etc in MPH. Many RVers are low or no time pilots and are most accustomed to using MPH. Perhaps that is the rationale for Vans decision. Or could it be when glancing at the airspeed indicator (as knots look lower than MPH) you are less likely to scare the sh-t out of yourself when you hit a bump :eek: with our extremely low maneuvering speeds, or are approaching VNE with little room for error at cruise, and would like to begin a decent? Seems like it would make sense to have airspeed indicator match the specifications on the plane. Am I rambling again? Allan

N395V 01-29-2012 10:23 AM

Centuries ago (before airplanes) the men who guided ships on the water were called pilots. In fact Merriam Webster lists this as the first definition of pilot.

So if we are to avoid nautical terms what must we call ourselves if not pilots?:D:D:D


Quote:

Originally Posted by Geico266 (Post 622850)
Knots are for ships. No one cares how fast a ship goes. ;) No one (the general public) knows how fast a knot is so you have to sit there and explain it every time. This is a waste of time, spent only attempting to make the pilot feel superior over the person asking. (Right Marty!??;))

Think of how many time you have had to ask; "Knots or MPH" at OSH or any other time you are talking speed. Folks! We are talking about wasting time at OSH! There should be a law against that!

MPH is for airplanes. Most pilots uses statue miles to a destination when traveling they usually don't use nautical miles. There is that term again "nautical".... is for ships! Why confuse the issue?

I hereby declare MPH the official measure of speed for RV's. ;)


Neal@F14 01-29-2012 10:33 AM

Quote:

Originally Posted by N395V (Post 623145)
So if we are to avoid nautical terms what must we call ourselves if not pilots?:D:D:D

Aviators!

;););)

L.Adamson 01-29-2012 10:34 AM

Quote:

Originally Posted by skylor (Post 623139)
Better brush up on the Pythagorean Theorem...A^2+B^2=C^2....the distance was only 380 feet.



I must have flunked Trigonometry.....42 years ago...:(

Mike S 01-29-2012 10:49 AM

Now I get it...
 
Real pilots fly taildraggers.

Real aviators fly MPH

hydroguy2 01-29-2012 11:01 AM

Quote:

Originally Posted by skylor (Post 623105)
I'm surprised you would post such a thing in a public forum, potentially monitored by the Feds.

I am guessing on all these numbers, there is a good chance that I was actually 250agl and 500' to the side. I've been known to embellish stories for dramatic effect. At no time was I ever pointed at anyone or even flew over them. It was sparse enough that if I had a different plane I would have cut the power and landed. Feel free to interview anyone who was on the lake that day, if anything I wasn't close enough for them to really enjoy them moment.

rv9aviator 01-29-2012 06:44 PM

Switched my EFIS over to Knots today. One more nice thing about electronics. Not a big deal in the 9. I just went from 70MPH to 60 knots on final and from 60 MPH over the numbers to 50 knots.

Geico266 01-29-2012 06:54 PM

Quote:

Originally Posted by N395V (Post 623145)
Centuries ago (before airplanes) the men who guided ships on the water were called pilots. In fact Merriam Webster lists this as the first definition of pilot.

So if we are to avoid nautical terms what must we call ourselves if not pilots?:D:D:D

Aviators! ;)


Ships going into port still require pilots. They come out on small boats and board the ship, and take control of the docking of the ship with tugs and side thrusters....... and you guest it....... they use MPH inside the harbor. ( I have no idea if that last part is true, I am getting bored again. :D)

Geico266 01-29-2012 06:55 PM

Quote:

Originally Posted by rv9aviator (Post 623326)
Switched my EFIS over to Knots today. One more nice thing about electronics. Not a big deal in the 9. I just went from 70MPH to 60 knots on final and from 60 MPH over the numbers to 50 knots.

See! You can gain 10 MPH by switching back to MPH!




;)

pilotian 01-29-2012 07:44 PM

knots
 
simple: Knots

Ron Lee 01-29-2012 08:35 PM

I am ambidextrous and can use all three systems in various situations. For flight planning, I use 150 knots along with knotical miles which makes it easy to roughly guess trip/leg durations. On the rare occasion I have to file a flight plan...knots.

Airspeed indicator...MPH.

ao.frog 01-29-2012 09:15 PM

Easy: knots are for airplanes and boats, mph are for cars...

Just ask any aircraft company (Boeing, Airbus, General Dynamics, Lockheed, etc...)

Since all charts are in NM, it makes sense to use knots both for planning and flying.

rvmills 01-30-2012 01:32 AM

Quote:

Originally Posted by Geico266 (Post 623334)
Aviators! ;)


Ships going into port still require pilots. They come out on small boats and board the ship, and take control of the docking of the ship with tugs and side thrusters....... and you guest it....... they use MPH inside the harbor. ( I have no idea if that last part is true, I am getting bored again. :D)

Yep...Harbor Pilots (and its a good gig, from all reports!)

and...Nope...not MPH (they'd be tossed out of the bridge, and overboard...in which case it wouldn't be such a good gig!) :eek:

Where's the popper?! ;)

Cheers,
Bob

islandmonkey 01-30-2012 01:57 AM

We should use Strawberries
 
We should use strawberries. After all it is just a number. Just make sure you use one number, stick with it, and have an easy way to convert to other measurements.

I use the numbers in the POH for the plane I am flying and ensure the ASI is referenced as to what it indicates. I do not mind doing the calculations between knots, statute miles or kph as I have flown all three many times.

I do prefer knots though as 1 nautical mile is one minute of arc on a great circle track.

I will use knots in my RV-4 as that is the standard here in Europe.

The use of knots has come out of maritime history and being British I am kinda proud of our history of circumnavigation, measurements of time and other discoveries.

NickAir 01-30-2012 04:03 AM

Older General Aviation/Military/Non Aviation Civilians
 
Older General Aviation/Military/Non Aviation Civilians

Started flying: General Aviation aircraft were with ASI's in MPH.

Military: Knots

Non Aviation Civilians: MPH

Best way that I have found is to fly using knots, now a days.

Exception: If aircraft is using an ASI carded with MPH. Many still are MPH.

Know the simple conversion: 1.15/0.87

prkaye 01-30-2012 07:05 AM

Quote:

Soon as they start marking maps with knots to show distance from place to place, then it will make sense to use them.
A Knot equals one minute of latitude. That's a pretty fundamental link to what you see on your charts.

Ron Lee 01-30-2012 08:40 AM

Quote:

Originally Posted by prkaye (Post 623501)
A Knot equals one minute of latitude. That's a pretty fundamental link to what you see on your charts.

Did you mean "nautical mile" instead of "knot?"

prkaye 01-30-2012 08:44 AM

Quote:

Did you mean "nautical mile" instead of "knot?"
Yes, clearly.

Another reason that I like nm (and, just to be clear about it, by extension, nm/hr or "knots") is that it is very close to exactly 2 km (similarly, 2 km/hr), which is the Canadian standard for speeds on the road. So when I talk to my non-aviation friends it makes the conversion to road speeds extremely easy to approximate in my head.


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