Greg Arehart
Well Known Member
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.
Van's Air Force
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Knots or MPH?? That Is The Question
- Thread starter Geico266
- Start date
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
Well Known Member
Knots...
You got a problem with that? See Above avatar from an 'ol carrier sailor in Naval Aviation...nuff sed...
You got a problem with that? See Above avatar from an 'ol carrier sailor in Naval Aviation...nuff sed...
Geico266
Well Known Member
You got a problem with that? See Above avatar from an 'ol carrier sailor in Naval Aviation...nuff sed...
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.
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skylor
Well Known Member
I'm surprised you would post such a thing in a public forum, potentially monitored by the Feds.
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L.Adamson
Well Known Member
dmaib
Well Known Member
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
Well Known Member
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
Senior Curmudgeon
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....
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
Well Known Member
Pythagorean Theorem
Better brush up on the Pythagorean Theorem...A^2+B^2=C^2....the distance was only 380 feet.
Better brush up on the Pythagorean Theorem...A^2+B^2=C^2....the distance was only 380 feet.
frankh
Well Known Member
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
Well Known Member
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? 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 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
....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?
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 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
Well Known Member
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?
So if we are to avoid nautical terms what must we call ourselves if not pilots?
Knots are for ships. No one cares how fast a ship goes.
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
Well Known Member
So if we are to avoid nautical terms what must we call ourselves if not pilots?
Aviators!
L.Adamson
Well Known Member
hydroguy2
Well Known Member
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
Well Known Member
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
Well Known Member
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?
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.
)
Geico266
Well Known Member
Ron Lee
Well Known Member
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.
Airspeed indicator...MPH.
rvmills
Well Known Member
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.
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!)
Where's the popper?!
Cheers,
Bob
islandmonkey
Well Known Member
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.
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
Well Known Member
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
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
Ron Lee
Well Known Member
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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longranger
Well Known Member
THE system for bragging rights is furlongs per fortnight, eighths of a mile (statute
) per two weeks.Flying at 7500ft is fairly handy in my 170 as the indicated mph is pretty close to true knots.
Knots
Learned to fly in an old 172 with MPH. My instructor told me to use the inner numbers (knots) not the outer ring with the wrong numbers. Since then I have been flying newer 172's with knots. Learned to fly IFR using knots. Started visiting this site and many RV'ers were using the MPH and I am thinking "What the heck".
Learned to fly in an old 172 with MPH. My instructor told me to use the inner numbers (knots) not the outer ring with the wrong numbers. Since then I have been flying newer 172's with knots. Learned to fly IFR using knots. Started visiting this site and many RV'ers were using the MPH and I am thinking "What the heck".
John Clark
Well Known Member
"Back in the day" when I bought my used B-55 Baron, it was equipped with a dual scale A/S with knots on the inside ring. I sent the gauge off to the instrument shop where they rescreened the face to show only knots. Come to think of it, the last airplane I had with an MPH A/S was my J3 Cub, which I sold in 1970
John Clark ATP, CFI
FAAST Team Representative
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA
John Clark ATP, CFI
FAAST Team Representative
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA
THE system for bragging rights is furlongs per fortnight, eighths of a mile (statute
Flying at 7500ft is fairly handy in my 170 as the indicated mph is pretty close to true knots.
I was wondering how long it would take for "furlongs" to be mentioned!
Flying Scotsman
Well Known Member
I was wondering how long it would take for "furlongs" to be mentioned!
I like slugs as the unit of mass, too.
MauiLvrs
Well Known Member
Heh, I vaguely remember "slugs" from my aerodynamic days at uni. But I don't think I ever did understand why someone came up with such a unit!
Hey Vlad, if it's any consolation, I like the metric system and think it makes emminent sense (we converted down under several decades ago, and I speak "both" languages despite my public disdain for mph). But I think the hotchpotch of "standard" aeronautical units is here to stay for a while!
Hey Vlad, if it's any consolation, I like the metric system and think it makes emminent sense (we converted down under several decades ago, and I speak "both" languages despite my public disdain for mph). But I think the hotchpotch of "standard" aeronautical units is here to stay for a while!
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Flying Scotsman
Well Known Member
I've actually never understood why certain manufacturers (certificated or experimental) would mark their systems in mph. The *system*, at least in the U.S., uses knots and nautical miles. I've never heard an ATC specialist ask for or assign any speed in miles per hour.
As some of us know all too well, mixing measurement systems can be a recipe for disaster...
At least nautical miles and meters are related to measurements of the earth...1 nm = 1 minute of arc, 1 meter = 1/10,000,000th of the distance from the equator to the pole). Statue miles are essentially arbitrary.
(BTW, a Roman pace was *two* steps, not one...)
(I don't know if it's actually true or not, but my physics prof asserted that if you use the furlongs/fortnight/slug system, virtually all physical constants end up being approximately 1 x 10^some power I suspect he just made that up to see if we were listening!)
Can you tell I'm up late and bored tonight? LOL!
As some of us know all too well, mixing measurement systems can be a recipe for disaster...
At least nautical miles and meters are related to measurements of the earth...1 nm = 1 minute of arc, 1 meter = 1/10,000,000th of the distance from the equator to the pole). Statue miles are essentially arbitrary.
(BTW, a Roman pace was *two* steps, not one...)
(I don't know if it's actually true or not, but my physics prof asserted that if you use the furlongs/fortnight/slug system, virtually all physical constants end up being approximately 1 x 10^some power
I suspect he just made that up to see if we were listening!)Can you tell I'm up late and bored tonight? LOL!
I think the feet verses meters issues was decided by Pan Am. Much of the worlds conventions on how we fly date back to their early days where there were no standards. Not all nations however use the ICAO standard of feet. Its a pain in the ____ flying in countries that do not with a aircraft set up for feet. Leveling at 11100 meters is one thing but when they ask you your altitude passing and its 26,700 feet by the time my slow brain has done the conversion to meters the number is history not where we are at the moment. Approaches get especially tricky because they often convert from meters standard to local altimeters at very low altitudes like 1200 meters. Add in another conversion since the same countries often use QFE instead of QNH for altimeter settings and things get interesting for the math inept among us.
George
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marchudson
Well Known Member
What I use
Personally I use the universal standard of all measurements, the Horse length.
http://en.wikipedia.org/wiki/Horse_length
Currently my RV-7 goes 151,840 horse lengths / hour or 2531 horse lengths / sec, commonly referred to in the industry as HLPS.
Matter of fact, I was racing a B-55 the other day and on the start, he had me by "the slimmest fraction of a nose." However, by the end of the 2 mile course I had pulled head by at least 25 horse lengths. It was at this point that he noticed a dark substance streaming from my aircraft. He radioed and asked what was coming out of the back end of my trusty steed. To which I replied, "It's horse......" Well, you get the picture.
Personally I use the universal standard of all measurements, the Horse length.
http://en.wikipedia.org/wiki/Horse_length
Currently my RV-7 goes 151,840 horse lengths / hour or 2531 horse lengths / sec, commonly referred to in the industry as HLPS.
Matter of fact, I was racing a B-55 the other day and on the start, he had me by "the slimmest fraction of a nose." However, by the end of the 2 mile course I had pulled head by at least 25 horse lengths. It was at this point that he noticed a dark substance streaming from my aircraft. He radioed and asked what was coming out of the back end of my trusty steed. To which I replied, "It's horse......" Well, you get the picture.
How far across your EFIS screen does a 6 digit speed tape go?
I typically use knots, but when I want to impress someone - I use Smoots. Hopefully Rob and crew will include an AFS update that will allow the EFIS to display in KSPH, SPS or SPM. 190.4 KSPH sounds faster than 175 knots. 3,174 SPM sounds a LOT faster.
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Flying Scotsman
Well Known Member
Isn't that because the weather observations are done by a certified weather observer (or automated system) that is certified by the National Weather Service? (which uses statute miles)?
Geico266
Well Known Member
Has anyone notice the performance numbers published by Van's Aircraft for our airplanes is in MPH? Hmmmm?
http://www.vansaircraft.com/public/rv-6per.htm
Why would we change what the engineers of our aircraft have determined to be a better unit of measure?
http://www.vansaircraft.com/public/rv-6per.htm
Why would we change what the engineers of our aircraft have determined to be a better unit of measure?
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David-aviator
Well Known Member
Has anyone notice the performance numbers published by Van's Aircraft for our airplanes is in MPH? Hmmmm?
http://www.vansaircraft.com/public/rv-6per.htm
Why would we change what the engineers of our aircraft have determined to be a better unit of measure?
Marketing, its all about marketing.
From the Reno Air Race web site "Five days of racing action. Six classes of aircraft and speeds exceeding 500 mph."
It reads and sounds better than 434.48 knots.
But here, clearly the KNOTS have it. Or is it we have KNOTS.
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Geico266
Well Known Member
Marketing, its all about marketing.
From the Reno Air Race web site "Five days of racing action. Six classes of aircraft and speeds exceeding 500 mph."
It reads and sounds better than 434.48 knots.
But here, clearly the KNOTS have it. Or is it we have KNOTS.
I think this sums it up pretty well.
Knots or MPH, the important thing is get out there and fly.
