How do you travel faster...

[joeheli]

I have a question:What is the faster way to get to some place?'

from point "X" to point "Y" at 100 feet?

from point "X" to point "Y" at 500 feet or higher?

Is the higher the better or the lower the better :confused: ?

[Brian Jackson]

I'll go out on a limb here... Higher is safer because you have more reaction time and more landing area options in the event of an emergency. But in terms of speed it makes little difference for these relatively low altitudes. Jet aircraft enjoy greater speed and fuel economy at 35,000 ft. because the air is "thinner". At 500 ft. the difference is negligible at best. If I'm wrong, someone please correct me.

[GyroRon]

Your right Brian.

[Chuck Irby]

Jose, if I am flying down a deserted beach that's conducive for landing just about anywhere, then it would be a waste to get much over 200 to 300 feet. Otherwise, the more unfriendly the terrain, the higher I fly. I once flew over a lake that was about a mile across. I went up to 3500 feet before I got over the water.

[quadrirotor]

all depends of the direction and the strengh of the wind!!!

[Thomas]

Call your weather station and tell them you are flight planning. They will give you winds aloft direction and speed. Ask for any altitude you want. They will ask for an aircraft number, just give them any number it is only for statistical purposes. :)

[PW_Plack]

Andre is right. Thomas is partly right.

Winds aloft forecasts in the US are given at intervals of 3,000 feet. Your weather briefer may not be of much help helping you choose between 500 and 1,000 AGL. If you have a GPS to help you accurately calculate ground track, you can do what balloon pilots do to steer. Climb a little, check the winds, climb a little more, check the winds...

[John_Read]

My understanding is that the higher you go the faster the wind will be, and the direction of the airflow will also veer as you climb, by about thirty degrees. If you watch the clouds and compare their movement to the windsock, you can see this for yourself. Baloonists use this phenomenon to give them some small control over where they get to.

Therefore, if you are travelling downwind you will get a stronger helpful tailwind at 3000 feet than at 2000 or 1000 so it makes sense to fly high.

Conversely, if you are forced to travel into wind, the best height to fly will be as low as you can.

[birdy]

Obviosly,if your going to use the wind to gain GROUND speed,then it all depends on wich way it's bowing.As John said,if your flyn into the wind,the lower you fly the faster your ground speed will be coz it'a usualy weaker down low.

For the record;On a cold winter morning here I'v experianced 3 different wind directions under 300',plus 0 wind on the ground.

It also depends on how far apart X and Y are.
If they are 100 miles apart,then the hight wont make a noticable difference if theres no wind advantage.
But if they are only a couple of miles apart,as in mustering,you don't want to waste time with slower ground speed while climbing.

[joeheli]

Thank you guys for the explanation.

[Whirlydog]

Another thing to think about as far as wind conditions,and altitude go, you can have the wind going in opposite directions at diferent altitudes. I know this might sound strange but it does happen. Every year in October We have the International Ballon fiesta here in Albuquerque NM. You'll will constantly hear what they refer to as the "BOX" . The "Box" is a wind condition where The hot air ballons leave the ground going one direction, lets say south, and then at a higher altitude they will begin to fly in a northly direction. There has been instances where some hot air ballons have left and landed in the same area by flying (floating) in this "box" routine.

Just thought I would throw that out there.

Shawn

[John_Read]

That is true, too. The winds at different levels can be quite different. You can see this sometimes by observing the cloud layers. But generally this will not affect us over much, because - I don't know about you - I don't fly very high as a rule. For one thing, it gets colder the higher you go, and that matters in our open gyros. OK for you RAF flyers, though! :)

[joeheli]

Good point!

[Heron]

If less drag equals more speed, than it should be the higher the faster ?
Also rotor speeds would be higher?
Heron

[birdy]

Heron,if your thinking of the air being less dense at altitude and consiquently less draggy,then you'd probably be right.But this means your engine is also sucking in thinner air and your rotors need to sipn faster to compencate the thinner air,so the less drag would be canceled out by the less performance.
If there was a gain ,it would be margional.

[Thomas]

Andre is right. Thomas is partly right.

Winds aloft forecasts in the US are given at intervals of 3,000 feet. Your weather briefer may not be of much help helping you choose between 500 and 1,000 AGL. If you have a GPS to help you accurately calculate ground track, you can do what balloon pilots do to steer. Climb a little, check the winds, climb a little more, check the winds...

Dear PW_Plack,

Your partly wrong.

The rest of you have the right idea.

Keep adding knowledge to the scenario and leave the ego based opinions to those who feel the need to be right.

You all have a callous sense of respect for each other, I suspect it is because you know each other and have a familiar understanding. Anybody with a GPS might want to invest in flight instruments also. And weather below 1000' is pretty much guess work for anybody. You might as well wet your finger and stick it in the air. How far can one of these things fly on a tank of fuel anyway? If you are flying to a specific spot within a forest in upper Canada to rescue a downed air crew and the flight was life critical, I could recognize the need to be specific about time and distance to a very specific spot. But a casual jount from X to Y doesn't seen to be a critical scenario.

Here's one to think about: Which direction will the wind most likely shift as you increase in altitude if you are in the northern hemisphere?

[Heron]

Thanks Birdy . . .I had not considered others factors, like engine perfomance.
But in case you have enough power is the cruise a littel easyer higher up?
Do FW's go faster also?
Heron

[Vance]

If you want to travel faster, something other than an autogyro would work better. For me autogyros are for low and slow, unless you are scaring cows. Thank You, Vance

[gyromike]

As an aircraft gains altitude, the density of the airmass decreases.
There is less resistance to forward flight, so the aircraft can cruise at a faster rate for the same power.

Many fixed-wing pilots will climb up to higher altitudes to take advantage of this (cooler temps too). Also wind speeds tend to be higher at altitude, which is great if you can catch a favorable tailwind.

However, it could also be a headwind. So no point in gaining all that altitude just to go slower :rolleyes:

Here is an excerpt taken from William Kershner's The Student Pilot's Flight Manual (http://search.barnesandnoble.com/booksearch/isbnInquiry.asp?userid=Yf7goRt93N&isbn=0813811538&itm=1) 7th edition:

"Lightplane airspeed indicators are calibrated for standard sea level operation (59°F and 29.92 inches of mercury). As you go to higher altitudes, the air will be less dense and therefore there will be less drag. The plane will move faster, but because of the lesser density, airspeed will register less than your actual speed. This error can be corrected roughly by the rule of thumb: "Add 2 percent per thousand feet." This means that if your "calibrated" airspeed is 100 mph at 5000 feet, your "true" airspeed is 5 x 2 = an additional 10 percent = (.10)(100) = 10 mph + 100 mph= 110 mph. This works generally up to about 10,000 feet, but for closer tolerances and altitudes above this a computer should be used.

The computer takes into consideration any deviation of temperature and pressure from the "normal lapse rate." The standard temperature at sea level is 59 °F (15°C). The normal lapse rate, or temperature drop, is 3'/2°F (2°C) per thousand feet. The "2 percent per thousand feet" rule of thumb uses this fact and does not take into consideration any change from the normal lapse rate or from standard conditions.
The calibrated airspeed mentioned above is the corrected indicated airspeed, so in order to find the true airspeed the following steps would apply:
1. Indicated airspeed (IAS) + instrument and position error = calibrated airspeed (CAS).
2. Calibrated airspeed plus pressure altitude and temperature correction (2 percent per thousand feet, or use a computer) gives the true airspeed (TAS). (Most lightplanes have IAS correction information, but for others, assume IAS to equal CAS.)"

Your Air Speed Indicator will show the same speed for a given power setting, but you True Air Speed will be faster.

Engine power will also decrease with altitude also, unless it's turbo/supercharged (and even that has it's limits), so there will be an altitude that you won't be able to climb past, even with decreased air resistance. The engine just can't get enough air to make full power even at Wide Open Throttle.

I would highly recommend Kershner's book to anyone learning to fly even if they don't pursue a pilot's license.

You can also pick up an E6B Manual Flight Computer (http://www.sportys.com/acb/showdetl.cfm?&did=19&product_id=3635) at your local FBO, or online. Sometimes you can get them cheap at fly-in swap meets since a lot of folks are going to the electronic versions.

http://www.sportys.com/terryc/images/7377-copyl.jpg

[birdy]

I should have known better than to post anything bout fly'n at alt. :o :D

[darrellwittke]

I believe the wind should deflect to the right (very generally speaking) in the northern hemisphere, opposite for down under. Correct?

What I've found much more useful is to use my left hand, with thumb pointed down towards the ground the fingers indicate the wind direction of a low pressure center (Macro or micro; large pressure front or small thunder cell) and if thumb is toward the sky, wind direction of a high pressure system.

Would this work correctly in Australia?

[Thomas]

Coriolis force (http://dictionary.reference.com/search?q=coriolis%20effect)

As you increase in altitude pressure decreases and is less effected by lower denser air.