Increasing aircraft range

[MachFly]

No, hardly ever will this be the case.  Best glide speed will almost always be higher than your best climb rate speed.  I won't get into the actual mechanics of it unless someone wants it, but a couple of points.  First, best glide speed changes with weight and altitude.  Second, for a rough estimate of best glide speed (without testing it), add 10-15% to your Alt-X climb speed.  If you're heavier (say a shot up engine with a good amount of fuel and ammo remaining) go for the 15% figure.  If you're light (ran out of gas and no ammo) go for the 10% figure.  This will get you closer to the actual.  Third, the easiest way to glide home, is to use the [.setspeed xxx] command.  If your Alt-X climb speed is 160, use the .setspeed 175 (adding 10% to your best climb speed) command line in the text box, and then hit Alt-X.  The game will trim the plane for 175 mph IAS, and it will keep you from scrubbing off distance from manual flying.  These are not exact, and may not be the best glide speed, but they're close approximations.  If you really want to know your favorite ride's best glide speeds, you'll have to do some testing in-game.

I have not flown a single airplane who's glide speed is greater than Vy, and don't think I know of any airplane who's glide speed is greater than Vy.
I am not aware of such rule of thumb but it seem that your mixing something up with the 10%, -10% from Vy seems to make more sense.

I have done some test in AH for this and take a look at what I came up with:

I made a series of tests today to figure out Spit14's best glide speed. I took a Spit14 with 50% fuel and used the SW spawn at A22 in the training arena. Prop RPMs were set to minimum.

TEST 1: Used 175mph for the first test (HTC's programed autoclimb speed for Spit14). After landing, I asked someone to serve as a reference point for my further tests. Had him put his airplane right where my is in order to measure distance for further tests.

TEST 2: 200mph, landed 5K before the reference point.
TEST 3: 165mph, landed 3.1K after the reference point.
TEST 4: 140mph, landed 3.3K after the reference point.
TEST 5: 130mph, landed 3.3K after the reference point.
TEST 6: 135mph, landed 3.8K after the reference point.

135 mph is the best glide speed for Spitfire mk XIV is this configuration.  


I know in reality the plane will glide further with prop stopped than feathered. So I decided to test if HTC implemented this in AH.

TEST 7: Used the same 135mph as before. With the engine ignition off I had pitch up and reduce my airspeed beyond stall to 20mph which caused the airplane to climb another 2000ft, then since the airplane was already in the stall I had to dive down to initial altitude to recover from the stall. Then I continued the glide. I landed beyond 6K from the reference point so I do not know the exact distance. Since in test 6 I landed 3.8K from the reference point I this test proves that the plane glides better with the prop stopped. Additionally in test 6 I overflew the reference point at 2000ft MSL, in test 7 I overflew the reference point at 4000ft MSL, which additional proves that gliding with prop stopped results in a longer & more efficient climb.


This demonstrates that the energy lost due to maneuvering to get the prop to stop can pay of assuming that the glide is from a relatively high altitude.

Note: It will not necessarily pay off if the glide is from a low altitude.

WARNING: DO NOT DO THIS AT LOW ALTITUDE AS YOU MAY NOT RECOVER FROM THE STALL.




Special thanks to Electric for dedicating his time acting as a reference point.

Now, to increase your overall range, you need to (1) only climb as high as you absolutely need to, and (2) pull power and RPM back below the "cruise" settings in the E6B.  If you have a long distance to travel, the best fuel economy occurs if you fly at that minimum power setting, as low as you can, and then at some point before you enter the combat area, climb to your desired altitude at full power, using your normal alt-x speed.  Once you get to your desired altitude, level off and accelerate to your chosen cruise/loiter speed, then pull power and rpm back to some combination that will give you the absolute minimum fuel consumption necessary to maintain that speed and altitude.  Once you're ready to RTB, descend back to the deck at idle, using your best glide speed, and then level off at some safe altitude above the terrain, and resume that min-power setting on your throttle/rpm.  Now, some of this may not be practical from a tactical standpoint, and it will either require some testing for you to figure out your best power settings, or you can look them up in a POH for your favorite aircraft.  You'll want to look for something like "Minimum Specific Fuel Consumption" on the engine charts for that aircraft, such as this one for the earlier P-47s:

I disagree, you need to know what altitude your airplane performs best at and the speed difference. For example normally all I need is 10K of alt but Spit14 is a lot faster at 12K than 10K, so I climb to 12K. Than you want to stay at mill power for some time to gain your speed and only than throttle down to cruise, if you throttle down to cruise right away than it will take you more time to teach your cruise speed so you will be waisting time and fuel. Also you mentioned that ones your at your cruise altitude you should throttle down the the minimum speed that will let you maintain that altitude, this will increase your endurance but will decrease your range, as you don't normally care about your endurance and it's the range that matters I recommend you use your cruise speed & power.  

Take a look at this chart. See it's not logical to fly at 10K when your so much faster at 12K and it takes you so little time to get there.

[Stoney]

I have not flown a single airplane who's glide speed is greater than Vy, and don't think I know of any airplane who's glide speed is greater than Vy.

If you've flown a P-47 in-game, you've flown a plane who's best glide speed is higher than Vy.  There are others.  Like I said in my last post, I don't know that the alt-x speed of the Spits = the Vy speed.  I haven't tested them to know, nor looked up the numbers in a Spit POH.  Could be that the alt-x speed of the Spit is a lot higher than the actual Vy.

I disagree, you need to know what altitude your airplane performs best at and the speed difference. For example normally all I need is 10K of alt but Spit14 is a lot faster at 12K than 10K, so I climb to 12K.

The altitude you determine is required is up to you, based on whatever tactical considerations you have.  If you decided 12k is what you want, only climb to 12k.  You misunderstood what I posted, as well as with what's quoted in the next part.  You don't want to gain excess altitude if you're trying to use the least amount of fuel possible.

Than you want to stay at mill power for some time to gain your speed and only than throttle down to cruise, if you throttle down to cruise right away than it will take you more time to teach your cruise speed so you will be waisting time and fuel. Also you mentioned that ones your at your cruise altitude you should throttle down the the minimum speed that will let you maintain that altitude, this will increase your endurance but will decrease your range, as you don't normally care about your endurance and it's the range that matters I recommend you use your cruise speed & power.

No, if you go back and read my post, I said very purposefully "Once you get to your desired altitude, level off and accelerate to your chosen cruise/loiter speed, then pull power and rpm back to some combination that will give you the absolute minimum fuel consumption necessary to maintain that speed and altitude." [emphasis added]

Take a look at this chart. See it's not logical to fly at 10K when your so much faster at 12K and it takes you so little time to get there.

Like I said, you determine what amount of altitude will be best.  If its 12k instead of 10k, that's your choice.  Just don't climb to 14k if 12k is all you need.

[MachFly]

If you've flown a P-47 in-game, you've flown a plane who's best glide speed is higher than Vy.  There are others.  Like I said in my last post, I don't know that the alt-x speed of the Spits = the Vy speed.  I haven't tested them to know, nor looked up the numbers in a Spit POH.  Could be that the alt-x speed of the Spit is a lot higher than the actual Vy.

By "flown" I meant actually flown, not in AH. I have a copy of P-47N's POH, could you tell me where exactly it tells you the glide speed and Vy. I just don't want to read though the whole thing and I'm sure if you looked at it before you know.
I just have very hard time believing that the number the P-47 POH gives you for best glide is higher than Vy. Vy changes with weight just as well as best glide so perhaps you looked at the low weight for Vy and a high weight for best glide?

The altitude you determine is required is up to you, based on whatever tactical considerations you have.  If you decided 12k is what you want, only climb to 12k.  You misunderstood what I posted, as well as with what's quoted in the next part.  You don't want to gain excess altitude if you're trying to use the least amount of fuel possible.

The higher you go the greater your speed while your fuel consumption does not change much. You said "only climb as high as you absolutely need to", so I'm trying to say that sometimes it's good to climb higher than you need to in order to save fuel (all relative to how far your going and how the specific airplane reacts to a few thousand feet).

No, if you go back and read my post, I said very purposefully "Once you get to your desired altitude, level off and accelerate to your chosen cruise/loiter speed, then pull power and rpm back to some combination that will give you the absolute minimum fuel consumption necessary to maintain that speed and altitude." [emphasis added]

Your right you said that, I just added a bit more explanation to it for everyone else.

[Blagard]

After reading about MachFly getting the prop to stop windmilling, I tried it using my base energy state of 180 MPH at 2000 Alt. You really have to get the nose very high to get the prop to stop. Almost straight up!

Even from the 2000 start I recovered (in line thank goodness) and got further on a 130MPH glide with the prop stopped compared to previous 130 MPH attempts with it windmilling. I can imagine from greater height the pay off would be even greater. I would not risk doing this as low as 2000 in game because the severe stall is difficult to keep straight.

Unlike MachFly having some-one to help, I used the film recorder and did my attempts along the coastline so the changing shoreline gave clear indicators of the landing points for comparison. (use F5 to get an excellent birds eye view)

I can see myself using this to get home under marginal conditions and saving the last few drops of fuel for landing or defense.

[Stoney]

By "flown" I meant actually flown, not in AH. I have a copy of P-47N's POH, could you tell me where exactly it tells you the glide speed and Vy. I just don't want to read though the whole thing and I'm sure if you looked at it before you know.
I just have very hard time believing that the number the P-47 POH gives you for best glide is higher than Vy. Vy changes with weight just as well as best glide so perhaps you looked at the low weight for Vy and a high weight for best glide?

The higher you go the greater your speed while your fuel consumption does not change much. You said "only climb as high as you absolutely need to", so I'm trying to say that sometimes it's good to climb higher than you need to in order to save fuel (all relative to how far your going and how the specific airplane reacts to a few thousand feet).

Your right you said that, I just added a bit more explanation to it for everyone else.

Best glide speed was tested in game.  Best climb speed of 155 mph is listed in the section about takeoffs.  As far as fuel consumption goes, do what you want.

[colmbo]

Best glide speed was tested in game.  Best climb speed of 155 mph is listed in the section about takeoffs.  As far as fuel consumption goes, do what you want.

Stoney,

When you talk of Vbg being higher than Vy are you talking in game only?  or were you thinking real world also?  Like Machfly, I can't think of anything I've flown where Vbg is higher than Vy (real life).

[MachFly]

Best glide speed was tested in game.  Best climb speed of 155 mph is listed in the section about takeoffs. 

Found it, but it only says 155mph, it does not give you the weight. So I'm thinking since the Jug can carry a lot of fuel perhaps it gives you a Vy at a lower weight than you tested your glide. That would make sense.

[Stoney]

Stoney,

When you talk of Vbg being higher than Vy are you talking in game only?  or were you thinking real world also?  Like Machfly, I can't think of anything I've flown where Vbg is higher than Vy (real life).

Maybe I'm all hosed up, but my testing in-game for the P-47 at the weight shown, is correct, and it has a Vbg that is higher than the alt-x speed.  And Machfly, I don't know buddy.  Normally all listed speeds for an aircraft are for @ gross weight unless otherwise noted, which I figure for a P-47N would be with full tanks, but no ordinance.  Obviously, a P-47M is a bit lighter than a P-47N, but also has less wing area, so it is probably close to a wash--I haven't tested that though, so take it with a grain of salt.  From my testing, the P-47M had a best glide ratio of 11.6:1 at 175mph IAS with 25% fuel and ammo.  I even tested the data I got with this website:  http://www.csgnetwork.com/glideratiocalc.html to make sure my math was correct.  What am I doing wrong then?

[Shuffler]

I found that draining all the oil from both engines lightens the load and you can fly far with 0 fuel burn.

[MachFly]

I found that draining all the oil from both engines lightens the load and you can fly far with 0 fuel burn.

How do you drain your oil without exiting the airplane, even in real life I don't think that's possible. Also there is not that much oil in the engine and it's not that heavy, I don't think that something like that can be significant.
How much further do you glide?

[Shuffler]

How do you drain your oil without exiting the airplane, even in real life I don't think that's possible. Also there is not that much oil in the engine and it's not that heavy, how much further do you get to glide with no oil?

The distance varies greatly based on what other parts are missing off the plane.

[Stoney]

How do you drain your oil without exiting the airplane, even in real life I don't think that's possible. Also there is not that much oil in the engine and it's not that heavy, I don't think that something like that can be significant.
How much further do you glide?

He's joking about having both engines shot out in-game and trying to glide home...

[Shuffler]

He's joking about having both engines shot out in-game and trying to glide home...

Umm all seriousness aside.... I am not joking.

[MachFly]

Maybe I'm all hosed up, but my testing in-game for the P-47 at the weight shown, is correct, and it has a Vbg that is higher than the alt-x speed.  And Machfly, I don't know buddy.  Normally all listed speeds for an aircraft are for @ gross weight unless otherwise noted, which I figure for a P-47N would be with full tanks, but no ordinance.  Obviously, a P-47M is a bit lighter than a P-47N, but also has less wing area, so it is probably close to a wash--I haven't tested that though, so take it with a grain of salt.  From my testing, the P-47M had a best glide ratio of 11.6:1 at 175mph IAS with 25% fuel and ammo.  I even tested the data I got with this website:  http://www.csgnetwork.com/glideratiocalc.html to make sure my math was correct.  What am I doing wrong then?

I don't want to say that your tests are wrong because I don't have any other number that contradicts what your saying and you seem to know what your talking about, perhaps the problem is that we just don't have the right number for Vy.

[MachFly]

The distance varies greatly based on what other parts are missing off the plane.

If you loose something that has a significant amount of weight to it theoretically your glide distance will increase. However if you take drag into account that there should be an opposite effect. If you loose something that means your airfoil is not as smooth any more and creates more drag, that drag significantly decreases your glide distance.

I know the Griffon engine uses 7 gallons of oil, that's 54lb (1gal of oil = 7.7lb). I don't think that's significant compared to an ~8500lb plane.