HE-111 is a glider

[SQB]

You guys are being a wee bit harsh today, did the economy start to crash again or something?

If it feels unnatural to him, and you are playing the game, why not test it out for yourself and see if it feels odd to you.

most of us don't play the game with a stopwatch lying around to record everything, its just a curious little thing he spotted....

[jf1981]

HE-111

1) 27 secs for decreasing speed from 300 to 200 km/h at constant alt 500 m.

2) Descending from 500 m to zero measured at 160 km/h (just above stalling speed) : 2'10"
Gliding ratio approx 1/11
Descent ratio 3,8 m/s

3) Same as 2) measured at 200 km/h : 1'37"
Gliding ratio approx 1/11
Descent ratio 5,1 m/s

4) Same as 2) measured at 250 km/h : 1'07"
Gliding ratio approx 1/9
Descent ratio 7,5 m/s

Bleinheim IV
1) 25"
2) Glide at 150 km/h, 500m-zero 1'45"
Gliding ratio approx 1/9
Descent ratio 4,8 m/s

Spitfire
1) 20"
2) Glide at 150 km/h, 500m-zero 1'50"
Gliding ratio approx 1/9,5
Descent ratio 4,5 m/s

BR.20
3) Glide at 200 km/h, 500m-zero 1'15"
Gliding ratio approx 1/8
Descent ratio 6,7 m/s

4) Glide at 250 km/h, 500m-zero 50'
Gliding ratio approx 1/7
Descent ratio 10 m/s

JU-88
3) Glide at 220 km/h, 500m-zero 55'
Gliding ratio approx 1/8
Descent ratio 6,7 m/s

4) Glide at 250 km/h, 500m-zero 50'
Gliding ratio approx 1/7
Descent ratio 10 m/s

G.50
3) Glide at 200 km/h, 500m-zero 56'
Gliding ratio approx 1/6
Descent ratio 8,9 m/s

Gliding at constant speed as smoothly as possible, power off. Fuel full, no bombs.
Rate of descent is maybe more interesting than gliding ratio since I measured it as close from stalling speed, unfavour of gliding ratio I assume.

[janpitor]

Hi,

If your second test was at 200kph, the gliding ratio vould be cca 1/14, at 300kph 1/20...this is possible. B737 has a gliding ratio of 1/26 for example.

[Furio]

I was writing this post, but then jf1981 beat me.

Saying it respectfully, we all could make an effort in better understandings what we are talking about (and correct me if I’m mistaken). For example, it’s not correct to say that the He111 “should glide well” because of its big wing area. Wing area has to do with minimum sink rate, but does very little for efficiency (lift over drag). For example, a Boeing 707 has an excellent glide ratio, in the order of 20:1, roughly twice the average light plane (and the He, probably). However, it has also a high wing loading, and its best glide speed is measured in mach numbers. For this same reason, modern sailplanes use water ballast. At higher weight, they have a higher best l:d speed.
Now, how should we measure the efficiency of any bird? First of all, we should know both the best glide and minimum sink speeds. If we don’t know them, we can guess the better glide at 1.3 times the clean stall speed (that varies with weight, of course), while minimum sink is a little slower. If we are flying at higher speed, some time will be needed to lose excess speed before starting descent. Once trimmed for better glide, we can easily made a rough estimates by just looking at a stopwatch for a couple of minutes, noting speed and altimeter readings. No particular precision is needed, but we must keep speed very carefully. Then some simple math can give us useful numbers. But beware: making the test away from best glide speed will give very different results. Above a certain speed, we’ll measure dive speeds.

Now, jg1981 made some reasonable tests. If you look at them, you’ll notice he found an l.d. of “around” 10 for all types, which is consistent with my guess above (comparing He111 to the B707), and is consistent with the average aspect ratio of WWII wings. With some allowance, we can say that CoD is accurate for all the type tested.

[jf1981]

Originally Posted by Furio

[...]

Another interesting post, thanks.

Regarding HE-111 I could not measure the glide improvement above stall speed. The margin is probably small.

[mazex]

Originally Posted by janpitor

Hi,

If your second test was at 200kph, the gliding ratio vould be cca 1/14, at 300kph 1/20...this is possible. B737 has a gliding ratio of 1/26 for example.

I'm lost here - you claim a B737 has a glide ratio of 26:1 with engines off?

Read about the "Gimli glider" incident (link below, interesting read!) which was an accident where a real 767 lost both engines at high altitude and had to try this in reality. A good thing the pilot was an experienced glider pilot... The glide ratio in reality was at 12:1 in that case even though most modern air liners are in the 16-18 range according to the "specs"?

http://en.wikipedia.org/wiki/Gimli_Glider

So 26:1 for 737 with engines off sounds very high to me...

[Boogz]

Originally Posted by janpitor

B737 has a gliding ratio of 1/26 for example.

Where did you get that number? For reference, the Gimli Glider (B767) had a glide ratio of approximately 12:1 with engines out.

http://en.wikipedia.org/wiki/Gimli_Glider

[janpitor]

It was only a number I remembered from a long time ago...but it seems I am mistaken. On several webpages they state it is 22/1 on a 737NG.

[jf1981]

HE-111 is indeed the best one in this aspect of all planes I tested. Meanwhile I did some measurements, you could find that in a post I updated a bit up to this one.

Regards

[Hunden]

Originally Posted by Kongo-Otto

Well reporting anything is the source of proper testing.
Well did yo mentioned anything else? Yes you did!

See here:


Well you mentioned a FM Issue without anykind of proof or proper test.
Thats Kindergarten Talk at least.
Now go back and watch Ice Road Truckers!

Wow a lot experts and a lot of a## holes here give the guy a break