best glide speed of a warrior

the best glide speed of a warrior is quoted as 73 kts. but best glide should
be at best lift /drag ratio which I recall is at about 4 degree angle of
attack. But this must be a function of weight. So my questions are what
weight is the 73 kts based on ? and how much does this best speed change say
between maximum weight and minimum wight , or lets just say an 80 kg ( 176
pounds for the folks up over ) pilot flying solo with half fuel? Why ? I
am just curious, I like practicising my forced landings ( solo) and just
wondered how much extra time /distance i might get by flying at a more
"correct" speed. My flying school actually rounds it off to 75kts,
regardless of weight.
Terry

73 kts is the stall speed at max gross and aft CG.

Vs(actual)=[sqrt(actual wt/gross wt)]*Vso(gross)


d&tm wrote:
the best glide speed of a warrior is quoted as 73 kts. but best glide should
be at best lift /drag ratio which I recall is at about 4 degree angle of
attack. But this must be a function of weight. So my questions are what
weight is the 73 kts based on ? and how much does this best speed change say
between maximum weight and minimum wight , or lets just say an 80 kg ( 176
pounds for the folks up over ) pilot flying solo with half fuel? Why ? I
am just curious, I like practicising my forced landings ( solo) and just
wondered how much extra time /distance i might get by flying at a more
"correct" speed. My flying school actually rounds it off to 75kts,
regardless of weight.

73k stall speed? a Warrior? I don't think so or I'd have crashed on final
many
times.




"john smith" wrote in message
...
73 kts is the stall speed at max gross and aft CG.

Vs(actual)=[sqrt(actual wt/gross wt)]*Vso(gross)


d&tm wrote:
the best glide speed of a warrior is quoted as 73 kts. but best glide
should
be at best lift /drag ratio which I recall is at about 4 degree angle of
attack. But this must be a function of weight. So my questions are what
weight is the 73 kts based on ? and how much does this best speed change
say
between maximum weight and minimum wight , or lets just say an 80 kg (
176
pounds for the folks up over ) pilot flying solo with half fuel? Why ?
I
am just curious, I like practicising my forced landings ( solo) and just
wondered how much extra time /distance i might get by flying at a more
"correct" speed. My flying school actually rounds it off to 75kts,
regardless of weight.

john smith wrote:
73 kts is the stall speed at max gross and aft CG.

Vs(actual)=[sqrt(actual wt/gross wt)]*Vso(gross)

Vbg is the stall speed at max gross and aft CG? Where did you get that
from???

Hilton


d&tm wrote:
the best glide speed of a warrior is quoted as 73 kts. but best glide
should
be at best lift /drag ratio which I recall is at about 4 degree angle of
attack. But this must be a function of weight. So my questions are
what
weight is the 73 kts based on ? and how much does this best speed change
say
between maximum weight and minimum wight , or lets just say an 80 kg (
176
pounds for the folks up over ) pilot flying solo with half fuel? Why ?
I
am just curious, I like practicising my forced landings ( solo) and just
wondered how much extra time /distance i might get by flying at a more
"correct" speed. My flying school actually rounds it off to 75kts,
regardless of weight.

Terry wrote:
the best glide speed of a warrior is quoted as 73 kts. but best glide
should
be at best lift /drag ratio...

It is.


which I recall is at about 4 degree angle of attack.

Who told you this? CFI? POH? Seems awful low to me; I've never seen an
AOA quote for Vbg for a GA aircraft.


But this must be a function of weight.

The airspeed is, not the AOA.


So my questions are what weight is the 73 kts based on?

Best lift over drag as you suggest.


My flying school actually rounds it off to 75kts, regardless of weight.

Stupid. Fly 73, not 75 - if you can't fly 73, you need practise. There are
numerous rules of thumb, to get it accurately, scale by sqrt(weight) /
sqrt(gross) - ensure you use CAS, not IAS.

Hope this helps,

Hilton

On Sun, 12 Dec 2004 22:43:48 GMT, "Hilton" wrote:

john smith wrote:
73 kts is the stall speed at max gross and aft CG.

Vs(actual)=[sqrt(actual wt/gross wt)]*Vso(gross)

Vbg is the stall speed at max gross and aft CG? Where did you get that
from???

It was either a brain fart, or a typo. :-)



Hilton


d&tm wrote:
the best glide speed of a warrior is quoted as 73 kts. but best glide
should
be at best lift /drag ratio which I recall is at about 4 degree angle of
attack. But this must be a function of weight. So my questions are
what
weight is the 73 kts based on ? and how much does this best speed change
say
between maximum weight and minimum wight , or lets just say an 80 kg (
176
pounds for the folks up over ) pilot flying solo with half fuel? Why ?
I
am just curious, I like practicising my forced landings ( solo) and just
wondered how much extra time /distance i might get by flying at a more
"correct" speed. My flying school actually rounds it off to 75kts,
regardless of weight.

The best glide speed in the book is calc'd at gross weight. At lighter
weights, the best glide will be lower. The calculation for best glide at
various weights is straight forward but I don't know it. I'm going to guess
that it will be about 6 knots slower at empty weight plus a standard pilot
(can't wait to find out what the real number is)

Flying that speed accurately is valuable but perhaps not as valuable as
understanding the other major variable in doing an engine out glide to a
spot on the ground. That variable is wind. Since this is a ground
reference manuever so to speak, wind plays a signinficant role. The task at
hand is generally "best glide speed for distance over the ground". If you
are flying upwind to a spot, best glide speed will be higher. Downwind to a
spot, a slower than best glide speed will take you further. Accurately
flying 73 knots to make maximum distance over the ground into a 20 knot
headwind is a mistake. (I'd guesstimate that 80-85 knots would be more like
it).

I don't know the formula for doing the calc and doubt you will have it if
faced with the problem. When faced with the problem, I had a gps driven
glide computer in my glider which would give you precise guidance based on
wind, glide polar, and vertical air motion.

A couple of rough rules of thumb
- err on the high side for upwind max distance glides - you really need to
go faster upwind and there is disportianate penalty for being slower than
optimal
- err on the high side for downwind - you can get a little more distance by
going slower than best glide speed, but not much. Just fly best glide if in
doubt

I'm really interested to see what the actual speeds are for different
weights and wind conditions.

"d&tm" wrote in message
...
the best glide speed of a warrior is quoted as 73 kts. but best glide
should
be at best lift /drag ratio which I recall is at about 4 degree angle of
attack. But this must be a function of weight. So my questions are what
weight is the 73 kts based on ? and how much does this best speed change
say
between maximum weight and minimum wight , or lets just say an 80 kg ( 176
pounds for the folks up over ) pilot flying solo with half fuel? Why ? I
am just curious, I like practicising my forced landings ( solo) and just
wondered how much extra time /distance i might get by flying at a more
"correct" speed. My flying school actually rounds it off to 75kts,
regardless of weight.
Terry

Maule Driver wrote:

Flying that speed accurately is valuable but perhaps not as valuable as
understanding the other major variable in doing an engine out glide to a
spot on the ground.

Several experts (people like Barry Schiff) claim that the best speed to use is
actually a speed which will keep you in the air longest. That gives you the most
time to attempt a restart and use the radio. The only time you should use best
glide is when you actually need to in order to reach a suitable spot to land.

George Patterson
The desire for safety stands against every great and noble enterprise.

According to the ASA "generic" Warrior Pilot's Guide, the Warrior II
(not the Cadet version) has the following airspeed limitations:

Vne 160 kts
Vno 126 kts
Va 111 kts at 2240 pounds
Va 88 kts at 1531 pounds
Stall 50 kts (clean)
Stall 44 kts (full flaps)

And remember, as per Kershner, stall & glide speed are dependent
on weight.

OBTW - same numbers for the Cadet (I just turned the page)

"G.R. Patterson III"
Flying that speed accurately is valuable but perhaps not as valuable as
understanding the other major variable in doing an engine out glide to a
spot on the ground.

Several experts (people like Barry Schiff) claim that the best speed to
use is
actually a speed which will keep you in the air longest. That gives you
the most
time to attempt a restart and use the radio. The only time you should use
best
glide is when you actually need to in order to reach a suitable spot to
land.

That makes some sense. My thinking for an engine failure at altitude is to:
1) Slow to best glide
2) Point the plane in a useful direction
3) Concurrent with one, troubleshoot and communicate

To maximize time in the air, one would want to fly at minimum sink speed
which will be slower than best L/D. So the experts are suggesting not
flying at best glide but flying minimum sink. Hmmm. Don't think I agree
unless I don't have anything landable under me (open water), or my best
landing option is well with gliding distance.