Effect of Subsidence on Night Flying

Hey Guys,

I was just wondering; would anybody be able to give me detailed
information on the effects of atmospheric subsidence during night
flying in terms of aerodynamic and engine considerations?

I would also appreciate it if someone could provide me with links
and detailed explanations of the said phenomenon.

"Ravi" wrote in message
oups.com...
Hey Guys,

I was just wondering; would anybody be able to give me detailed
information on the effects of atmospheric subsidence during night
flying in terms of aerodynamic and engine considerations?

I would also appreciate it if someone could provide me with links
and detailed explanations of the said phenomenon.

http://www.google.com

In a previous article, "Matt Barrow" said:
"Ravi" wrote in message
roups.com...
I was just wondering; would anybody be able to give me detailed
information on the effects of atmospheric subsidence during night
flying in terms of aerodynamic and engine considerations?

http://www.google.com

I think you mean:
http://www.just****inggoogleit.com/s...ric+subsidence


--
Paul Tomblin http://xcski.com/blogs/pt/
As convenient as it is for information to come to us, libraries do have a
valuable side effect: they force all of the smart people to come together in
one place where they can interact with one another. -- Neal Stephenson

"Paul Tomblin" wrote in message
...
I think you mean:
http://www.just****inggoogleit.com/s...ric+subsidence


THat is one of the greatest things I have seen on the internet ever.

"Ravi" wrote in message
oups.com...
I was just wondering; would anybody be able to give me detailed
information on the effects of atmospheric subsidence during night
flying in terms of aerodynamic and engine considerations?

As funny as Paul's reply is, I doubt you'll find anything specific to your
question there. I'm still looking for a good explanation of what exactly
"atmospheric subsidence" actually is.

Assuming the dictionary definition is appropriate, there would be little, if
any, affect of atmospheric subsidence during night flying in terms of
aerodynamic and engine considerations. It might affects density altitude,
but since you can determine that directly, and since there are many other
factors that would affect that in a MUCH more significant way, atmospheric
subsidence is irrelevant from a practical standpoint.

Hope that helps.

Pete

I agree. Not worth spending a single brain cell on.

Bob Gardner

"Peter Duniho" wrote in message
...
"Ravi" wrote in message
oups.com...
I was just wondering; would anybody be able to give me detailed
information on the effects of atmospheric subsidence during night
flying in terms of aerodynamic and engine considerations?

As funny as Paul's reply is, I doubt you'll find anything specific to your
question there. I'm still looking for a good explanation of what exactly
"atmospheric subsidence" actually is.

Assuming the dictionary definition is appropriate, there would be little,
if any, affect of atmospheric subsidence during night flying in terms of
aerodynamic and engine considerations. It might affects density altitude,
but since you can determine that directly, and since there are many other
factors that would affect that in a MUCH more significant way, atmospheric
subsidence is irrelevant from a practical standpoint.

Hope that helps.

Pete

Unless we are talking about low canyon flying, rising terrain, or a small or
obstructed or sloping airstrip affected by mountain leaside or solar
subsidence or catabatic flow, particularly if off a glacier.

Just my .02

"Bob Gardner" wrote in message
...
I agree. Not worth spending a single brain cell on.

Bob Gardner

"Peter Duniho" wrote in message
...
"Ravi" wrote in message
oups.com...
I was just wondering; would anybody be able to give me detailed
information on the effects of atmospheric subsidence during night
flying in terms of aerodynamic and engine considerations?

As funny as Paul's reply is, I doubt you'll find anything specific to
your
question there. I'm still looking for a good explanation of what
exactly
"atmospheric subsidence" actually is.

Assuming the dictionary definition is appropriate, there would be
little,
if any, affect of atmospheric subsidence during night flying in terms of
aerodynamic and engine considerations. It might affects density
altitude,
but since you can determine that directly, and since there are many
other
factors that would affect that in a MUCH more significant way,
atmospheric
subsidence is irrelevant from a practical standpoint.

Hope that helps.

Pete

"Paul Tomblin" wrote in message
...
In a previous article, "Matt Barrow" said:
"Ravi" wrote in message
roups.com...
I was just wondering; would anybody be able to give me detailed
information on the effects of atmospheric subsidence during night
flying in terms of aerodynamic and engine considerations?

http://www.google.com

I think you mean:
http://www.just****inggoogleit.com/s...ric+subsidence

BIG :~)

You'd do all that stuff at night?
I ain't flying with you

Tony

--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE


Unless we are talking about low canyon flying, rising terrain, or a small or
obstructed or sloping airstrip affected by mountain leaside or solar
subsidence or catabatic flow, particularly if off a glacier.

Hello Tony,

The weather is not aware of the definition of legal night and begins its
process of night time cooling and ciculation long before dark.

IMHO summertime catabatic evening downslope flow can be expected on the
eastern slope of any of the Rockies. Lots of destinations with lights will
tempt a late takeoff for a night flight across foothills/praire or down the
middle of your interior valley. Late in the day the slope in the shade will
be cooling, and cold air from the higher ground and glaciers to the west,
combined with the prevailing westerlies may result in large areas of sinking
air that can surprise those who think the density altitude has improved
because the sun is low in the sky. The sinking air will be warmed somewhat
by compression and the density altitude may not be much better than earlier
in the day. Combine an airport on the wrong side of the valley, with a
loaded aircraft and some rising ground and we have another failure to climb
situation.

I seem to recall a thread about the best side of a mountain valley to fly
and this would be the classic trap when flying the eastern slope/western
side of our valleys late in the day. If you have lots of altitude and power
to burn it will be smooth, but not the best place to be low and heavy, and
any turn away from terrain will likely be downwind.

Just my .02 YMMV


"tony roberts" wrote in message
news:nospam-9F1FC6.21063024062005@shawnews...
You'd do all that stuff at night?
I ain't flying with you

Tony

--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE


Unless we are talking about low canyon flying, rising terrain, or a
small or
obstructed or sloping airstrip affected by mountain leaside or solar
subsidence or catabatic flow, particularly if off a glacier.