angle of approach or landing range question

Orval Fairbairn wrote:
I wasn't sure what the poster wanted -- whether he meant glide angle (as
seen from an observer on the ground) or the deck angle (as seen by a
passenger aboard). I think that he meant deck angle.

I think I meant treating the plane as a point source at its center of
mass (as done in physics class). I didn't have a glide angle and deck
angle distinction in mind, and I wasn't clear about that.

I always thought the angle was much greater before I heard about it
from a pilot. I think I had 30 degrees in mind. Tell me I'm not the
only one.

I always thought the angle was much greater before I heard about it
from a pilot. I think I had 30 degrees in mind. Tell me I'm not the
only one.

Some years back I measured the "acceleration G angle" on takeoff on a
commercial jet and found it to be about 30 degrees. What I did was hang
a weight from a protractor and held the protractor level with the floor.
On the takeoff run the weight was lagging back 30 degrees (half a g
acceleration) and then when climbing out it remained at that angle
(combination of forward acceleration and deck angle). When the forward
acceleration stopped (climbing at a constant airspeed) the actual deck
angle would be indicated, and that was also 30 degrees.

I did not do this on landing. Perhaps I should have.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

Tim923 wrote:
I always thought the angle was much greater before I heard about it
from a pilot. I think I had 30 degrees in mind. Tell me I'm not the
only one.

Unless you're viewing a slope exactly from the side, it will always
appear steeper than it is. Slope = rise / run. If you're watching the
plane land from an angle, your perception of the "run" length could be
drastically reduced, which would make the apparent angle much steeper
than it is. Sometimes a plane can appear to have a glide slope of 30
degrees.

Are you asking about the angle of decent? That's about 3 degrees.
Or are you asking about the deck angle (how high the nose is).

The quality of the landing has nothing to do with it because the plane
"flares" i.e. levels off to some degree before touching down. The angle
the for the last 2 feet is probably something like 0.5 degrees although
only an autopilot programmer would really know. Pilots don't flare by
measing angle of decent at touch down.

-Robert

Tim923 wrote:
I don't have an aviation background. What is the typical angle of
landing/approach for commercial airliners? There's an illusion for
novices, and it seems like the angle is much greater, even 30 degrees
or more, but I remember hearing it is much less, like under 10. At
what angle would the passengers complain of a rough landing.

"Robert M. Gary" wrote in message
oups.com...
Are you asking about the angle of decent? That's about 3 degrees.
Or are you asking about the deck angle (how high the nose is).

The quality of the landing has nothing to do with it because the plane
"flares" i.e. levels off to some degree before touching down. The angle
the for the last 2 feet is probably something like 0.5 degrees although
only an autopilot programmer would really know. Pilots don't flare by
measing angle of decent at touch down.


....and occasionally they don't flare at all!

Oops, we must be on the ground.

-------------------------------------------------
DW

"Darkwing" theducksmail"AT"yahoo.com wrote

...and occasionally they don't flare at all!

Oops, we must be on the ground.

Though, if you are a navy pilot, you go BAM.. we're on the ground! g
--
Jim in NC

"Robert M. Gary" wrote in message
oups.com...

Pilots don't flare by easing angle of descent at touch down.

Hi Gary;
I'm sure you know this and don't need me to mention it, but just for a
slight addition to your comment can I respectfully add a caveat?
I've always found that you have to be REAL careful with this area. It works
somewhat in the general aviation scenario when getting into the
idiocyncrices of the "flare" so to speak, but after that, a general
statement on landing can cause some confusion as pilots move up to higher
performance airplanes.
The problem is that easing rate of descent is EXACTLY how you land both
airliners and high performance jets, especially aircraft with long fuselage
to wing mass ratios and airplanes where tail strikes are an issue at
touchdown.
Dudley Henriques

Dudley Henriques wrote:
"Robert M. Gary" wrote in message
oups.com...

Pilots don't flare by easing angle of descent at touch down.

Hi Gary;
I'm sure you know this and don't need me to mention it, but just for a
slight addition to your comment can I respectfully add a caveat?
I've always found that you have to be REAL careful with this area. It works
somewhat in the general aviation scenario when getting into the
idiocyncrices of the "flare" so to speak, but after that, a general
statement on landing can cause some confusion as pilots move up to higher
performance airplanes.
The problem is that easing rate of descent is EXACTLY how you land both
airliners and high performance jets, especially aircraft with long fuselage
to wing mass ratios and airplanes where tail strikes are an issue at
touchdown.

Sorry, I probably could have worded that better. What I meant to say is
that pilots aren't going to know that angle, in terms of degrees at
flare. That's not how we land, we don't pull back while watching some
soft of indicator of approach slope. Only an autopilot programmer would
know that.

-Robert

"Robert M. Gary" wrote in message
ups.com...

Dudley Henriques wrote:
"Robert M. Gary" wrote in message
oups.com...

Pilots don't flare by easing angle of descent at touch down.

Hi Gary;
I'm sure you know this and don't need me to mention it, but just for a
slight addition to your comment can I respectfully add a caveat?
I've always found that you have to be REAL careful with this area. It
works
somewhat in the general aviation scenario when getting into the
idiocyncrices of the "flare" so to speak, but after that, a general
statement on landing can cause some confusion as pilots move up to higher
performance airplanes.
The problem is that easing rate of descent is EXACTLY how you land both
airliners and high performance jets, especially aircraft with long
fuselage
to wing mass ratios and airplanes where tail strikes are an issue at
touchdown.

Sorry, I probably could have worded that better. What I meant to say is
that pilots aren't going to know that angle, in terms of degrees at
flare. That's not how we land, we don't pull back while watching some
soft of indicator of approach slope. Only an autopilot programmer would
know that.

-Robert

That's the way I would approach it as well. I'll check with my wife and find
out if both of us are right :-)))
Dudley

An ILS approach glide slope is 3° and the aircraft will be
flown so that is reduced in the flare to nearly zero.


"Tim923" wrote in message
...
|I don't have an aviation background. What is the typical
angle of
| landing/approach for commercial airliners? There's an
illusion for
| novices, and it seems like the angle is much greater, even
30 degrees
| or more, but I remember hearing it is much less, like
under 10. At
| what angle would the passengers complain of a rough
landing.