angle of approach or landing range question

[Tim923]

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.

[rod]

It is typically 3 to 3.5 degrees.

Rod

"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.

[Tauno Voipio]

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.

Unless the terrain or noise considerations require otherwise,
the standard approach glide angle is 3 degrees (about 1 to 20).

--

Tauno Voipio
tauno voipio (at) iki fi

[Orval Fairbairn]

In article >,
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.

They follow a three degree glideslope to landing. They do, however,
flare for landing, which raises the deck angle at touchdown.

[Dudley Henriques]

"Orval Fairbairn" > wrote in message
...
> In article >,
> 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.
>
> They follow a three degree glideslope to landing. They do, however,
> flare for landing, which raises the deck angle at touchdown.

Hi Orval;

My airliner experience is somewhat limited to say the least. I did put a
stretch DC8 down once as a "guest of the line", but that's about it :-))

Although the glide slope angle is correct, the deck angle for a normal
approach should be somewhat higher than the 3 degree glide slope and will be
related to angle of attack on the wing, which for an airliner should be a
function of the GW, airspeed, and configuration for the approach.
In a fighter like the Viper for example, on approach, the Hud will show a
difference between the FPM (flight path marker....the extension of the
velocity vector or where the airplane is actually going) and the GC (gun
cross.....the actual line through the airplane's nose or longitidudinal
axis.)
The difference between these two indicators is the AOA on the wing. Normal
approach AOA for the Viper is on speed between 12.75 and 13.25 degrees. You
fly the approach at 13 max. For an airliner using GW and a computed airspeed
for that GW on approach, I would be looking for the deck angle to be
somewhat higher and stabilized above that 3 degree glide slope.
Dudley

[Robert M. Gary]

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.

[Dudley Henriques]

"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

[Darkwing]

"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

[Robert M. Gary]

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

[Dudley Henriques]

"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

[Jim Macklin]

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.

[Morgans[_2_]]

"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

[Peter Dohm]

> 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.

ILS approach slopes are around 3 degrees, and I don't recall ever hearing of
any greater than 3.5 degrees or less than 2.5 degrees. I presume that PAPI,
and the earlier VASI, lighting systems conform to the same approach angle
that is (or would be) used for each runway. Instrument traffic and nearly
all multi-engine traffic uses the ILS and PAPI approach slope.

Single engine traffic, when using a power-off approach will typically have a
gliding approach between 5 degrees and 10 degrees depending upon wind and
flap setting. This is frequently done in training, and also as an expedited
arrival procedure, in addition to the obvious usefulness in the even of an
engine failure.

Credible, and occasionally impassioned, arguments have been advanced on all
sides regarding which is the correct normal procedure for single engine
aircraft under visual conditions...

Peter

[Ron Natalie]

Orval Fairbairn wrote:
> In article >,
> 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.
>
> They follow a three degree glideslope to landing. They do, however,
> flare for landing, which raises the deck angle at touchdown.

The deck angle isn't the same as the glideslope during a lot of
the approach (and the same goes for takeoff). That's a common
misconception that non-pilots have...that the airplane is always
flying along it's longitudinal axis.

[Orval Fairbairn]

In article >,
Ron Natalie > wrote:

> Orval Fairbairn wrote:
> > In article >,
> > 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.
> >
> > They follow a three degree glideslope to landing. They do, however,
> > flare for landing, which raises the deck angle at touchdown.
>
> The deck angle isn't the same as the glideslope during a lot of
> the approach (and the same goes for takeoff). That's a common
> misconception that non-pilots have...that the airplane is always
> flying along it's longitudinal axis.

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.

[Capt.Doug]

>"Dudley Henriques" wrote in message
> My airliner experience is somewhat limited to say the least. I did put a
> stretch DC8 down once as a "guest of the line", but that's about it :-))
> Although the glide slope angle is correct, the deck angle for a normal
> approach should be somewhat higher than the 3 degree glide slope and will
be
> related to angle of attack on the wing, which for an airliner should be a
> function of the GW, airspeed, and configuration for the approach.

Most airliner pax will feel their seats tipped back between 2 and 10 degrees
on downwind, -1 to 6 degrees on final, and 2 to 10 degrees at touchdown.
Airspeed is usually adjusted to maintain a similar deck angle for each
approach, however, individual techniques of pilots and/or autopilots will
vary.

If you land a stretch -8 and hit anywhere near the runway environment, you
are doing good ;-)

D.

[Dudley Henriques]

"Capt.Doug" > wrote in message
...
> >"Dudley Henriques" wrote in message
>> My airliner experience is somewhat limited to say the least. I did put a
>> stretch DC8 down once as a "guest of the line", but that's about it :-))
>> Although the glide slope angle is correct, the deck angle for a normal
>> approach should be somewhat higher than the 3 degree glide slope and will
> be
>> related to angle of attack on the wing, which for an airliner should be a
>> function of the GW, airspeed, and configuration for the approach.
>
> Most airliner pax will feel their seats tipped back between 2 and 10
> degrees
> on downwind, -1 to 6 degrees on final, and 2 to 10 degrees at touchdown.
> Airspeed is usually adjusted to maintain a similar deck angle for each
> approach, however, individual techniques of pilots and/or autopilots will
> vary.
>
> If you land a stretch -8 and hit anywhere near the runway environment, you
> are doing good ;-)

I have to admit; that bird was about the laziest airplane on approach I've
ever been in :-)) About halfway down the slope I managed to get ahead of it
somewhere in the vicinity of where I had to be to satisfy the FD109. It was
the flattest touchdown I've ever made. Had the chief pilot of the line in
the right seat. (Just a crew on board for a ferry flight) At least he didn't
seem all that scared :-))
Dudley Henriques

[Tim923]

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.

[Jose[_1_]]

> 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.

[Gary Drescher]

"Jose" > wrote in message
. com...
> When the forward acceleration stopped (climbing at a constant airspeed)
> the actual deck angle would be indicated, and that was also 30 degrees.

How were you able to tell that the acceleration had stopped?

--Gary

[Jose[_1_]]

>>When the forward acceleration stopped (climbing at a constant airspeed)
>> the actual deck angle would be indicated, and that was also 30 degrees.
> How were you able to tell that the acceleration had stopped?

I was not able to tell that. However, now that I am a pilot, I know
that aircraft tend to climb at constant airspeed, and are generally
limited to 200-250 knots down low. So, the horizontal acceleration
certainly stopped before I stopped measuring.

What I found was that the combined angle reached 30 degrees partway down
the takeoff roll, and stayed that way through initial climb out.

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.

[Bucky]

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.

[Capt.Doug]

>"Dudley Henriques" wrote in message
> I have to admit; that bird was about the laziest airplane on approach I've
> ever been in :-)) About halfway down the slope I managed to get ahead of
it
> somewhere in the vicinity of where I had to be to satisfy the FD109. It
was
> the flattest touchdown I've ever made. Had the chief pilot of the line in
> the right seat. (Just a crew on board for a ferry flight) At least he
didn't
> seem all that scared :-))

I got to watch some sim evaluations for job interview candidates once. It
was wonderfully entertaining. The candidates came from regionals flying
glass cockpit CRJs. They were used to sprightly performance with good power.
Their scanning skills were diminished because of the glass and the
autothrottles. The evals took place in the stretch DC-8 sim. One of
candidates actually landed close to the runway. All of them went out of box
with a ghostly shade of gray. Very humbling.

D.

[Dudley Henriques]

"Capt.Doug" > wrote in message
...
> >"Dudley Henriques" wrote in message
>> I have to admit; that bird was about the laziest airplane on approach
>> I've
>> ever been in :-)) About halfway down the slope I managed to get ahead of
> it
>> somewhere in the vicinity of where I had to be to satisfy the FD109. It
> was
>> the flattest touchdown I've ever made. Had the chief pilot of the line in
>> the right seat. (Just a crew on board for a ferry flight) At least he
> didn't
>> seem all that scared :-))
>
> I got to watch some sim evaluations for job interview candidates once. It
> was wonderfully entertaining. The candidates came from regionals flying
> glass cockpit CRJs. They were used to sprightly performance with good
> power.
> Their scanning skills were diminished because of the glass and the
> autothrottles. The evals took place in the stretch DC-8 sim. One of
> candidates actually landed close to the runway. All of them went out of
> box
> with a ghostly shade of gray. Very humbling.
>
> D.

I know it was humbling for me. I did manage to get it there and down in one
piece, but I had the advantage of one hell of a good "coach" riding shotgun
with me.
Coming out of fighters and into something like the stretch 8 cold is a hell
of a shock. Naturally, being at least "somewhat experienced :-)" I expected
the airplane to be sluggish and a handful. It wasn't really. I found it
fairly predictable actually, and after a bit of "learning" I managed a fair
takeoff through a smooth double rotation to clear the tail.
I decided early on that a stabilized approach would be my only chance at
putting it on the runway, and taking it around would have cost the company a
few bucks to say the least, so I was careful and got it stabilized at the
marker. From then on it was just flying the director and trying to grease it
on. It jarred just a bit at touchdown and that was my own fault having
slightly misjudged the distance from the cockpit to the ground :-)
Anyway, I walked away with a new respect for folks who handle these monsters
on a daily basis.
Don't tell anyone, but secretly I was glad to get back in the old P51
again!! :-)
Dudley Henriques

[Darrell S[_2_]]

> I got to watch some sim evaluations for job interview candidates once. It
> was wonderfully entertaining. The candidates came from regionals flying
> glass cockpit CRJs. They were used to sprightly performance with good
> power.
> Their scanning skills were diminished because of the glass and the
> autothrottles. The evals took place in the stretch DC-8 sim. One of
> candidates actually landed close to the runway. All of them went out of
> box
> with a ghostly shade of gray. Very humbling.

You can get lazy using flight directors. I did some evaluations for a
start-up airline while working for Flight Safety Boeing (now Alteon).
Because the candidates normally wouldn't be experienced in the MD-80
simulator we used for the evaluation we had them fly without flight
directors, autopilot, or auto-throttles. One of the 2 pilots was flying the
MD-80 for another airline and the other pilot was a lady from a fixed base
operator with no jet time at all. I figured the MD-80 guy would do much
better than the lady. WRONG! He was so used to the MAGIC he couldn't fly
basic instruments worth a crap. The gal who normally only had basic
instruments flew much better. (but to be honest I heard one of our
instructors had let her have sim time on the side to help her prepare).

[Capt.Doug]

>"Darrell S" wrote in message
> You can get lazy using flight directors. I did some evaluations for a
> start-up airline while working for Flight Safety Boeing (now Alteon).
> Because the candidates normally wouldn't be experienced in the MD-80
> simulator we used for the evaluation we had them fly without flight
> directors, autopilot, or auto-throttles.

That is the truth. Most of the airline pilots I fly with would have a bad
day if they had to handfly an ILS to mins on raw data. They've been using
flight directors and autothrottles for so long, their scan is gone. I
brought this up to our training department. The director of training's
response was that in his 29 years of A-320 experience, he had never known of
a dual FD failure. I showed him a copy of the discrepency I had written up
that morning, after hand-flying a raw data ILS to mins with a full load of
pax.

D.

[Scott Skylane]

Capt.Doug wrote:


>
> /snip/The director of training's
> response was that in his 29 years of A-320 experience, he had never known of
> a dual FD failure. /snip/

Hmmm, I *seriously * doubt he has 29 years of A-320 experience.

Happy Flying!
Scott Skylane

[Capt.Doug]

>"Scott Skylane" < wrote in message
> Hmmm, I *seriously * doubt he has 29 years of A-320 experience.

He is no longer with the company either.

D.