Time to revamp traffic patterns at non-towered airports?

The FAA is expecting to publish its final rule covering Light Sport
Aircraft, Sport Pilots, and the training and repair requirements
sometime this year. I'm wondering what impact this rule will have on
traffic pattern operations at non-towered airports.

Most non-towered airports have a single traffic pattern that all
aircraft share. Some airports specify different altitudes for
different types of aircraft, but they all end up using the same
rectangular traffic pattern. In the current environment, this seems to
work. I think the reason that it works is because the greatest speed
differential likely to be encountered is a factor of two. By this, I
mean a typical non-towered airport has training aircraft that fly
approaches as slow as about 55 knots. At the upper end are twin-engine
aircraft that may fly as fast as 120 knots. The difference is about a
factor of two.

With the introduction of sport aircraft, many of which fly at approach
speeds well below 55 knots, I'm wondering how they should be
integrated into the traffic pattern. One option would be to have them
use the same pattern every other single-engine aircraft uses (but
perhaps at a lower altitude?). However, this will just increase the
speed differential encountered in the pattern, perhaps as high as a
factor of three or four. This can't be a good idea. Imagine trying to
merge onto the highway if traffic had speed differentials of four
times (operating between 30 and 120 m.p.h.).

Advisory Circular 90-66A provides guidelines for traffic patterns by
ultralight operators at non-towered airports. One suggestion is to use
a traffic pattern that is lower than the single-engine traffic pattern
and inside of it. Would this be the best option for sport aircraft? It
eliminates conflicts in the downwind and base leg, but there is still
a possibility of a conflict on final.

What's the best way to reduce traffic pattern risk when there is a
wide range in approach speeds – vertical separation for different user
groups, or a different pattern for different user groups? Or are the
current traffic pattern practices at non-towered airports archaic and
need to be completely revamped?

"Ace Pilot" wrote in message
om...
The FAA is expecting to publish its final rule covering Light Sport
Aircraft, Sport Pilots, and the training and repair requirements
sometime this year. I'm wondering what impact this rule will have on
traffic pattern operations at non-towered airports.

Probably little to none.

Most non-towered airports have a single traffic pattern that all
aircraft share. Some airports specify different altitudes for
different types of aircraft, but they all end up using the same
rectangular traffic pattern. In the current environment, this seems to
work. I think the reason that it works is because the greatest speed
differential likely to be encountered is a factor of two. By this, I
mean a typical non-towered airport has training aircraft that fly
approaches as slow as about 55 knots. At the upper end are twin-engine
aircraft that may fly as fast as 120 knots. The difference is about a
factor of two.

With the introduction of sport aircraft, many of which fly at approach
speeds well below 55 knots,

Don't know where you pulled this from but most sport aircraft will perform
equal to or better than most current light singles. Sport aircraft are not
ultralights. Current airplanes that qualify as sport aircraft such as J3s,
Champs, etc. fit in the pattern just fine and have been for 60 years or
more.

I'm wondering how they should be
integrated into the traffic pattern.

Same as any other airplane.

One option would be to have them
use the same pattern every other single-engine aircraft uses (but
perhaps at a lower altitude?). However, this will just increase the
speed differential encountered in the pattern, perhaps as high as a
factor of three or four.

Huh? Three or four? Where did you get these numbers?

This can't be a good idea. Imagine trying to
merge onto the highway if traffic had speed differentials of four
times (operating between 30 and 120 m.p.h.).

Advisory Circular 90-66A provides guidelines for traffic patterns by
ultralight operators at non-towered airports. One suggestion is to use
a traffic pattern that is lower than the single-engine traffic pattern
and inside of it. Would this be the best option for sport aircraft? It
eliminates conflicts in the downwind and base leg, but there is still
a possibility of a conflict on final.

What's the best way to reduce traffic pattern risk when there is a
wide range in approach speeds -

1st Hint..........keep your eyes open!! Second hint......refer to first
hint.

vertical separation for different user
groups, or a different pattern for different user groups? Or are the
current traffic pattern practices at non-towered airports archaic and
need to be completely revamped?

"Dave Stadt" wrote in message:
"Ace Pilot" wrote in message:
With the introduction of sport aircraft, many of which fly at approach
speeds well below 55 knots,

Don't know where you pulled this from but most sport aircraft will perform
equal to or better than most current light singles.

Depends on your definition of "perform."

Sport aircraft are not ultralights.

True. But all ultralights (including most "fat" ultralights) can be
certified under the proposed sport aircraft rule. In fact, this is one
of the basic reasons for the proposed rule – to better regulate
ultralights, especially those with two seats.

Current airplanes that qualify as sport aircraft such as J3s,
Champs, etc. fit in the pattern just fine and have been for 60 years or
more.

True. However, J3s and Champs represent the higher end of sport
aircraft. You are completely ignoring powered parachutes, trikes and
lower performance aircraft that are most likely to be sport aircraft
(because of their lower cost) and have significantly lower approach
speeds (typically 20% to 40% lower than a Cub).

One option would be to have them
use the same pattern every other single-engine aircraft uses (but
perhaps at a lower altitude?). However, this will just increase the
speed differential encountered in the pattern, perhaps as high as a
factor of three or four.

Huh? Three or four? Where did you get these numbers?

Many powered parachutes operate around 25 knots. Put one of those in
the pattern with an aircraft with a 100-knot approach speed and you
have a four factor difference. That's the extreme case. A sampling of
other aircraft with low approach speeds (source - manufacturer's web
pages):

Quicksilver Sport 2S – 40 knots
Quicksilver MX Sprint – 34 knots
Airborne Redback trike – 31 knots

It seems reasonable to me that the lower cost of these aircraft will
increase their presence at airports (either privately owned, or more
likely, flight school owned).

What's the best way to reduce traffic pattern risk when there is a
wide range in approach speeds -

1st Hint..........keep your eyes open!! Second hint......refer to first
hint.

Since sport aircraft are not required to have radios (nor are sport
pilots required to be trained in their use), see and avoid will be an
integral component for safe sport aviation activity. However, it's
been well documented that see and avoid is not fail safe. Its
effectiveness is limited, but by having standardized traffic patterns,
that effectiveness can be enhanced. I'm asking whether changes to the
current traffic patterns, in light of expected future activity, might
enhance the see and avoid system even further.

"Ace Pilot" wrote in message
Many powered parachutes operate around 25 knots. Put one of those in
the pattern with an aircraft with a 100-knot approach speed and you
have a four factor difference. That's the extreme case.

We have two power parachutes based at our home field, and we have no problem
landing with them. They land on the grass and we land on the pavement. I've
done touch and goes with them. We have Lear Jets, powerchutes and everything
in between here with no major hassles. It's just not a big deal because we
all try hard to share the space and play nice.

Deb

--
1946 Luscombe 8A (His)
1948 Luscombe 8E (Hers)
1954 Cessna 195B, restoring (Ours)
Jasper, Ga. (JZP)

Ace, you need to get out more!

I fly my 1945 no electrical system Champ into Class B/C/D airspace
quite often during the year. And that's just the controlled airspace
fields. I also frequently fly into and out of uncontrolled airports
without using a radio.

It is really fun to watch pilots following do a go around because they
haven't paid attention to spacing. I fly my approaches at 65 MPH/56 KTS
on downwind, 60 MPH/52 KTS, and final at 55 MPH/48 KTS.

Considering that this is at the stall speeds of the most common,
modern, single engine aircraft, you are either going to have to fly a
pattern at slower than normal airspeeds or fly a bigger pattern.

On the other hand, I fly my patterns low and tight, so as long as there
are not many aircraft in the pattern, I will be on the ground and clear
of the runway, by the time you turn base.

Following traffic on final, if I am abeam the numbers, I can fly a
right 270 to a short base and land. My airplane will turn a 360 in less
than 300 feet.

There are aircraft currently flying that qualify as a "light sport"..that
fit just fine in the standard traffic pattern..

Every one keeps talking about the new "light sport aircraft" being designed
to meet the criteria, but I've yet to see any.

The still have max and min speeds AFAK that should fit in just fine.

If the Bonanza pilot (or light twin pilot) cannot self adjust his spacing to
fit in behind a J-3 at an uncontrolled airfield without ATC assistance, then
I sure as heck don't want him mixing it up with our gliders that currently
fly approaches any where from 45-70knts.

I don't like the idea of a "lower altitude pattern" for a LiteSportAircraft,
that may have a high wing, and the "regular" low wing ASEL aircraft above
him. We have enough problems with Cessna's and Pipers mixing it up on final
as is.. at least one or two a year.. and they "fly the same pattern"
supposedly.

BT

"Ace Pilot" wrote in message
om...
The FAA is expecting to publish its final rule covering Light Sport
Aircraft, Sport Pilots, and the training and repair requirements
sometime this year. I'm wondering what impact this rule will have on
traffic pattern operations at non-towered airports.

Most non-towered airports have a single traffic pattern that all
aircraft share. Some airports specify different altitudes for
different types of aircraft, but they all end up using the same
rectangular traffic pattern. In the current environment, this seems to
work. I think the reason that it works is because the greatest speed
differential likely to be encountered is a factor of two. By this, I
mean a typical non-towered airport has training aircraft that fly
approaches as slow as about 55 knots. At the upper end are twin-engine
aircraft that may fly as fast as 120 knots. The difference is about a
factor of two.

With the introduction of sport aircraft, many of which fly at approach
speeds well below 55 knots, I'm wondering how they should be
integrated into the traffic pattern. One option would be to have them
use the same pattern every other single-engine aircraft uses (but
perhaps at a lower altitude?). However, this will just increase the
speed differential encountered in the pattern, perhaps as high as a
factor of three or four. This can't be a good idea. Imagine trying to
merge onto the highway if traffic had speed differentials of four
times (operating between 30 and 120 m.p.h.).

Advisory Circular 90-66A provides guidelines for traffic patterns by
ultralight operators at non-towered airports. One suggestion is to use
a traffic pattern that is lower than the single-engine traffic pattern
and inside of it. Would this be the best option for sport aircraft? It
eliminates conflicts in the downwind and base leg, but there is still
a possibility of a conflict on final.

What's the best way to reduce traffic pattern risk when there is a
wide range in approach speeds - vertical separation for different user
groups, or a different pattern for different user groups? Or are the
current traffic pattern practices at non-towered airports archaic and
need to be completely revamped?

Your comment: "Every one keeps talking about the new "light sport
aircraft" being designed to meet the criteria, but I've yet to see any."

Just a bit of info...

Maule showed a prototype Light Sport Aircraft at Oshkosh 2003.

Mooney is partnering to sell a Toxo LSA.





"BTIZ" wrote in message
news:7nXTb.7273$IF1.7065@fed1read01...
There are aircraft currently flying that qualify as a "light sport"..that
fit just fine in the standard traffic pattern..

Every one keeps talking about the new "light sport aircraft" being
designed
to meet the criteria, but I've yet to see any.

The still have max and min speeds AFAK that should fit in just fine.

If the Bonanza pilot (or light twin pilot) cannot self adjust his spacing
to
fit in behind a J-3 at an uncontrolled airfield without ATC assistance,
then
I sure as heck don't want him mixing it up with our gliders that currently
fly approaches any where from 45-70knts.

I don't like the idea of a "lower altitude pattern" for a
LiteSportAircraft,
that may have a high wing, and the "regular" low wing ASEL aircraft above
him. We have enough problems with Cessna's and Pipers mixing it up on
final
as is.. at least one or two a year.. and they "fly the same pattern"
supposedly.

BT

"Ace Pilot" wrote in message
om...
The FAA is expecting to publish its final rule covering Light Sport
Aircraft, Sport Pilots, and the training and repair requirements
sometime this year. I'm wondering what impact this rule will have on
traffic pattern operations at non-towered airports.

Most non-towered airports have a single traffic pattern that all
aircraft share. Some airports specify different altitudes for
different types of aircraft, but they all end up using the same
rectangular traffic pattern. In the current environment, this seems to
work. I think the reason that it works is because the greatest speed
differential likely to be encountered is a factor of two. By this, I
mean a typical non-towered airport has training aircraft that fly
approaches as slow as about 55 knots. At the upper end are twin-engine
aircraft that may fly as fast as 120 knots. The difference is about a
factor of two.

With the introduction of sport aircraft, many of which fly at approach
speeds well below 55 knots, I'm wondering how they should be
integrated into the traffic pattern. One option would be to have them
use the same pattern every other single-engine aircraft uses (but
perhaps at a lower altitude?). However, this will just increase the
speed differential encountered in the pattern, perhaps as high as a
factor of three or four. This can't be a good idea. Imagine trying to
merge onto the highway if traffic had speed differentials of four
times (operating between 30 and 120 m.p.h.).

Advisory Circular 90-66A provides guidelines for traffic patterns by
ultralight operators at non-towered airports. One suggestion is to use
a traffic pattern that is lower than the single-engine traffic pattern
and inside of it. Would this be the best option for sport aircraft? It
eliminates conflicts in the downwind and base leg, but there is still
a possibility of a conflict on final.

What's the best way to reduce traffic pattern risk when there is a
wide range in approach speeds - vertical separation for different user
groups, or a different pattern for different user groups? Or are the
current traffic pattern practices at non-towered airports archaic and
need to be completely revamped?

"BTIZ" wrote in message:
There are aircraft currently flying that qualify as a "light sport"..that
fit just fine in the standard traffic pattern..

Agreed, but there will also be sport aircraft with approach speeds as
low as 25 knots. At some point, the speed differential between
aircraft in the pattern should become a concern. I see the potential
for doubling the speed differential between aircraft at the extreme
ends of the spectrum and I think this should be a concern. But I'm
open to anyone that can show how an increase in speed differential
won't increase the risk.

I don't like the idea of a "lower altitude pattern" for a LiteSportAircraft,
that may have a high wing, and the "regular" low wing ASEL aircraft above
him. We have enough problems with Cessna's and Pipers mixing it up on final
as is.. at least one or two a year.. and they "fly the same pattern"
supposedly.

I've never liked the idea of putting different aircraft with different
performance at different pattern altitudes either (e.g. singles at
1,000 AGL and twins at 1,500 AGL). I can see how it would prevent
faster aircraft from overrunning slower aircraft, but, from what I've
read, mid-airs in the pattern are more typically the result of
climbing/descending into blind spots. Perhaps different pattern
altitudes based on aircraft wing position would work better, i.e.,
high wings fly a 1,500-foot pattern and low wings fly a 1,000-foot
pattern. That still leaves other problems (where do biplanes fit in,
for instance), but it might be better than the current situation.

"BTIZ" wrote in message:
There are aircraft currently flying that qualify as a "light
sport"..that
fit just fine in the standard traffic pattern..

Agreed, but there will also be sport aircraft with approach speeds as
low as 25 knots. At some point, the speed differential between
aircraft in the pattern should become a concern.

Agreed.. isn't that why they created an "Ultra light" pattern.. so if you
are that slow.. fly the ultra light pattern.. if you can keep up with a
J-3.. fly the regular pattern...

and as for the SEL and MEL differences at some patterns.. I agree there can
be problems... and "at most times but not always".. the MEL pattern if
higher is also out farther from the runway so he can see the SEL downwind
and base.

BT

Absolutely right, BT. At airports that have space for a separate
ultralight pattern and runway (typically grass), I think it is an
ideal solution.

But there are airports that don't have this luxury and all aircraft
have to share the same runway. Putting the ultralights on the "inside
and lower" from the regular (SEL) traffic pattern, which may be
"inside and lower" the MEL puts the burden for see and avoid on the
faster aircraft. As you point out, the MEL pattern is outside and
above the SEL pattern so the MEL guy can see the SEL on downwind and
base. However, the SEL will have a great deal of difficulty seeing the
MEL that is overtaking him. Likewise, the ultralights will have
difficulty seeing any SEL or MEL that are overtaking them. Is this
system really the best way to minimize the risk in the traffic
pattern?

"BTIZ" wrote in message news:cqgUb.7670$IF1.5507@fed1read01...
"BTIZ" wrote in message:
There are aircraft currently flying that qualify as a "light
sport"..that
fit just fine in the standard traffic pattern..

Agreed, but there will also be sport aircraft with approach speeds as
low as 25 knots. At some point, the speed differential between
aircraft in the pattern should become a concern.

Agreed.. isn't that why they created an "Ultra light" pattern.. so if you
are that slow.. fly the ultra light pattern.. if you can keep up with a
J-3.. fly the regular pattern...

and as for the SEL and MEL differences at some patterns.. I agree there can
be problems... and "at most times but not always".. the MEL pattern if
higher is also out farther from the runway so he can see the SEL downwind
and base.

BT