Why fly fast approaches?

[EDR]

I did my BFR last month in a PA28-181. It is an airplane new to the
flying club I belong to and although I have more than 60 hours in type,
the owner requires anyone who desires to rent it, have an instructor
checkout.

Prior to the flight I calculated a weight and balance and appropriate
speeds for the actual takeoff and landing weights.

I started to pull for takeoff at the calculated speed and the
instructor said, "No, no, wait until 65 kts."
Okay.

For the first landing, I stated the calculated 1.5Vso and 1.3Vso speeds.
The instructor again said, "No, no, that's too slow. Use 75 kts."

When we were on the ground, I asked him why he wanted the faster speeds.
His answer was that this was not a new airplane, so the book values
needed to be increased to allow for age related things that could
affect the noted V-speeds.

I can understand the reasoning for a student pilot, the likes of which
this instructor does a lot of training with, but I am 1200+ and over 20
years of flying. I am thinking in terms of performance as would apply
to the Commercial standards. Hence, the reason for calculating the
necessary speeds prior to flight.

I will add that flying at the instructor's recommended speeds leads to
float in the roundout and required more runway. Flying at the
calculated speeds would have resulted in a full stall landing at the
threshhold and clearing at the first turnoff.

What is the perspective of the instructors in this group?
The instructor I fly with knows me. Why would he not hold me to
Commercial standards?

[Bob Gardner]

Good landings are slow landings. It is all energy management, and his method
increases the amount of kinetic energy to be dissipated by floating, heating
the brakes, or wearing flat spots on the tires. His argument is fallacious.

Bob Gardner

"EDR" > wrote in message
...
> I did my BFR last month in a PA28-181. It is an airplane new to the
> flying club I belong to and although I have more than 60 hours in type,
> the owner requires anyone who desires to rent it, have an instructor
> checkout.
>
> Prior to the flight I calculated a weight and balance and appropriate
> speeds for the actual takeoff and landing weights.
>
> I started to pull for takeoff at the calculated speed and the
> instructor said, "No, no, wait until 65 kts."
> Okay.
>
> For the first landing, I stated the calculated 1.5Vso and 1.3Vso speeds.
> The instructor again said, "No, no, that's too slow. Use 75 kts."
>
> When we were on the ground, I asked him why he wanted the faster speeds.
> His answer was that this was not a new airplane, so the book values
> needed to be increased to allow for age related things that could
> affect the noted V-speeds.
>
> I can understand the reasoning for a student pilot, the likes of which
> this instructor does a lot of training with, but I am 1200+ and over 20
> years of flying. I am thinking in terms of performance as would apply
> to the Commercial standards. Hence, the reason for calculating the
> necessary speeds prior to flight.
>
> I will add that flying at the instructor's recommended speeds leads to
> float in the roundout and required more runway. Flying at the
> calculated speeds would have resulted in a full stall landing at the
> threshhold and clearing at the first turnoff.
>
> What is the perspective of the instructors in this group?
> The instructor I fly with knows me. Why would he not hold me to
> Commercial standards?

[Richard Kaplan]

"EDR" > wrote in message
...>

> What is the perspective of the instructors in this group?

What you did was fine.

The instructor either is used to primary students or perhaps is not
comfortable himself with the airplane at 1.3 Vso.


--------------------
Richard Kaplan, CFII

www.flyimc.com

[C J Campbell]

I think the instructor's reasoning is faulty. Why would the stall speed
increase as the airplane ages? If it has increased measurably, then
something needs to be repaired.

I don't even teach student pilots to fly faster than necessary. It is too
easy for a student to lose control on a fast approach, especially if he
balloons or bounces.

[Steven P. McNicoll]

"EDR" > wrote in message
...
>
> I did my BFR last month in a PA28-181. It is an airplane new to the
> flying club I belong to and although I have more than 60 hours in type,
> the owner requires anyone who desires to rent it, have an instructor
> checkout.
>
> Prior to the flight I calculated a weight and balance and appropriate
> speeds for the actual takeoff and landing weights.
>
> I started to pull for takeoff at the calculated speed and the
> instructor said, "No, no, wait until 65 kts."
> Okay.
>
> For the first landing, I stated the calculated 1.5Vso and 1.3Vso speeds.
> The instructor again said, "No, no, that's too slow. Use 75 kts."
>
> When we were on the ground, I asked him why he wanted the faster speeds.
> His answer was that this was not a new airplane, so the book values
> needed to be increased to allow for age related things that could
> affect the noted V-speeds.
>
> I can understand the reasoning for a student pilot, the likes of which
> this instructor does a lot of training with, but I am 1200+ and over 20
> years of flying. I am thinking in terms of performance as would apply
> to the Commercial standards. Hence, the reason for calculating the
> necessary speeds prior to flight.
>
> I will add that flying at the instructor's recommended speeds leads to
> float in the roundout and required more runway. Flying at the
> calculated speeds would have resulted in a full stall landing at the
> threshhold and clearing at the first turnoff.
>
> What is the perspective of the instructors in this group?
> The instructor I fly with knows me. Why would he not hold me to
> Commercial standards?
>

Fast approaches are good when there is fast traffic behind you. But fast
landings are another matter entirely.

[Michelle P]

Richard,

Well then this instructor will be really un-comfortable in my airplane.
Final is done at 70-65 MPH (61-56 Knots).
Final landing is around 55 MPH (48 knots). ;-)

Michelle

Richard Kaplan wrote:

>"EDR" > wrote in message
...>
>
> > What is the perspective of the instructors in this group?
>
>What you did was fine.
>
>The instructor either is used to primary students or perhaps is not
>comfortable himself with the airplane at 1.3 Vso.
>
>
>--------------------
>Richard Kaplan, CFII

>www.flyimc.com
>
>
>
>

--

Michelle P ATP-ASEL, CP-AMEL, and AMT-A&P

"Elisabeth" a Maule M-7-235B (no two are alike)

Volunteer Pilot, Angel Flight Mid-Atlantic

Volunteer Builder, Habitat for Humanity

[zatatime]

On Thu, 01 Jul 2004 00:09:18 GMT, EDR >
wrote:

>I did my BFR last month in a PA28-181. It is an airplane new to the
>flying club I belong to and although I have more than 60 hours in type,
>the owner requires anyone who desires to rent it, have an instructor
>checkout.
>
>Prior to the flight I calculated a weight and balance and appropriate
>speeds for the actual takeoff and landing weights.
>
>I started to pull for takeoff at the calculated speed and the
>instructor said, "No, no, wait until 65 kts."
>Okay.

Why do you want to hold it on the ground that long? I own a '67
PA28-235 and couldn't tell you the actual rotation speed. When it
wants to fly, let it fly! I do know it is well below 65Kts though
cause I've seen the airspeed pass through it as I'm gaining altitude.
>
>For the first landing, I stated the calculated 1.5Vso and 1.3Vso speeds.
>The instructor again said, "No, no, that's too slow. Use 75 kts."
I'd rather 70kts as a rule of thumb. The only advantage this gives
you is slightly better control effectiveness, otherwise use what
you're comfortable with.

>
>When we were on the ground, I asked him why he wanted the faster speeds.
>His answer was that this was not a new airplane, so the book values
>needed to be increased to allow for age related things that could
>affect the noted V-speeds.
Puppycock! (And many other expletives as well). Arguments can be made
that dirt and grime accumulate and make an airplane heavier. No one
considers the fact that radios way back when weighed a heck of a lot
more than they do now. I took about 30 lbs. of extraneous crap and
wiring out of my plane when I bought it. IMO it's a trade off and his
rule is not a good one. How's it Feel at the speed you're flying. If
it feels good great, if it doesn't feel good adjust a little bit.

>
>I can understand the reasoning for a student pilot, the likes of which
>this instructor does a lot of training with, but I am 1200+ and over 20
>years of flying. I am thinking in terms of performance as would apply
>to the Commercial standards. Hence, the reason for calculating the
>necessary speeds prior to flight.
>
>I will add that flying at the instructor's recommended speeds leads to
>float in the roundout and required more runway. Flying at the
>calculated speeds would have resulted in a full stall landing at the
>threshhold and clearing at the first turnoff.
If you start your "round out" earlier you can still land on the
threshold, but then you'd be going below his required speeds. So, yes
listening to him wastes runway needlessly.

>
>What is the perspective of the instructors in this group?
He's a 141 rat that needs to learn how to fly a wing, and not the
airspeed indicator. (I know I'm being hard and don't know the guy,
but what you wrote doesn't make sense.)

>The instructor I fly with knows me. Why would he not hold me to
>Commercial standards?
This is not (yet) required for completion of a BFR.

[Greg Esres]

<<What is the perspective of the instructors in this group?>>

Cowardice on the instructor's part. Much of the art of flying
requires that our brain rule our emotions. The instructor appears to
have surrendered to fear.

[Bela P. Havasreti]

On Thu, 01 Jul 2004 03:05:54 GMT, Michelle P
> wrote:

Sorry for the "me too" post, but I approach at 60mph
and when the tires chirp onto the pavement, I'm probably
doing 40-45mph. 8^)

Bela P. Havasreti

>Richard,
>
> Well then this instructor will be really un-comfortable in my airplane.
>Final is done at 70-65 MPH (61-56 Knots).
>Final landing is around 55 MPH (48 knots). ;-)
>
>Michelle
>
>Richard Kaplan wrote:
>
>>"EDR" > wrote in message
...>
>>
>> > What is the perspective of the instructors in this group?
>>
>>What you did was fine.
>>
>>The instructor either is used to primary students or perhaps is not
>>comfortable himself with the airplane at 1.3 Vso.
>>
>>
>>--------------------
>>Richard Kaplan, CFII

>>www.flyimc.com
>>
>>
>>
>>

[Nathan Young]

On Thu, 01 Jul 2004 00:09:18 GMT, EDR > wrote:

>I did my BFR last month in a PA28-181. It is an airplane new to the
>flying club I belong to and although I have more than 60 hours in type,
>the owner requires anyone who desires to rent it, have an instructor
>checkout.
>
>Prior to the flight I calculated a weight and balance and appropriate
>speeds for the actual takeoff and landing weights.
>
>I started to pull for takeoff at the calculated speed and the
>instructor said, "No, no, wait until 65 kts."
>Okay.
>
>For the first landing, I stated the calculated 1.5Vso and 1.3Vso speeds.
>The instructor again said, "No, no, that's too slow. Use 75 kts."
>
>When we were on the ground, I asked him why he wanted the faster speeds.
>His answer was that this was not a new airplane, so the book values
>needed to be increased to allow for age related things that could
>affect the noted V-speeds.

Unless the instructor was joking with you, it might be time for a new
instructor. Aircraft age has nothing to do with V speeds.

I fly final in my PA28-180 at 80mph, and slow to 75 crossing the
threshold. This is right at 1.3Vso, (57*1.3=74) and it works well.

[AJW]

>
>>I did my BFR last month in a PA28-181. It is an airplane new to the
>>flying club I belong to and although I have more than 60 hours in type,
>>the owner requires anyone who desires to rent it, have an instructor
>>checkout.
>>
>>Prior to the flight I calculated a weight and balance and appropriate
>>speeds for the actual takeoff and landing weights.
>>
>>I started to pull for takeoff at the calculated speed and the
>>instructor said, "No, no, wait until 65 kts."
>>Okay.
>>
>>For the first landing, I stated the calculated 1.5Vso and 1.3Vso speeds.
>>The instructor again said, "No, no, that's too slow. Use 75 kts."
>>
>>When we were on the ground, I asked him why he wanted the faster speeds.
>>His answer was that this was not a new airplane, so the book values
>>needed to be increased to allow for age related things that could
>>affect the noted V-speeds.
>
>Unless the instructor was joking with you, it might be time for a new
>instructor. Aircraft age has nothing to do with V speeds.
>
>I fly final in my PA28-180 at 80mph, and slow to 75 crossing the
>threshold. This is right at 1.3Vso, (57*1.3=74) and it works well.
>
>
Approach speeds really depend on the airplane. If it can dump speed and energy
fast once you're over the fence -- 172s can do that -- you can still enter the
flare slow enough. On the other hand, if you are carrying 80 kts in an
airplane like a Mooney, you'll need a lot of runway to fly over before you want
to get down to where ground effect makes it even more efficient.

Maybe the question should be at what speed do you want to enter ground effect.

[OtisWinslow]

I think this instructor needs some recurrent training. He's got some issues.
Why is
he afraid to fly slow? I've always used 1.3Vso on final and 1.2Vso over the
fence.
I adjust that depending on my weight. If you don't use the right airspeed
you're not
going to get a good landing. As for takeoff, when it wants to fly it will. I
just start
applying light back pressure at around 55mph (151 Warrior, 2 notches flaps)
and when it's ready
it will leave the ground.


"EDR" > wrote in message
...
> I did my BFR last month in a PA28-181. It is an airplane new to the
> flying club I belong to and although I have more than 60 hours in type,
> the owner requires anyone who desires to rent it, have an instructor
> checkout.
>
> Prior to the flight I calculated a weight and balance and appropriate
> speeds for the actual takeoff and landing weights.
>
> I started to pull for takeoff at the calculated speed and the
> instructor said, "No, no, wait until 65 kts."
> Okay.
>
> For the first landing, I stated the calculated 1.5Vso and 1.3Vso speeds.
> The instructor again said, "No, no, that's too slow. Use 75 kts."
>
> When we were on the ground, I asked him why he wanted the faster speeds.
> His answer was that this was not a new airplane, so the book values
> needed to be increased to allow for age related things that could
> affect the noted V-speeds.
>
> I can understand the reasoning for a student pilot, the likes of which
> this instructor does a lot of training with, but I am 1200+ and over 20
> years of flying. I am thinking in terms of performance as would apply
> to the Commercial standards. Hence, the reason for calculating the
> necessary speeds prior to flight.
>
> I will add that flying at the instructor's recommended speeds leads to
> float in the roundout and required more runway. Flying at the
> calculated speeds would have resulted in a full stall landing at the
> threshhold and clearing at the first turnoff.
>
> What is the perspective of the instructors in this group?
> The instructor I fly with knows me. Why would he not hold me to
> Commercial standards?

[EDR]

I think you pretty well identified the situation, Richard.
The instructor does a great deal of initial/primary student training.
This is the first Archer we have had in our flying club in seven years,
and he didn't begin flying with out club until after that. I don't know
what his experience was prior to that, so it may be that he is not that
familiar with the Archer. (Howerver, we do have a Cherokee Six and a
Turbo Arrow IV. I fly all these Piper's and I think there are some
cross platform similariities.)

[pilot]

1.3 Vso makes a lot of people nervous :D especially inexperienced pilot

-
pilo

http://www.pilotboard.com I love this place
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[Thomas Borchert]

Edr,

> His answer was that this was not a new airplane, so the book values
> needed to be increased to allow for age related things that could
> affect the noted V-speeds.

Things like? Ah, thought so.

>
> I can understand the reasoning for a student pilot,
>

I can't! Not at all! Student pilots absolutely need to learn to fly by
the book, fly slow and make use of the capabilities of the airplane.

A simple explanation: This is not a good instructor.


--
Thomas Borchert (EDDH)

[Snowbird]

EDR > wrote in message >...
> When we were on the ground, I asked him why he wanted the faster speeds.
> His answer was that this was not a new airplane, so the book values
> needed to be increased to allow for age related things that could
> affect the noted V-speeds.

I'll be interested in what others say, but my take on this is:

As far as I know, all the V-speeds you're talking about are a direct
function of stall speed.

It is possible for age-related items to affect stall speed.

But if that's the case, I think the correct course of action is to
go stall the plane at gross weight and lower weights, and see how well
the actual stall speed corresponds to the "book" stall speed at gross
weight and the stall speed calculated at lower weights.

I also think if the plane is known to stall at higher than "book"
speeds, it's something the instructor should discuss with pilots
he's checking out, on the ground.

> I can understand the reasoning for a student pilot

I can't, actually. Adding "5 kts for gust factor (ok), 5 kts
for Grandma, 5 kts because I'm not so sure where this plane really
stalls" leads to a lot of accidents IMO -- overrun accidents when
the pilot lands on a "short" 2000 ft runway instead of the 4000+
beheamoths where extra speed doesn't matter, and directional control
accidents because IMHO the trickiest phase of landing is transitioning
from flight to taxi, and the longer one "floats", the longer one
spends in this phase with extra time for a strong gust of wind
to cause trouble. The temptation to "force it on" also increases
as the plane floats and floats and the pilot starts seeing the end
of the runway approaching.

Airspeed control is one of the most critical aspects of flight --
why not demand it of student pilots from the start, and train
pilots who are capable of operating safely at high DA and short
fields?

JMO,
Sydney

[Snowbird]

zatatime > wrote in message >...
> Puppycock! (And many other expletives as well). Arguments can be made
> that dirt and grime accumulate and make an airplane heavier.

Then the owner should clean it :). Dirt and grime inside the
cockpit and fuselage hold moisture and promote corrosion.

> I took about 30 lbs. of extraneous crap and
> wiring out of my plane when I bought it. IMO it's a trade off

It's a very valid point that airplanes "age" as they get older,
and that the actual weight of the plane may be heavier (or lighter)
than calculated.

But if one suspects that the empty weight on the W&B is inaccurate,
it seems to me that the correct "fix" is not to tell all the pilots
flying it to T/O and land at faster speeds -- it's to WEIGH THE PLANE
and calculate a new, accurate empty weight.

There's also the point that if one stalls the plane and the stall
speed differs substantially from 'book' (or at less than gross weight,
calculated value), one can then adjust -- pretty close to your point
"fly the wing" except that I suggest exploring the envelope at altitude
first, in a new-to-the-pilot plane....

Cheers,
Sydney

[Andrew Gideon]

EDR wrote:

> I am thinking in terms of performance as would apply
> to the Commercial standards.

This is completely reasonable. I just did my annual club checkride. This
requires flight to PPL standards. But since I'm (slowly) working on my
CPL, that's what I aimed for and what the CFI and I discussed.

If nothing else, this made the ride a lot more fun.

I think your instructor has some issues with slow flight. In fact...how
does he handle the situation when you're at MCA? When you stall?

- Andrew

[Hankal]

> Well then this instructor will be really un-comfortable in my airplane.
>Final is done at 70-65 MPH (61-56 Knots).
>Final landing is around 55 MPH (48 knots). ;-)

Instructor would be very un-comfortable.
On final no more than 60 knts
Over the numbers at 40 or below.
Increase RPM to 155 just prior to touchdown.
I have a 172 Skyhawk withe the Horton stohl and a 180 HP engine.
Hank

[G.R. Patterson III]

Michelle P wrote:
>
> Well then this instructor will be really un-comfortable in my airplane.
> Final is done at 70-65 MPH (61-56 Knots).
> Final landing is around 55 MPH (48 knots). ;-)

Nya - Nya! My Maule's slower than your Maule. My Maule's slower than yours! :-)

George Patterson
None of us is as dumb as all of us.

[Michael]

EDR > wrote
> Prior to the flight I calculated a weight and balance and appropriate
> speeds for the actual takeoff and landing weights.

This is required in large airplanes (Vref, anyone) and perfectly
reasonable in ANY airplane. All speeds change with weight. I think
what you did was fine. On the other hand, lots of people don't do it,
and simply use the full-gross speeds as published - and then maybe add
a few knots.

> When we were on the ground, I asked him why he wanted the faster speeds.
> His answer was that this was not a new airplane, so the book values
> needed to be increased to allow for age related things that could
> affect the noted V-speeds.

This is nonsense. If you have that much deformation of the wing, or
that much weight that is unaccounted for, the plane is not airworthy.

> I can understand the reasoning for a student pilot

I can understand the reasoning for a student pilot too - but I don't
agree with it. Better to teach it right from the start.

> I am thinking in terms of performance as would apply
> to the Commercial standards. Hence, the reason for calculating the
> necessary speeds prior to flight.

As I said - there's nothing wrong with your thinking.

> I will add that flying at the instructor's recommended speeds leads to
> float in the roundout and required more runway.

No kidding...

> What is the perspective of the instructors in this group?

My perspective is that at 1200 hours, you might want to start thinking
about becoming an instructor yourself. What you experienced is,
unfortunately, more the rule than the exception, and is the kind of
nonsense that eventually prompted me to become an instructor.

Michael

[zatatime]

On 1 Jul 2004 07:03:22 -0700, (Snowbird)
wrote:

(If you suspect a problem..)
>WEIGH THE PLANE
>and calculate a new, accurate empty weight.
>
>There's also the point that if one stalls the plane and the stall
>speed differs substantially from 'book' (or at less than gross weight,
>calculated value), one can then adjust -- pretty close to your point
>"fly the wing" except that I suggest exploring the envelope at altitude
>first, in a new-to-the-pilot plane....

I completely agree.

z

[Peter Duniho]

"Snowbird" > wrote in message
m...
> I'll be interested in what others say, but my take on this is:
>
> As far as I know, all the V-speeds you're talking about are a direct
> function of stall speed.

For landing, true. For takeoff, not true. Vx and Vy, being the result of
excess thrust and excess power (respectively), depend not just on the fixed
characteristics of the airframe, but also the declining characteristics of
the engine (and are not directly related to stall speed in any case).

Now, that said, I agree with the others who point out that if the airplane's
performance has changed enough that the published V speeds are not correct,
then the airplane needs fixing. A slight reduction in engine power might be
expected, but one large enough that Vx and Vy have changed enough for the
pilot to notice warrants repair.

And as you say, even the airframe can suffer during its lifetime in ways
that might affect stall speed. But again, I'd say that if the stall speed
has increased above the published speeds, the correct course of action is to
fix the airplane.

And generally speaking, I wouldn't expect the stall speed to change in a way
noticeable to any but the most detail-oriented test pilot; changes in gross
weight are going to be much more significant, and those mostly occur due to
differences in loading (how many passengers, what weights, amount of fuel
carried, etc.). 30 pounds of accumulated junk, while not unheard of, is
still unusual, and even that much extra weight isn't going to produce a
noticeable change on the airspeed indicator when stalling the airplane.

I'm in complete agreement that it's foolish to add airspeed on landing. The
extra speed might put you farther away from some problems (premature stall)
but it's guaranteed to put to closer to other problems (long landing,
porpoising, nose strike, etc.). Adding airspeed to compensate for gusts is
reasonable, but adding airspeed just because you think the airplane is old
is not, and is unsafe.

Pete

[Ash Wyllie]

C J Campbell opined

>I think the instructor's reasoning is faulty. Why would the stall speed
>increase as the airplane ages? If it has increased measurably, then
>something needs to be repaired.

Bugs, dents, dirt would all change the shape of the wing. How much that would
change the stall speed is an open question. Perhaps the FAA could be useful
and do some research.

>I don't even teach student pilots to fly faster than necessary. It is too
>easy for a student to lose control on a fast approach, especially if he
>balloons or bounces.





-ash
Cthulhu for President!
Why vote for a lesser evil?

[Henry and Debbie McFarland]

"EDR" > wrote in message
...
> His answer was that this was not a new airplane, so the book values
> needed to be increased to allow for age related things that could
> affect the noted V-speeds.

Our airplanes are nearly sixty years old. Age hasn't affected their stalls
speed, but engine conversions, modifications, etc... do.

All the instructor has to do is go up and stall the airplane in various
configurations to get the actual numbers if he really thinks they are not
as published.

I fear the "more is better syndrome" has affected your CFI. A shame.

Deb

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

[Ron Rosenfeld]

On Thu, 01 Jul 2004 00:09:18 GMT, EDR > wrote:

>What is the perspective of the instructors in this group?
>The instructor I fly with knows me. Why would he not hold me to
>Commercial standards?

I'm not an instructor. But my perspective is that the person giving you
the checkout is just not doing it correctly.

Also, when you did your stall series as part of the checkout, it would be
pretty simple to verify the actual vs book stall speeds.

And when you did slow flight, it would be pretty simple to see how the a/c
behaves at 1.1-1.3 Vso.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[Michelle P]

Nya - Nya! Mines a little heavier than yours. I am hauling around a 400
pound engine.
Michelle

G.R. Patterson III wrote:

>Michelle P wrote:
>
>
>> Well then this instructor will be really un-comfortable in my airplane.
>>Final is done at 70-65 MPH (61-56 Knots).
>>Final landing is around 55 MPH (48 knots). ;-)
>>
>>
>
>Nya - Nya! My Maule's slower than your Maule. My Maule's slower than yours! :-)
>
>George Patterson
> None of us is as dumb as all of us.
>
>

--

Michelle P ATP-ASEL, CP-AMEL, and AMT-A&P

"Elisabeth" a Maule M-7-235B (no two are alike)

Volunteer Pilot, Angel Flight Mid-Atlantic

Volunteer Builder, Habitat for Humanity

[Snowbird]

"Peter Duniho" > wrote in message >...
> "Snowbird" > wrote in message
> m...
> > I'll be interested in what others say, but my take on this is:
> >
> > As far as I know, all the V-speeds you're talking about are a direct
> > function of stall speed.
>
> For landing, true. For takeoff, not true. Vx and Vy

'Scuse, Peter, but I said "all the V speeds you're talking about",
not "all V-speeds".

As best I can tell, the original poster was talking about
Vr, and landing speed.

I don't think he discussed being asked to climb out at a different
speed than Vx or Vy, but in any event I think a better argument
can be made for that practice in appropriate circumstances.

Now, if you want to argue for Vr being a function of excess thrust
and excess power -- go ahead.

Cheers,
Sydney

[zatatime]

On Fri, 02 Jul 2004 03:01:25 GMT, wrote:

>
>On page 4-14 of the PIM (revised 6-18-84) in section 4.29, the following
>text appears:
>
> “The airplane should be trimmed for to an initial approach speed of 75 KIAS
> with a final approach speed of 66 KIAS with flaps extended”
>
>When I got checked out to fly the Cherokee Archer II ....

I'm not trying to throw stones, but I belive the Archer II has
slightly higher speeds referenced than the older models. The taper
wing has slightly different characteristics than the straight Hershey
bar wing.

z

[Peter Duniho]

"Snowbird" > wrote in message
om...
> 'Scuse, Peter, but I said "all the V speeds you're talking about",
> not "all V-speeds".
>
> As best I can tell, the original poster was talking about
> Vr, and landing speed.

Whatever. I find Vx and Vy to be perfectly relevant in this thread, even
looking at only the first post. You want to be offended, go right
ahead...wouldn't be the first time.

[Thomas Borchert]

Edr,

> The instructor does a great deal of initial/primary student training.
>

It still doesn't make sense with primary students to fly faster,
either.

--
Thomas Borchert (EDDH)

[Thomas Borchert]

Ash,

> Perhaps the FAA could be useful
> and do some research.
>

IMHO, that research would be totally useless. From common experience
with the planes we all fly, what effect do you expect? Zilch, nada,
niente. So why bother to do research?

--
Thomas Borchert (EDDH)

[OtisWinslow]

If you fly the same plane regularly you're going to figure out in
short order what indicated speeds work for what weight. Make note
of them and adjust accordingly. When using 1.3Vso also keep
in mind how the speeds are listed in the POH. If calibrated airspeed
then you'll have to adjust to the correct indicated airspeed if needed
if you're calculating it from the book stall speed.


"Ash Wyllie" > wrote in message
...
> C J Campbell opined
>
> >I think the instructor's reasoning is faulty. Why would the stall speed
> >increase as the airplane ages? If it has increased measurably, then
> >something needs to be repaired.
>
> Bugs, dents, dirt would all change the shape of the wing. How much that
would
> change the stall speed is an open question. Perhaps the FAA could be
useful
> and do some research.
>
> >I don't even teach student pilots to fly faster than necessary. It is too
> >easy for a student to lose control on a fast approach, especially if he
> >balloons or bounces.
>
>
>
>
>
> -ash
> Cthulhu for President!
> Why vote for a lesser evil?
>

[Snowbird]

"Peter Duniho" > wrote in message >...
> "Snowbird" > wrote in message
> om...
> > 'Scuse, Peter, but I said "all the V speeds you're talking about",
> > not "all V-speeds".

> > As best I can tell, the original poster was talking about
> > Vr, and landing speed.

> Whatever. I find Vx and Vy to be perfectly relevant in this thread, even
> looking at only the first post. You want to be offended, go right
> ahead...wouldn't be the first time.

Vx and Vy are certainly relevant to bring into the discussion, but
they weren't mentioned in the original poster's description, and I
referred to that. You were responding to my post, and saying "not true"
to me. I simply clarified what I'd meant.

That doesn't mean that Vx and Vy aren't relevant to introduce, as
additional factors which *are* dependent on factors other than stall
speed. It's a reasonable point -- provided it's not introduced in a
way which puts words into someone else's mouth or refutes a claim
they weren't making.

I await your explanation of Vr and what it depends upon, and I note
that one can fly behind an engine later shown to have one cylinder
completely flat, and not notice any particular changes to Vy, the
rate of climb obtained at that speed (under DA conditions not near
the edge of the envelope, admittedly), or cruise airspeed.

Cheers,
Sydney

[[email protected]]

On Fri, 02 Jul 2004 03:01:25 GMT, wrote:

>I fly a 1979 PA-28-181 all the time,

>I really love flying this plane. It handles nicely and takes bumps more
>gracefully then high wing planes.
>
>--Michael

In what way do you mean takes bumps more gracefully? Is there some
way to quantify this?

Thanks, Corky Scott

[C J Campbell]

"Michael" > wrote in message
om...
>
> My perspective is that at 1200 hours, you might want to start thinking
> about becoming an instructor yourself. What you experienced is,
> unfortunately, more the rule than the exception, and is the kind of
> nonsense that eventually prompted me to become an instructor.

We have one second-hand report of an instructor like this. Every other
instructor who posts here disagreed with him. Yet you think this single
instructor represents the "rule" rather than the "exception."

[C J Campbell]

"Andrew Gideon" > wrote in message
online.com...
> EDR wrote:
>
> > I am thinking in terms of performance as would apply
> > to the Commercial standards.
>
> This is completely reasonable. I just did my annual club checkride. This
> requires flight to PPL standards. But since I'm (slowly) working on my
> CPL, that's what I aimed for and what the CFI and I discussed.
>

Every instructor I know requires a pilot to fly up to the standards of his
certificates and ratings when he does a check-out, flight review, or
whatever. If you sign a guy off and he has a commercial certificate and
instrument rating and he can't fly to those standards then I think you might
have some liability there.

[C J Campbell]

> wrote in message
...
> On Fri, 02 Jul 2004 03:01:25 GMT, wrote:
>
> >I fly a 1979 PA-28-181 all the time,
>
> >I really love flying this plane. It handles nicely and takes bumps more
> >gracefully then high wing planes.
> >
> >--Michael
>
> In what way do you mean takes bumps more gracefully? Is there some
> way to quantify this?


The way a plane handles bumps is a function of wing loading instead of where
the wing is located.

[Andrew Gideon]

C J Campbell wrote:

> Every instructor I know requires a pilot to fly up to the standards of his
> certificates and ratings when he does a check-out, flight review, or
> whatever. If you sign a guy off and he has a commercial certificate and
> instrument rating and he can't fly to those standards then I think you
> might have some liability there.

I doubt it, although I cannot explain the reasoning myself.

First, we just redid our insurance. Naturally, they reviewed our rules.
But for adding a tighter currency requirement for a retract, they had
nothing but praise for our operational rules - which included the checkouts
we do.

As I said, I cannot explain the reasoning myself. I did, when I first
joined, expect precisely what you're suggesting.

Second, keep in mind that this wasn't a checkout mandated by anything other
than club rules. We're essentially a large partnership. As an ownership
situation, this is different from a "rental" type of environment.

As an owner, the only requirements "mandated" (beyond the FAA rules, of
course) are those dictated by insurance. As I mentioned, we satisfy
these...although, as I also said, I originally expected precisely what
you've suggested.

- Andrew

[Peter Duniho]

"Snowbird" > wrote in message
om...
> I await your explanation of Vr and what it depends upon

I've never flown an airplane with a published Vr. Since you're the one
making claims about how it's determined, how about YOU explain Vr and what
it depends on.

As far as Vy and Vx not varying with engine power (your claim regarding "one
cylinder completely flat"), you may not have noticed the difference in the
cockpit, but that doesn't mean they didn't change.

Pete

[Ash Wyllie]

Thomas Borchert opined

>Ash,

>> Perhaps the FAA could be useful
>> and do some research.
>>

>IMHO, that research would be totally useless. From common experience
>with the planes we all fly, what effect do you expect? Zilch, nada,
>niente. So why bother to do research?

Because for a sort period of time, the FAA will not be doing something else
which will make life worse for us.


-ash
Cthulhu for President!
Why vote for a lesser evil?

[Peter Duniho]

"C J Campbell" > wrote in message
...
> > >I really love flying this plane. It handles nicely and takes bumps more
> > >gracefully then high wing planes.
> >
> > In what way do you mean takes bumps more gracefully? Is there some
> > way to quantify this?
>
> The way a plane handles bumps is a function of wing loading instead of
where
> the wing is located.

Seems to me one either needs to define "handles bumps" more specifically, or
one needs to accept that wing position does affect how an airplane "handles
bumps" as well as wing loading.

Just as putting the CG fore or aft of the main gear affects an airplane
moving forward on the ground, I would expect putting the CG above or below
the wing would affect the airplane moving about in the air. For example,
ignoring the horizontal stabilizer for a moment, if an airplane pitches up
or down in response to a gust, it will have negative stability with the CG
above the wing, and positive stability with the CG below the wing.

Of course, a properly designed horizontal stabilizer cures many ills, and
this effect may or may not be perceptible in actual airplanes. But surely
one can't say that there's no effect due to wing placement.

As a corallary, I find it puzzling that someone would claim low-wing
airplanes are superior to high-wing airplanes with respect to "bumps", since
the only theoretical difference I can think of implies that high wings would
be better.

Pete

[Michael]

(Snowbird) wrote
> I await your explanation of Vr and what it depends upon, and I note
> that one can fly behind an engine later shown to have one cylinder
> completely flat, and not notice any particular changes to Vy, the
> rate of climb obtained at that speed (under DA conditions not near
> the edge of the envelope, admittedly), or cruise airspeed.

What you say is true, but only because what you refer to as a
completely flat cylinder is not in any way equivalent to a cylinder
not making power. A completely flat cylinder is what a mechanic will
call a cylinder that is not anywhere close to making compression in a
static test - meaning it only makes, say, 20/80 or even less.

I have in fact had this happen - sometime between compression checks,
which I tend to do at about 100 hour intervals, I had a cylinder go
from 76/80 to 20/80 due to a leak past the exhaust valve (it had 1400+
hours and 12+ years since major, and was not new even then, so I
wasn't terribly disappointed). There was no noticeable impact on
performance, but that's because it was still making nearly full power,
and would have continued to do so right up until the valve got stuck
or munched.

If you fly with a cylinder that isn't making power at all (for example
because you managed to foul both plugs - ask me how I know) but is not
otherwise interfering with the rest of the engine, there will be an
immediate and obvious change to the rate of climb and the cruise
airspeed - and that's when you have eight cylinders.

Vr is sort of a funny speed, and is indeed affected by power
available. Ideally, you want to rotate as soon as possible to reduce
wear on the tires. However, too early a rotation can back you into a
corner - as you lift the nose, the weight is transferred from wheels
to wings, and that can actually increase drag dramatically, especially
if you are taking off from a smooth paved runway. However, at lower
weights you have significantly more excess power available, and can
indeed rotate early - so Vr goes down with decreasing weight as well.
It will go up with increasing density altitude because excess power
available goes down, so you need to get closer to an optimum climb
speed before you add the aerodynamic drag.

A good way to look at it is this - you always rotate at less than Vy
and accelerate to Vy, but how much less depends on your ability to
accelerate - which depends on excess power.

All else being equal, reducing Vr by the same factor as the approach
and landing speeds is sensible, and indeed conservative because a
greater reduction is actually possible.

Michael

[Michael]

"C J Campbell" > wrote
> We have one second-hand report of an instructor like this.

No, we have the latest report of an instructor like this. Over the
years, I've noticed that they pop up with great regularity. In fact,
I remember contributing one myself a bit over a decade ago.

> Every other instructor who posts here disagreed with him.

Thank heaven for small favors. But the instructors here are hardly
representative of the instructor population as a whole.

> Yet you think this single
> instructor represents the "rule" rather than the "exception."

My experience indicates to me that this is indeed the case. Using
some highly sophisticated tools (lawnchair and cold beverage) I have
been able to observe the speeds flown on final many times, and at many
airports. The vast majority are flying final too fast.

Michael

[Matt Young]

Someone correct me if I'm wrong, but changes in engine performance
wouldn't affect Vx or Vy would they? It might affect the power settings
necessary for these speeds, or the plane effectiveness in holding them,
but my understanding is that Vx and Vy are determined by the
aerodynamics of the design of the plane and it's weight. Changes in an
engines performance with age shouldn't affect these speeds, should they?



Snowbird wrote:

> "Peter Duniho" > wrote in message >...
>
>>"Snowbird" > wrote in message
om...
>>
>>>'Scuse, Peter, but I said "all the V speeds you're talking about",
>>>not "all V-speeds".
>
>
>>>As best I can tell, the original poster was talking about
>>>Vr, and landing speed.
>
>
>>Whatever. I find Vx and Vy to be perfectly relevant in this thread, even
>>looking at only the first post. You want to be offended, go right
>>ahead...wouldn't be the first time.
>
>
> Vx and Vy are certainly relevant to bring into the discussion, but
> they weren't mentioned in the original poster's description, and I
> referred to that. You were responding to my post, and saying "not true"
> to me. I simply clarified what I'd meant.
>
> That doesn't mean that Vx and Vy aren't relevant to introduce, as
> additional factors which *are* dependent on factors other than stall
> speed. It's a reasonable point -- provided it's not introduced in a
> way which puts words into someone else's mouth or refutes a claim
> they weren't making.
>
> I await your explanation of Vr and what it depends upon, and I note
> that one can fly behind an engine later shown to have one cylinder
> completely flat, and not notice any particular changes to Vy, the
> rate of climb obtained at that speed (under DA conditions not near
> the edge of the envelope, admittedly), or cruise airspeed.
>
> Cheers,
> Sydney

[Peter Duniho]

"Matt Young" > wrote in message
nk.net...
> Someone correct me if I'm wrong, but changes in engine performance
> wouldn't affect Vx or Vy would they?

As I mentioned before, Vx and Vy are functions of excess thrust and power,
respectively. In particular, they are the airspeeds at which excess thrust
and power are at their maximum.

If thrust were constant, Vx would happen at minimum drag airspeed regardless
of engine power. But thrust isn't constant; it varies with airspeed, and
the airspeed at which the thrust in excess of drag is at its maximum depends
on how much engine power you have.

For the same reason that thrust isn't constant (propeller efficiency changes
with airspeed), power isn't constant either, and again, the airspeed at
which the power in excess of power required for level flight is at its
maximum depends on how much engine power you have.

You can demonstrate for yourself that Vx and Vy depend on engine power, by
considering the difference between relevant airspeeds when there's no engine
power. Best glide airspeed isn't the same as Vx, even though both airspeeds
provide the best performance of the aircraft in terms of altitude change
over distance. Likewise, minimum sink airspeed isn't the same as Vy, even
though both airspeeds provide the best performance of the aircraft in terms
of altitude change over time.

Generally speaking, the differences between all of these airspeeds isn't
huge, but it's important to understand that they aren't the same.

> [...] Changes in an
> engines performance with age shouldn't affect these speeds, should they?

Not significantly enough for the published speeds to be unusable. If the
engine performance has changed enough to affect Vx and Vy significantly,
there's something wrong with the engine. But it's false to say that they
aren't affected at all.

Pete

[Dan Luke]

"Michael" wrote:
> What you say is true, but only because what you
> refer to as a completely flat cylinder is not in any
> way equivalent to a cylinder not making power.
> A completely flat cylinder is what a mechanic will
> call a cylinder that is not anywhere close to making
> compression in a static test - meaning it only
> makes, say, 20/80 or even less.
>
> I have in fact had this happen - ...There was no
> noticeable impact on performance,

Yep, I've even had this happen on *two* cylinders on the same side of a
LYC O-360 and noticed nothing until a just-for-the-hell-of-it
compression test revealed the bad news. The engine was running nice and
smooth.
--
Dan
C172RG at BFM

[C J Campbell]

"Michael" > wrote in message
om...
>
> My experience indicates to me that this is indeed the case. Using
> some highly sophisticated tools (lawnchair and cold beverage) I have
> been able to observe the speeds flown on final many times, and at many
> airports. The vast majority are flying final too fast.

Well, OK. But I want to see how you measure the speed of airplanes using a
lawnchair and cold beverage. :-)

[zatatime]

On Fri, 2 Jul 2004 19:19:53 -0700, "C J Campbell"
> wrote:

>
>"Michael" > wrote in message
om...
>>
>> My experience indicates to me that this is indeed the case. Using
>> some highly sophisticated tools (lawnchair and cold beverage) I have
>> been able to observe the speeds flown on final many times, and at many
>> airports. The vast majority are flying final too fast.
>
>Well, OK. But I want to see how you measure the speed of airplanes using a
>lawnchair and cold beverage. :-)
>

That's no problem. The more cold beverages the faster the approaches.
The lawn chair provides a stable platform to conduct the test.

z

[Peter Duniho]

"zatatime" > wrote in message
...
> That's no problem. The more cold beverages the faster the approaches.

I think you have that backwards. The more cold beverages you can consume
during an approach, the *slower* it was. Maybe you had too many cold
beverages? :)

[Michael]

"C J Campbell" > wrote
> > My experience indicates to me that this is indeed the case. Using
> > some highly sophisticated tools (lawnchair and cold beverage) I have
> > been able to observe the speeds flown on final many times, and at many
> > airports. The vast majority are flying final too fast.
>
> Well, OK. But I want to see how you measure the speed of airplanes using a
> lawnchair and cold beverage. :-)

It's quite simple. I sit in the lawn chair and face the runway. I
note the beverage level in the container, and begin drinking at a
known calibrated rate as the plane crosses the runway threshold. I
stop drinking as the plane makes its touchdown. By noting the point
at which the airplane touched down and the amount of beverage
consumed, I can easily calculate the average speed flown on very short
final.

Is this not common knowledge?

Michael

[EDR]

In article >, Michael
> wrote:

> "C J Campbell" > wrote
> > > My experience indicates to me that this is indeed the case. Using
> > > some highly sophisticated tools (lawnchair and cold beverage) I have
> > > been able to observe the speeds flown on final many times, and at many
> > > airports. The vast majority are flying final too fast.
> >
> > Well, OK. But I want to see how you measure the speed of airplanes using a
> > lawnchair and cold beverage. :-)
>
> It's quite simple. I sit in the lawn chair and face the runway. I
> note the beverage level in the container, and begin drinking at a
> known calibrated rate as the plane crosses the runway threshold. I
> stop drinking as the plane makes its touchdown. By noting the point
> at which the airplane touched down and the amount of beverage
> consumed, I can easily calculate the average speed flown on very short
> final.
> Is this not common knowledge?

That's fine as long as it is a stable approach.
What happens when things get interesting?
Do you stop drinking?
Do you take a big gulp?
Do you spew out what you have in your mouth?
Do you throw the bottle/can down, jump out of the chair to a) get out
of the way, or b) run to the aid of the injured?
I guess it all depends on how interesting the approach gets.

[Robert M. Gary]

EDR > wrote in message >...

> For the first landing, I stated the calculated 1.5Vso and 1.3Vso speeds.
> The instructor again said, "No, no, that's too slow. Use 75 kts."

Was this a busy airport? Was there traffic behind you? I like to slow
to around 75 knots in my Mooney but have been known to use 100. If the
airport is really busy (class B's especially) and you have high speed
turn offs, he might have been suggesting you use a higher speed.

-Robert, CFI

[EDR]

> > For the first landing, I stated the calculated 1.5Vso and 1.3Vso speeds.
> > The instructor again said, "No, no, that's too slow. Use 75 kts."

> Was this a busy airport? Was there traffic behind you? I like to slow
> to around 75 knots in my Mooney but have been known to use 100. If the
> airport is really busy (class B's especially) and you have high speed
> turn offs, he might have been suggesting you use a higher speed.

No. It was a rural airport and we were the only ones there.

[Darrell]

B-58 Hustler History: http://members.cox.net/dschmidt1/
-

"Michael" > wrote in message
om...
> "C J Campbell" > wrote
> > > My experience indicates to me that this is indeed the case. Using
> > > some highly sophisticated tools (lawnchair and cold beverage) I have
> > > been able to observe the speeds flown on final many times, and at many
> > > airports. The vast majority are flying final too fast.
> >
> > Well, OK. But I want to see how you measure the speed of airplanes using
a
> > lawnchair and cold beverage. :-)
>
> It's quite simple. I sit in the lawn chair and face the runway. I
> note the beverage level in the container, and begin drinking at a
> known calibrated rate as the plane crosses the runway threshold. I
> stop drinking as the plane makes its touchdown. By noting the point
> at which the airplane touched down and the amount of beverage
> consumed, I can easily calculate the average speed flown on very short
> final.
>
> Is this not common knowledge?
>
> Michael

What an excellent activity!!!! I'm going to take a case of beer to LAX and
practice your fine procedure.