Review of John T. Lowry's "Performance Of Light Aircraft"
Fred Woodbridge
maximum performance; their poor introduction to this important area of
aviation being the oftentimes insufficient lessons from their flight
instructors or from hangar flying. The aircraft's POH (pilots operating
handbook) does indeed list several performance-oriented facts and
figures but these are usually only valid for aircraft at theirmaximum
gross weights! To add insult to injury, high performance flying is not
readily intuitive and, in some situations, is outright counter-
intuitive.
Considering how many accidents occur due to this lack of knowledge,
a new approach is needed, an approach which entails generating
intelligent data and figures tailored specifically to the pilot's
particular aircraft and flying conditions so that one can, as the old
aviation adage admonishes, "Fly by the numbers."
Such an approach is outlined in the new book, Performance of Light
Aircraft by John T. Lowry, PhD, of Flight Physics. Lowry is based in
Montana where, due to the mountains, I suspect every flight needs high
performance! The conscientious reader is rewarded with the information
required to determine aircraft performance by employing what the author
terms "The Bootstrap Approach," basically a precise, step-by-step
process for determining a propeller-driven aircraft's performance data.
One actually gets to be a test pilot, as it were, in order to collect
and then generate performance numbers for the particular airplane. The
most noteworthy aspect of this process is that once these numbers are
in place, the pilot can use them over and again and for different
altitudes, aircraft weights, and wind conditions! This is truly an
excellent book.
I do, however, have to point out several things:
1. This is a very expensive book, coming in at close to $70. One would
have expected a lower price for a soft-bound book or at the very least,
an included CD or disk containing software to help in recording and/or
generating the above numbers! (Note: While there is a disk of
spreadsheet templates available privately from the author, it costs an
additional $45.)
2. Be prepared to spend some time and effort understanding the theory
behind the Bootstrap Approach. If one just wants to get the necessary
formulae and plug in numbers, contact the author at jlo...@mcn.net for
his other book, essentially a field guide to implementing the Bootstrap
method.
--
Frederic Woodbridge
fre...@my-dejanews.com
Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.
Thomas Wimmer
(...)
> Such an approach is outlined in the new book, Performance of
> Light Aircraft by John T. Lowry, PhD, of Flight Physics.
Do you have a ISBN ?
amazon can't find it.
Thomas
--
Thomas Wimmer | When you're in a fight with an idiot,
tho...@wimmer.net | its difficult for other people
Stuttgart, Germany | to tell which one the idiot is.
Fred Woodbridge
Thomas Wimmer <tho...@wimmer.net> wrote:
> Fred Woodbridge schrieb:
>
> (...)
>
> > Such an approach is outlined in the new book, Performance of
> > Light Aircraft by John T. Lowry, PhD, of Flight Physics.
>
> Do you have a ISBN ?
> amazon can't find it.
>
> Thomas
Sure Thomas:
ISBN: 1-56347-330-5
Enjoy...
John J. Miller
<37E15EF4...@wimmer.net>:
>Fred Woodbridge schrieb:
>
>> Such an approach is outlined in the new book, Performance of
>> Light Aircraft by John T. Lowry, PhD, of Flight Physics.
>
>Do you have a ISBN ?
>amazon can't find it.
>
1563473305
Notice that Amazon puts the author's name field before the title in the
Book Search section - easy to overlook.
John J. Miller
jo...@mcdata.com
William Smythe
(snip)..
> 2. Be prepared to spend some time and effort understanding the theory
> behind the Bootstrap Approach. If one just wants to get the necessary
> formulae and plug in numbers, contact the author at jlo...@mcn.net for
> his other book, essentially a field guide to implementing the Bootstrap
> method.
So many aviation books, so little time.
I wish much success for Professor John T. Lowry PhD books, but hope its
not another complicated bunch of useless charts & graphs, ala -
Professor David F. Rogers, PhD.
What do you suppose these guys talk about when flying? Do they talk
about beer & women?
Frederic Woodbridge
wrote:
::>So many aviation books, so little time.
::>I wish much success for Professor John T. Lowry PhD books, but hope its
::>not another complicated bunch of useless charts & graphs, ala -
::>Professor David F. Rogers, PhD.
::>What do you suppose these guys talk about when flying? Do they talk
::>about beer & women?
Hahah...say, John, what DO you PhD guys talk about when flying?
You know, that's another book out there that I really like and it's by
Lewis Bjork: "Piloting for maximum performance"
It's written in the same "style" as Barry Schiff's Profficient Pilot
series, if I may be so bold.
For those non-mathematicians amongst us, check out that book. It's a
wonderful example of great (and straightforward) writing.
Cheers,
Fred
--
Frederic Woodbridge
http://www.ifconfig.com
John T. Lowry
What do we PhDs talk about while flying? Well, after we put on our pants
(unlike ordinary mortals) both legs at the same time, we talk about...beer
and women! Not necessarily in that order.
You guys need to cut me a little slack. I agree the book has lots of charts,
graphs, and equations. However, ANYONE who can hold air speed within a knot
or so while climbing, gliding, and cruising, and who can punch a hand
calculator, can use the Bootstrap Approach. It's sort of like learning to
fly -- one step at a time...
John.
John T. Lowry, PhD
Flight Physics; Box 20919; Billings MT 59104
Voice: 406-248-2606
--
John T. Lowry, PhD
Flight Physics; Box 20919; Billings MT 59104
Voice: 406-248-2606
Frederic Woodbridge wrote in message <37e3c0c9...@news.gate.net>...
St Stephen Ames
I ordered it from Amazon and am looking forward to learning more...I
also love reading books when I have the author at my fingertips to
question and commend!...I just got B. Schiffs Proficient Pilot
series(I,II & III) also!...
Blue skies,
St Stephen Ames
PP-ASEL
N16402
My flying site: http://www.stephenames.com/flying/flying.html
---------------------------------------------------------------
- Another part of my pre-flight pax briefing -
Be assured that in all my time aloft, I have never lost a
passenger, however your results may vary.
Now sit back, relax, and enjoy your flight.
Dave Hyde
> ...but hope its not another complicated bunch of useless
> charts & graphs, ala - Professor David F. Rogers, PhD.
One man's opinion. My copies of Dr. Roger's papers on minimum-altitude
-loss turns dogeared from overuse. If you don't like 'em, don't read
'em, but no need to be insulting.
Dave 'simplex' Hyde
na...@brick.net
Matthew Whiting
Insults are the refuge of those who lack intellect.
Matt (no Ph.D. just a P.E.)
Dave Hyde
> My copies of Dr. Roger's papers on minimum-altitude
^^^^^^^^^^^
My apologies to Dr. Rogers, not Dr. Roger. And if you're reading the
post and have a long memory, I'm still working the problems we discussed
several years ago.
Dave 'possession is 9/10' Hyde
na...@brick.net
StevenV
--
-StevenV (sorry, just couldn't help myself this one time)
looking forward to having enough time to read this and other good books
myself.
St Stephen Ames
math!...I'm now reading Barry Schiff's 3 book Series called the
Proficient Pilot...That's my speed!...Sorry John, since alot of pilots
are 'techie's' I'm sure it will do well...Good luck with it...
Blue skies,
St Stephen Ames
PP-ASEL
N16402
My flying site: http://www.stephenames.com/flying/flying.html
---------------------------------------------------------------
- Another part of my pre-flight pax briefing -
'Be assured that in all my time aloft, I have never lost a
no sit back, relax and enjoy the ride!'
David
I submit that due to the extensive math in the book coupled with its
rather high price, that you include the math models with the book
instead of soaking another $50 from folks to get them on a floppy. My
preferences, in order, for modeling is 1) Mathcad, 2) Mathematica, or 3)
spreadsheet format.
David
"John T. Lowry" wrote:
>
> Dear St. S, and Probably Others,
>
> Sorry it didn't work out for you, but that's a good aspect of books from
> AIAA. And you certainly won't go wrong with Barry Schiff's writings!
> John.
> --
> John T. Lowry, PhD
> Flight Physics; Box 20919; Billings MT 59104
> Voice: 406-248-2606
>
> St Stephen Ames wrote in message <37ED74...@stephenames.com>...
John T. Lowry
Including the "math models" on a disk is an option I intend to take up with
the publisher, AIAA (American Institute of Aeronautics and Astronautics). I
doubt they'll want to do that without raising the price even higher,
however. By the way we poor authors don't set those prices. I was surprised
it came out as high as it is ($65). Specialized books are just plain
expensive. If Boeing or Martin Marietta is footing the bill, that's not much
problem; but the audience for my book goes down into the educated general
aviation readership and it IS a problem there.
As far as how to do the modelling, spreadsheets suffice for 95% of the
calculations and have the advantage of being universally available at low
cost. For someone who wants to follow the book's method (the Propeller
Master Equation) for doing propeller charts from scratch, something more
elaborate might be preferable. But even then spreadsheets, with a little
work, will do the job.
John.
--
John T. Lowry, PhD
Flight Physics; Box 20919; Billings MT 59104
Voice: 406-248-2606
David wrote in message <37EF756C...@bellsouth.net>...
John T. Lowry
My first Editor-in-Chief at AIAA, Paul Zarchan, suggested MatLab and I
looked into it. With the possible exception of the de novo propeller chart
calculation, which I expect almost no geneal aviation types to actually
perform, MatLab was way way overkill. Most of the bootstrap calculations are
on the high school level, just plugging numbers into algebraic relations.
The bootstrap approach is NOT some sort of massive curvefit or simulation
program. Just basic physics, propeller theory, and elementary aerodynamics.
A spreadsheet is nice to have, granted, because you may want to use the same
formula with say ten different values of air speed or for four different
weights or half a dozen different density altitudes. And so a hand
calculator can get tiresome. But no computational tour de force is needed.
John.
John T. Lowry, PhD
Flight Physics; Box 20919; Billings MT 59104
Voice: 406-248-2606
--
John T. Lowry, PhD
Flight Physics; Box 20919; Billings MT 59104
Voice: 406-248-2606
Matthew Whiting wrote in message <37F005C8...@epix.net>...
>David wrote:
>>
>> Dr. Lowry,
>>
>> I submit that due to the extensive math in the book coupled with its
>> rather high price, that you include the math models with the book
>> instead of soaking another $50 from folks to get them on a floppy. My
>> preferences, in order, for modeling is 1) Mathcad, 2) Mathematica, or 3)
>> spreadsheet format.
>
>I believe MATLAB is the biggest seller. You should switch to that...
>
>Matt
Calvin R. Walker
equations. I did. No problem. When it comes to aerodynamics and such
don't expect everything to be "2+2". And as far as the price, this is one
of the cheapest engineering books I have bought recently. Okay?
Calvin
Matthew Whiting <whi...@epix.net> wrote in message
news:37F0138D...@epix.net...
> "John T. Lowry" wrote:
> >
> > Dear Matthew, and All:
> >
> > My first Editor-in-Chief at AIAA, Paul Zarchan, suggested MatLab and I
> > looked into it. With the possible exception of the de novo propeller
chart
> > calculation, which I expect almost no geneal aviation types to actually
> > perform, MatLab was way way overkill. Most of the bootstrap calculations
are
> > on the high school level, just plugging numbers into algebraic
relations.
> > The bootstrap approach is NOT some sort of massive curvefit or
simulation
> > program. Just basic physics, propeller theory, and elementary
aerodynamics.
> > A spreadsheet is nice to have, granted, because you may want to use the
same
> > formula with say ten different values of air speed or for four different
> > weights or half a dozen different density altitudes. And so a hand
> > calculator can get tiresome. But no computational tour de force is
needed.
>
> John,
>
> My reply was tongue-in-cheek and meant as unsolicited advice to a person
> who was giving you unsolicited advice. I know that MATLAB is quite
> expensive and probably overkill for many things, but the Ph.D.'s who
> work for me (I'm a lowly BSEE/BSCS, but manage a sizeable engineering
> department), virtually insist on it for our control systems research and
> development work. And given the salaries that good EE's command these
> days, it makes no sense to quibble over a few grand for tools that make
> them happy and, hopefully, productive.
>
> Matt
St Stephen Ames
What type of spreadsheets did you program?...I'm trying to find the
practical applications related to flying of those heavy math
equations....
Blue skies,
St Stephen Ames
PP-ASEL
N16402
PA-28-180
My flying site: http://www.stephenames.com/flying/flying.html
---------------------------------------------------------------
- Another part of my pre-flight pax briefing -
'Be assured that in all my time aloft, I have never lost a
passenger, however your results may vary,
no sit back, relax and enjoy the ride!'
Newps
out when to take off uphill into the wind or downhill with the wind. It
gave a formula and directions on how to use it. I've since lost it.
Could you post it here with the directions? Thanks.
Matthew Whiting
Matthew Whiting
>
> Dear Matthew, and All:
>
> My first Editor-in-Chief at AIAA, Paul Zarchan, suggested MatLab and I
> looked into it. With the possible exception of the de novo propeller chart
> calculation, which I expect almost no geneal aviation types to actually
> perform, MatLab was way way overkill. Most of the bootstrap calculations are
> on the high school level, just plugging numbers into algebraic relations.
> The bootstrap approach is NOT some sort of massive curvefit or simulation
> program. Just basic physics, propeller theory, and elementary aerodynamics.
> A spreadsheet is nice to have, granted, because you may want to use the same
> formula with say ten different values of air speed or for four different
> weights or half a dozen different density altitudes. And so a hand
> calculator can get tiresome. But no computational tour de force is needed.
John,
Ron Rosenfeld
Performance Computer I received when I took a Mooney mountain flying course.
If you're interested, I'll see if I can dig up the address. It basically
takes sea level performance, and adjusts for density altitude, type of
runway surface, runway slope, headwind/tailwind, and weight, and gives you
your takeoff distance.
--ron
Newps <ne...@mcn.net> wrote in message news:37F0291A...@mcn.net...
St Stephen Ames
>
> John, I read an article in Mountain Pilot from you about how to figure
> out when to take off uphill into the wind or downhill with the wind. It
> gave a formula and directions on how to use it. I've since lost it.
> Could you post it here with the directions? Thanks.
Chapter 11 in Barry Schiff's The Proficient Pilot is all about that
subject with 2 charts...1 is determining climb gradient/slope from
groundspeed and climb rate...Ex: Climbing at 600 fpm with a groundspeed
of 90 kts = 6.6%...This should be 2x the runway gradient, Ex: Runway is
3000' long, 100' difference between ends, runway slope is determined by
dividing 100 by 3000, you get 3.3 percent...Using the scenario in both
situations, you should be able to safely takeoff...
2nd chart refers to the approx effect of hdwind/tlwind components on
takeoff and landing distances...Ex: Ratio of hdwind component,
determined by dividing touchdown speed of 80 KTAS with a 16-knot
tailwind...Ratio of wind to airspeed is .20...Based on that, chart says
tailwind will increase landing/takeoff distance by 44 %...If it was a
16-kt headwind we would decrease out takeoff/landing distances by
36%!...
John T. Lowry
be explained):
Vbehw = dRB*Theta*(1-hRho/70000)/(5*VR)
where dRB is your airplane's Base distance to Rotation (on a flat runway
with the same type surface at the same altitude with no wind); Theta is the
slope of the actual runway in degrees; hRho is the density altitude in feet;
and VR is your airplane's rotation speed in KCAS.
Vbehw is the wind speed for which it makes no difference whether you take
off uphill into the wind or downhill with the wind. If the actual wind is
greater than Vbehw then go uphill into it; if actual wind is less than Vbehw
then go downhill with it.
Derived on pp. 375-379 of Performance of Light Aircraft. Remember that it's
perfectly possible, if you have two airplanes about to take off on the same
sloped runway at the same time, that one of them (the one with more power)
is better off taking off uphill, the other one better off taking off
downhill.
John.
--
John T. Lowry, PhD
Flight Physics; Box 20919; Billings MT 59104
Voice: 406-248-2606
Newps wrote in message <37F0291A...@mcn.net>...
>John, I read an article in Mountain Pilot from you about how to figure
>out when to take off uphill into the wind or downhill with the wind. It
>gave a formula and directions on how to use it. I've since lost it.
>Could you post it here with the directions? Thanks.
>
>
nort...@capeonramp.net.com
of Hunter Mountain, NY.
David
Why borrow a map, it might get you lost.
On Tue, 28 Sep 1999 08:45:11 -0400, St Stephen Ames
<ste...@stephenames.com> wrote:
>Newps wrote:
>>
>> John, I read an article in Mountain Pilot from you about how to figure
>> out when to take off uphill into the wind or downhill with the wind. It
>> gave a formula and directions on how to use it. I've since lost it.
>> Could you post it here with the directions? Thanks.
>
glan...@gmail.com
Gary Lanthrum
glan...@gmail.com
On Tuesday, September 28, 1999 at 12:00:00 AM UTC-7, John T. Lowry wrote:
> Here's the formula for Vbehw = speed (in knots) for break-even headwind (to
> be explained):
>
> Vbehw = dRB*Theta*(1-hRho/70000)/(5*VR)
>
> where dRB is your airplane's Base distance to Rotation (on a flat runway
> with the same type surface at the same altitude with no wind); Theta is the
> slope of the actual runway in degrees; hRho is the density altitude in feet;
> and VR is your airplane's rotation speed in KCAS.
>
> greater than Vbehw then go uphill into it; if actual wind is less than Vbehw
> then go downhill with it.
>
> Derived on pp. 375-379 of Performance of Light Aircraft. Remember that it's
> perfectly possible, if you have two airplanes about to take off on the same
> sloped runway at the same time, that one of them (the one with more power)
> is better off taking off uphill, the other one better off taking off
> downhill.
>
> John.
> --
> John T. Lowry, PhD
> Flight Physics; Box 20919; Billings MT 59104
> Voice: 406-248-2606
>
> Newps wrote in message <37F0291A...@mcn.net>...
> >out when to take off uphill into the wind or downhill with the wind. It
> >gave a formula and directions on how to use it. I've since lost it.
> >Could you post it here with the directions? Thanks.
> >
> >
Richard
http://books.google.com/books/about/Performance_of_Light_Aircraft.html?id=3oc9llQai5YC
But it's for sure here...
Library of Congress!
Personal name
Lowry, John T., 1935-
Main title
Performance of light aircraft / John T. Lowry.
Published/Created
Reston, Va. : American Institute of Aeronautics and Astronautics,
c1999.
Description
xxv, 475 p. : ill. ; 23 cm.
ISBN
1563473305 (pbk. : alk. paper)
LC classification (full)
TL671.4 .L68 1999
LC classification (partial)
TL671.4
Subjects
Private planes--Performance.
Notes
Includes bibliographical references and index.
LCCN
99034583
Dewey class no.
629.133/343
Type of material
Book
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CALL NUMBER
TL671.4 .L68 1999 FT MEADE
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