Communication of weather theory and information about weather service products to pilots in an accurate and comprehensible manner is essential to flying safety in general. Probably no one needs weather knowledge more than the people who fly through it. The specific subject of this overview is General Aviation's Meteorological Requirements

Newton, D.

English

NASA Technical Reports Server

Improved upper-air forecasts have been a special 
requirement since the dawn of commercial avia- 
tion. It is even more significant today. Operating 
costs of most airlines have quadrupled during the 
past decade. There has been very little improve- 
ment in the forecast models that could offset some 
of these rising costs. We are encouraged with the 
work of NASA’s Bob Steinberg and his MERIT 
program. This kind of research is encouraged by 
the aviation community. Some examples of the 
impact of upper winds on operating costs are the 
following: 
For an airline the size of Delta, that operates ap- 
proximately 1,500 flight segments per day, a change 
in wind that affects the flight time by as little as 
six seconds and 20 pounds of fuel adds up to ap- 
proximately $ 3,900.00 per day in operating costs. 
This is almost $ 1.5 million per year. This kind 
of money is more than enough to cover the oper- 
ating budget of an airline’s meteorological/flight 
planning department. One knot of tailwind for a 
DC-10 operating between Los Angeles and Hon- 
olulu is worth 200 pounds of fuel. One knot! 
These are real numbers. Wind speeds equal to 40 
percent or more of a commercial jet’s true airspeed 
occur. Not all of the time, but they do happen, 
and we feel that ATC system does not consider the 
impact of this phenomenon. We could plan and 
fly great circle routes on every trip. However, we 
must use the wind as an energy source, a free en- 
ergy source. Atmospheric winds are not constant; 
large variations with time, as well as vertically and 
horizontally, mandate that we plan and fly in order 
to reduce the negative impact of headwinds and 
increase the beneficial effect of tailwinds. Tem- 
peratures are important also but wind makes the 
greater impact on economy. Upper wind forecasts 
must be improved. 
Finally, the requirement for meteorological instru- 
mentation needs to be mentioned. Many of you 
in the audience probably deal with this and have 
a similar interest. The low-level wind shear alert 
system (LLWSAS) is an airline requirement - ab- 
solutely! We need further development and instal- 
lation of the Doppler Radar System. These, and 
all other weather measureqent instruments and 
systems, are going to be of interest to the airlines 
for many years to come. 
This concludes our presentation on Airline Mete- 
orological Requirements. I thank you for listening 
and bearing with us. 
“GENERAL AVIATION’S METEOROLOGICAL REQUIREMENTS” 
Den& Newton 
The theme of this year’s workshop is Communi- 
cation and Appplication of Atmospheric Data for 
Aviation Needs. One could certainly say that this 
theme has been implicit in all of these workshops. 
However, the stress on communication seems to 
me to be both important and appropriate, for two 
reasons. First, the value of weather data to avi- 
ation is often extremely perishable. It becomes 
quite useless if not quickly and accurately commu- 
nicated to the people who need it. Furthermore, 
communication of weather theory and information 
about weather service products to pilots in an ac- 
curate and comprehensible manner is essential to 
flying safety in general. Probably no one needs 
weather knowledge more than the people who fly 
through it. 
General Aviation. In the broad view, the term 
can be, and &!en is, taken to mean all of civil 
aviation except the airlines. It would be virtually 
impossible to cover the meteorological needs of all 
of that in a single paper, in addition to which, 
one result of trying would be considerable overlap 
with Mr. Olcott’s forthcoming paper. Therefore, 
I would like to limit the subject somewhat by list- 
ing some common characteristics of that portion 
of the broad category of General Aviation with 
which this paper will be‘ concerned. The follow- 
ing items should not be taken as a definition, but 
more as a working hypothesis derived from expe- 
rience of the makeup of the spectrum of weather 
customers, if you will, whose needs are considered 
here. 
The specific subject of this overview paper is Gen- 
era1 Aviation’s Meteorological Requirements. How- 
ever, before one addresses the subject of General 
Aviation’s requirement for anything, it is well to 
say something about what is meant by the term, 
1) The segments of General Aviation treated 
here will be those which operate below an alti- 
tude of about 25,000 feet. Within that operating 
regime, there is a broad spectrum of aircraft types, 
ranging from light, single-engine airplanes to pres- 
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surized twins powered by turbocharged piston or 
small turboprop engines, and a few helicopters. 
2) The operations considered are non-revenue 
transportation of persons and property under both 
the visual and instrument flight rules of FAR Part 
91. Non-revenue should not be taken to necessar- 
ily imply non-business; however, as much of this 
transportation is business related. 
3) The pilots are generally the owners or 
renters of the aircraft, as opposed to persons who 
make their living flying. They encompass a broad 
sepctrum of flying qualifications. Many of them 
are instrument-rated pilots. Some of them, pratic- 
ularly pilots of higher performance aircraft, have 
Commercial Pilot Certificates. However, they are 
not often rated as Airline Transport Pilots. 
4) Of the aircraft flown, only the pressur- 
ized models can generally be considered to be fully 
equpped for weather flying, Le., to be equipped 
with weather radar and certified for flight in known 
icing conditions. Among the non-pressurized mod- 
els, the amount of thunderstorm avoidance equip- 
ment and ice protection equipment is widely vari- 
able, down to frequently none in the fixed land- 
ing gear and in many of the retractable single- 
engine models. Most of these aircraft carry, at 
least, the basic equipment required for flight un- 
der IFR, however. 
5) The financial resources of this segment 
of General Aviation are more limited, and more 
limiting, to its operations than those of, for exam- 
ple, a corporate flight operation. The necessity of 
sometimes having to cancel trips is accepted, al- 
beit, probably reluctantly, as the price of not hav- 
ing some types of equipment or services available. 
In this regard, this segment of General Aviation is 
much less likely to employ a private weather ser- 
vice than is a corporate or commuter operator. 
The above elements describe a very broad, active 
segment of aviation. Furthermore, it is a segment 
which is very dependent on the skill of its pilots 
in coping with weather for the safety of its flights; 
and on the quality of the weather services it uses, 
which services are almost exclusively provided by 
the National Weather Service (NWS) and the Fed- 
eral Aviation Administration (FAA). Its aircraft 
do not, in general, have the performance to rapidly 
climb and descend through the weather. It must, 
therefore, frequently operate in the weather, or not 
at all. 
It is essential to both its safety and usefulness 
that this segment of aviation be provided with 
the training to give its pilots an adequate knowl- 
edge of weather, in general; and the avoidance of 
hazardous weather, in particular. This done, it 
is then essential that these pilots have available 
to them weather products and services which will 
enable them to make intelligent decisions about 
routes, altitudes, times, fuel, and everything else 
influenced by weather down to, and including, the 
consideration of whether or not they should even 
be thinking about making this flight today. Let’s 
think a bit about training first, and then about 
the products and services. 
It is easy to wax hopelessly philosophical about 
weather training for pilots. Question: How much 
training is enough? Answer: Enough to be safe! 
Question: How much is THAT? The discussion 
goes rapidly downhill from there. In keeping with 
the function of this paper as an overview, and, 
hopefully, as a basis of later discussion, I would 
like to set forth just a few basic observations on the 
subject, together with a suggestion or two. First, 
I submit that the amount of training, which is the 
minimum necessary for pilots at any given skill 
level, is that which 
1) Instills in them a profound respect for 
weather which is beyond their capabilities (or the 
capabilities of their equipment) at whatever cur- 
rent stage of flying development they may be; and 
2) Provides them with the knowledge re- 
quired to recognize and avoid that weather. 
For example, a beginning pilot, whose flying is en- 
tirely visual, must be trained in visual recognition 
of hazardous weather. He must also be trained 
in recognition of conditions conducive to reduced 
ceilings and visibilities which are hazardous, in 
themselves, at that stage. This training must also 
include the elements of weather briefing necessary 
to anticipate such conditions prior to flight. If the 
pilot’s limitations are to expand, further weather 
training, to permit recognition of the new limits, 
is required. 
Now, how much training will a pilot actually get? I 
submit that this is driven primarily by the require- 
ments for weather knowledge on the FAA written 
tests for pilot ratings. People are most willing to 
invest time, effort and money in training for which 
there is some tangible reward, such as meeting a 
requirement for a license. I, therefore, suggest 
24 
that, realistically, the amount of weather train- 
ing which these pilots will acquire is strongly af- 
fected by the weather content of the Private Pilot 
and Instrument written examinations. There are, 
essentially, no other requirements to demonstrate 
weather knowledge, unless the pilot seeks an Air- 
line Transport Pilot Certificate. These tests are, 
therefore, among the first things to look at if one 
wishes to do something which will actually have 
an effect on weather training of pilots. At present, 
weather questions constitute, roughly, 15% to 20% 
of the Intsrument Pilot written test. Since a pass- 
ing score on the test as a whole is 70%, it is possi- 
ble to miss most (or even, conceivably, all) of the 
weather questions and still pass the test. I can, 
personally, think of nothing which would be more 
likely to have an effect on the quality of weather 
training than to score this section of this test (and, 
perhaps, also the weather section of the Private Pi- 
lot Test) separately from the rest of the test; and 
to make a passing score on this section of the test, 
by itself, a requirement for passing the entire test. 
The requirements for recurrent training of Gen- 
eral Aviation pilots (as limited for the purposes 
of this paper) are, at present, minimal. There 
is, however, a requirement for a biennial flight re- 
view to be given by a flight instructor. There is 
also a much stiffer requirement for the renewal of 
Flight Instructor certificates biennially, which in- 
structors can meet (among other ways) by tak- 
ing a three-day refresher course. I would suggest 
that a refresher course for the renewal of Flight 
Instructor certificates devoted entirely (or nearly 
so) to weather and to the teaching of weather be 
created, and that this be accepted as satisfying 
the renewal requirement instead of the regular re- 
fresher course on something like an every-other- 
renewal basis. It would be no big trick to put 
together such a course, which could and should be 
made available to any pilot. The carrot of actu- 
ally giving something tangible for taking it (;.e., 
the instructor revalidation) would induce far more 
people than would ever take an avanced weather 
course otherwise. What better people to take it 
than flight instructors? It would then be, at least, 
plausible to expect a general improvement in pi- 
lot weather training to take place over a period 
of time, and to expect that pilots might get more 
and better exposure to weather knowledge during 
Biennial Flight Reviews given by these instructors. 
Turning to the subject of the weather products and 
services needed by General Aviation, I would like 
to submit some fairly specific comments for later 
consideration in the working sessions (including 
some of my own personal value judgments as to 
where improvements have been made and where 
they are needed), as follows: 
1) Thunderstorm products are generally very 
good. Among those products.of most value to pi- 
lots, I would list convective outlooks and the asso- 
ciated severe weather outlook charts, severe thun- 
derstorm and tornado watches and warnings, sta- 
bility charts, radar summary charts, and convec- 
tive SIGMETS. I believe that little in the way of 
additional products is required in this area. Fast 
dissemination is critical to their utility, howver. 
This is particularly true of the convective SIG- 
METS and radar summary charts. In addition, 
the stability chart is a very valuable briefing tool 
and should be given much faster and wider dis- 
semination. 
2) Icing products are grossly inadequate. 
Despite the seriousness of the hazard, there is no 
long list of products hke the one above relating 
to icing. The quality of icing forecasts has been 
generally conceded at these workshops to be poor. 
This, in my opinion, starts with the total lack of 
a generally accepted definition of the intensity of 
icing conditions in terms of forecastable physical 
parameters, particularly that of cloud liquid water 
content. I am aware that a great deal of research 
into this subject is underway at the present time. 
In the interim, however, much better use could be 
made of methods presently in hand. A reason- 
able definition of icing intensities was proposed by 
NACA in 1947, and a method of forecasting them 
has existed since ‘1952. They are not perfect, but 
they are a lot better than nothing. 
3) There are many airports which have in- 
strument approaches but no weather observations. 
There are also some remote locations, such as moun- 
tain passes, where observations would be very use- 
ful. Various types of automatic equipment are now 
being developed and installed to make such obser- 
vations, which is good. I wonder, however, in these 
days of stuffing digital video data down wires, if 
remote television cameras at these sites might not 
be a better, and perhaps less expensive, solution. 
I realize that this will go against the grain of the 
natural deire of technical minds for quantitative 
data. However, the TV camera at Stampede Pass, 
which once provided a picture at the Seattle Flight 
Service Station, went out of service about six years 
ago and there is now a remote observation site in 
25 
its place. I have never found anyone who had used 
them both, myself included, who didn’t prefer the 
picture. 
4) On the subject of pictures, they are worth 
far more than a thousand words in a weather brief- 
ing. I refer, in this case, to the usefulness of a 
direct look at charts, particularly surface maps, 
weather depiction charts, radar summary charts, 
severe weather outlook charts, stability charts, con- 
stant pressure charts, and the various prognostic 
charts. No telephone weather briefing will ever 
come close to giving a pilot the information which 
can be had from a look at the charts. The in- 
creasing automation and consolidation of Flight 
Service Stations has, unfortunately, seriously re- 
duced or eliminated the General Aviation pilot’s 
opportunity to peruse charts in many locations. It 
is obviously not possible to put the system back 
the way it was. It was changed in the first place 
largely because it had become impossible to keep 
it the way it was. However, it seems to me that the 
proliferation of home and office computers may of- 
fer a good opportunity to restore pilots’ access to 
the charts. I believe that a high priority should 
be given to making charts and other data, such as 
sequence reports and forecasts, available to those 
having equipment capable of displaying or printing 
them. 
In the meantime, dissemination of weather data to 
General Aviation users is, and will continue to be, 
largely dependent on voice communication, either 
by telephone or radio. This, of course, is labor 
intensive and takes a lot of time. Due largely to 
these two factors, voice dissemination lends itself 
to the omission of items of data which are impor- 
tant to understanding of the weather situation. 
One of these items is recent past weather. It is 
unfortunate that most weather briefings are given 
as if nothing was known about what the weatherd 
had been from the dawn of recorded history un- 
til the phone rang; but it will probably continue 
to be the case simply due to time and workload 
constraints on the part of both pilots and briefers. 
Some automation of this process is possible, how- 
ever, and some steps have been taken in this di- 
rection. Comments on these are as follows: 
2) A scheme has been impIemented at the 
Seattle Flight Service Stations, and perhaps else- 
where by now, in which the caller receives a record- 
ed announcement of briefings for various routes, 
also recorded, which can be accessed by proper 
keying of a touch-tone phone. Upon completion 
of the selected briefings, or if none are selected, 
a briefer answers if the caller stays on the line. 
This is also an excellent idea and its use should be 
expanded. 
3) Transcribed weather broadcasts are of- 
fered over navigation frequencies throughout the 
country, and these can also often be listened to 
by dialing a telephone number listed in the local 
phone directory. These are good if kept current; 
but they are quite general, and it is often necessary 
to listen for a fair amount of time until the data in 
which one is interested comes around. In this re- 
gard, I would strongly recommend that Notices to 
Airmen (NOTAMS) be removed from these broad- 
casts. Unlike weather information, NOTAMS for 
airports and routes not involved in a given flight 
(and even some which are) are of no value what- 
ever to a pilot in flight. There are few more ag- 
gravating wastes of time than listening to a recita- 
tion of NOTAMS, meanwhile flying an airplane, 
maintaining communication with air traffic con- 
trol, etc., in the sometimes vain hope that the 
desired weather information will eventually come 
around. There is no way of knowing how often 
it happens that a pilot tunes up a TWEB for 
weather information, hears NOTAMS instead, and 
then simply turns it off and calls a briefer. I can 
testify that it is not uncommon. There are plenty 
of preflight sources of NOTAMS, and the TWEB 
would be a lot more useful without them. 
4) Finally, the EFAS system (commonly 
called Flight Watch) of direct inflight pilot-to-briefer 
communication is an excellent service for General 
Aviation. It could be better if more frequencies 
were available for it,  but functions very well oth- 
erwise. 
1) A system using touch-tone phones allow- 
ing pilots to obtain exactly the weather they want 
by following recorded instructions and entering the 
necessary commands has been used in a few lo- 
cations. This concept is excellent and should be 
pursued and expanded. 
26 


General aviation's meteorological requirements

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