Approach to Landing

by Bill Bird

In 1996 Flight Standards Division of the Federal Aviation
Administration issued Advisory Circular 91-71, Operation of
Hot Air Balloons with Airborne Heaters. A Special Report, with
commentary, on the AC appeared in the September 1996 issue of
Balloon Life. In part, the AC discussed approach and landings.
This article, with minor editorial changes, first appeared in
Balloon Life, February 1991. Editor

About 20 percent of all balloon accidents happen during the
approach to landing phase. Mostly running into things, buildings,
other balloons, trees, powerlines, radio/TV towers, etc. So, keep
your eyes open and look all around as well as above and below.
The crew can also help spot above. There is nothing more helpful
to a pilot than an experiencedcrew who spots potential airborne
and surface hazards. Passengers can be very helpful as well. The

more eyes at workthe betterthechance of beingabletoavoid
those problems hazards. Don’t be so proud as to not ask for help
from your passengers. Many of them will not volunteer informa-
tionunless youlet them know theyare helping you. It alsolets
them feel important andthat they are part of the flightteam.
where werunintoawholerangeofcontroversiesabouttech-
niques anda greatdeal of misrepresentation oftermsandcon-
phase in terms of a “glide slope” approach. Balloons donotglide.
Theyclimb, flyat a constant altitude (levelflight), or descend.
Theycan nomore glide thancan a truck. Glide,whenusedfor
other aircraft, refers to a lift over dragratio and is figured as the
unitsof forwarddistance traveled for eachunitof altitude lost.
For example, a glide ratio of 7:1 means that an aircraft will move

IMAGE landing010301.gif
IMAGE landing010302.gif

Figure 1A
BasicStepDown ApproachProfile,SlideView

Figure 1B
Typical StepDownApproach Profile, Side View




forward seven feet for every one foot of vertical altitude lost. To
accomplishthis, the aircraftis flown at what is referred toasbest
angle of glide airspeed.It is also figured out that the airfoil,
primarilythe wing or rotors, willgenerateenoughliftto maintain
thatratioat therecommended airspeedeven ifthere isa complete
loss of power from the engine.
Nowaswe allknow,balloonsdonotfunctionthisway. Their
forward motionis the windand nomechanical means of forward
propulsion are used. If a balloon looses power, it looses lift and
willincrease itsdescentrate until itreachesthe “terminal veloc-
ity”for the given conditions. Clearly there is no liftover drag or
glide ratioor best angle of glide airspeed for balloons. It is time
for us to educate the FAAconcerning thesedifferences and
develop authoritative reference manuals with proper terms spe-
cific to balloons. Part of our problems with the FARsis that we
accept the use of terms applied to other aircraft. “Glide”isone of
those terms. Another is “level flight.” Both of these terms are
important in the description of the approach to landing phase of
There are basically three types of approaches which can be
made by aballoon and it is pilot’s choicedepending on the
conditions that prevail. These three types are:The Step Down
Approach, The Rapid Descent and Round Out Approach
times called the Dive Bomber or Steep approach) and theCon-
stant Rate Descent Approach.
Acombination ofthese three
approaches can also be employed but the techniques and skills
needed are those used in the basic three. (During our discussion
of these three approaches, we willassume there are no low level
wind shears.This is a separate topic and is covered in other
articles in this issue.)
What is below you in terms of obstacles and what the winds
are doing both in direction and speed, will determine to a great

degree what type approach you make to your intended landing
site.The “stepdown”approach isthemethod accepted and taught
as the mostappropriate for balloons. What we mustbe carefulof
isflying at a low level cruise altitudefor any extended length of
time or distance when making our approach. In fact, we should
make an effort not to fly level for more than a few minutes at a
time during this approach until we are close to the touchdown
point. A typical diagram of a step down approach is depicted in
Figure 1A.
During the step down approach the pilot is going through a
seriesofdescent andleveling offmaneuverswhiledrifting
toward the landing site. The keyhere is touse thismethodto find
thelower levelwindstohelpsteer youtoyourtargetlandingfield.
Many times there will be a series of step up climbs associated
with this type of approach to take advantage of the wind direc-
tionsat various heights above the ground. Thus the typical step
down approach may include a series of descents, climbs and
periodsof relatively levelflightduringthe approach(Figure1B).
If we looked at this in profile and from behind the balloon, it
would look like several circles or boxes decreasing in size. Sort
ofa “corkscrew”profile withclimbsand descentsanintegralpart
of this approach (Figure 1C). What we must be cautious of is
stayingtoo low in level flightwhich mightbe seen as a violation
of the FARs. Tree-topping or roof-topping for periods of30
minutes has been given as the reason for past FAA citations.
Thesecondtypeof approach, therapiddescent(divebomber,
steep) approach takes practice and skill. The steep approach
requires the application of knowledge and your abilityto judge
timing, the response of the balloon you are flying, wind condi-
tionsbelow and on the surface, as well as being able to see any
obstacles andjudge other balloons’flightpathsbelowyou. Many
ofthe rallyeventwaivers have specified maximum ratesof climb

IMAGE landing010303.gif
IMAGE landing010304.gif

Figure 1C
Typical StepDown Approach Profile, Rear View

Figure 2
RapidDescent Rate Profile, SideView

Average descent rate = 500 fpm
T ime = 2 minutes




and descent (usually300 fpm or less)which would preclude you
from using this type of approach. In profile, the steep approach
would look like Figure 2 assuming a 500fpm descent. As you can
see, the skill will be to estimate the time to the target field, and
when theround out for thetouchdown.Many ofthese type
approaches end up with high impact rates (hard landings) or
missed landings because of the over burn with a resultantclimb.
This means that the pilot must now search for anotherlandingsite
and rush the next approach. These steep landing approaches need
to be taught by instructors and practiced by the pilot to stay
proficient in their execution. These steep approaches have also
lead to false reports ofa balloon “crashing” as it disappears
rapidly from the view of the casual ground observer.
The steep approach can be used in conjunction with the
normal stepdown approach. Whenused thisway, itisusuallythe
first part of the approach from a higher altitude followed by the
smaller steps being done when closer to the ground. (Figure3)It
isalso the type of approach which may be necessary when there
are lightwindsnear the surface and you need tobe higher togain
the movement necessary to reach your landing site. (Figure 4)
Thethird style approach,the constant approach(the so
called “glide slope” approach, Figure 5) is one that people who
fly airplanes always seem to want to attempt. In the hundreds of
hours that I have given balloon flight instruction, invariable a
person who has an airplane license, no matter the number of
hours, will always attempt to approach and land the balloon using
this style approach. To successfully execute this style approach
to a landing at a preselected site requires a lot of skill, a set of
perfect climatic conditions (constant velocity, constant direction
winds)from altitudeto the landing site.I do notrecommend this
approach, but let’s examine how it might look. The assumption
is that the approach is started at 1,000 ft. AGL. Now the skill
comes in determining wind speed (translated into ground speed),
rate of descent needed and distance from the landing sitetobegin
the approach and then fly it. For example; given a ground speed
of 8 mph, the descent would need tobe approximately44 fpm or
greater and begun 3 miles prior to the touchdown point. Why 3
miles?Because the AIM (airman’s Information Manual) de-
scribesthenormal approachbeginningat1,000feetanda
distance of 3 nautical miles. It is also based on the ability of the
aircraft(readairplane)to maintaina constantairspeed and rateof
descent and to remain on track (steered) to the planned landing
field. How were these ratesdetermined for your descentyou ask?
Wellyou dothe quickmathwithyour onboard computer and you
determine that youhave 22.5 minutes to landing. Now you enter
that into yourflight director and auto pilot (your brain) and
determine that you need to have a constant descent rate of 44.4
fpm to achieve thisapproach with a landing atthe landing point.
Now I’mcertain that we can all peg our VSI at 44.4 fpmto
achieve this. Let’s get serious. To really attempt this is ridiculous,
but the concept does let us start our approach a long way outand
as long as we don’t ever reduce the descentbelow the calculated
minimum rate we could not be cited for an illegal approach.
So maybe we can incorporate this with the other two. As
previouslystated, a combinationof the three basic techniques can
give theballoon pilot the necessaryflexibility to achievea
comfortable landing in the intended landing field.

IMAGE landing010305.gif
IMAGE landing010306.gif
IMAGE landing010307.gif

Figure 3
Combination Rapid Descent and Step Approach Profile,
Slide View

Figure 4
Light Wind: Dropin Approach, Slide View

Figure 5
Constant Rate Descent (“Glide Slope”) Profile

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