Hot air balloon in flight
Hot air balloons shaped as bees
Hot air balloon shaped as a
turtle
The
hot air balloon is the oldest successful
human-carrying
flight technology and is a
subset of
balloon aircraft.
On November 21, 1783, in Paris, France, the first manned flight was
made by
Jean-François Pilâtre
de Rozier and
François Laurent d'Arlandes
in a hot air balloon created by the
Montgolfier brothers. Recently, balloon
envelopes have been made in all kinds of shapes, such as hot dogs,
rocket ships, and the shapes of commercial products. Hot air
balloons that can be propelled through the air rather than just
being pushed along by the
wind are known as
airships or, more specifically,
thermal airships.
A hot air balloon consists of a bag called the
envelope that is capable of containing heated air.
Suspended beneath is the
gondola
or
wicker basket (in some long-distance or
high-altitude balloons, a
capsule) which carries the passengers and
(usually) a source of heat, usually an open flame. The heated air
inside the envelope makes it
buoyant since
it has a
lower density than the
relatively cold air outside the envelope. Unlike
gas balloons, the envelope does not have to be
sealed at the bottom since the air near the bottom of the envelope
is at the same pressure as the surrounding air. In today's sport
balloons the envelope is generally made from
nylon fabric and the mouth of the balloon (closest to
the burner flame) is made from fire resistant material such as
Nomex.
History
Premodern and unmanned balloons
Unmanned hot air balloons are popular in Chinese history.
Zhuge Liang of the
Shu
Han kingdom, in the
Three
Kingdoms era (220–80 AD) used airborne lanterns for military
signaling. These lanterns are known as
Kongming lanterns (孔明灯).
There is also some
speculation, from a demonstration led by British modern hot air
balloonist Julian Nott in
the late 1970s and again in 2003, that hot air balloons could have
been used by people of the Nazca
culture of Peru
some 1500 to
2000 years ago, as a tool for designing the famous Nazca ground figures and
lines
. The first documented balloon flight in
Europe was demonstrated by the
Brazilian priest
Bartolomeu de Gusmão.
On August 8, 1709, in
Lisbon
, Bartolomeu de
Gusmão managed to lift a small balloon made of paper full of
hot air about 4 meters in front of king John V and the Portuguese court.
First manned flight
The first clearly recorded instance of a balloon carrying
passengers used hot air to generate
buoyancy and was built by the brothers
Joseph-Michel and Jacques-Etienne
Montgolfier in Annonay, France. After
experimenting with unmanned balloons and flights with animals, the
first
tethered balloon flight with humans on board took
place on October 19, 1783 with the scientist
Jean-François Pilâtre
de Rozier, the manufacture manager,
Jean-Baptiste Réveillon and
Giroud de Villette, at the
Folie Titon in Paris. The first
free flight with
human passengers was on November 21, 1783.
King Louis XVI had originally decreed
that condemned criminals would be the first
pilots, but de Rozier, along with
Marquis Francois
d'Arlandes, successfully petitioned for the honor.
Today
A pair of Hopper balloons
Modern hot air balloons, with an onboard heat source, were
pioneered by
Ed Yost, beginning in the
1950s; his work resulted in his first successful flight, on October
22, 1960. The first modern-day hot air balloon to be built in the
United Kingdom (UK) was the
Bristol
Belle in 1967. Today, hot air balloons are used primarily for
recreation.
Hot air balloons are able to fly to extremely high altitudes. On
November 26, 2005,
Vijaypat
Singhania set the world altitude record for highest hot air
balloon flight, reaching .
He took off from downtown Bombay
, India, and
landed south in Panchale. The previous record of had been set by
Per Lindstrand on June 6, 1988 in
Plano,
Texas
. As with all unpressurized aircraft, oxygen
is needed for all crew and passengers on any flight that exceeds an
altitude of about .
On January 15, 1991, the
Virgin Pacific Flyer balloon
completed the longest flight in a hot air balloon when
Per Lindstrand (born in Sweden, but resident
in the UK) and
Richard Branson of
the UK flew from Japan to Northern Canada. With a volume of 74
thousand
cubic meters (2.6 million
cubic feet), the balloon envelope was the
largest ever built for a hot air craft. Designed to fly in the
trans-oceanic
jet streams the
Pacific
Flyer recorded the highest ground speed for a manned balloon
at . The longest duration record was set by Swiss psychiatrist
Bertrand Piccard, Auguste Piccard's grandson, and Briton Brian
Jones, Flying in the Breitling Orbiter 3. It was the first nonstop
trip around the world by balloon. The balloon left Château-d'Oex,
Switzerland, on March 1, 1999, and landed at 1:02 a.m. on March 21
in the Egyptian desert 300 miles (482 kilometers) south of Cairo.
The two men broke distance, endurance, and time records, traveling
19 days, 21 hours, and 55 minutes. Steve Fosset broke the record
for shortest time around the world on 3 July 2002. The new record
is 320 h 33 min.
Construction
A hot air balloon for manned flight uses a single-layered, fabric
gas bag (lifting "envelope"), with an opening at the bottom called
the mouth or throat. Attached to the envelope is a basket, or
gondola, for carrying the passengers. Mounted above the basket and
centered in the mouth is the "burner" which injects a flame into
the envelope, heating the air within. The heater or burner is
fueled by
propane, a
liquefied gas stored in pressure
vessels, similar to high pressure
forklift cylinders.
Envelope
Modern hot air balloons are usually made of light-weight and strong
synthetic fabrics such as
ripstop
nylon, or
dacron (a
polyester).
A hot air balloon is partially
inflated with cold air from a gas-powered fan, before the propane
burners are used for final inflation.
During the manufacturing process, the material is cut into panels
and sewn together, along with structural
load
tapes that carry the weight of the gondola or basket. The
individual sections which run from the throat to the crown (top) of
the envelope are called
gores or gore
sections. Envelopes can have as few as 4 gores or as many as 24 or
more.
Envelopes often have a crown ring at their very top. This is a hoop
of smooth metal, usually aluminium and approximately in diameter,
to which vertical load tapes attach.
Seams
The most common technique for sewing panels together is called the
double lap seam. The two pieces of fabric are folded over
on each other at their common edge, possibly with a load tape as
well, and sewn together with two rows of parallel stitching.
Other methods include a
flat seam in which the two pieces
of fabric are held together simply with two rows of parallel
stitching, and a
zigzag in which parallel zigzag stitching
holds a double lap of fabric.
Coatings
The fabric (or at least part of it, the top 1/3 for example) may be
coated with a sealer, such as
silicone or
polyurethane, to make it impermeable to
air. It is often the degradation of this coating and the
corresponding loss of impermeability that ends the effective life
of an envelope, not weakening of the fabric itself. Heat, moisture,
and mechanical wear-and-tear during set up and pack up are the
primary causes of degradation. Once an envelope becomes too
porous to fly, it may be retired and used
as a 'rag bag': cold inflated and opened for children to run
through. Products for recoating the fabric are becoming
commercially available.
Sizes
A range of envelope sizes is available. The smallest, one-person,
basket-less balloons (called "
Hoppers" or "Cloudhoppers") have as little as
21,000 ft³ (595 m³) of envelope volume (for a perfect
sphere this would mean a radius of around ). At the other end of
the scale are the balloons used by large commercial sightseeing
operations that carry well over two dozen people and have envelope
volumes of up to 600,000 ft³ (16,990 m³). However, most
balloons are roughly 100,000 ft³ (2,832 m³) and carry 3
to 5 people.
Vents
The top of the balloon usually has a vent of some sort. This
enables the pilot to release hot air to slow an ascent, start a
descent, or increase the rate of descent, usually for landing. Some
hot air balloons have
turning vents which are side vents
which, when opened, cause the balloon to rotate. Such vents are
particularly useful for balloons with rectangular baskets in order
to align the wider side of the basket for landing.
The most common type of top vent is a disk-shaped flap of fabric
called a
parachute vent. The fabric is connected around
its edge to a set of "vent lines" that converge in the center. (The
arrangement of fabric and lines roughly resembles a
parachute -- thus the name.) These "vent lines"
are themselves connected to a control line that runs to the basket.
A parachute vent is opened by pulling on the control line. Once the
control line is released, the pressure of the remaining hot air
pushes the vent fabric back into place. A parachute vent can be
opened briefly while in flight to initiate a rapid descent. (Slower
descents are initiated by allowing the air in the balloon to cool
naturally.) The vent is pulled completely open to collapse the
balloon after landing.
An older, and today less commonly used, style of top vent is called
a "
Velcro-style" vent. This too is a disk of
fabric at the top of the balloon. However, rather than having a set
of "vent lines" that can repeatedly open and close the vent, the
vent is secured by "hook and loop" fasteners (such as Velcro) and
is only opened at the end of the flight. Balloons equipped with a
Velcro-style vent typically have a second "maneuvering vent" built
into the side (as opposed to the top) of the balloon.
Shape
Besides special shapes, possibly for marketing purposes, there are
several variations on the traditional "inverted tear drop" shape.
The simplest, often used by home builders, is a
hemisphere on top of a truncated
cone. More-sophisticated designs attempt to
minimize the circumferential
stress
on the fabric, with different degrees of success depending on
whether they take fabric weight and varying air density into
account. This shape may be referred to as "natural". Finally, some
specialized balloons are designed to minimize
aerodynamic drag (in the vertical
direction) to improve flight performance in competitions.
Basket
A wicker basket capable of holding 16 passengers
Baskets are commonly made of
woven
wicker or
rattan. These
materials have proven to be sufficiently light, strong, and durable
for balloon flight. Such baskets are usually rectangular or
triangular in shape. They vary in size from just big enough for two
people to large enough to carry twenty-four. Larger baskets often
have internal partitions for structural bracing and to
compartmentalize the passengers. Small holes may be woven into the
side of the basket to act as foot holds for passengers climbing in
or out.
Baskets may also be made of
aluminium,
especially a collapsible aluminium frame with a fabric skin, to
reduce weight or increase portability. These may be used by pilots
without a ground crew or who are attempting to set altitude,
duration, or distance records. Other specialty baskets include the
fully enclosed gondolas used for around-the-world attempts, and
baskets that consist of little more than a seat for the pilot and
perhaps one passenger.
Burner
A burner directing a flame into the
envelope
The burner unit gasifies liquid
propane,
mixes it with air, ignites the mixture, and directs the flame and
exhaust into the mouth of the envelope. Burners vary in power
output; each will generally produce 2 to 3 MW of heat (7 to 10
million
BTUs per hour), with
double, triple, or quadruple burner configurations installed where
more power is needed. The pilot actuates a burner by opening a
propane valve, called a
blast valve. The valve may
be spring loaded so that it closes automatically, or it may stay
open until closed by the pilot. The burner has a
pilot light to ignite the propane and air
mixture. The pilot light may be lit by the pilot with an external
device, such as a
flint striker or a
lighter, or with a built-in
piezo electric spark.
Where more than one burner is present, the pilot can use one or
more at a time depending on the desired heat output. Each burner is
characterized by a metal coil of propane tubing through which the
flame shoots in order to preheat the incoming liquid propane. The
burner unit may be suspended from the mouth of the envelope, or
rigidly supported over the basket. The burner unit may be mounted
on a
gimbal to enable the pilot to aim the
flame and avoid overheating the envelope fabric. A burner may have
a secondary propane valve that releases propane more slowly and
thereby generates a different sound. This is called a
whisper burner and is used for flight over
livestock to lessen the chance of spooking them. It also generates
a more yellow flame and is used for night glows because it lights
up the inside of the envelope better than the primary valve.
Fuel tanks
Propane fuel tanks are usually cylindrical
pressure vessels made from
aluminium,
stainless
steel, or
titanium with a valve at one
end to feed the burner and to refuel. They may have a
fuel gauge and a
pressure gauge. Common tank sizes are
10 (38), 15 (57), and 20 (76) US
gallons
(
liters). They may be intended for upright or
horizontal use, and may be mounted inside or outside the
basket.
Stainless steel fuel tanks, wrapped in
red insulating covers, mounted vertically, and with fuel gauges,
during refueling
The pressure necessary to force the fuel through the line to the
burner may be supplied by the
vapor
pressure of the propane itself, if warm enough, or by the
introduction of an inert gas such as
nitrogen. Tanks may be preheated with electrical
heat tapes to produce sufficient vapor
pressure for cold weather flying. Warmed tanks will usually also be
wrapped in an insulating blanket to preserve heat during the setup
and flight.
Instrumentation
A balloon may be outfitted with a variety of instruments to aid the
pilot. These commonly include an
altimeter, a
rate of climb
indicator, envelope (air) temperature, and ambient (air)
temperature. A
GPS
receiver can be useful to indicate ground speed (traditional
aircraft air speed indicators would be useless) and
direction.
Combined mass
The combined mass of an average system can be calculated as
follows:
- {| class="wikitable"
using a
densityof 0.9486 kg/m³
for dry air heated to 210 °F (99 °C).
Theory of operation
Generating lift
Thermal image showing temperature variation in a hot air
balloonRaising the air temperature inside the envelope makes it
lighter than the surrounding (ambient) air. The balloon floats
because of the buoyant force exerted on it. This force is the same
force that acts on objects when they are in water and is described
by
Archimedes'
principle. The amount of lift (or
buoyancy) provided by a hot air balloon depends
primarily upon the difference between the temperature of the air
inside the envelope and the temperature of the air outside the
envelope. For most envelopes made of nylon fabric, the maximum
internal temperature is limited to approximately 120 °C
(250 °F).
It should be noted that the melting point of nylon is significantly
higher than this maximum operating temperature — about 230 °C
(450 °F). However the lower temperatures are generally used
because the higher the temperature, the more quickly the strength
of the nylon fabric degrades over time. With a maximum operating
temperature of 120 °C (250 °F), balloon envelopes can
generally be flown for between 400 and 500 hours before the fabric
needs to be replaced. Many balloon pilots operate their envelopes
at temperatures significantly below the maximum in order to extend
the longevity of their envelope fabric.
The lift generated by 100,000 ft³ (2831.7 m³) of dry air
heated to various temperatures may be calculated as follows:
- {| class="wikitable"
The
density of airat 20 °C,
68 °F is about 1.2 kg/m³. The total lift for a balloon of
100,000 ft³ heated to (99 °C, 210 °F) would be
1595 lb, 723.5 kg. This is just enough to generate
neutral buoyancy for the total system mass (not including the
heated air trapped in the envelope, of course) stated in the
previous section. Liftoff would require a slightly higher
temperature, depending on the desired rate of climb. In reality,
the air contained in the envelope is not all the same temperature,
as the accompanying thermal image shows, and so these calculations
are based on averages.
For typical atmospheric conditions (20 °C, 68 °F), a hot
air balloon heated to (99 °C, 210 °F) requires about
3.91 m³ of envelope volume in order to lift 1 kilogram
(62.5 ft³/lb). The precise amount of lift provided depends not
only upon the internal temperature mentioned above, but the
external temperature, altitude above sea level, and humidity of the
surrounding air. On a warm day, a balloon cannot lift as much as on
a cool day, because the temperature required for launch will exceed
the maximum sustainable for nylon envelope fabric. Also, in the
lower atmosphere, the lift provided by a hot air balloon decreases
about 3% for each 1,000 meters (1% per 1,000 ft) of
altitude gained.
Montgolfiere
Standard hot air balloons are called
Montgolfiere
balloonsand rely solely on the buoyancy of hot air
provided by the burner and contained by the envelope. This style of
balloon was developed by the
Montgolfier brothers, and had its first
public demonstration on 4 June 1783 with an unmanned flight lasting
10 minutes, followed later that year with manned flights.
Hybrid
The 1785
Rozière balloon, a
type of
hybrid balloon, named after its creator,
Jean-François Pilâtre de Rozier, has a separate cell for a lighter
than air gas (typically
helium,) as well as a
cone below for hot air (as is used in a hot air balloon) to heat
the helium at night.
Hydrogengas was used
in the very early stages of development but was quickly abandoned
due to the obvious danger of introducing an open flame near the
gas. All modern Roziere balloons now use helium as a lifting
gas.
Solar
Solar balloonsare hot air balloons
that use just
solar
energycaptured by a dark envelope to heat the air inside.
Safety equipment
To help ensure the safety of pilot and passengers, a hot air
balloon may carry several pieces of safety equipment.
In the basket
In order to relight the burner, in case the pilot light goes out
and the optional piezo ignition fails, the pilot should have ready
access to a
flint spark lighter.
Many systems, especially those that carry passengers have
completely redundant fuel and burner systems: two fuel tanks,
connected to two separate hoses, which feed two distinct burners.
This enables a safe landing in the case of a clog somewhere in one
system or if a system must be disabled because of a fuel
leak.
A
fire extinguishersuitable for
extinguishing propane fires is a useful piece of safety equipment
in a balloon. Most balloons carry a 1 kg
AB:Etype fire extinguisher.
A handling or drop line is mandatory safety equipment in many
countries. It is a rope or webbing of 20 - 30 metres in length
which is attached to the balloon basket with a quick release
connection at one end. In very calm wind conditions the balloon
pilot can throw the handling line from the balloon so that the
ground crew can safely guide the balloon away from obstructions on
the ground.
On the occupants
At a minimum the pilot should wear flame resistant gloves. These
can be made of leather or some more sophisticated material, such as
nomex. These will enable the pilot to shut off
a gas valve in the case of a leak even if there is a flame present.
Quick action on the pilot's part to stop the flow of gas can turn a
potential disaster into an inconvenience. In addition, the pilot
should wear clothes made of natural fibers. These will singe and
not burn readily if brought into contact with an open flame. Many
synthetic fibers, unless especially formulated for use near flame
or high temperatures like nomex, will melt onto the wearer and can
cause severe burning. Finally, some balloon systems, especially
those that hang the burner from the envelope instead of supporting
it rigidly from the basket, require the use of helmets by the pilot
and passengers.
On the ground crew
The ground crew should wear gloves on their hands whenever the
possibility of handling ropes or lines exists. The mass and exposed
surface to air movement of a medium sized balloon is sufficient to
cause rope burns to the hands of anyone trying to stop or prevent
movement. The ground crew should also wear sturdy shoes and at
least long pants in case of the need to access a landing or landed
balloon in rough or overgrown terrain.
Maintenance and repair
Taken from the basket, the reflection
of the balloon can be seen in the lake below.
Obstacles in the landscape can inhibit smooth retrieval of the
balloon upon landing.
As with aircraft, hot air balloons require regular maintenance in
order to remain airworthy. As aircraft made of fabric and that lack
direct horizontal control, hot air balloons may occasionally
require repairs to rips or snags. While some operations, such as
cleaning and drying, may be performed by the owner or pilot, other
operations, such as sewing, must be performed by a qualified repair
technician and recorded in the balloon's maintenance log
book.
Maintenance
To ensure long life and safe operation, the envelope should be kept
clean and dry. This prevents mold and mildew from forming on the
fabric and abrasion from occurring during packing, transport, and
unpacking due to contact with foreign particles. In the event of a
landing in a wet (because of precipitation or early morning or late
evening dew) or muddy location (farmer's field), the envelope
should be cleaned and laid out or hung to dry.
The burner and fuel system must also be kept clean to ensure safe
operation on demand. Damaged fuel hoses need to be replaced. Stuck
or leaky valves must be repaired or replaced. The wicker basket may
require occasional refinishing or repair. The skids on its bottom
may require occasional replacement.
Balloons in most parts of the world, are maintained in accordance
with a fixed manufacturer's maintenance schedule which includes
regular (100 flight hours or 12 month) inspections in addition to
the maintenance work that must be done to correct any damage. In
Australia, balloons that are used for carrying commercial
passengers must be inspected and maintained by approved
workshops.
Repair
In the case of a snag, burn, or rip in the envelope fabric, a patch
may be applied or the affected panel completely replaced. Patches
may be held in place with glue, tape, stitching, or a combination
of these techniques. Replacing an entire panel requires the
stitching around the old panel to be removed, and a new panel to be
sewn in with the appropriate technique, thread, and stitch
pattern.
Licensing
Depending on the size of the balloon, location, and intended use,
hot air balloons and their pilots need to comply with a variety of
regulations.
Top of balloon during inflation.
Crew is securing parachute vent.
Balloons
In the USA, balloons below a certain size (empty weight of less
than 155 pounds or 70 kg including envelope, basket,
burners and empty fuel tanks) can be used as an
ultralight aircraftand
cannot carry passengers, except for
pilot training. Anything larger than that
must be registered (have an
N-number), have an
airworthinesscertificate, and pass annual
inspections.
Pilots
In the United States of America
In the United States, a pilot of a hot air balloon must have a
pilot
certificatefrom the
Federal Aviation
Administration(FAA) and it must carry the rating of
"Lighter-than-air free balloon", and unless the pilot is also
qualified to fly gas balloons, will also carry this limitation:
"Limited to hot air balloons with airborne heater". A pilot does
not need a license to fly an
ultralightaircraft, but training is
highly advised, and some hot air balloons meet the criteria.
In order to carry paying passengers for hire (and attend some
balloon festivals), a
pilot must have a
commercial
pilot certificate. Commercial hot air balloon pilots may also
act as hot air balloon
flight
instructors. While most balloon pilots fly for the pure joy of
floating through the air, many are able to make a living as a
professional balloon pilot. Some professional pilots fly commercial
passenger sightseeing flights, while others fly corporate
advertising balloons.
In the UK
In the UK, the person in command must hold a valid Private Pilot's
License issued by the Civil Aviation Authority specifically for
ballooning; this is known as the PPL(B). There are two types of
commercial balloon licences: CPL(B) Restricted and CPL(B) (Full).
The CPL(B) Restricted is required if the pilot is undertaking work
for a sponsor or being paid by an external agent to operate a
balloon. The pilot can fly a sponsored balloon with everything paid
for with a PPL unless asked to attend any event. Then a CPL(B)
Restricted is required. The CPL(B) is required if the pilot is
flying passengers for money. The balloon then needs a transport
category C of A (certificate of air worthiness). If the pilot is
only flying sponsor's guests, and not charging money for flying
other passengers, then the pilot is exempted from holding an AOC
(air operator's certificate) though a copy of it is required. For
passenger flying, the balloon also requires a maintenance
log.
In Australia
In Australia, a commercial operation must operate with a nominated
Chief Pilot and under an Air Operators Certificate from the
Australian Civil Aviation and Safety Authority (CASA). Pilots must
have different levels of experience before they are allowed to
progress to larger balloons. Hot air balloons must be registered
aircraft with the CASA and are subject to regular airworthiness
checks by authorised personnel.
Manufacturers
Three balloons prepare for liftoff in
Orlando, Florida.
, England,
who also own Lindstrand Balloons
of Oswestry
,
England.Aerostar International, Inc. of
Sioux
Falls
, South
Dakota
was North America's largest balloon manufacturer
and a close second in world manufacturing before ceasing to build
balloons in January 2007.Firefly
Balloons, formerly known as The Balloon Works, is another
popular manufacturer of hot-air balloons located in Statesville
, North
Carolina
.Another long time producer of hot air
balloons is Head Balloons, Inc.,
located in Helen
, Georgia
.The major manufacturers in Canada
are Sundance Balloons and Fantasy Sky
Promotions.There are many other manufacturers around
the world including Ultramagic (Spain
), Kavanagh
Balloons (Australia), Schroeder Fire
Balloons (Germany
) and Kubicek
Balloons (Czech
Republic
).
Cameron Balloons,
Lindstrand Balloonsand another English
balloon manufacturing company,
Thunder
and Colt(since acquired by Cameron), have been the main
innovators and developers of special shaped balloons. These hot air
balloons use the same principle of lift as conventional inverted
teardrop shaped balloons but often sections of the special balloon
envelope shape make no contribution to the balloon's ability to
stay afloat.
See also
References
- The Ten Thousand Infallible Arts of the Prince of
Huai-Nan
- [1]
- [2]
- Scientific American Inventions and
Discoveries, p 177, Rodney P. Carlisle, John Wiley and
Sons, 2004, ISBN 0471244104
- Needham, Joseph (1986). Science and Civilization in China:
Volume 4, Physics and Physical Technology, Part 2, Mechanical
Engineering. Taipei: Caves Books Ltd.
External links
- [6465]
British Balloon and Airship Club - source for lighter-than-air
flight information.
- [6466]
Balloon Federation of America
Manufacturers
Construction techniques
History
Misc
|
| component |
| pounds |
| kilograms |
|
| 100,000 ft³ (2831.7 m³) envelope |
| 250 |
| 113.4 |
|
| 5-passenger basket |
| 140 |
| 63.5 |
|
| double burner |
| 50 |
| 22.7 |
|
| 3 20-gallon (75.7-liter) fuel tanks full of propane |
| 3 × 135 = 405 |
| 183.7 |
|
| 5 passengers |
| 5 × 150 = 750 |
| 340.2 |
|
| sub total |
| 1595 |
| 723.5 |
|
| 100,000 ft³ (2831.7 m³) of heated air |
| 5922 |
| 2686.2 |
|
| total |
| (3.76 tons) 7517 |
| 3409.7 |
|
| air temperature |
| air density |
| air mass |
| lift generated |
|
| 68 °F, 20 °C |
| 1.2041 kg/m³ |
| 7517 lbs, 3409.7 kg |
| 0 lbs, 0 kg |
|
| 210 °F, 99 °C |
| 0.9486 kg/m³ |
| 5922 lbs, 2686.2 kg |
| 1595 lbs, 723.5 kg |
|
| 250 °F, 120 °C |
| 0.8978 kg/m³ |
| 5606 lbs, 2542.4 kg |
| 1912 lbs, 867.3 kg |
Wikis
Quiz
Facts
Map
Misc
Search
