Normally, the military aircraft uses the brake to come to a halt after landing. But there is a
little difference with giant plane like the Boeing B-52 Stratofortress when it comes to a stop.
Well, something not everyone knows about the B-52 is that it requires more than simply brakes
to stop it after landing. The stopping needs the use of a parachute known as a drag chute. However,
this parachute does not magically pack itself. So, while the pilot, co-pilot,
and navigator are only the beginning of what it takes to fly the B-52, here is when other
aircrews play an important role in bringing the huge B-52 to a halt using the drag parachute.
The drag parachute was initially designed by the Russian professor and parachute specialist,
Gleb Kotelnikov, in 1912, who also invented the backpack parachute.
During the mid-1930s, the Soviet Union launched its first aircraft equipped with drag parachutes.
Currently, the drag parachutes have been installed
on a variety of jet-powered aircraft, notably the Boeing B-52 Stratofortress.
Drag parachutes are longer and have a much smaller surface area than regular parachutes,
resulting in significantly less drag. The drag parachute may be launched at rates that would
shatter ordinary parachutes, but it does not slow an object as much as a conventional parachute
would. Because of its simpler structure, the drag parachute is also easier to deploy,
lessening the possibility of becoming tangled while unfolding or failing to inflate properly.
In terms of flight equipment preparation, the job to pack this parachute is actually not difficult.
It is, in fact, more tedious than anything. To complete the task, it needs a solid teamwork,
consistent practice, a little patience, and a lot of perfectionism. There is zero tolerance
for error. This is mainly because in the Air Force, attention to detail can be the difference
between life and death. The presence of pebbles and debris in the parachute might cause it to
fail to release properly. The tiniest knot can mean the difference between a flawless
deployment and a failure, putting both the pilots and the aircraft at risk. Therefore,
this crew is in charge of the lives of the pilots that fly the Stratofortress on a daily basis.
They must jump on top of the parachute and attempt to flatten it out. Although
you might think it would be fun, it is far more difficult than you can imagine. The
crew need to stomp on the 90-foot-long chute in order for it to fit into a
3-and-a-half-foot-tall bag. After that, the task is passed onto the maintenance crew,
who is in charge in placing two types of parachutes onto the plane’s tail.
The drag parachute is used for a variety of purposes. It is
usually utilized whenever it rains, or when crosswinds exceed 30 knots,
and when the runway is less than a mile long. They are also very effective to be deployed for
the aircraft landing on wet or icy runways, as well as for high-speed emergency landing.
So, how does the drag parachute work to stop the B-52 and extend the life of its brakes?
As you can see in the video, a drag parachute on a B-52 Stratofortress is opened after landing.
When used to shorten an aircraft’s landing, a drag chute is referred to as a braking parachute. The
goal is to decelerate the Stratofortress during landing. It starts off with a pilot chute. So
when the pilots pull the handle upstairs, the small pilot chute pops out, gathers wind,
and then grabs the larger chute, bringing the aircraft to a stop. This, therefore, can reduce
wear and tear on the aircraft’s ceramic pads, which leads to extending the brake life span.
An example of drag chute deployment that can lengthen the brake life span is the
NASA’s B-52B experimental drag chute, which took place on August 2, 1990, shortly after
landing on Rogers Dry Lake at Edwards Air Force Base in California. At that time,
the researchers at NASA’s Dryden Flight Research Center at Edwards utilized a modified NB-52B in
1990 to test the drag parachute system that would be used on shuttle orbiters.
The B-52 landed at speeds ranging from 160 to 230 miles per hour on one of the lakebed
runways as well as the 15,000-foot concrete strip in a series of eight chute deployment
tests. A 39-foot-diameter braking parachute was employed to decelerate the aircraft,
lowering the landing rollout by up to 2,000 feet and relieving load on the brakes and tires. During
the chute deployment test, the B-52’s instruments collected data to evaluate estimated weights that
an operational shuttle orbiter would endure with a drag chute deployed during landing and rollout.
The larger the parachute, the greater the drag. Believe it or not, the drag chute
on the current B-52 weighs around 200 pounds. The landing of space shuttle Endeavour on the
15,000-foot concrete runway using the drag parachute showcased a new capability for the
shuttle fleet. The test resulted in the proof that the use of a drag chute on the B-52 assisted in
reducing rollout distance and brake wear during landings. The drag chute mechanism was then
installed onto the space shuttle Endeavour as a result of successful test findings.
So, on May 16th, 1992, the Endeavour took its first operational demonstration of the drag
parachute technology. The drag chute was deployed as the nose gear touched down, making the orbiter
came to a stop after a 9,490-foot landing roll. Despite the fact that this fairly typical rollout
was the result of conservative mission planning, later Endeavour landings revealed that the drag
chute could minimize landing rollouts by 700 to 1,500 feet, leading to extending the life of its
brake. It is important to note that Endeavour was the first orbiter to be designed with the
drag chute, which soon became a regular feature on the shuttle fleet. Columbia,
Discovery, and Atlantis were other three orbiters installed with the drag parachute
while they were undergoing routine maintenance. Currently, the drag parachute is not only fitted
on the B-52 Stratofortress, but also on other aircraft like Eurofighter Typhoon multirole jet.
So, that’s all for today. Thanks for watching and see you next time.