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In my last blog entry, I described my work with a team of RPI undergraduates who are competing
in "Lift! More LIFT!", this year's Request for Proposal (RFP) from the American
Helicopter Society (AHS). The foundation
of our team's design must be a helicopter that is currently in service. The
existing design is then modified by the team so that two of the aircraft, when
flying together, can lift significantly more payload than either could alone.
The beginning of our team's design process focused upon
which helicopter to select as the basis for the design. Our selection will
affect every aspect of this project – the load bearing mechanism, engine and
transmission requirements, rotor blade modifications, and the flight
configuration of the two helicopters.
We researched several designs, but two helicopters stood out
from the rest: Boeing's CH-47 Chinook and the Russian MI-26 HALO. Because I
found this information to be of interest (as I had with the Black Hawk), I thought I
would share my research with CR4.
 CH-47 Chinook
Boeing's tandem-style cargo helicopter has been in
production since 1962 and continues to serve the United States Army to this
day. After seeing service in Vietnam, the
CH-47 Chinook was flown in the Iran-Iraq War (1980 – 1988) and the Falklands War
(1982). Most recently, the aircraft has been used in Iraq
and Afghanistan. Japan uses the CH-47 as an asset
for its ground forces. Royalty from the Netherlands often travel via a
Chinook.
The CH-47 Chinook requires a crew of three and is quite
large – almost 100 feet long with rotors that have a diameter of 60 feet. The structure alone weighs over 23,000
pounds, but can take off up to a weight of 50,000 pounds. It can carry about 50
troops or 28,000 pounds of cargo. Although
this helicopter can reach speeds of up to 170 knots, the CH-47 usually cruises
around 130 knots. It can travel a
distance of 400 nautical miles, with a service ceiling of 18,500 feet. And yet, the Chinook does carry machine guns
for protection.
MI-26 HALO
If you thought the Chinook was large, think again. The heavy-lift
helicopter that the Russians use can carry the Chinook and make it look as
light as a feather (in fact, it has even rescued a Chinook). The MI-26 HALO was introduced in 1983 and to
this day remains the largest, most powerful helicopter ever produced. The Ukranian and Indian Air Forces became so
fond of this aircraft that they, too, have adopted the design.
The MI-26 Halo features a single-main-rotor-tail-rotor
(SMRTR) design. While requiring a crew
of six may seem like a lot, understand what this beast of a vehicle is capable
of - carrying 80 troops or 44,000 pounds of cargo. Of course, the helicopter's size may offer a
downside, considering that its rotors span more than 100 feet across.
The AHS Request for
Proposal
So which heavy lift helicopter has the RPI team decided to
fly with? I'll leave you in suspense for
a few more weeks. Regardless, it's
phenomenal what these two very different aircraft vehicles are capable of achieving.
Resources:
http://en.wikipedia.org/wiki/CH-47_Chinook
http://en.wikipedia.org/wiki/Mi-26_Halo
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Re: Heavy Lift Helicopters
