Friday, May 27, 2005

Airwolf

What do Jessie Mach, Michael Knight and Stringfellow Hawke have in common? They were characters played by Rex Smith, David Hasselhoff and Jan-Michael Vincent in Street Hawk, Knight Rider and Airwolf respectively. These three shows filmed in the 1980s were probably among the most exciting action adventure serials ever aired on television.

While all 3 shows (with very catchy theme tunes) were exciting Airwolf was unique in that it added an aerial element to the whole concept of a high tech crime fighting machine. It featured a state of the art helicopter fitted with high tech weapons and gadgets and capable of supersonic speeds. It was also the show that first got me interested in helicopters and made me decide that I would one day get a helicopter pilots license (until of course I grew up and mortgage concerns got in the way..darn). This post as you would have guessed by now is about the helicopter.

Here is a brief history of the chopper. Around 2000 years ago some bored Chinese bloke (apparently called Ko Hung) who didnt have shows like Airwolf to keep himself entertained (and no girlfriend either) decided to attach some feathers around a stick to create a flying toy. Hung found out that when he rapidly spun the toy in his hands and let it go it would rise vertically and fly by itself for a few seconds. Overjoyed by his new invention he proudly displayed it to his mates who all thought it was totally cool. This became the Play Station 2 of their generation and came to be called the Chinese Flying Top.

Over the years that followed several people around the world envisaged a larger flying machine based on the principles of the chinese flying top. In the 15th century Leonardo Da Vinci studied the possibility of a human carrying helicopter. The word helicopter is derived from the Greek words helix (spiral) and pteron (wing). However it was not until the invention of the internal combustion engine and the advent of powered fixed wing flight that actual helicopter models were produced.

Unlike the Wright Brother's first flight there is no specific date or inventor to whom the first flight of the helicopter can be credited. However a Frenchman named Paul Cornu is credited with the first piloted rotary wing flight in 1907 when he reached a staggering altitude of 1 ft with his twin rotor craft. The long history of development of rotary wing flying machines around the world which eventually led to the modern helicopter is too detailed to go into in a simple blog post (and also too boring). I will however mention Igor Sikorsky who is credited with building the world's first practical helicopter the Vought-Sikorsky 300 in 1939.

Here is a little bit about how a helicopter flies. A conventional fixed wing aircraft flies due to the lift generated by the wings. A rotary wing aircraft or helicopter is not that dissimilar. Each blade of a helicopter is effectively a wing that generates lift as it goes around. However as the main rotor blades spin and generate lift they tend to spin the body of the helicopter in the opposite direction and hence the need for a tail rotor to compensate and provide yaw control. There are helicopters that use 2 sets of rotor blades each moving in opposite directions to cancel out the spin so they do not require tail rotors. There are also NOTAR (no tail rotor) helicopters that use a jet of air to provide yaw control and stability instead of a tail rotor.

Most modern helicopters use gas turbine or jet engines (from the Bell Jet Ranger to the Apache attack helicopter). Most people think jet engines are only fitted to aircraft but in addition to solely producing thrust to power an aircraft they can also be converted to use most of that power to drive propellers or rotors (turbo-shaft and turbo-prop engines).

The helicopter probably has more uses than any other flying machine ever invented. It is used for search and rescue, transport, sightseeing, fire fighting, traffic monitoring, news reporting, police surviellance, troop support, Medevac..the list is almost endless.

Here are some interesting helicopter facts:

1. The Fastest

The world speed record for a helicopter stands at 249.1 mph. This was set in 1986 in the United Kingdom by a modified British Army Westland Lynx helicopter. The helicopter neither looks fast nor does the speed seem all that high. A helicopter's forward speed is severely limited due to the increased stress on the blades at high speeds. As the forward speed of a helicopter increases the rotor blades start approaching supersonic velocities. At this point the stress and vibration levels and the power requirements drastically increase making any further speed increases difficult and dangerous (at least with current design and materials).


Westland Lynx

2. The Biggest

The Mil Mi-26 "Halo" is currently the biggest helicopter in the world. Built and first flown in 1977 by the Mil helicopter company in Russia this helicopter is currently used in military transport, fire fighter and medevac roles.


Mi-26

3. The Deadliest

The Boeing AH-64 Apache attack helicopter and the Boeing-Sikorsky RAH-66 Comanche stealth helicopter are probably the closest real world equivalents of Airwolf and Blue Thunder (although the Comanche project has now been cancelled).


Apache


Comanche


4. The Hybrids

The Bell-Boeing V22 Osprey tilt rotor is an example of a helicopter/aeroplane hybrid which takes off like a conventional helicopter and tilts the rotors forwards to fly like an aeroplane once in the air. Another unusual flying machine was the large Fairey Rotodyne which was a cross between an autogyro and a helicopter.


V-22 Osprey


Fairey Rotodyne

and finally......

5. Airwolf & Blue Thunder

A modified Bell 222 helicopter was used for the popular Airwolf TV series. Once the series ended the modifications were removed and the helicopter was sold to a German charter company. It crashed in the early 90s killing all on board.

2 modified Aerospatiale Gazelle helicopters were used for the Blue Thunder movie and TV series. After the Blue Thunder series ended one was sold to a salvage company and the other was sent to a hollywood museum somewhere in the States.


Airwolf


Blue Thunder

There ends my little story of the helicopter. Hope you enjoyed reading it.

Cheers

Wednesday, May 04, 2005

The Caspian Sea Monster

If you think the A380 is big and impressive read on. Try and imagine a flying machine powered by 10 jet engines (yes 10 jet engines) bigger than the A380, bigger than the Antonovs, bigger than every aircraft listed on my previous post flying at close to 350 mph just a few feet above water. Something out of a Flash Gordon comic book or an episode of the Thunderbirds perhaps?

This post is about one of the most awesome flying machines ever built and sadly one of the least known.

During the Cold War military analysts at the Pentagon were routinely tasked with studying various reconnaisance photographs taken over the Soviet Union by American spy satellites and Francis Gary Powers and his mates. One such set of photographs taken over the Caspian Sea stunned the Pentagon analysts. The photographs showed a giant high speed unidentified object over the Caspian Sea. The analysts were unable to immediately identify the UFO or call on the services of Mulder & Scully (little Mulder would probably have been searching for the truth in his school's playground and little Scully would probably have been conducting autopsies on Barbie dolls at the time).

The Americans aptly nicknamed the object The Caspian Sea Monster. In later years further details about this extraordinary machine began to emerge.

Designed and built in the 1960s under a veil of secrecy by the Alexeiev Central Hydrofoil Design Bureau in the Soviet Union the KM Ekranoplan was a flying machine like no other. Weighing in at 540 tons, 300 ft from nose to tail and powered by 10 turbo jets it was capable of flying at close to 350 mph just a few feet above the surface of the sea. Its unique design enabled it to fly low enough to avoid conventional radar detection and high enough to avoid submarine sonar detection making it ideal for the Soviet Navy.

The Ekranoplan made use of an aerodynamic principle known as Ground Effect. When an aircraft flies close to the ground the efficiency of the wing or the lift generated is greatly enhanced. This is due partly due to the creation of a cushion of air between the wing and the ground and also a reduction in the wing tip vortices which in turn reduces induced drag. A vehicle purely designed to fly in the ground effect regime is called a GEV or a WIG (wing in ground effect). The Ekranoplans in spite of their massive weight were able to fly in this regime due to the reduced lift requirements. Not quite a ship, not quite a hovercraft and not quite an aircraft either. Now you know why I did not mention this in my previous post :)

Several variants of this unique machine were developed including the fully armed LM Ekrnaoplan which was equipped with anti ship missile launchers. As the Cold War drew to an end and the funds dried up the project gradually wound down.


KM Ekranoplan (www.se-technology.com/wig)


KM Ekranoplan (www.se-technology.com/wig)


LUN Ekranoplan (www.se-technology.com/wig)

However WIG aircraft might be about to make a dramatic comeback. Few years ago Boeing announced that it was looking at building what would become the largest flying machine in the history of aviation. The Boeing "Pelican" transporter would utilise the ground effect principle flying at just 20 ft above the ocean and have a wingspan close to 500 ft. It would have a fuselage longer than a football pitch and be capable of carrying close to 1400 tonnes. According to Boeing the competitor in this case would not be Airbus but container ships. The far greater speed advantage coupled with a sensible load carrying capacity, range and fuel economy which is significantly higher in the GEV regime just might make this an attractive proposition to freight transport companies.

Certainly an interesting concept but whether it will become a reality in today's world remains to be seen.

Shreyan: The ugly cargo planes with funny noses you mentioned are probably the Super Guppy and the Airbus Super Transporter also known as the Beluga. I will write a short post on those two soon.

Sunday, May 01, 2005

Sky Giants

It has been a while since my last post. My apologies to regular readers (if indeed there are any).

The A380 finally took to the skies last week and more importantly landed in one piece. A great job by all involved. The first flight was touted as the most significant event in commercial aviation since the first flights of Concorde and the Boeing 747. The A380 is an impressive aircraft no doubt however I think once it is in the air it looks a lot like "any other plane". It is certainly not as distinctive as the Concorde or the Boeing 747 were when they first took to the skies.

There appears to be a misconception in some quarters that this is the biggest aircraft in the world. I have compiled a list of the 5 biggest aircraft ever built (purely because I have nothing better to do at the moment). It is difficult to compare aircraft sizes as some have a bigger wing span and others greater length etc. I have used wing span as the measure for my list.

1. Hughes H-4 Hercules "Spruce Goose"
Wingspan: 319 ft 11 in (97.54 m)
Length: 218 ft 8 in (66.65 m)

Believe it or not this aircraft still holds the record for the largest wingspan of any aircraft ever built. Those who have seen the "The Aviator" will probably be familiar with it. Although it only flew once and never really got beyond ground effect flight it still deserves to be mentioned.

2.Antonov 225 "Mriya"
Wing Span 290 feet (88.4m)
Length 275 feet, 7 inches (84m)

Built by the Antonov Company based in Ukraine and first flown in 1988 this aircraft was designed to transport the Russian space shuttle Buran and is currently the largest aircraft in the world still in service. There is only one aircraft in use today and is used to transport oversized cargo/freight. Demand for this aircraft has been quite high and there is talk of building another one of these monsters.

3. Airbus A380
Wingspan 261 ft 10 in (79.8 m)
Length 239 ft 6 in (73 m)

Enough has been said about this airplane.

4. Antonov 124 "Condor"
Wingspan: 240 ft 5 in (73.3 m)
Length: 226 ft 3 in (69 m)

Again built by the Antonov company it was first flown in 1982. This is a popular heavy lift transport aircraft with approximately 50 to 60 having been built. The 6 engined Antonov 225 is a derivative of the 4 engined Antonov 124.

5. Lockheed C5 Galaxy
Wingspan 222.9 ft (67.89 m )
Length 247.1 ft (75.3 m )

Built by Lockheed and first flown in 1968 this is currently the largest aircraft in the US Air Force inventory and is used as a military transport.

Trying to get back to blogging mode after a long break is always difficult! I will try and post something more interesting next time.

Cheers