Huges 500P: The quiet helicopter

THE "QUIET ONE"

America's First Stealth Copter

The Hughes 500 helicopter was widely used in civilian and military efforts.  The first manufactured Hughes 500 took to the air in 1963.  These helicopters are still being produced to this day albeit under the name McDonnell Douglass who acquired the company in 1984. 

This helicopter featured  robust landing skids, a short diameter rotor and tail boom, and very agile and surprisingly quiet performance for a helicopter.  It was this quiet operation that spawned the idea for the Hughes 500P:  the quiet one.  It didn't just have to be quiet, it also had to be fuel efficient, large enough to carry the team of men, and have a powerful enough engine to do all of the lifting.

Possibly a prototype of the Huges 500P

 Near the end of the Vietnam War, President Nixon was meeting with the North Vietnamese at the negotiating table in Paris.  Unsure of the intentions of the communist nation at the time, he requested Intel on what the leadership of the North Vietnamese were thinking or planning.  The CIA came up with a plan to helicopter some commandos into North Vietnam and place a listening device on a switchboard for their phones.  A small radio antennae would then broadcast the information back to South Vietnam.  In order for this to succeed they needed a helicopter that could get them in (it was a long ways) and not be detected as helicopters made a great deal of noise.

Probably another prototype of the 500P

The CIA finally found some civilian contractors that would help them build the quiet helicopter (notably from Lockheed) with one of them even building a prototype engine in his garage at home.  Two helicopters were made and sent to South Vietnam to train local pilots for the mission. After an accident scrapped one of the helicopters, the CIA resorted to using Air American pilots to do the mission..

A typical Hughes 500 (MD500)

The mission was carried out with success and the negotiations continued until the end of the war, thanks to the quiet helicopter.  The CIA never really released all the information about the helicopter and its capabilities and no one really knows just how quiet it was for sure, but everyone who worked with it were in awe of just how incredibly quiet it was. 

The Maligned P-39 Airacobra

The P-39

Perhaps one of the most maligned air craft of WWII, the Bell P-39 Aircobra was in many ways a fascinating design and unique aircraft.  Some of the more outstanding features that many hated and some liked included the car door-like cockpit doors, the rear fuselage engine that sat behind the pilot in an awkward place causing the driveshaft to run beneath the pilots legs,  and the 37mm cannon that shot through the front propeller.  The tricycle landing gear was also unique as many of its contemporaries were tail draggers but other than a few front landing gear collapses no one complained of this feature. 

The P-39 was doomed, however, by the Allison v-12 non supercharged engine that was to be its power plant.  Although a supercharger was put in the original prototype engine, it was later taken out to improve aerodynamics thus robbing the aircraft of high altitude performance.  It is of some note to consider that the P-51 had the same Allison non-supercharged engine when it first came out as well.  It was not until the P-51 was fitted with the Merlin engine by the Brits that it became the top notch fighter of the war.  So when the plane was rushed off to the Brits as a fighter, they quickly shipped it off to the Russians because it couldn't compete at high altitudes with German fighter planes.  The Russians put it to good use as both a fighter and ground attack weapons platform but it never saw the notoriety that the P-51 or Spitfire did.  

An American P-39 probably in New Guinea

The Weapons

The P-39 was also unique when it came to armaments. The outstanding and probably most notable armament that it boasted was the 37mm cannon fired through the propeller.  A cannon fired through the propeller was not new, the German Folke Wulf-190 had a nose cannon and so did the Bf-109.  It was the size of the cannon that was impressive.

The Oldsmobile M4 37mm cannon

37mm installed in the nose of a P-39

  The shells of the 37mm were so large that it was actually possible to watch them drop like an orange baseball after firing the cannon.  It had a slow rate of fire but was deadly to large air planes or ships.  Many pilots hated it because of the huge bullet drop: it was after all a low velocity shell, but against softer targets it was devastating.  The plane also sported two .30 caliber machine guns fired through the propeller blades and two .50 caliber machine guns in wing roots.  Many planes were refitted by the Brits and Russians to eliminate the 37mm cannon and replace it with a 20mm cannon.  The Russians replaced the nose .30 caliber guns with two .50 machine guns as well.  It seems the 37mm was left out in the cold except by the Americans who used it successfully as a ground attack weapon against the Japanese and on PT boats that scavenged the gun from P-39 wrecks on Guadalcanal.  Eventually it was standard on the PT boats as a highly effective anti-shipping weapon.

A P-39 Firing all its weapons at once

Sadly it was not to be the ultimate weapons platform that the U.S. Army wanted at the time.  Even though an American pilot became an ace flying the P-39, Lt. Bill Fiedler who shot down three Japanese A6M Zero fighters in one battle with his P-39, rather it was the Russians who put this warbird to good use.  One Russian pilot scored 53 kills with his P-39.  It was the ideal weapon for the Russians due to the nature of how they were fighting the German army at the time.  They put a bigger engine in it, eliminated the wing guns and were never given any ammo for the 37mm cannon so they installed two .50 cals in the nose and put extra ammo in it. 

Final Thoughts on the P-39

While the P-39 was not the idea fighter for the Americans and certainly not the Brits, it is not the fault of the aircraft that it was not put to its proper use.  It was never designed to be a high altitude interceptor, certainly not after the turbo charged supercharger was removed.  Issues with flat spins and tumbles were documented due to the rear engine placement and the cannon in the nose:  not a ringing endorsement for a front line fighter.  It did however have a lot of things going for it.  It had a high seated cockpit due to the driveshaft under the pilots feet.  The great visibility was certainly helpful to ground attack missions and overall observation.  The tricycle landing gear was a first.  This landing gear allowed the plane to clear tough terrain in the jungles and was far safer than the typical taildragger arrangement.  Most fighter aircraft come with tricycle landing gear now days so that is noteworthy.  It is also important to note that the P-39 was ostensibly built around the 37mm cannon.  This large weapon was primarily put on early WWII tanks as an anti-tank weapon. The 1 lb. bullet that it fired was particularly devastating when used on non hardened targets.  There is perhaps another aircraft that has been designed in this manner:  the A-10 Thunderbolt II.  The A-10 has also been maligned and is under the same scrutiny as the P-39 was in WWII.  It is thought to be outdated, redundant, and too old to accomplish modern day battlefield supremacy.  However it was also designed around the 30mm cannon that takes up most of its fusalage.  It is this weapon that has kept it, along with the extended loiter time it has, in the front lines as no other aircraft can compete with its firepower.

The Steam Engine- Yesterday's technology still in use today

THE STEAM TURBINE ENGINE

The steam turbine is an ancient invention long forgotten by the modern world:  that is unless you work in power stations.  Even the most uneducated person has heard of steam engines but not many realize the enormous power they put out.  The steam turbine was used successfully in early warships to make a ridiculously heavy ship plow through the water at 30 knots(40mph).  No other engine could do this successfully for long periods of time with the same fuel consumption. The amount of torque (twisting force) these turbines put out is second to none.  Today the steam turbine is used primarily in power plants to produce electricity.  Nuclear power plants all use steam turbines.

An idea of the size of a typical steam turbine

The origins of the steam turbine go all the way back to ancient Greece to the inventor Archimedes.  He came up with a simple turbine that used steam to propel a teapot type contraption to spin in a circle.  Why it took centuries to exploit this is unknown, but the power of trapped steam is readily obvious to anyone who has used a pressure cooker on their stove.   Hot water in steam form wants to escape its confinement and will do so even if forced to push on metal blades like the one in the picture above.  This can be exploited to do an amazing amount of work.  Water has amazing properties, not the least of which all life on earth would not exist without, but one of its most useful qualities in the power of steam turbines has been largely ignored. Obviously modern jets use turbines to power their aircraft but that relies on hot gasses from fossil fuels exiting the turbine.  The water of steam turbines is reused (after being cooled) and only needs a heat source.  This is how nuclear power plans operate. Below is an example of a nuclear steam turbine.

It is estimated that 85% of power in the United States is nuclear steam turbine production.  That is a lot of power for an invention that showed up in 1884 in Charles Parsons steam turbine.  How does it feel to be using 1800s tech in the 2000s?  Some things cannot be improved on in terms of originality and the steam turbine is no exception.  It's efficiency can be improved, it's existence cannot.