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Post Apocalyptic Aircraft

Page history last edited by Michael 1 year, 10 months ago

back to the Index or to the Post-Apocalyptic Vehicle page

 


Asa

 

     A very basic small, mid-wing monoplane, with fixed tricycle landing gear and a T-tail. There are one- and two-person versions (the two-person version is an unarmed trainer). The motor is a 100 HP four-cylinder air-cooled 3.3 liter gasoline engine; top speed is 240 kph, economical cruise speed is 210 kph, and the range is 800 km on 75 liters of fuel. Ceiling is 4500 meters, take-off run is 150 meters. Empty weight is only 340 kg for the single-seat version; with pilot, full fuel and stores the aircraft weighs 575 kg. Length is 6 meters, wingspan is 7.4 meters. The airplane is built to withstand 4.4 G maneuvers (or -1.8 G). Two underwing pylons can carry weapons -- a six-round 68mm rocket pod is currently in development.

     The Asa is being developed by the Nigerian military.

 

battlecopter

 

     A combination motorcycle and autogyro, built from motorcycle parts. The engine is a single-cylinder 650cc four-stroke water-cooled 37 HP multi-fuel engine. Fuel capacity is 5 liters, along with 2.5 liters of oil; fuel usage is 4 liters per 100 km. Range in the air is thus about 130 kilometers. The ceiling is 3500 meters. Top speed is 60 kph, lowest speed is about 20 kph; it will land in about its own blade diameter. The engine can power the rear wheel, to get the vehicle more quickly up to takeoff speed (and for showing off). It has two "training wheels" mostly for use when taking off or landing, and 'regular' motorcycle wheels at the front and rear. Sometimes a CB radio is carried. Due to the propeller being mounted close to the center of gravity, these are safer to fly than most other gyrocopters. Empty weight is 200 kg including fuel and oil; maximum takeoff weight is 320 kg.

     In 2140, a larger version was seen, with a seat for a passenger. Range 200 kilometers, or 1200 kilometers if a fuel tank is fitted instead of the passenger cockpit.

 

ultra-light gyrocopter

 

     This very small aircraft can carry a pilot and not much else. Top level flight speed is about 100 kph, depending on the design. These weigh about 150 kg including fuel, and will carry 100 kg of pilot and cargo. The air-cooled engine is about 25 HP; the fuel tank holds 20 liters of fuel (either alcohol or gasoline), and fuel consumption is about 6 liters per hour, giving a range of 300 kilometers. There's a pull-start rope, to get the rotor turning for takeoff.

 

light gyrocopter

 

     This small aircraft can carry a pilot and passenger, or a pilot and armament or cargo. The rotor diameter is about 8 meters. Weight without crew or cargo is 250 to 300 kg; maximum takeoff weight is 450 to 500 kg. Cruising speed is about 150 kph. It's powered by two 40 or 50 HP motorcycle engines, either joined through a gearbox to drive one propeller, or each driving a separate propeller. Fuel consumption (either alcohol or gasoline) is 17 liters per hour.

 

light aircraft

 

     This represents all sorts of light, single-engine monoplanes of the second half of the 20th Century. Specific stats for this example are from a Cessna Model 170, or 172 Skyhawk (the most commonly built airplane in the world). Mathias Rust flew one of these from Helsinki to Moscow in 1987 ... which damaged the reputation of the Soviet military, and led to many Soviet generals being dismissed.

     A simple high-wing monoplane produced between 1948 and 1986. It's powered by an air-cooled 150 HP 4 cylinder 5.24 liter displacement gasoline engine; cruise speed is 200 kph, stall speed is 87 kph, and service ceiling is 4100 meters. 212 liters of fuel are carried (although this could optionally be up to 250 liters), providing a maximum range of 1460 kilometers. Maximum gross weight is 1050 kg, empty weight in its original form was about 770 kg. Besides the pilot it can carry three passengers.

     Simple bomb or gun mounts could be fitted; these aircraft have sometimes been mounted on skis or floats (often with wheels which can be used without removing the skis or floats).

 

A-2 Skyraider II

 

C-4 Atlas

 

Hamael

 

     A Foundation courier/recon/artillery spotter/light transport. It's a high-wing two-seat monoplane, with long, sturdy landing gear for rough airfields. Various V-6 and V-8 methanol engines (with major components from 1980s muscle cars) around 150 HP are fitted, giving a top speed of about 200 kph; stall speed is 70 kph. Range is 650 kilometers on a full (130 liters) tank, ceiling is 5500 meters. Maximum takeoff weight is 800 kg, empty weight is 420 kg. Length 7 meters, wingspan 10.7 meters. Fitted with a radio, and sometimes with four underwing smoke-marking rockets. Thirty have been built (and a few have been lost), usually one per installation and several others at Fortress Dis for training purposes.

 

Super Hamael

 

     A rare Foundation aircraft, fitted with the electric motor from a Depot Alpha truck, and with a Mk 1 Fusion Generator, these aircraft can fly for a day or so; the limit is mostly pilot fatigue and the need for some maintenance and lubrication. Speed and other performance are about the same; the radio equipment is the best the Foundation can arrange. There are currently two of these aircraft, used for long-range reconnaissance and as couriers, but never for attack; they are based at Fortress Crux.

 

Cherub

 

     A Foundation pulsejet/turboprop-powered gyrocopter gunship, based on examples obtained from the DRA. Engines are two 1000-lb thrust pulsejets, each running a heat-recovery turboprop. Normally 1 pilot and 1 gunner, although a version to carry 4 passengers has been designed. Top level speed is 160 kph, cruise speed is 140 kph. Ceiling is 5000 meters, but it cannot "jump off" above 2000 meters. Normal takeoff distance when rolling, with rotors turning but no wind, is 10 meters. Maximum weight is 1800 kg, empty weight is 900 kg. Range at cruise speed is 200 kilometers with full methanol tanks. Twelve have been built:  4 serve at Fortress Dis, 4 at Fortress Phlegethos, and 4 at Fortress Crux.

 

Cherubim

 

     A Foundation propeller-powered lightweight 2-seat gyrocopter, mostly for training (not so noisy!). Fitted with two 150 HP methanol engines, top speed only 150 kph. Maximum weight is 800 kg, empty weight is 600 kg. There are eight of these currently, all based at Fortress Dis.

     There are also a few older prototype gyrocopters, not used much now, which look a lot like Morrow Project Air Scouts.

     Note that the Foundation isn't really very educated in ancient languages ...

 

Gabriel

 

     A Foundation pulsejet/ramjet-powered fighter/ground attack craft. The crew consists of a pilot and a radio operator. The engine consists of three pulsejets, feeding into a ramjet. It's got enough armor to be almost rifle-proof, but maneuverability, range and payload are a bit poor; takeoff and landing speeds are high, and several have been lost in accidents. Top speed 500 kph (300 mph). There are only half-a-dozen of these, all based at Fortress Dis for now.

 

Malaysian scout drone

 

     Seen on the west coast of North America, never more than 250 kilometers from the Pacific Ocean.

 

 

     They are about a meter across, with enclosed rotors. Multiple cameras and other small sensors are mounted on it. They are quiet and not very fast.

 

SmiK-7V

 

 

     The Democratic Republic of America operates a number of pulsejet/turboprop-powered gyrocopter aircraft. Engines are two 1000-lb thrust pulsejets, each running a heat-recovery turboprop. Crew varies by type:  pilot, or pilot and gunner, or pilot and passengers. Top level speed is 160 kph, cruise speed is 140 kph. Ceiling is 5000 meters, but it cannot "jump off" above 2000 meters altitude. Normal takeoff distance when rolling, with rotors turning but no wind, is 10 meters. Maximum weight is 1800 kg, empty weight of assault transport is 900 kg; rotor diameter 9.5 meters. Range at cruise speed is 200 kilometers with full methanol tanks.

     Variants include an assault troop transport (the most common); an attack gunship; and a "straddle lift" cargo transport. All versions have a four-gun nose, with limited traverse and depression.

 

Viking

     A simple high-wing monoplane operated by the Canadian military, it's mostly a copy of the Norseman Mark V (but with the all-metal wing of the Mark VII). Engines -- P&W R1340-AN1 Wasp radials of 600 HP -- and other difficult-to-produced parts were stored with the Project Paragon forces; most of the structure is simple steel tubing (with some spruce bits), covered by fabric. Half-a-dozen can be built in a year -- there are about 30 currently. It is flown by one pilot (although there are two front seats, which both have rudder pedals and share the same control column and center console); up to 8 passengers can be carried on bench seats (or 6 infantry, or 4 litters). Cruise speed is 240 kph, range is 1500 kilometers. They are often fitted with skis in the winter.

     While simple bomb or gun mounts could be fitted, Tim Fraser didn't think this was done very often, and none of the pilots were trained in bombing or air-to-ground gunnery. There are at least 20 more engines still in storage (as of late 2140).

 

double-X wing

 

     The Officer Training Corps at Princeton builds and uses cruciform tail-dragger biplanes (the upper and lower wing surfaces consist of a cross arrangement) with automotive engines. Sometimes called the Tiger, they can carry two persons, or one person and a small amount of ordnance -- they don't always even have a fixed forward-firing weapon. They are mostly made of fabric-covered steel tubing.

 

 

     The oil supply and one of the fuel tanks are gravity-fed; don't fly this aircraft upside-down. Also, parachutes are not available in Princeton.

 

a photograph of a Tiger biplane

 

     Crew, one or two; various gasoline engines of about 110-130 horsepower, with a total of 60 liters of fuel in two tanks. Wingspan 11 meters, length 9 meters, wing area 62 square meters, weight without pilots, fuel or ordnance 660 kg, maximum takeoff weight 840 kg. Cruise speed 115 kph, top speed 140 kph, slowest level speed about 40 mph, range 390 kilometers.


 

Ethanol and Methanol Notes

 

     Consumption of alcohol, compared to gasoline is 2.2:1, so the distance you can travel with the same gas tank is less than half. Methanol is very corrosive, unlike ethanol.

 

Modifying Engines

 

     Older radial aicraft engines run on avgas:  100 octane gasoline. They might run on gas as low as 80 octane. Water contamination in avgas can destroy an engine in one flight!

     Alcohol does not lubricate valves and moving parts, and destroys a lot of gaskets, hoses, etc.. Modifying an engine to run on alcohol can be done, but you'd need to take the engine completely apart, fabricate non-rubber substitutes for various synthetic materials (fuel hoses, seals, gaskets), adjust fuel systems, ignition systems, etc. Valve systems especially rely on lead in fuel to keep lubricated. Modern (21st Century) American cars operate on up to 10% alcohol, normally, but of course they're designed for that.

     Alcohol burns most efficiently at a 9:1 ratio with air (whereas gasoline is 14:1 to 16:1, depending on the engine and fuel); hence the alteration to the engine's fuel injection system. Alcohol has about 34% less energy per gallon than gasoline, but can produce a bit more power; range will be reduced about 10% if the engine runs well otherwise. More improvement in fuel efficiency would require changing the compression ratio of the cylinders -- unlikely in the field with minimal tools!

     Alcohol will loosen dirt; good fuel filters are even more important in an alcohol-fuel engine. Charcoal can be used to pre-filter the alcohol before it's put into the vehicle. Alcohol-fuel engines don't start well in cold weather -- ethanol doesn't vaporize sufficiently below about 60 degrees fahrenheit. Using a bit of gasoline, propane or ether for starting is common in older, simpler alcohol-fuel engines.

     The engine will still need regular lubricants -- oil, basically. Probably some very nice animal oils could be handwaved as good enough to substitute for motor oil. 

 

Alcohol Production

 

     Ethanol is the best fuel, but uses raw materials that might be better used as food. It's produced in bulk by the fermentation of sugars -- wheat, corn, rice, sugar beets and cane are examples of vegetation with high sugar content; they give a high yield when fermented and distilled. A basic fermenter takes 50 gallons of water, 130 pounds of sugar, and some yeast to produce basic alcohol in about 24 to 48 hours (varies by temperature). Then you'd need to run it through a reflux still ... the basic pot still only makes about 70% alcohol. The output from that water-sugar fermenter + a reflux still is about a gallon of reasonably-pure ethanol in a day or so. Of course, more or bigger fermenters, and bigger stills, gives more output.

     In a general way, using sorta-woody, sorta-sugary "feed" in a fermentation-distillation process, 1 ton of "dried plant matter" will produce 20 to 40 gallons of ethanol -- at best.

     The construction of fermenter tanks and reflux stills calls for some effort. The body of the still and the tubing needed for the actual distillation coils will be the hardest part to build.

 

"We hauled in wagon loads of sugar beets, chopped them up in a chipper and fed them to the big fermenter tanks (made like large enclosed wooden vats). Drawing off the raw alcohol after a day, we ran it though the reflux still; a fire fed with plant debris and stalks kept the still hot and bubbling along. Out the other end of the still dribbled hot, pure alcohol, to be filtered through charcoal and poured into the drums.

 

Other Gasoline Substitutes

 

     Grease or vegetable oils need to have their wax components removed before being useful in a converted motor. However, some sort of super-peanut could be imagined, that, when pressed and filtered, produced something that could be used in the engine -- again, at least some adjustment of the fuel pumps and fuel injectors would be needed, but (with some handwaving) perhaps less than for ethanol conversion. A biological-derived oil would probably need more cleaning and de-gunking of the engines -- they're not a happy in the high temperatures of an internal combustion engine, and produce a lot of gunky deposits (compared to gasoline or ethanol). Peanut oil, butter, animal fat, deep-fryer oil (used in "frybrid" engines), algae oils, etc. have been used to operate internal combustion engines -- especially diesel engines (in fact Rudolf Diesel's first engines ran on peanut oil). You need to add a pre-heater to the fuel feed system -- natural oils of this sort need to be heated to reduce their viscosity.

     From the Experimental Aircraft Association, regarding partially-alcohol "gasoline" in modern aircraft:

 

Alcohol in autogas when used in aircraft has caused numerous problems such as fuel leaks and fires due to rapid deterioration and swelling of rubber gaskets and seals. Fuel tank quantity floats made of cork and/or composite materials are attacked by the alcohol in fuel and allow particles to float in the fuel, clogging fuel screens, plugging carburetors, etc. Sloshing compound used in many fuel tanks to seal leaks also reacts with the alcohol, causing fuel leaks and fuel system contamination.

 

Marvel Schebler carburetors that have the old composite floats are damaged by 100LL fuel as well as autogas and are particularly sensitive to alcohol in the fuel. Aircraft owners should have the newest metal float installed. Stromberg carbs such as used in the TCM-C and A 65/75/85 models that have an old style of neoprene-tipped float needle in the carburetor is attacked equally by 100LL and autogas and should be replaced with the newest style needle. Swollen float needle tips cause a lean mixture and eventual engine damage. Cessna aircraft with rubbertipped fuel strainer plungers are also damaged by the use of autogas with alcohol and frequently leak after a short time of use with an autogas/alcohol mix.

 

Most recently a “malfunction” appeared in the FAA alerts describing a Piper aircraft that caught fire in flight due to a leaking fuel strainer gasket that was swollen by the use of alcohol mixed with autogas. The pilot was able to turn off the fuel to stop the fire and save himself but he was forced into becoming a glider pilot.

 

Any rubber part such as fuel lines, fuel cells, and 0-rings in fuel selectors are subject to damage from alcohol mixed in the fuel. In addition to problems associated with alcohol in autogas, oxygenated fuels have been tested and shown to provide 3 to 5 percent less BTU output than avgas, thus decreasing range somewhat.

 

 

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