The brand new 5th-generation fighterjet Shenyang J-31 – or F60, which would be nicknamed Gyrfalcon – took off on October 31, 2012. She thus performed a test flight – probably her maiden flight – on Wednesday.
This futuristic PLAAF (People’s Liberation Army Air Force) stealth multirole jetfighter looks like an F-35 Lightning II though the Gyrfalcon (or Falcon Eagle?) turns out to be a twin-engine a/c. She would be more maneuverable but smaller than the latest Chengdu J-20 Black Eagle stealth fighter. Her radar cross section (RCS) might be very small, and stealthier than recent 5th-generation fighter aircraft as the radome mounting looks as if it were – like the rest of the airframe – designed with reentrant shapes.
This fighter aircraft would not exceed Mach 2, and she features a DSI (Diverterless Supersonic Inlet) so that the airspeed can be reduced while entering the air intake, thus preventing the engine from breaking up.
As you may have heard, the mythical Lockheed SR-71 Blackbird was a strategic reconnaissance aircraft able to fly at more than Mach 3 – Mach 3.3 ie around 3,500 km/h; or 1,900 kts; and at a maximum flight level of… FL 850 or 26 kilometers high!
The Blackbird indeed had a unique flight envelope with a particular doghouse plot (since she could not exceed 3.5 G), and an exceptionnal coffin corner limited by her CIT – Compressor Inlet Temperature of 427°C maximum.
This aircraft was also unique for her engines were two J58 ramjets fuelled by JP-7 especially refined for extreme flying purpose. This special fuel could drip and leak abundantly as the airframe made up of titanium was retracted while taxiing, and became airtight only when it got its operating shape while flying very fast and very high because of the air density, and surrounding pressure plus the heating caused by the air friction at such speeds. In short, the whole structure considerably expanded when airborne.
The irony – I heard it on the grapevine, or read it somewhere on the web – that titanium which turned into dark blue while flying (SR-71s probably deserved those unofficial other nicknames « Bluebird », or « Habu » viper) was « imported » from… USSR!
Pilots must have taken significant risks inherent in flying such an aircraft as mentioned in this previous post. These pilots used to fly over the USSR to take strategic reconnaissance photographs during the Cold war. They wore pressurized spacesuits so that their blood could not boil in case of decompression or ejection at such altitudes.
The Blackbird travelled faster than a rifle bullet, and the air friction could have melt aluminum-skinned aircraft. At Mach 3.2, fuel cycled behind the chine surface in order to cool the aircraft! The inner windshield temperature could reach 120°C even though a heavy-duty cooling system was on a full function. On landing, the outside temperature of the canopy could reach 300°C, and it must have been far beyond on the fuselage, and wing surfaces while flying at high speeds. The pilot could feel the heat behind his protective gloves!
Foreign Object Damage (FOD) can be caused by Foreign Object Debris (called FOD too). FOD can also mean « Foreign Object Detection« . Watch the video, and read its transcript below:
Our Air Force has the most technically advanced aircraft in the world – deadly fighters, and bombers, mighty cargo and tanker workhorses, our many helicopters, and a variety of specialty aircraft.
But they can all be easily grounded by FOD.
Foreign objects cause damage to our aircraft in many ways. For example, cut tires, and jammed flight or engine controls. FOD has caused at least six fighter aircraft to crash over the last twelve years! Some of the items that caused these mishaps were:
Safety wire pliers;
A piece of aluminum foil;
A one-inch piece of safety wire;
Even a small washer!
These incidents show that poor housekeeping, and work practices are still the two major contributors to preventable FOD. We can eliminate FOD. To do so, we must make these six commonsense steps, part of our every job, every step, every day.
The first step – be aware that you can make a difference, and that FOD is a constant problem. Every time you sign out a tool box, work a job, or just step out to help someone, keep your eyes open for tools, rocks, and other debris. And when you see something, stop, and pick it up. Occasionally, you may need a sweeper to clean up an area. MAC usually coordinate with base OPS. MAC (Military Airlift Command) usually coordinates this support with base OPS.
The second step – keep your work area clean. Check your shoes for foreign objects, and empty your pockets of keys, change, pencils, and trash. Place these items into a FOD bag before entering the cockpit, intake, other confined areas, or before working on top of the aircraft. Are you covering all of those lines, houses, cannon plugs, and ducts during extended maintenance? The ACES II ejection seat is the most reliable, and safest seat in the world, as long as nothing gets in the way. Somebody did not report losing this pencil tip. It then migrated in flight to the sequence start switch which activates the seat computer as it departs the aircraft. It was discovered during a visual inspection of the seat when it was removed for other maintenance. Because of the protective shield over the switch, and the tight clearance in the cockpit, it normally would never have been found. How do you think the pilots felt when they heard about it? Do you check the area one more time before you leave? It is possible the person before you left something behind.
Step three – we have to keep our vehicles clean. We know foreign objects get around, and many times are, vehicles carry them out to the flight line. Tire checks – are you constantly doing them every time you went to the flight line? How about after you drove out of the taxiway to let the jet pass? How clean is your vehicle? Is there safety wire, trash, or fasteners on the floor? Is the FOD can overflowing before you empty it? If you have a vehicle magnet installed, are you checking it daily?
Step four – Thorough FOD walks. Are you looking, or are you out there just stretching your legs? Pay special attention to the grounding points, and cement grooves, and cracks. These areas are always filling up with trash, rocks, and hardware. A good daily FOD walk helps us keep up with all the debris that still manages to get onto the ramp. A FOD walk should have found this bolt. Instead, it was sucked up, off of the ramp by a B-1. Three first-stage compressor blades, and one inlet guide vane were damaged. It cost us 56 man-hours, and over $ 35,000 to remove and fix this engine.
Step five – good tool and hardware control is a must. Remember the last time you lost a tool, or a nut? How long did you look for it? Did you find it? When was the last tool report started? Remember – tool control starts when you receive a toolbox. Before you sign for it, make sure all missing tools are written up, and check the box for pieces of safety wire, and other trash. Woe, slow down, and look. Is that a tool, or the tool cutout? If you find a tool missing, don’t accept the box, and make sure a last tool report, and investigation is started. Also, never leave tools in hardware in or on the aircraft. Do a good inventory of your toolbox, and TOs* after every job. This alone will narrow the search area, and greatly increase your chances of finding a last tool. Think about it, what would you rather check? One aircraft, or three? When you do find a tool missing, start looking for it immediately. If you can find it after a short search, report it immediately to the expediter, or dock chief, and get some extra help to look for the missing tool or hardware. For tight or inaccessible areas, you can also use a borescope** or X-ray equipment to locate lost items. How would you tell the pilot if the jet has just taxied? What if it is flying? A file about this size was left behind after blending two engine blades on a C-5, possibly fallen behind a nacelle blocker door*** during the job. Four people then signed for the box over the next several days before someone finally noticed, and reported the last tool. The file was not located, and then came loose in flight the next day. This incident caused over 550 men-hours of work, and $ 66,000 in damage to the engine. Hardware control is simply taking only what you need, and counting how many nuts, bolts, or other hardware you take from bench stock. After the job, make sure you account for all the hardware. If you don’t complete the job, annotate the screw bag with the quantity, the type of hardware, and your name. This will help the person who finishes the job track down any missing hardware. Here is what a misplaced ¼ inch nut did to a C-130 engine. Over 30 blades were damaged beyond repair, not counting depot costs – the damages have already taken 64 man-hours, and exceeded $ 38,000 in damages. Sometimes, we accidentally leave items inside the intake danger area, or in the intake before an engine start. These have included VTR tapes, flashlights, cleaning bottles, and aircraft forms. Are you paying attention? Or have you just been lucky?
Step six – follow the T.O.. For tight or inaccessible access areas, you can also use a borescope, or X-ray equipment to locate lost items. How would you tell the pilot if the jet has just taxied? What if it is flying? A file about this size was left behind after blending two engine blades on a C-5, possibly fallen behind a nacelle blocker door*** during the job. Four people then signed for the box over the next several days before someone finally noticed, and reported the last tool. The file was not located, and then came loose in flight the next day. This incident caused over 550 men-hours of work, and $ 66,000 in damage to the engine. Hardware control is simply taking only what you need, and counting how many nuts, bolts, or other hardware you take from bench stock. After the job, make sure you account for all the hardware. If you don’t complete the job, annotate the screw bag with the quantity, the type of hardware, and your name. This will help the person who finishes the job track down any missing hardware. Here is what a misplaced ¼ inch nut did to a C-130 engine. Over 30 blades were damaged beyond repair, not counting depot costs – the damages have already taken 64 man-hours, and exceeded $ 38,000 in damages. Sometimes, we accidentally leave items inside the intake danger area, or in the intake before an engine start. These have included VTR tapes, flashlights, cleaning bottles, and aircraft forms. Are you paying attention? Or have you just been lucky?
6. Step six (again and further) – Follow the T.O.. Several times we have had equipment, and panels come off during an engine run, or in flight, causing serious damage. On the last job before a three-day weekend, an experienced crew chief and his assistant were preparing an F-16 for an engine run. He skipped the warning, and the step to check the run screen safety pin for security. During the engine run, one pin came out, and after whipping around in the intake for a few seconds, the lanyard broke. The pin destroyed over 426 blades. Total cost – $ 69,000 and 366 man-hours. What was the cost of the crew chief? How do you think he felt? Think of what he went through. The de-certification, the investigation, the waiting. Was the two or three seconds saved worth it? Sometimes, confusing or incomplete TOs are part of the problem. Improper installation caused by poor tech aide, and inexperience created a stress crack in the upper anti collision light lens in a KC-10.
* T.O.: Technical Order
** (or boroscope)
*** Thrust reverser (pelle d’inverseur de poussée)
The DARPA and USAF FALCON project might give anybody the thrill of speed as this « aerospacecraft » has been designed to reach Mach 20 i.e. around 20,000 km/h; 5.6 km/s; 10,800 knots; or 12,400 mph depending on the air temperature, and the altitude which might be above at least FL900!
Unfortunately, the project seems to encounter major difficulties as the last test which unfolded on August 11, 2011 failed again. The previous one – also on an HTV2 – had failed in April. Click on the right-hand side picture to get further information on the first test. The Blackswift (HTV-3X) had been designed by ATK; Boeing; Lockheed Martin; and Skunk Works to provided a strategic strike anywhere in the world within an hour. It was cancelled due to a lack of funds (see the HTV-3 shown in the following video):
DARPA stands for Defense Advanced Research Projects Agency
FALCON stands for Force Application and Launch from CONtinental United States
FL stands for Flight Level (FL x 100ft = altitude)
HTV stands for Hypersonic Test Vehicle or Hypersonic Technology Vehicle
RCS means here in the videos: Reaction Control System (and not Radar Cross Section)
Click on the picture below, and then on the blue arrows to watch the different phases of light:
This is the brand new project being designed by EADS, and supported by Japan as well as the French DGAC (Direction Générale de l’Aviation Civile – FAA or CAA equivalent). The European consortium has just unveiled its ZEHST project as the Paris Air Show 2011 is opening. ZEHST stands for Zero Emission Hypersonic Transportation.
This aircraft would be both a commercial airplane, and a rocket. It could cruise at « flight level 1056 » i.e. 20 miles or 32 kilometers above the mean sea level… The ZEHST specifications feature a speed of Mach 4 but according to the video below, it might reach Mach 4.5 i.e. 5,500 km/h or 3,000 kts through the stratosphere. It would use two independent turbojets for taking off, then it would gain speed thanks to two cryogenic rocket engines, finally two ramjets would propell the aircraft to hypersonic speeds.
The ZEHST is supposed to pollute far less than the Concorde as it would have a main cruise stage in the stratospheric layers, and according to EADS, its carbon footprint should be very low. There could between 60 and 100 passengers on board who could join Tokyo from Paris in 2.5 hours instead of 11.5, and New-York in 1.5 hours instead of 8! The prototype is expected to fly by 2020, and the first passengers might enjoy stratospheric flights around 2050.