F-22 Raptor "sucks"

[BIGNEWY]

http://rt.com/usa/news/force-air-f-22-wilson-731/

 

American Air Force pilots have continuously complained about the F-22 jet’s peculiar habit of leaving servicemen unusually sick after flying the stealth plane. They’ve reported blacking out and developing symptoms mid-air that are on par with serious oxygen deprivation. At least one of them has even died. Despite these problems, the Pentagon continues to pressure its own pilots into climbing into the cockpits of the fighter jets and risking their lives.

[aaron886]

Surprise, time for a sycophantic liberal response from Russia Today.

[tflash]

Pinpointing the cause seems elusive, they now are thinking the extreme flight profile enabled by the F-22 just takes its toll physiologically on the pilots: http://www.aviationweek.com/Article.aspx?id=/article-xml/AW_05_07_2012_p31-454218.xml

[Pilotasso]

Dont think the pilots are too soft to fly the F-22 :D (thats the most ludricous thing i ever read) the plane does have a technical glitch and to me its apalling that they did not take higher levels of measures to solve this without last minute improvisations.

 

If they cant pinpoint the problem the normal way,they need to think out of the box like recreate the conditions in a full scale working mockup inside a vacum room or something like that.

[hassata]

Raptor Cough:

http://abcnews.go.com/Blotter/22-fighter-pilots-battle-mysterious-raptor-cough/story?id=16303962

[hassata]

More restrictions:

http://www.bbc.co.uk/news/world-us-canada-18081936

[Pilotasso]

Yeah its not funny getting pilots gasping in the pit. I never imagined how the title of this thread could ever be so accidentally appropriate!

[RIPTIDE]

It sure does Suck monkeys.

[mikoyan]

can somebody explain how the oxigen system works on the raptor

[Daze]

can somebody explain how the oxigen system works on the raptor

 

http://www.youtube.com/watch?v=z8l4rw_dPEY - Go to 5:31, it gives a brief description.

[aaron886]

Just google OBOGS. When she says "passes it through the engine" with reference to the air, it's worth noting that OBOGS draws bleed air, which means it's air that has gone through the compression stages of the engine, and has not yet seen fuel or combustion.

[mvsgas]

can somebody explain how the oxigen system works on the raptor

Here you go.

2.3.2.3. Air Cycle System

The Air Cycle System (ACS) takes bleed air from the engines (which comes in to the

system at between 1,200-to-2,000 degrees Fahrenheit) and cools it down in the Primary

Heat Exchanger (PHX) to approximately 400 degrees. From the heat exchanger, the air

is fed into the Air Cycle Refrigeration Package (ACRP). The air must be dry, so the

system also includes water extractors. The air, when it comes out of the ACRP, is now

chilled to approximately 50 degrees Fahrenheit. The flight-critical equipment, the

systems that are for keeping the aircraft flying, are cooled by this air. This air is also fed

into the On-Board Oxygen Generating System (OBOGS) to provide breathable oxygen to

the pilot, operate the Breathing Regulator/Anti-G (BRAG) valve on the pilot's ensemble,

provide canopy defogging, and cockpit pressurization.

 

5.0. Environmental Control System

The Environmental Control System (ECS) is combined with the fuel Thermal

Management System (TMS) to form an integrated aircraft thermal conditioning system

providing the aircraft and crew with control and monitoring of heating, cooling,

pressurization, and weather protection. The ECS interfaces with the Auxiliary Power

Unit (APU), both air and liquid-cooled avionics, canopy, cockpit, fuel, Missile Launch

Detectors (MLD), On-Board Inert Gas Generation System (OBIGGS), On-Board Oxygen

System (OBOGS), and the pilot life support systems. The ECS uses ram air, bleed air,

and electrical power for operation. Two dedicated ECS controllers from the Integrated

Vehicle Subsystem Controller (IVSC), primary being A4 and backup being A3, control

ECS performance and operation along with backup control signals. ECS contains three

elements; the Air Cycle System (ACS), liquid coolant loop, and TMS. Heat generated by

aircraft systems is carried away by aircraft fuel, refrigerated air, or liquid coolant. Heat

absorbed by the liquid coolant and generated by the Air Cycle Machine (ACM) is

transferred to the fuel system. Fuel temperatures are then controlled by transferring fuel

heat into the ambient air via ram air heat exchangers or by burning the fuel in the engines.

The ACS receives bleed air from the engines and provides cockpit climate control,

cooling air for air-cooled avionics, and air for OBOGS and the pilot suit. The Vapor

Cycle System (VCS) provides liquid-loop cooling and cools the forward avionics and

provides heat transfer from the ACS. Polyalphaolefin (PAO) fluid removes the heat from

the VCS condenser utilizing the TMS. TMS uses fuel as a heat sink for the airframe heat

loads through PAO, Airframe Mounted Accessory Drive (AMAD) oil, and hydraulic-to-fuel heat exchangers. The ACS automatically supplies pressurization for cockpit

pressurization, OBOGS, G (gravity)-suit, canopy seal, Stored Energy System (SES)

compressor, and OBIGGS. Cockpit pressure uses air entering from the cooling vents and

is controlled by the cockpit pressure regulator and dump valve. The pressure regulator

regulates the outflow of cockpit air to maintain cockpit pressure. The cockpit is not

pressurized below 8,000 feet Mean Sea Level (MSL). Between 8,000 feet MSL and

23,000 feet MSL, cockpit pressure altitude is maintained at 8,000 feet. Above 23,000

feet MSL, a 5.0 psi differential pressure altitude is maintained. A cockpit safety valve

allows pressure to be dumped. The ECS is designed so a failure of any single Line

Replaceable Unit (LRU) will not result in secondary damage to other system

components. The IVSC provides continuous performance monitoring and fault tolerant

reconfiguration of the ECS. The ECS cockpit control panel, located on the right console,

allows input for certain control functions such as cabin temperature, suit temperature,

cockpit pressure dump, canopy defog, and air source selection.

 

16.0. Oxygen System

The oxygen system provides sufficient breathing gas flow and pressure to allow the pilot

to perform at all operational gravity (g) and altitude conditions, and provides emergency

air for breathing. The crew and On-Board Oxygen Generation System (OBOGS)

subsystems comprise the oxygen system. An emergency oxygen system is also available.

It is part of the escape system. The system consists of a pressure bottle and pressure

reducer mounted on the left side of the ejection seat with a hose routed to the breathing

regulator on the right side of the seat. The system automatically activates upon ejection,

or may be manually selected by pulling a green ring on the left side of the seat

16.1. Crew Subsystem

The crew subsystem controls and distributes oxygen, anti-G air, and cooling air (cooling

air feature up to aircraft 04-4083). A Breathing Regulator and Anti-G (BRAG) valve

automatically provides positive pressure breathing in the oxygen mask with concurrent

inflation of the upper pressure garment in response to altitude and G force. The anti-G

valve provides automatic inflation for the lower G garment in response to altitude and G

force.

16.1.1. Breathing Regulator And Anti-G Valve

The Breathing Regulator and Anti-G (BRAG) valve is on the cockpit right console and

contains the following controls: OBOGS ON/OFF, NORMAL/BYPASS, MIXTURE

MAX/AUTO, TEST button, and a FLOW indicator. The OBOGS OFF controls power to

the OBOGS and allows OBOGS to remain off when the aircraft is powered for unrelated

ground maintenance. BYPASS allows the pilot to breathe filtered Environmental Control

System (ECS) or direct bleed air without removing the oxygen mask if OBOGS or the

emergency oxygen system is not available. The MIXTURE MAX/AUTO switch in the

MAX position provides constant maximum oxygen concentration. The TEST button

provides pressure breathing in the mask with counterpressure to the pilot's pressure

garments.

16.2. On-Board Oxygen Generation System

The OBOGS subsystem is the primary producer of oxygen-enriched breathing gas

requiring both electrical power and conditioned ECS air to operate. An ECS bypass

supplies conditioned engine bleed air as a backup. During operation, OBOGS

automatically provides oxygen-enriched breathing gas based on cabin altitude. Cabin

pressure sensors supply altitude information to the Integrated Vehicle Subsystem

Controller (IVSC) which relays the information to the OBOGS. At cockpit altitudes less

than 11,000 feet OBOGS automatically controls the percent oxygen to less than 60

percent. At altitudes greater than 11,000 feet OBOGS produces the maximum oxygen

concentration of up to 94 percent. IVSC A4 assembly monitors OBOGS for low system

pressure, oxygen concentration, internal control/monitor faults, and the OBOGS position

switch.

 

As you can see, not a very simple system.

Edited May 18, 2012 by mvsgas

[Vekkinho]

Man, that's too messed up to be reliable. What's the purpose of such system?! I'd add few diving bottles of compressed oxy to solve this "clean" air for Raptor driver problem.

Edited May 18, 2012 by Vekkinho

[GGTharos]

In theory it reduces maintenance requirements.

[Vekkinho]

It's gotta be streamlined as much as possible...it's obviousely the most important system on Raptor.

[GGTharos]

It is sctreamlined. What you're looking at is the entire air-cycle, not just the OBOGS. This is not the only aircraft with a complicated cooling/air cycle arrangement.

[Yurgon]

There's one aspect I don't understand about these continuing problems. Has it ever been confirmed that there actually is too little oxygen in the air in these incidents?

 

The official talk is about "hypoxia-like symptoms". Quite simply, is it hypoxia or is it not? If not, is it some kind of poison? Obviously, something is wrong. And while I fully understand that it is very difficult to identify the root cause, my question is, has the Air Force ever been able to verify what was wrong with the air supplied to the pilots?

 

I mean, now that everyone is aware of the problem, can't the experts supply pilots with some test tubes that fit into the flight suit so that if an incident occurs they'll at least have an idea whether it was too little oxygen or some kind of poisonous compound?

 

Or do they already test for such things and the information just hasn't made it out to the public yet? I believe the whistle-blower pilots said they felt like test subjects - but if no additional data is recorded, how would one try to find out what actually happened?

[aaron886]

The official talk is about "hypoxia-like symptoms".

 

Yeah, they're unfortunately rather common and ambiguous symptoms. It could be a lack of oxygen partial pressure (hypoxic) or toxic gasses in the air. (hypemic.) There are multiple types of hypoxia; but the LOC, dizziness, difficulty breathing, and headaches are all consistent symptoms.

[Griffin]

Yurgon: Articles posted in this thread say that the experts are doing exactly that.

[mvsgas]

Find it hard to believe that so many people are surprise ( some sound appalled) at the USAF decision to fly and aircraft with inherent dangers without correcting them. I'm sure if we look back at the history of military aviation we can find hundreds (if not more) if instances/ examples of aircraft unfit for flight, given to pilots to fly in combat. From the Sopwith Camel, to the ME-163. From the F-100 to the F-16, military pilot from many different Air Forces, have been told/ ordered to fly aircraft that could kill them. How many pilots flew the ME-163 with it's highly toxic fuel? How many flew the Helldiver? A carrier based dive bomber that was under powered, and would come apart in dives. How long did the F-100 flew with the small tail or with its hydraulic problems that could lead into a departure? F-104 with its downward ejection seat, what was the percentage of successful ejection from the F-104A, and how many pilots survive to tell the story? This combine with engine flames outs during take off. Did the F-84 had problems with it catching fire? I believe Bud Day almost got killed in a F-84 because of this. P-38 compressibility, F-4 departing flight at high alpha if centerline stores where installed. Remember when the F-15 came apart in flight, what do you guys think they did to fix the problems? Did some aircraft fly before fixed? How about the F-117, does any one know how many time that aircraft was grounded and instead of fixing the situations, they just updated/change manuals and training. How many F-14 crashed due to engine problems? How many of you guys knew that the F-16, in many occasions, had several severe and dangerous problems. Engine exhaust coming apart in flight, loosing all power. Do you guys think that was fix or did it took several months and several accidents? I remember having to change hydraulics pump every 2 to 3 weeks, every time they discovered another batch that was causing accidents. Electrical problems, landing gear problems. This stuff happens all the time, it just that the media does not normally care, just my two cents.

[Vekkinho]

Coughing is a symptom of lungs being polluted. Looks like there not enough oxy but lots of other stuff coming thru Raptor oxy mask.

[vanir]

Statistically when in regular service in the Luftwaffe, throughout its career on average an F-104 crashed every 6.765 flying hours.

From memory in the first five years of service 70% crashed, many were fatalities, and it was still being hailed as a great aircraft.

 

The "sabre dance" was infamous, you only have to watch videos of century series landing mishaps where every one of those birds kill pilots regularly on the runway. One great F-104 death it actually came to a complete sliding stop on its wheels, waited a moment then backlash from an engine compressor stall or something, like a delayed reaction, suddenly pancakes the stationary bird and it explodes on the tarmac.

Numerous vids of F-100 tumbling explosions all over the airfield are equally shocking.

 

The F-14A prototype looks scary when it suddenly noses down on approach and hits the ground in a fireball. That bird was almost cancelled because congress was starting to think the technology for such an advanced warbird was just too premature for the time.

 

The modern media climate has become a little silly with its sheer disregard of the fact military careers are not stamp collecting but inherently dangerous and an environment where, in actual fact deaths are just loss ratios as part of a strategic calculation.

I think perhaps the encroaching modern role of the US military as an international policing claim has bred a public expectation that a typical deployment should involve zero losses and plenty enemy deaths as a sign of superior force, where this simply isn't the case. It's a little more like how much enemy devastation you can trade your servicemen deaths for, the losses are a given.

 

 

One thing I was thinking about with the O2 system in the F-22 is, the data handling system for the entire O2 system is done the same way as the engine management system, right? By digitally modelling a simulation of optimum performance under given conditions, and auto-adjusting the physical equipment until sensors match the modelled prediction?

 

So...a bug in the system could be human error in the computer model used to simulate the operating system during flight, that is being used to manage the system in realtime. Anything not accounted for in the software management program will inherently lead to a disparity between what the system is doing and what it is being told to do.

 

? maybe?

[aaron886]

Find it hard to believe that so many people are surprise ( some sound appalled) at the USAF decision to fly and aircraft with inherent dangers without correcting them.

 

 

Yeah, it is a little bit ridiculous. It's a war machine after all isn't it.

[Moa]

Coughing is a symptom of lungs being polluted. Looks like there not enough oxy but lots of other stuff coming thru Raptor oxy mask.

 

 

Actually the "Raptor Cough" has nothing do with the On Board Oxygen Generator (OBOG) and everything to do with pulling Gs - technically it is known as "acceleration atelectasis" and AFAIK it can happen to any pilot pulling Gs when on oxygen.

 

It is slightly more prevalent with Raptor pilots but there is the possibility that this is psychosomatic given the stressful nature of the mysterious OBOG issue, rather than a true physical cause.

 

Edit: Here's an interesting article on it (specifically mentions F-15/F-16/A-10 jocks getting it as well)

http://findarticles.com/p/articles/mi_m0IBT/is_3_58/ai_84091382/

Edited May 19, 2012 by Moa

[Moa]

...

So...a bug in the system could be human error in the computer model used to simulate the operating system during flight, that is being used to manage the system in realtime. Anything not accounted for in the software management program will inherently lead to a disparity between what the system is doing and what it is being told to do.

 

? maybe?

 

Well, the famous instance with the F-22 was when it did its first overseas deployment to East Asia via Hawaii. After tanking up with fuel from a KC after leaving Hawaii the Raptors computers all started crashing and rebooting them wouldn't solve the issue. The Raptors had no nav and no radios. Fortunately they could see the tanker in the distance so followed it back to Hickam (right next to Honolulu International).

 

After analysis it turned out that the Raptor software (written in ADA, I believe) was not designed to handle the crossing of the International Date Line. This is just one of those kinks that needed to be sorted out.

 

nb. I believe a substantial amount of the delay in getting the F-35 project finished on time is the difficulty of getting all its C++ to work correctly (the first big use of C++ for a USAF aircraft). Software is hard, reliable software is even harder!

 

Also, lots of older USAF aircraft use a language called 'JOVIAL' for their software (betcha never heard of that language before). See http://en.wikipedia.org/wiki/JOVIAL for more info.