Radiation used during maitanence

[QFCPT747]

Hey guys i have a few question about radiation and how its used?

Im pretyt sure that BETA radiation is used, but how does it work?
also do they do this at the airport or is there a special site where they do this? because as we all know, radiation can be pretty dangerous.

How small a fualt can it detect? and what areas of the plane are checked the most frequently or closely?

and how long have they been doing this for? and finally, Does the radiation effect the strength of the plane?

Thanks guys

[P3_Super_Bee]

X-Rays is only thing I can think of off the top of my head. And it isn't used very often at all, and then when it is, there is a 95% chance the part will be removed from the aircraft and taken to the NDI shop for the X-Ray. In 20 years in the Navy on P-3's I seen the need for zero X-Rays. I think the tailhook guys use it more with the high stress those aircraft go through.

Our biggest NDI's are Eddy Current and Dye-Pen. Examples of Dye-Pens would be Landing Gear Wheel tie bolts, Landing Gear Trunion Bolts. Some Eddy Current Landing Gear wheel radius' where the tire bead sits. Spar Inspections

[Dmmoore]

The only types of radiation used for inspection are Gama from either X-Ray or Isotope sources.

X-Ray is used as indicated by P-3. We typically X-Ray the aircraft its self 4 or 5 times during its life (747 / DC-10 / MD-11) in the few areas where structure is inaccessible and other procedures are not effective. X-Ray inspections are carried out with the area around the aircraft secured. No personnel are allowed in the area during the procedure.

Isotope inspections are used for inspecting some engines (JT-3D-7 for one) for internal damage in areas where borescope inspection is not possible. Once again, the inspection is carried out with the area around the aircraft evacuated.

Gama radiation is absorbed by material or the atmosphere and poses no danger to anyone not in close proximity to the event.

Defects as small as 0.01" can be detected 100% of the time. Defects 0.001 can be detected about 50% of the time. If the defect is aligned with the structure exactly, the defect can hide from the procedure. For that reason, two views (different angles of exposure) are taken.

X-Ray can be used for most NDT inspections but is the process least used because of cost and schedule disruption (work stoppage during the process).

Most ferrous metal (magnetic) parts (bolts and pins) are inspected using the "Magnaflux" process. This process is superior to visual penetrant inspections because it can detect a sub-surface flaw.

[QFCPT747]

thanks for that guys. Dmmoore, gamma is the most powerfull radiation known to man, its pure energy and can only be deflected or stopped by lead, are you 100% sure its used?

thanks

[Star Alliance]

...gamma is the most powerfull radiation known to man, its pure energy...

Along with light, alpha particles, gamma particles, heat, and all other forms of electromagnetic waves and particles. Saying "pure energy" is rather redundant because everything in the universe is either "pure" energy or "pure" matter. But I digress.

Both of my parents are in the nuclear medicine field and have been since they graduated college, in one way or another (at one point they were nucmed technologists, mom used to teach at a Jesuit University in West Virginia, is now a sales representative for a prominent radiopharmaceutical company, dad used to own a medical physics consulting firm, is now the programme coordinator for the Nuclear Medicine Education programme at a local hospital, etc.), so I have been around the topic my whole life, and I can't remember a dinner conversation that hasn't in some way involved radiation (that's what happens when both parents are in the same field, I guess). If there's one thing I've picked up, it's that no radiation is too dangerous if you don't receive a lot of it, or if a lot is not received in a short period of time. Both beta and gamma rays are used in the treatment of various forms of cancer (look up the "gamma knife" sometime).
Also, this :

can only be deflected or stopped by lead,

Is not true.
"For example, gamma rays that require 1 cm (0.4 inches) of lead to reduce their intensity by 50% will also have their intensity reduced in half by 6 cm (2½ inches) of concrete or 9 cm (3½ inches) of packed dirt."
Courtesy of Wikipedia. So long as anything has sufficient mass and/or density, it can stop pretty much any form of energy.
By the way, since alpha particles can be stopped by something with the mass and density of a piece of paper, and beta particles can be stopped with something the mass and density of a sheet of aluminum foil, that pretty much leaves gamma rays.
Not to mention, I'm pretty confident that Don knows what he's talking about.

[QFCPT747]

Any idea where i can find more information on this matter? I want to know more about how radiation is used during aircraft maintenence.
thanks

[Dmmoore]

As stated earlier, radiation is rarely used during maintenance.

Only in places where no other inspection method will work. It's not the radiation danger as much as the costs associated with lost time.

The link below is not a detailed account of what you asked for but it gives you an idea of what can be done. Just remember radiation inspections are the last choice.

http://www.aaeaerospace.com/Capabilities.htm

[Dahai]

I was working in an aircraft maintenance company in Victoria some years ago. They used X-ray on a number of B747's undergoing heavy maintenance. It was always at night as the workforce was less. The area was cordoned off with signs prominently displayed and the hangar doors closed.

[Gabriel]

The only types of radiation used for inspection are Gama from either X-Ray or Isotope sources.

A small correction: X rays and Gamma rays are similar in that both are electromagnetic waves, but of different wavelength. Also the source is different. X rays are obtained from a sort of radio transmitter (thus "radiography"). Gamma radiation is the result of radioactive decay (i.e. obtained from radioactive isotopes).

When I was studying, in the mid nineties, they were experimenting with another form of radiation from isotopes: The neurography, which uses neutrons emitted from a radioactive decay (again from a radioactive isotope). Unlike X and Gamma radiation, this one is not an electromagnetic wave. Neutrons rays are easily stopped by water. This technology was being experimented, and with good results by that time, to detect delamination in composite PRF parts. Delamination happens between layers, and the only practical way to take a radiography (X ray) of a laminated part like a control surface (a rudder, an aileron, etc) is perpendicular to the surface. Thus the X ray would not be able to detect delamination because the amount of PRF material between the source and the sensible film is the same, delaminated or not, and the space between the delaminated layers has nothing capable of stopping X rays. But that space in the delamination is usually filled with air, water vapour included. And the water vapour is a strong stopper of neutrons rays, so a delaminated area would show as a less exposed zone on the film.

However, there were practical application issues, like with gamma rays. I don't know if that NDT method ever saw the light beyond the experimentation stage.

[Highkeas]

A small correction: X rays and Gamma rays are similar in that both are electromagnetic waves, but of different wavelength. Also the source is different. X rays are obtained from a sort of radio transmitter (thus "radiography"). Gamma radiation is the result of radioactive decay (i.e. obtained from radioactive isotopes).

When I was studying, in the mid nineties, they were experimenting with another form of radiation from isotopes: The neurography, which uses neutrons emitted from a radioactive decay (again from a radioactive isotope). Unlike X and Gamma radiation, this one is not an electromagnetic wave. Neutrons rays are easily stopped by water. This technology was being experimented, and with good results by that time, to detect delamination in composite PRF parts. Delamination happens between layers, and the only practical way to take a radiography (X ray) of a laminated part like a control surface (a rudder, an aileron, etc) is perpendicular to the surface. Thus the X ray would not be able to detect delamination because the amount of PRF material between the source and the sensible film is the same, delaminated or not, and the space between the delaminated layers has nothing capable of stopping X rays. But that space in the delamination is usually filled with air, water vapour included. And the water vapour is a strong stopper of neutrons rays, so a delaminated area would show as a less exposed zone on the film.

However, there were practical application issues, like with gamma rays. I don't know if that NDT method ever saw the light beyond the experimentation stage.

It sounds like you are referring to thermal neutron radiography, sometimes referred to as N-ray. This inspection technique has been used for 30 years and the current spec is ASTM E748. I use this inspection method on new components quite often to check for presence of elastomeric items such as o-rings.

[QFCPT747]

again, any websites i can research this in further detail?

[Highkeas]

To deviate from the thread slightly newer airport baggage inspection equipment uses a variety of techniques using radiographic and nuclear techniques. Lots of info on the internet but not much detail. I suspect TSA/FAA does not want info too broadly disseminated.

[Dmmoore]

Use "Google" or any search engine to find the web sites you are looking for.

Try searching for "inspections using radiation" or the specific radiation type desired. X-Ray, N-Ray, Gama, etc.

There are too many foe me list to list.

[Mungous]

again, any websites i can research this in further detail?

I think you and Wikipedia should go on a date sometime

Beta rays = Not so lethal, it's what comes out of CRT monitors
X-rays = Tad on the hazardous side, hence why it's only used in tiny bursts