Radiation During Airplane Flight - PART 2

[Brotoro]

I was on a little vacation this week, so I took some more in-flight radiation exposure data using my RADEX 1212. I used its automatic recording feature to store the radiation level in the plane every 5 minutes.

NOTE that all takeoff/landing times below are Mountain Daylight Time (since that's the time set in the RADEX). The zero time for each recording was before takeoff so that a couple data points could be gathered on the ground. Similarly, the recording was not turned off until I left the plane so that ground level readings could be collected after landing.

Flight 1 was Southwest Airlines Flight 718 Albuquerque (ABQ) to Houston Hobby (HOBBY), May-25-2015, takeoff 11:35 AM.

The pilot made no announcement about the cruising altitude, but he did say that the flight detoured way south of its intended flight path to avoid thunderstorms over Texas, so we landed 10 minutes late.

Flight 2 was Southwest Flight 3976 from Houston Hobby (HOBBY) to Nashville, TN (BNA), May-25-2015, actual takeoff time 3:13:30 PM MDT.

The pilot announced that the expected cruising altitude would be 35,000 feet. This flight experienced two very sharp turbulence bumps (largest I've ever felt) out of nowhere, three minutes apart at 32 minutes into the flight.

Flight 3 was Southwest Flight 826 Nashville, TN (BNA) to Kansas City, MO (MCI), on May-29-2015, takeoff around 9:35 AM MDT.

Pilot announced cruising allude as 38,000 feet. Landed at 11:02 AM MDT.

Flight 4 was Southwest Flight 1017 Kansas City (MCI) to Albuquerque (ABQ), on May-29-2015, listed takeoff time was 2:20 PM MDT but was 10 minutes late.

Pilot did not specify cruising altitude.

Of particular note is that the radiation levels measured on these flights were considerably lower than what I measured on my flight to Seattle back in February (see old thread)

Edited May 30, 2015 by Brotoro

[Brotoro]

The friend I was visiting had some Fiestaware plates, bowls, cups, etc. from the 1930s that has the orange pigment made from Uranium. The picture below shows the RADEX inside one of the cups, with another cup sitting to the side (the RADEX's geiger tube is along its left side), showing an impressive 51.6 microSieverts per hour. Later Fiestaware used a different pigment for the red/orange that was not based on Uranium...although the color was not a good.

Edited May 30, 2015 by Brotoro

[Darnok]

How did you manage to bring on board a device whose function can not understand average stewardess?

After all, in airplanes is forbidden even to to use the phone during takeoff and landing.

[Brotoro]

It was in my camera bag along with all my other assorted small electronic devices, and it passed through security check-in with no problem.

On the plane they said people could use small handheld electronic devices all through the flight as long as they were set to some mode where they did not transmit. Large laptops needed to be stowed for takeoff and landing, but my iPod set to Airplane mode was OK. And my RADEX does not transmit in any case...although there are new versions that have Bluetooth. They let people use their phones the whole way if they were "set to Airplane or Game mode"). These rules were more relaxed compared to what I've encountered before.

That, and I didn't upset any flight attendant by simply not showing them my RADEX.

[Scotius]

We live in a sad world Anyways, i wonder if decrease in radiation levels wasn't caused by staying farther south this time. Maybe increased thickness of atmosphere shielded you better?

[Brotoro]

The flights were lower than the Seattle flight, which was at 40,000 feet (but not THAT much lower in the case of the 38,000 ft. flight). And the Seattle flight had high readings soon after takeoff while I was still far south. Maybe it's because of a difference in solar activity.

[Darnok]

You seem to forgeting that Earth magnetic field is getting weaker and it is not stable

http://www.scientificamerican.com/article/earth-s-magnetic-field-flip-could-happen-sooner-than-expected/

that means Sun activity can be normal, but we get more radiation and energy because of weaker magnetic field.

Edited May 30, 2015 by Darnok

[Brotoro]

But if the magnetic field is getting weaker over the last six months, I'd expect the cosmic ray background level to have increased, not decreased.

[Darnok]

But if the magnetic field is getting weaker over the last six months, I'd expect the cosmic ray background level to have increased, not decreased.

Past 6 months counting from July 9, 2014? And key word - fluctuations.

[WestAir]

Personally I keep my phone on during flight. I think I've only heard complaints about it twice now. I find putting it on airplane mode and keeping it stowed during departure and arrival is enough to keep cabin crew content.

Security doesn't mind any type of electronic device though they may swipe it with explosive trace detection equipment if you have too many wires or it's (obviously) modified with parts added/removed.

Back to the main topic of radiation: That's pretty amazing. I remember your first thread and it made me wonder why I don't bring a lead apron on board!

[DerekL1963]

Of particular note is that the radiation levels measured on these flights were considerably lower than what I measured on my flight to Seattle back in February (see old thread)

The Radex 1212 is an uncalibrated consumer grade unit - some variation is to be expected.

[Camacha]

The Radex 1212 is an uncalibrated consumer grade unit - some variation is to be expected.

A lack of calibration would mostly mean a fixed deviation and less a different deviation every time.

[Brotoro]

I made four more airplane flights recently. Below are the plots of the radiation measurements I made during the flights with my Radex RD1212. Each data point is the average value over a 5-minute integration time. The black points are data taken before and after landing.

The units are micro-Sieverts per hour vs. minutes.

In the cases of the two short flights, the pilot did not announce an altitude. In the case of the longer flights, the cruising altitude was announced AND those planes had W-Fi that allowed me to monitor the planes reported altitude (which was always shown to be within 100 feet of the announced value...except for the BNA to PHX flight that increased altitude 2,000 feet to avoid turbulence partway through the flight).

The ground-level readings were about 0.10 for Albuquerque, 0.12 for Denver, 0.08 for Nashville, and 0.09 for Phoenix... so the peak radiation levels at 39,000 feet were 25 to 35 times ground level (depending on which of those ground levels you want to work from).

I have not gained any noticeable superpowers from this additional cosmic ray exposure.

[pandaman]

1 hour ago, Brotoro said:

I have not gained any noticeable superpowers from this additional cosmic ray exposure.

That's because you need to return to Kerbin for your experience to take effect 

Jokes aside it's a very interesting thread.  I suppose it obvious once you think about it that less atmosphere to shield us will lead to increased exposure, but it never crossed my mind until now.  Not going to panic or refuse to fly though.  Thanks for the insights.

[Kerbart]

You can always go to flightaware.com and get the altitude readings from there. Here's a randomly picked sample:

https://flightaware.com/live/flight/UAL920/history/20160601/0537Z/KLAS/KEWR/tracklog

[tater]

You in ABQ?

[Brotoro]

No.  I have to drive 2 hours to get to Albuquerque.