new to this board but not new to cluster headaches.  I have been suffering for about 35 years, some chronic and some episodic.  For the last  10 years I would get one episode a year. Usually use a combination of verapamil and O2 to control th beast.  This time completely different.  I had my usual 8 week episode and disappeared, I thought, in September.  A month later, to my surprise, the beast returned. 
This time I decided to try the vitamin D regimen.  Been following the regimen for almost 3 weeks.  Sometimes I get a headache during the day and often no headache for a few days. The pain is less severe and O2 seems to work quickly,maybe 5 minutes, amazing!  When do I become PF?
Flying always triggers a headache.  I have a long flight soon. Does anyone know how to avoid headache on airplane?  Thanks for your help.

Hi George and welcome

There is no magic way to avoid a CH on a plane if it is going to happen (other than using preventives to cut down the risk). So what you need to do is to be prepared with an abortive to hand. Being on a plane rules out oxygen, so an imitrex / sumatriptan injection is the best option.

I've flown several hundred times with sumatriptan injections, mainly domestic, but quite a few international flights too and have never had any questions from security. But do make sure you've a copy of your prescription with you and there should be zero issues.

So far I've only had to use it once, but having it to hand was invaluable. Just make sure it is to hand and easily accessible.

What Hoppy said.  Vit D did not make me PF, but I'm a 12+ yr refractory chronic. I did get about an 80% reduction though, and love the stuff. Other effects have been most encouraging, as it has helped my mood tremendously and I haven't had a cold or the flu since I started using it.

As for flying, I have never had a problem with flight, though I know others say they do. I always carry a 5hr ENERGY in my pocket, whether flying or not, because that is the easiest way for me to have an abortive at hand when out and about. Another suggestion is to alert the flight attendant in your area of your situation and ask him/her to have a Red Bull on standby for you at a moments notice. That way if he/she sees you going into distress he/she can bring it to you without you having to get his/her attention and asking for it. I have done this on a couple of occasions, and though I did not need it, they were very happy I alerted them of the possibility of a problem so they could be proactive and not trying to ask what is wrong while I am in no condition to talk about the issue. It also give opportunity to spread info about our disease.

Jerry