A crashpad is an optional expense. You always have a choice whether or not you wish to live where you are based. Completely voluntary, and completely non-deductible.
-Not fair to anyone who chooses to live in a less-than-desirable domicile....
It may be allowed if you reasonalbly expected to be in that base for less than a year. Examples would be if you are TDY'd somewhere and your company doesn't pay for a hotel, then it is deductable. Or, if you go to NYC to get the first upgrade and then are awarded another base giving you the reasonable assumption you will be there less than a year, then it might be deductable.
Other than that, you can deduct it and hope you don't get audited. Chances are you will get away with it. LOTS of people write off crap they shouldn't knowing that statistically speaking, you are very unlikely to get audited. Don't forget that if you do get audited and the IRS see's your doing this stuff, they will audit you back three years and nail you hard. If you get caught, you will spend alot more than you are making by including stuff that is not deductable.
There is a caveat that might help get you some money back:
If you have a temporary job assignment, which you reasonably expect to last (and which does last) less than a year, you can deduct the travel expenses. I used that provision during one of the many times that CommutAir closed a domicile on me, which helped defray the travel costs.
I deducted the driving expense to Syracuse (550-mile round trip), while I waited for my apartment lease to expire so I could move to a different base. At the current rate of 50.5 cents per mile, that was a deduction of $277.75 for each roundtrip to my domicile. That helped a lot. If you're commuting indefinitely, you can't use this provision, but it might help some folks here.
Here's some information from the IRS; look at page 4, specifically: