Pilots flying amerijet's freight are scabs. They are helping management attempt to break the pilot group (management's goal in a strike is to continue operating long enough that the pilot group can no longer maintain the strike).
They aren't helping Amerijet at all. Its not just some small 10% overhead or whatever for Amerijet to have another another company to send a few airplanes to MIA to cover their runs. Not only are these other companies' aircraft more expensive to operate (because the pilots are paid more) but you also have to pay positioning costs and other such things. Anytime you have a company whose sole industry is to transport goods, and they are made so they can no longer transport stuff, then that company has problems. Major problems. Amerijet of not making a profit by paying other people to come in and do their business. These companies are not "helping" Amerijet. If anything they're taking advantage of them.
The only way any of these companies would be helping Amerijet is if they were to fly their cargo at such a price that would allow Amerijet to still turn a profit. If that were to happen, then the other company is either eating the costs (and they're stupid), or they are somehow paying their pilots less to fly that cargo. If it's the latter, then you could argue they are scabs. Its still not technically scabbing since those pilots didn't actively choose to go out and be scabs (their company basically forced it upon them), but their actions do have the same effect as in it is enabling Amerijet to do business just like it did before the strike in a sustainable way.
The way I see it, there are basically two sins to "real" scabbing: #1, Enabling the company being struck against to continue operating under the protested conditions. This is bad because it renders the strike basically powerless. Why would the company give in to the strikers demands when they can just hire new people?
Sin #2 is how the scab takes the job completely knowing that his actions are effectively rendering another person unemployed. And not only that, but the scab is only able to get the job because the striker is in a vulnerable state.
There are four "levels" of scabbing:
The negative scab - This is someone who is actively or passively hurting the company being struck against. These are the people who hold picket signs and refuse to fly anything with the Amerijet logo on it. Neither sin #1 or #2 is being committed.
The zero scab - Someone who is neither hurting nor helping the company/strikers in any way. Most people fall into this camp. Neither sin is being committed. Most pilots doing contract work for Amerijet right now are in this camp too. Its not so much they these people are hurting the striker's cause, they just aren't helping. They aren't jamming any knifes in, but they aren't taking any out either.
The slight scab - Sin #1 being committed, but sin #2 isn't. GoJet pilots fall into this category. GoJets pilots aren't setting out to take jobs away from people, but through a chain of indirect cause and effect, thats kind of what ends up happening. If you decide to continue flying for another company who is covering Amerijet's runs in such a way that allows Amerijet to continue doing what they've been doing, you are indeed undermining the strikers cause, but the distinction here isn't that you aren't taking anyone's job away from them. You already have your own job. In my opinion, people in this group get too much flak than what they deserve. There are hundreds of things that could undermine a strike's cause. Sheesh, if Amerijet were to go to a bank and get an operating loan to help them get through thins thing, you could argue the bank is helping undermine the strike because they're helping Amerijet continue their operations. The truck drivers who carry the freight off the planes and onto the roads are scabs too, right? The janitor who cleans the headquarters bathrooms are helping the company run, so he's a scab too, right?
The "Full Frontal" scab - Both sins are being committed. This is when a person actively and knowingly takes a job when he is 100% aware that the only reason he is being offered the job is because the person who normally holds the job is on strike. Not only is he completely undermining the strike effort, by allowing the company to operate under its old rules, but he is also benefiting himself by taking advantage of someone else who is in a weakened state. This is by far the worse of all types of scabs. What elevated these people above "slight" scabs is the intent of their actions.
The problem with these discussions is that people reduce all these types into either "negative scab" or "full frontal scab". Either you're with us or you're against us. Either you're doing everything you can to screw over Amerijet, or you're a scab who deserves to have your career ended and be spit on and have your flight bag pee'd into, etc...