If there was a commercial pilot in the back and you left them "standby" in the cabin, and then you do something like maybe run off the end of the runway or some other incident that might be explained by you being distracted or overworked how are you going to explain that? Even a private pilot can talk on the radios, and then thats one thing you don't have to do.
Spiral, This is not directed at you but just issues at hand and maybe give folks something to think about.
When you say "commercial pilot" are you talking about someone with 250 hrs in single engine Cessna's or a commercial airline pilot with possible hundreds or thousands of hours in type. It really does make difference.
And, in thinking along your stated line of reasoning, let's say you let someone up front that is not current and/or qualified on that aircraft and you go off the end of the rwy. Was it because you were distracted giving flight instruction to your newly appointed "crewmember"? Did that person accidently flip a switch, push a button, misunderstand your instructions and disable something at the wrong time, yell..."Yeeeee-Haaaaw" while in the flare causing you to flub the landing? The lawyers would have a field day and the company would probably fire you. Unfortunately, in our sue happy society that is something to think about.
Bottom line, you are just as liable if you let someone up front as if you didn't. Damned if you do, damned if you don't kind of thing. You have to weigh your options, the severity of the situation and the asset/liability credentials of who you let up front. That's why I'd be looking for a crewmember from the same company and qualified on the aircraft I'm flying. That's a no brainer and easy decision if you have an asset like that in the back. I don't have time nor the inclination to instruct a private pilot on the switchology of modern jet communication consoles or the verbage to be used during communication with ATC, company and FA's in the back.
Also, If you think talking on the radio is as simple as pushing a button I'd love to put anyone with just a private license in a MD11, A300 or B757 sim and have them call ATC, notify the company and talk to folks in the back with little help from me....I mean, you are up there to help
me, right? It's not the other way around. If I have to distract myself from what I'm doing to explain things to you.....how does that help me?
Simple tasks such as reading or understanding normal checklist, let alone, abnormal/emergency checklist for the uninitiated can become overwhelming to say the least. I can actually do it faster and more efficiently myself and still fly and monitor the autopilot. It's not an ego thing nor am I boasting. Any qualified airline pilot should be able to perform all task required to safely get the airplane back on the ground and doing so solo. It's just easier, safer and more efficient when two "qualified" crewmembers split the tasks.
BTW, I have been stressful situations. One time we lost the main hyd system on the A300 and the hyd eng pump almost took out the entire engine while going into KEWR). The implication of that would've been the failure of 2 out of 3 hyd systems, engine failure, manually cranking the gear down and no nose wheel steering upon landing. Both myself and the f/o (it was his first flight after completing IOE and who did an outstanding job!!) were very busy and there were also other issues that complicated the problems we were already having.
On our list of to-do's we had to manually extend the gear. On the A300 it requires inserting a long metal rod (no porn jokes!) in the floor and turning for what seems like an eternity to get it to free fall and lock in place (kinda like the B727 days). The f/o was very task saturated running checklist and communicating with ATC/company etc, that he failed to make my coffee the way I like it...that's the real tragedy Here!!
Seriously though, we happened to have a DC8 FE riding in the back. We got him up there and had him break a sweat while cranking down the gear.....annnnd, making my coffee! We were glad to have an extra pair of hands that day from another experienced crewmember from the same company riding in the back. , I'd like to say that it was my f/o's idea to get the extra crewmember to crank the gear down.....great idea and I told him so! He's now a 744 Capt in ANC.
Couple that with flying the metro single pilot for years and it was a piece of cake.
