However it is definitely possible to climb out and comply with the 250kt rule. Yes it may require flaps but it is perfectly possible and safe.
Economic; probably not, but since when has economy been the yardstick of "minimum safe airspeed"?
I'm not saying low level climbs at >250kt aren't done, just that it sounds like an airline accountant's interpretation of the rules.
No, it's not. We don't climb with gear and flaps out for a good reason; our climb performance, ability to meet departure procedure and climb gradient requirements, etc, is met in a clean configuration. We don't clean up because it's cheapest. We clean up because once we've met our immediate segment and obstacle climb gradient criteria, we clean up to meet our best rate criteria.
Flying a large airplane isn't the same as flying a Cessna 172 in this respect. Everything is numbers-driven. We have minimum performance criteria which requires certain operational practices, and it's part of the certification (and thus use) of the aircraft. We're also constrained by operational practices dictated through various policies, both governmental, industry, and standardized practices that have been evaluated to meet governmental and international guidelines.
Bear in mind that we operate everywhere but Antarctica, regularly. We're fully ICAO compliant, and we operate in a lot of places where terrain, noise abatement, airspace, and other requirements dictate that we stick to our climb profiles. After a standard departure, we clean up at 3,000', accelerate to V2 + 100, which is our minimum safe speed clean, and climb to 10,000, where we normally accelerate to 320 to 340 knots indicated for the initial climb.
Under what permission do you do that?
As a function of our IFR clearance, and our operations specifications issued to us by the government agency that oversees our operation...which includes operation in uncontrolled airspace. We don't ask what type of airspace we're in during a flight under IFR. We don't particularly care if it's class A, B, C, D, E, G, etc.
If you're asking about the permission for making a high speed climb, the requirement for 250 knots below 10,000, where applicable, applies only if the minimum safe speed of the aircraft is below 250 knots. We don't need permission. We "ask" as a courtesy, for a high speed climb, but also often simply inform ATC about our climb speed. ATC expects it. The one exception will be times when a departure procedure may require a slower speed and a configuration change may be delayed because until those requirements are met, the SID or DP establishes the speed. At that point, our primary concern is meeting climb gradients and crossing restrictions.
Accordingly, we also utilize turn procedures for engine-out situations on takeoff, at many locations, which are different than what are published for themasses. Our turn procedures are issued specifically to us, and may very well take us into uncontrolled airspace. If our turn procedure is a left turn to 180 degrees and our performance calculations give a level off altitude of 800', then we're climb to 800', leveling off, turning to 180 degrees,and advising ATC that we'll get back to them. ATC doesn't have this procedure; we advise them of what we're doing, make appropriate requests or statements, and handle the problem.
As another aside, part of our protocol when returning to land with certain malfunctions is to inhibit the TCAS RA functions by going to a TA mode only; we'll get traffic alerts, but not a resolution advisory. Our changes in performance or capability dictate that we don't presume to act on that traffic information. What that does is enables our TCAS to interface with other TCAS to require the other aircraft to come up with a resolution that doesn't need us to deviate. Such situations are specific, but tied to the idea where that we have performance limitations and procedures to abide, and before others in an uncontrolled situation elect to take full advantage of the extreme limits of their uncontrolled airspace (and let their PCAS do the traffic scan for them), they should be aware that three quarters of a million pounds of aluminum might be getting set to come through their windscreen. Plan accordingly.
Again, I suspect you have a reigonally-biassed view - In many parts of the world, being allowed to play in controlled airspace is unlikely at best; furthermore, in my part of the world the bottom of your controlled, protected areas is remarkably close to the ground - leaving us mere mortals quite a narrow zone in which to fly. When the controlled airspace is 1000ft AGL, and I have little hope of a clearance, you can bet your last dollar I'm going to have my fin right up against the bottom of it. You might equally well ask why the professionals need fly so close to the base, and the wild, uncontrolled chaos that reigns beyond..
I'm not sure how much of a regional bias I could possibly have. At the moment I'm typing from a hotel room in Korea. A little later I'll be in China. I was recently in the middle east, and Europe just before that. I operate about as globally as you can possibly get, so which region is it that influences me? Did you form an impression off what you thought you knew based on the little bit of information under my screen name? I've lived and flown and worked all over the world, and still do. Where my mail goes doesn't necessarily influence or color my "regional bias."
I've spent a lot of hours and years flying close to the surface in utility operations (ag, firefighting, animal survey, back country charter law enforcement, etc), much of it VFR. Much of that VFR flying, in fact transitions in and out of controlled and uncontrolled airspace without any regard to which is which, due to operational necessity. One thing I always do, however, is maintain a high awareness of where traffic conflicts can occur.
A buffer between the lower surface of a busy controlled terminal area and the upper limit of uncontrolled airspace is a potential conflict area. Giving it a buffer is in your best interest.
Sure, as a pedestrian you have the right of way over motor traffic. Betting your life on exercising that right of way against a road train or semi-truck is stupid at best, and extremely dangerous. Betting your uncontrolled rights in your spam can against the sanctity of the lower limits of the local controlled airspace, is likewise not a smart move on your part. Insisting on "sticking your fin" out of the uncontrolled tank may not be your wisest act.
How often is the empty weight checked and by who?
As often as one wants. The question is why check it more often than necessary, or more often than it's changed? Re-weighing is generally done at every annual inspection or every three years, depending on the aircraft and maintenance program under which it's operated.
By whom? Authorized personnel.
If equipment is removed, the weight and balance paperwork must be amended before the aircraft is released for service, again.
It cannot be checked more often than at the Annual, so..... you remove the transponder for the Annual, possibly leaving behind just the antenna. The antenna can be installed (concealed) inside the hull if the hull is composite.
Sure the weight can be checked more often than the annual. However, if a change is made in the weight and balance of the aircraft, the weight and balance paperwork must reflect this change, and should be amended by the person removing the equipment.
The empty weight is meaningless in safety terms because all the pilot has to do is eat a few more burgers and ... and GA pilots are hardly a health conscious lot.
The weight of the pilot is meaningless and irrelevant to the topic of empty weight, is it not? Pilot health consciousness has no bearing on empty weight of the airplane