Warning This Post is Long
I have coloured each idea to break it into easy sections.
1) I think that the the sale and leasing could be made more realistic in a couple of ways:
i) A negotiation feature could be implemented in which the 2 parties involved work out what price it should be leased at this could be done in 2 ways:
a) the leasee fills in a form of a couple of things such as the approximate number of passengers at the airport at which it would be based and how much they think they could make daily the system could then suggest a price range in which the leasor should base their pricing when offered the leasee would be told whether the price offered is below in or above the range that the computer suggested.
b) when the two parties start the negotiation the system looks at a number of factors e.g. airline value and number of daily passengers and then it suggests a suitable range again the leasee will see if it is below, in or above the range.
ii) Sales and leases should be done round a contract system this is in 3 major parts:
a)When a contract is designed the owner of the aircraft can either pre-sign it or they can sign it after the buyer if the first is chosen the plane will go straight to the buyer/bidder if the second is chosen then the owner can decline the sale/lease of the aircraft but could agree to it for another airline
b)When an aircraft is sold or leased it may not be at the airport that it will serve from there for i think that an aircraft should have some kind of basic log that remembers where it was flown from most on its previous routes (e.g lets that a plane has been with an airline for 2 years and has had 1 change in the routes so in the first year it flew only from LHR but in the second it flew one flight from LHR and the rest from CDG therefore it would be based at CDG not LHR.) this would mean that the aircraft may need to be transported from one airport to another in the contract the owner could specify if they will provide transport or if the buyer/bidder must provide their own transport of the AC. If the owner provides transport it will cost more initially but if the buyer/bidder provides transport then it could cost more it would be upto the owner.
c)The owner could put a clause in that means that when someone buys or leases an AC the owner could demand it back at any point if sold the owner has only a couple of months (game months) to reclaim it but if leased the owner could have it back whenever they wish but they would need to give a couple of months (game months) notice to the owner so they can make preparations for the return of the route. This is an option that would be part of the contract and therefore if signed by both parties it should have minimal problems, if however this option is not selected it should still be possible to ask for it back but this would need the consent of both parties and if aggreed the same process applies but the buyer/bidder does not have to agree if they want to keep the AC in operation.
2) This next idea would rely on hot swapping being implemented it would be a function most likely premium due to the sofistication called Fleet optimization, this would review all your aircraft and work out if there was any way to increase the number of spare planes i.e. take routes away from planes and re-assign them to other planes so that the number of planes with 24 hours of free time is increased, it would also try not to lower the DOC and prompt you if you can free planes but decrease DOC, when run it would have a couple of settings:
i) All Aircraft - this would look at every aircraft and work out the best way to change the routes around it might mean routes run by a Bombardier CRJ 200 are transfered to a Boeing 767
ii)Family Specific -this would look at aircraft families such as the airbus a320 family which is made of a318s a319s a320s and a321s and it would then do the same process but you wouldn't get a route moving from an a320 to boeing 767 as they are not the same family. Families would be variants within a model e.g 747-400 and 747-100 would be the same family.
iii) Fleet Specific - This would look at your custom fleets and sorts within those with no overlap occurring between fleets if you have no fleets it is the same as all aircraft.
iv) Custom - This would let you select which exact aircraft to switch between e.g. you have 5 of every type of basic 737 i.e. 737-100 to 737-900 you may only want to switch between your -900 and -800 so you can select those options
3) I think that there should be a customer perception of your business this would be based on things like the number of destinations, the price of tickets (in comparison to competitors this is not like loadfactor as although you might have a full plane you may be charging €500 and your competiors only €200 so customers would perfer them to you) If you have a terminal then customers may be happier as they know that it belongs to your airline and isn't split with other operators, the age of the plane the older they are the less well received they are and the type of plane as some people may like a roomy 737 to a small ATR (just an example) all of these would affect your company image which could have an effect on your company value.
4) Maintenance of the plane as i have said in previous topics this is an annoyance for me my suggestions to improve this are as follows
i) each aircraft has it's own maintenance cost this increases slowly and steadily whilst it is still in production but a few years after production stops the price climbs much fast as parts are harder to source a message could be sent to the owner to inform them that the plane will go out of production the next year rather than messaging about each plane indiviually it will be a single message either stating the number or listing each plane number.
ii) at your hangers you could bring in the concept of contracting staff i.e you can choose a company that provides your maintenance depending on 4 areas quality(how well it is done), cost(how much it costs), appearence (the condition that the plane is left in this affects customer rating (see point 3)) and ethicalness ( how the workers are treated this affects customer rating (see point 3)). You could get Very High Quality, Very High Cost, Very High Appearence and Very High ethicalness all the way down All Very Low with different suppliers providing different options that can fluctuate over time
5) Marketing this is a section that allows you to advertise in different ways i.e radio, TV, newspaer etc each one costs a different amount, has a different quality and will do various things. The quality is like asking how much is to be spent from very low budget to very high budget with some outlets overlapping in price. When you have decided what type of advert and the budget for it you can then choose the run time in months all of this is calculated and a quote is given if this is too high you can go back and alter parts when you are happy with you advert you can buy it at the same time as the quote is given a percentage is also quoted this could be any size including negative this percentage is the affect that the adverts will have on your prices when you start the campaign ALL your prices increase by this much with no change to your airline there may be changes to other airlines but what ever seems fair i guess.
I know they are complicated and would be difficult to implement but i think they would make the game more realistic. Sorry for making it SO long.