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Improving Direct Operating Cost (DOC) help please
Hi guys,
I need to improve the DOC of the Fokker F27 specifically in terms of the avionics and control system (if applicable). Searching google for an exact definition of aircraft DOC is proving a bit difficult as most sites just give some formula to calculate it but don't really mention anything specifically in terms of time-scales involved. We are told that modifications have to be cheap because of DOC. So how do I justify a new avionics suite for the F27 to improve DOC? Does it need to pay for itself in a week, a month, a year? And the second thing is, would it be feasible to change the control system to something else (e.g. FBW) for lower maintenance costs? Again, I am not 100% by which point a modification has to pay for itself. (P.S. I know its stupid "improving" the F27 as its obviously a century behind modern technology but nonetheless that's the little assignment I need to do). Any info and advice welcome. Thanks |
D.O.C.s
" The Operation of Airlines " by J.E.D.Williams, although perhaps dated, is of a similar vintage to the F27. (I think that it may have been digitised.)
Some of the aspects you must know already. How long do you expect the aircraft to be in service, a week, a year or ten years How many flying hours or landings can be anticipated in that period. Then add 10%, because you never can tell ! How readily are ordinary routine spares available ? To get the aircraft airworthy requires a C of A. For a projected service life of one week... or one flight... THAT IS EXPENSIVE. At one stage in history, aircraft were "Cheap to buy- and dear to fly." Now the pattern is reversed to "Dear to buy-and (relatively) cheap to fly." because of the economies of scale, with many more passenger/miles/day. ( An Empire flying boat cost £37,000, new.) Good luck LT PS I am not an engineer and I have never even boarded an F27, but I suspect that installing FBW and then getting it approved as airworthy... MIGHT BE DIFFICULT, to put it mildly ! Upgrading the avionics sounds easier, a new box with a new dial sounds so much simpler. RR used to supply some engines on a " Power by the hour" contract. Do some basic calculations for the various alternatives and then graph them out to see if any look promising. Graph paper and coloured felt tips may be sufficient. ( A computer program will tell one the answer that it has been instructed to give, by the programmer.) LT |
Three things come mind: Avionics ie GPS to allow direct instead of via airways, new interior using lighter materials to improve payload, and new engines with better efficiency.
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Bearcat.
SERIOUSLY no offence intended- but to even suggest changing a flight control system in a 50+ YO Turbo Prop to FBW "To save money" shows an incredible lack of knowledge of the basics of running a commercial aircraft operation. You would be up for- seriously- MILLIONS of dollars (in fact it goes beyond that- it simply wouldn't be possible). There are many, many faqr modern, fuel efficient types available than the F-27. Why are you even considering the type? May I ask what, where and by whom you are propossing this operation? ETA- AH! This is a Uni Project? Gotcha. Yes, it will still depend on the actual end-use of the aircraft as to how much modification is actually worth the cost- weight saving interior is easy, avionics less so, FBW- Forget it!! |
Thanks guys. I am tasked specifically with the avionics and control system if it's applicable. The materials, engines or any stability changes are not my job. But any specific avionics/ GPS you might suggest, I will have a look at. Is there any good place where I could find out the cost of second-hand units?
Three things come mind: Avionics ie GPS to allow direct instead of via airways, new interior using lighter materials to improve payload, and new engines with better efficiency. ETA- AH! This is a Uni Project? |
Is there a possibility to install some sort of FMC that would tailor all the a/p and throttle responses to a lower operating cost? Or am I talking out of my ass now... :rolleyes:
I'm guessing the F27 doesn't have any sort of FMC, so could this possibly be a good option to install one? But most importantly, is there any relatively easy formula to calculate DOC? I googled it but all the ones I have come across so far seem complex in that I wouldn't know the value of some of the variables. Is there a way of doing this without touching a complex equation? i.e just say that maintenance savings = something and more efficient operation can be estimated as = something, hence the saving over X amount of hours = something? Or is this a bit daft? |
I may be being simplistic here but, having flown the F27 and the Airbus family, we are talking apples and pears.
Savings on DOCs for an F27 cannot involve changing the basics of the thing - far, far too expensive to develop. Anyway, which F27 are we talking about; a basic one or a curly-prop one? You are down to crew costs (first option), airfield fees, fuel price and engineering costs. OK, you can mix these up with FOCs a bit but we're talking costs here. Will the local authority permit only one cabin-crew? I am assuming you have about 44 seats. What is the local equivalent of Eurocharges (ATC fees)? Any room there? It never ends... |
Actually, with modern electronics, something as simple as a class one EFB- nothing but a Windows lap-top and tailored software- could allow you to optimise feild calculations (including Flex thrust which has a substantial effect on DOC) and even do a good job of calculating optimum levels and speeds.
Add an RNAV approved GPS (Just a panel mounted GARMIN will do) and you have direct-to capability. Beyond that, I don't see what a G1000 panel would do for you- they are a great interface, but only give the same info analog instruments do in a nice, user freindly fashion, but at a high cost! If the exersize in purerly DOC without factoring ROI, I guess you might make a case for lower operating costs. Similarly, FBW improves handling and saftey, but not DOC unless the airframe is designed for it from inception (e.g reduced drag from relaxed stablility) so EVEN disregarding the prohibitive cost, I can't see that helping DOC. |
F27 revamp
Why not just get a Fokker 50?
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Wizofoz, ok I gocha. The FBW was just a "maybe". Its the avionics or any part of the intellectual brain of the a/c that is of interest to me.
Can you suggest anything besides a Garmin GPS unit and a laptop? Speaking of the laptop, I think we need to "modify" the a/c so I might have to stick an FMC unit into the aircraft or somehow make the laptop part of the flight deck... sort of what Airbus is doing. Is there anything I can do with the instruments? Even if not a G1000, some smaller King Air-style MFD units maybe? Would they lower maintenance costs? Vc10, because the project is to modify an F27, not an F50. There is nothing I can do about that. Personally I would much rather be modifying a 767 or an old 747 but I don't have a choice :ok: |
Ok - any limitation on where the aircraft must operate?
If you can accept daylight VMC only - take the aircraft off IFR capability and tear out all instruments but those required for day VFR. You have saved weight, mx cost and improved dispatch reliability tremendously. OK, you can only fly cargo in N Africa and the ME, but I bet your assignment didn't stipulate anything about that ;-) |
F8F – Forget all the Hollywood stuff such as FBW, A/T, FMC/FMS, etc. Ask your uni professors if they actually know anything about aviation and if they have any common sense! Tell them you cannot take a Ford Model T and convert it into a “would be” late model (2013) Mustang, or Prius.
The F27 was a very fine aircraft. If I had such an aircraft [project], time & money, here is what I would install (or something like): Dual Garmin G600 SVT (with synthetic vision – e.g., L3 IRIS or Max-Viz 1500, or Max-Viz 600) This would make a real cool flight deck and, I would fly the bird to the AirVenture!Dual GTN 750 (or one GTN 750 and one GTN 650) L3 TRILOGY ESI-2000 GWX 70 GTX 33ES GTS 8000 (TCAS II) or GTS 850 (TCAS I) Sandel ST3400 etc. But, most important is replacing the RR Dart engines with newer, quieter, easy to maintain and more fuel efficient turboprops. You will have to research which “today” turboprop make & model would be appropriate (and which shp is required). There are probably no STCs, therefore field approval F337s would have to be obtained. All this could probably be done with the FAA; but no chances with EASA! IMHO. Actually, I would try to get a FAA special airworthiness certificate - Experimental - Exhibition (or Research and Development in your case), no STCs required. Improving “DOC” of a F27 Friendship is a futile exercise, but again, you will have a real cool airplane, the envy of many museums. Good Luck, |
Perhaps the cheapest way of reducing the DOC of an aircraft is to operate EMPTY. You could even remove the seats, too !
I lack information on the effect that this would have on the F27. A ball park figure for a B707 was that each extra tonne used 30kg./hour, ie. on a 7 hour flight this one tonne would have used 210 kg. more fuel. To reduce the total cost, one airline was said to schedule flights to depart Base in the early evening - because otherwise ground staff would have to be paid overtime. Flight crew were not paid extra for night flying ! Can your F27 be operated at night to your destinations ? Night curfews may restrict some operations. Or can reduced landing fees be arranged at times when the traffic would otherwise be slack ? You could increase the profitable utilisation by keeping operating throughout the 24 hours. Passengers may be prepared to travel at 2am for a low enough fare. Passengers normally return. Freight tends to have a single flight, so a different return load ought to be found, if possible. Freight can be carried throughout the 24 hours. Not all freight comes under the traditional list of "Urgent, Fragile or Valuable". While a freight door can make turnarounds faster, I carried a lot of 40 gallon oil drums, which had been loaded through an ordinary passenger door, and some garden wheel barrows we carried 3000 nm.! There is a "Zero Distance Cost" to be considered, somewhere, ie. all those costs without actually moving the aircraft. LT |
Bearcat, regarding the GPS I certainly was *not* thinking about installing a G1000 nor anything else of that ilk. This is a transport category aircraft so approvals for changes can be expensive. Whatever GPS that supports datacard or USB upgrades (for cost effective database upgrades) that can gain installation approval. If GPS approaches are available in the region of operation then also a GPS that's approved for GPS approaches too.
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What is it uni wants? Isn't this more or less an exercise in defining and controlling DOC?
I mean... there is no universal definition of DOC so go ahead and decide that certification and everything that requires a one-time king-size payment is irrelevant to your definition of DOC. Then load your F27 with whatever equipment that has even a microscopic effect on DOC. |
Thanks a lot for the help and suggestions guys.
I know its very stupid that our assignment doesn't have a certain criteria for operations. In other words its presumed we can use the aircraft for whatever we want. So with each modification I could perhaps tailor it to a specific type of operation. i.e. for ferrying freight in Africa and no night capability etc. My bit in particular is to do with systems and avionics. Someone else is considering engines/ materials etc. I think I have a much clearer picture now of what I can do depending on the operating environment however I still find the available formulas for DOC calculation quite confusing. I can't find anything simple and straight forward that I we can use to calculate DOC but I guess that's the nature of DOC. |
i.e. freight in Africa and no night capability |
Ok I see :ok:
But given its all dirt strips I assume no need for IFR equipment? Just an iPad? And is there anything I could do with the landing gear to improve DOC? Or is it one of those things that is really pretty much the same now in the 21st century as it used to be in the 50s? |
no need for IFR equipment? |
PAX or freight ops? Does the aircraft fly a time-critical schedule to interface with a daily central package-sort schedule? If so, component reliability might be a major issue, so research in this arena might reveal weak points it its systems.
ABF was flying rehabbed DC-9s in such a operation and had an instrument failure at an outstation. They had to hire a LearJet to deliver a replacement. This was the incentive for them to investigate retrofitting DC-9s with glass cockpit - lower DOC plus reliability. Engine (maybe prop) upgrade could pay off too in fuel savings; Many carriers liked the CFM56 refit on the DC-8. The airframe had lots of structural life left, but needed modern engines. |
ABF was flying rehabbed DC-9s in such a operation and had an instrument failure at an outstation. They had to hire a LearJet to deliver a replacement. This was the incentive for them to investigate retrofitting DC-9s with glass cockpit - lower DOC plus reliability. |
Given the nature of the ABF operation - hub & spoke, daily pkg sorting window, timing is everything - reliability was a major issue. I am not sure if the glass cockpit would drop into the beancounters' DOC bin, but it was apparently a big issue for them. :=
To be honest, I do not know if it was finally adopted; I only know that they had one glass bird (20 yrs ago) flying with an Experimental tag. Even if it were an increased DOC, if it provided greater earnings (lower refund & reputation losses), it might have been seen as an worthwhile upgrade. |
Still haven't read the reason, the impetus for changing out the 'system'.
I saw a flight department close because the chief pilot took months to change a GNS XL to a UNS1. He said the GNS was 'dangerous'. Long before glass and GPS units, planes still went from Point A to B. Big surprise huh? This thread lives and dies in the world of people wanting new toys in the cockpit and having such a lack of situational awareness that the only way they can fly comfortably is by following a little white airplane on a screen. |
I need to improve the DOC of the Fokker F27 specifically in terms of the avionics and control system (if applicable). Searching google for an exact definition of aircraft DOC is proving a bit difficult as most sites just give some formula to calculate it but don't really mention anything specifically in terms of time-scales involved. A good start might be to establish, for typical F-27 operators, what proportion of DOCs is actually represented by maintenance. That will then give you a better idea of the maximum savings that maintainability improvements would produce, which you can then compare with the cost of any such changes. |
Bear,
WRT the laptop, simply make it an installed class 2 EFB and that should cover the "Modification" criteria. It could also cover a lot of the functions of an FMC at a much lower cost. |
You mentioned mods cannot be too expensive. Right at the beginning of your assignment it will be necessary to define the chosen F27 model and the limitations of your studies, as it does not sound like this has been done for you. If all those working on the project could agree on a common philosophy, it would be a tiny bit more like the real world where there would be an overall project manager for such considerations.
You might just need to show innovative thought, not just a rehash of what some VIP operator did to one aircraft 20 years ago. F27 had water injection available for take-off. This provided a respectable amount of extra power for more difficult conditions or for high weight take-off. If these conditions did not exist, water injection is not needed, meaning there was less power and quite a bit less wear on the engine. Reduced wear is a DOC advantage. That is an existing procedure, but could be further refined by "reduced thrust take-off", common on modern jets. Using a Dry Take-off with further reduction in power would further reduce engine wear. A laptop (avionics) program for each planned airfield could provide the further refined take-off power settings. You would need to co-operate with those who are responsible for engines. Maybe such co-operation is an intended feature of your studies? Improved navigation would be relatively inexpensive. Even the type of GPS fitted to light aircraft would be usefull. One navigation advantage is more direct tracking can be authorised by ATC with this equipment. A less obvious advantage is that fast and accurate recording of head and tailwinds can help in selection of efficient flight levels. Lower cruising levels are less efficient, but if there is a tailwind at 10000 ft and a 50 knot headwind at 20000 ft, a lower level should be considered to save time and therefore fuel. Again, co-operation with those responsible for operating procedure DOC would be essential. Some older electronics might be expensive to maintain. Over a few years, a modern full or partial suite of communication and navigation gear might reduce DOC. I cannot think of any practical thing that could be done with flight controls. Closest would be a modern autopilot. Expensive to fit, but might also be less expensive to maintain. There would be obvious certification problems that might be very costly. Rather than just not mention controls, there would be scope in your studies to list modifications that were considered but rejected. |
Still haven't read the reason, the impetus for changing out the 'system'. I saw a flight department close because the chief pilot took months to change a GNS XL to a UNS1. He said the GNS was 'dangerous'. Long before glass and GPS units, planes still went from Point A to B. Big surprise huh? This thread lives and dies in the world of people wanting new toys in the cockpit and having such a lack of situational awareness that the only way they can fly comfortably is by following a little white airplane on a screen. You appear to be considering operating costs purely in terms of maintenance cost, whereas that only accounts for a proportion of DOCs. A good start might be to establish, for typical F-27 operators, what proportion of DOCs is actually represented by maintenance. That will then give you a better idea of the maximum savings that maintainability improvements would produce, which you can then compare with the cost of any such changes. My biggest problem is the "fuel" part of the formula. The calculation for this is extremely complex with variables I simply can not fimd out from the public domain so I have no idea how to apply the formula or if I can just use verbal reasoning with respect to a fuel saving for a system. WRT the laptop, simply make it an installed class 2 EFB and that should cover the "Modification" criteria. It could also cover a lot of the functions of an FMC at a much lower cost. You mentioned mods cannot be too expensive. Right at the beginning of your assignment it will be necessary to define the chosen F27 model and the limitations of your studies, as it does not sound like this has been done for you. If all those working on the project could agree on a commom philosophy, it would be a tiny bit more like the real world where there would be an overall project manager for such considerations. You might just need to show innovative thought, not just a rehash of what some VIP operator did to one aircraft 20 years ago. F27 had water injection available for take-off. This provided a respectable amount of extra power for more difficult conditions or for high weight take-off. If these conditions did not exist, water injection is not needed, meaning there was less power and quite a bit less wear on the engine. Reduced wear is a DOC advantage. That is an existing procedure, but could be further refined by "reduced thrust take-off", common on modern jets. Using a Dry Take-off with further reduction in power would further reduce engine wear. A laptop (avionics) program for each planned airfield could provide the further refined take-off power settings. You would need to co-operate with those who are responsible for engines. Maybe such co-operation is an intended feature of your studies? Improved navigation would be relatively inexpensive. Even the type of GPS fitted to light aircraft would be usefull. One navigation advantage is more direct tracking can be authorised by ATC with this equipment. A less obvious advantage is that fast and accurate recording of head and tailwinds can help in selection of efficient flight levels. Lower cruising levels are less efficient, but if there is a tailwind at 10000 ft and a 50 knot headwind at 20000 ft, a lower level should be considered to save time and therefore fuel. Again, co-operation with those responsible for operating procedure DOC would be essential. Some older electronics might be expensive to maintain. Over a few years, a modern full or partial suite of communication and navigation gear might reduce DOC. I cannot think of any practical thing that could be done with flight controls. Closest would be a modern autopilot. Expensive to fit, but might also be less expensive to maintain. There would be obvious certification problems that might be very costly. Rather than just not mention controls, there would be scope in your studies to list modifications that were considered but rejected. |
Blogname: Long before glass and GPS units, planes still went from Point A to B. Big surprise huh? F8F ... speaking of the a/p, could it be removed altogether to save weight? ... fly happily without a/p The real problem with old, obsolete avionics such as the systems you find in a F27 is that they will probably not work for very long, if they do work at all in the first place. The avionics in F27s date from the 1950s (and up to the early 1980s for late models), they cannot be repaired and it is [almost] impossible to find spare parts. Reason why you need entirely new, modern day IFR avionics suite (which, incidentally, are also lighter in weight and offer much more functionality, redundancy and safety). EFBs (and other gizmos such as iPad, etc.) do not replace panel mounted avionic systems, they are merely tools to improve productivity to some degree within large airlines with large number of flight crew members and well established SOPs. Some airlines use them as an approved way (approved case by case) to store and replace paper documents such as instrument approach plates, airport taxiway diagrams, aircraft POH, MEL, company OPS manuals, etc. EFBs are never approved for navigation, they are usually assigned to a flight crew member, not to the aircraft (NB: if you employ a large number of flight crew members, savings can be substantial). They are not essential in your case, with just one aircraft, just a distraction, IMHO. Not sure if you have looked into the Garmin suites I mentioned in an earlier post, here are some pics of older turboprops after "affordable" avionics upgrade and, an interesting G1000 video. Glass panel, airport taxiway diagrams and more. http://kingair.org/wp-content/upload...37-500x375.jpg http://www.bartintl.com/sites/defaul...ines/01_48.jpg http://www.beechtalk.com/forums/down...e.php?id=29876 Total installed cost less than 200K USD (no A/P included). Total installed cost slightly more than 300K USD (fully integrated GFC700 A/P included) |
As you work through the problem, one aspect you will confront is this: "Is the problem adequately specific? Are there enough constraints to determine if a given 'solution' is appropriate?" Anticipated service life of the mod(s) is an example, in which case you could calculate a break-even point where the mod has its initial cost covered and begins to pay off.
OTOH the problem can be OVERSPECIFIED - one constraint conflicting with another. := In either case, point this out to the instructor - backed up of course with an example or two. |
avionmc, thanks for the opinion, much appreciate it. WRT to EFBs I honestly think its rude not to include one. In the worst case scenario, an iPad can be considered a Class 2 EFB. Although I'm unsure if an iPad can be loaded with the required software for takeoff thrust calculations etc. Maybe it can? If not, I am keen on finding some affordable EFBs as it sounds like it's a pretty easy way to improve engine wear and tear, fuel burn and reduce weight.
With that said, I do very much appreciate the need for a new instrument panel. That King Air pit looks great, which brings me onto the next point where I'm struggling: Is there a place online that I could find out some of the costs associated with these bits of equipment? i.e. new GPS, avionics suite, EFBs etc? Ideally I would also need to work out the depreciation cost and maintenance cost of the unit for DOCsys calculations. But even just the starting cost of buying one of these either new or 2nd hand would be great. P.S. Whats the reason for having 2 (identical?) GPS units like in the King Air cockpit above? And also, which GPS's support direct routing? All of them? |
Cost definition
I think I have a much clearer picture now of what I can do depending on the operating environment however I still find the available formulas for DOC calculation quite confusing. I can't find anything simple and straight forward that I we can use to calculate DOC but I guess that's the nature of DOC. DOC normally consists of four major cost categories ie. crew cost, fuel and oil cost, depreciation cost (including insurance cost) and maintenance cost. In your case it might be more transparent to apply the LCC(Life Cycle Cost, the total cost incurred by an item along its entire life / life cycle)concept,instead of the standard Cost Benefit Analysis (CBA) methods. the research is focused on aircraft maintenance and engineering, as the main subject !!! From LCC point of view, all cost categories resulting from aircraft acquisition and exploitation are included in the LCC, only two cost categories are excluded : Ticketing/Sales/Promotion and General Administration cost !!! |
Would something like this dual display pay for itself in a year of operation by saving on maintenance costs associated with the original 1950s avionics of the F27?
Garmin G3X System Dual Display So this G3X is £6594. Sounds pretty expensive. Is there any cheaper 2nd hand units such as this? The thing I don't know is actually how much it costs to maintain the original avionics of the F27 in the 1st place. Any guesses on that? Pretty impossible to find such figures online. DOC is per definition operating costs which are directly attributable to the aircraft being operated. The rest are IOC(Indirect Operating Cost), DOC+IOC= TOC (Total Operating Cost) DOC normally consists of four major cost categories ie. crew cost, fuel and oil cost, depreciation cost (including insurance cost) and maintenance cost. In your case it might be more transparent to apply the LCC(Life Cycle Cost, the total cost incurred by an item along its entire life / life cycle)concept,instead of the standard Cost Benefit Analysis (CBA) methods. the research is focused on aircraft maintenance and engineering, as the main subject !!! From LCC point of view, all cost categories resulting from aircraft acquisition and exploitation are included in the LCC, only two cost categories are excluded : Ticketing/Sales/Promotion and General Administration cost !!! We were told as part of the assignment that mods have to pay for themselves within a year or so. |
DOC
The DOCsys formula (for aircraft) has 3 major components. Depreciation + Fuel burn + Maintenance. In the real world, it looks more like that......... Method for Calculating Direct Operating Cost The following is an estimation method known as DOC+I (Direct operating cost plus interest). This method is based on the work of Liebeck and has been applied by Ross for wide body commercial aircraft. By definition the DOC+I method takes into account the following operating expenditures; flight & cabin crew cost, airframe maintenance, engine maintenance, landing fees, depreciation, interest, and insurance. Flight Crew & Cabin Crew The flight deck and cabin crew cost are all based on Block Hours (BH), which is equivalent to the number of trips per multiplied by the average flight time per trip. For the flight crew there salary is a function of the maximum takeoff weight of the aircraft as seen in Equation 1. The flight attendants or cabin crew cost is based on an assumed pay rate of 60 dollars per hour. (# ) (440 0.532*( /1000) gross Flight Crew = BH × of flight crew × + W (Eq. 1) Cabin Crew = BH ×(#of flight crew)×60 (Eq. 2) Airframe Maintenance Cost of airframe maintenance is broken down into three parts; labor, materials, and burden or the cost of taking the aircraft out of operation. Airframe Maintenance Labor: Notice that for both the labor and material cost, are based on a historical curve fit developed by Liebeck and are dependent of the number of trips per year, average trip time and the airframe weight. Landing Fee The landing fee is based on the operational empty weight of the aircraft and an average of landing fees in the United States. They may heavily vary in Europe, with possible additional fees such as NOX emissions or community noise. However this is not captured in this method. Depreciation, Interest & Insurance For all of the following methods the total airframe cost must be known, which can be found using methods found in Raymer. Notice that all of the following equations are dependent on gross weight that will be found by your sizing code. Depreciation (1 residual ) Airframe Cost Airframe Spares Airframe Cost Engine Spares Airframe Cost For the interest calculation it is ok to set the future value of the aircraft to zero since it is difficult to predict this value, especially at the very early stages of preliminary design. Finally, from all of these the total direct operating cost of a commercial transport can be found: DOC = Flight Crew + Cabin Crew + Airframe Maintenance + Engine Maintenance +Depreciation + Insurance + Interest |
Bearcat, You seem to be on a steep learning curve here on pprune, so it seems like you came to the right place.
Reading between the lines, I think the details of your set F27 project are a bit thin. For instance, is your F27 a clapped out piece of s*** that has had a hard life in some aviation backwoods, or is it a VIP aircraft with low hours and no expense spared sourcing a collection of unused or expertly overhauled avionics spares that came with the aircraft? Your class colleages would be interested to know if it was fitted with low time engines and props and who completed the last major service and when. In the absense of such information, you might need to make a formal assumption about the state of the aircraft and spares. |
Stallfail
That is the biggest amount of academic bull!!!! that I've heard in my 40 years in the industry. Only the Lufthansa Cost Method was as ridiculous.
AIRLINES DON'T HAVE "METHODS" THEY HAVE CASH IN AND CASH OUT. Bearcat F8F: Concentrate on cash, cash, cash, not formulae. Cash in vs cash out is what matters. Forget classic DOC methods which include depreciation. Depreciation is not a cost. That's just accountant's mumbo-jumbo. Think about what you could take to the bank (or out). If the changes don't pay off in a year or two your airline could be bust. Stallfail: what the fuk has cabin crew cost got to do with the problem in hand? Bearcat has to concentrate on the changes, not worry about what stays the same. Luckily academics don't run airlines. At least not successful ones. P.S. Bearcat: JUST CONCENTRATE ON WHICH COSTS CHANGE, BEFORE vs AFTER. DON'T TRY TO LIST ALL DOC ITEMS. ITS POINTLESS. You've been given a task unrelated to the real world. You have to do it, but remember the tosser's name for future reference! |
toffeez, Yes, completely agree. I am concentrating on the costs involved in the difference between initial purchase cost + maintenance Vs how much it saves. These DOC formulas are driving me mad. We were not given any realistic data to start with so there is no way on Earth any student could get access to all the costs associated with a F27! so yes, I'm doing exactly what you have suggested.
autoflight, Thanks. I would be quite interested in finding out more relevant equipment for the a/c though. What is the cheapest useful GPS taht I can get for example? And I can not find a good classifieds website to see listings of 2nd hand units so struggling to find out how much these units cost to buy and maintain and install. Any help appreciated. |
Aircraft modification such as flight control and engine retrofits etc unless they are an existing mod are going to cost too much to consider for any normal size operator. So other than removing anything you don't need, to save weight, there is little you can do on this front.
Avionics mods can save you three thing: maintenance costs, weight, and time (direct tracking and lower minimas so less holding or diversions). The equipment in an original F27 will be pretty old and hard to maintain and weighs lots. Wholesale replacement of avionics is expensive but if you can't maintain it the opportunity costs from missed flights could cover the high cost. If the aircraft has supportable avionics keep what you can and go simple. Integration costs can be very high so adding a stand alone GPS will be better value than trying to fit a fully integrated solution. . Best bang for buck is likely to be dual TSO C145 or 146 GPS and remove the ADF(s). 145/146 allows you to use the GPS as your only destination nav aid which means you can get into more places more often. The ADF then becomes superfluous. Removing it saves you maintenance costs and weight. |
Not sure when your assignment is due but if its after Avalon and you can get yourself along to a trade day there will be lots of component companies there who can give you rough order of magnitude costs.
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Avalon in the UK? Afraid its a bit far for me to go just for a university project. Thanks for the suggestion though.
Is there no good websites where they sell used 2nd hand avionics? All the websites that I come across are limited in the amount of equipment they sell or they don't have a price tag online. |
Aircraft modification such as flight control and engine retrofits etc unless they are an existing mod are going to cost too much to consider for any normal size operator. So other than removing anything you don't need, to save weight, there is little you can do on this front. Avionics mods can save you three thing: maintenance costs, weight, and time (direct tracking and lower minimas so less holding or diversions). The equipment in an original F27 will be pretty old and hard to maintain and weighs lots. Wholesale replacement of avionics is expensive but if you can't maintain it the opportunity costs from missed flights could cover the high cost. If the aircraft has supportable avionics keep what you can and go simple. Integration costs can be very high so adding a stand alone GPS will be better value than trying to fit a fully integrated solution. . Best bang for buck is likely to be dual TSO C145 or 146 GPS and remove the ADF(s). 145/146 allows you to use the GPS as your only destination nav aid which means you can get into more places more often. The ADF then becomes superfluous. Removing it saves you maintenance costs and weight. |
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