Improving Direct Operating Cost (DOC) help please

[Bearcat F8F]

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

[Linktrained]

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

[Tinstaafl]

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.

[Wizofoz]

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!!

[Bearcat F8F]

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.

So are you saying its better to stick with just the addition of a GPS unit Vs a G1000 suite or something along those lines? I wish I could figure out how much in maintenance this could save But good thinking on flying direct. Is this generally allowed in the real world? I am not IFR rated so possess limited knowledge.

ETA- AH! This is a Uni Project?

Yes, correct. Which is why I said its a stupid idea but nonetheless I have to do it lol

[Bearcat F8F]

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...

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?

[fantom]

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...

[Wizofoz]

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.

[Vc10Tail]

F27 revamp

Why not just get a Fokker 50?

[Bearcat F8F]

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

[Empty Cruise]

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 ;-)

[avionimc]

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)
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.

This would make a real cool flight deck and, I would fly the bird to the AirVenture!

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,

[Linktrained]

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

[Tinstaafl]

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.

[dusk2dawn]

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.

[Bearcat F8F]

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.

[avionimc]

i.e. freight in Africa and no night capability

Usually freight is flown at night, even in Africa. And, night capability is not expensive, basically only a few light bulbs.

[Bearcat F8F]

Ok I see

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?

[avionimc]

no need for IFR equipment?

YES, you do need the aircraft to be fully IFR capable (in Africa, and anywhere else for that matter)! And that too, is not a big deal, nor is it expensive, compared to being unable to dispatch the aircraft in marginal [VFR] WX, or compared to the cost of fuel burn of such aircraft. Also, many regulators mandate the aircraft to be IFR, and the pilots to be instrument rated, to operate VFR at night. NB: Only small private recreational aircraft such as LSA are strictly VFR.

[barit1]

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.