Purchasing ex training aircraft

[skippydiesel]

What, if any, devaluation would you put on an aircraft that has been used for training ?

 

I would assume greater wear/tear on almost all components due to:

More frequent cycles (engine start - climb (heating) - decent (cooling) TO/Landing, etc

Inexperienced handling - undercarriage (landings) taxi, (brakes and landing long).

ETC

[facthunter]

More so if they are aerobatic They have a reduced service life and some spars are "lifed". Aluminium alloys "fatigue" and I don't know any way of determining the level of fatigue without strength testing and that's not very useful for small component in larger assemblies..Fatigue tests of whole aircraft are costly. Australia did the test of the Mirage fighter which is essentially a lot of highload reversed cycles. Nev

[Kenlsa]

We have had a number of Jabs over the last 22 years for training, with at least one sold at 3000hrs (4 engines from memory, it was an early SK with every iteration of the Gen 1 ever made) and one other near that as well. But most are sold 1-2k hrs.

All are still flying.

We ensure that it has 3-400hrs still left on the engine and the airframe is is sound order, though the paint may look a little tired. ASC has enjoyed a close working relationship with the factory and have been used for beta testing from time to time.

Our club of 300 members looks after our a/c and we fly them non stop and don't sit around "rusting" away.

I would not hesitate to look at a club plane for purchase.

BTW - glass is very forgiving in an airframe.

Ken

[facthunter]

Probably the easiest of all structures to live with that you are likely to find in a plane. Nev

[Flightrite]

If you have a choice buy an airframe that's not been used for training or that has a documented accident history, both reduce their value.

[skippydiesel]

Thanks all BUT by how much as a % would you expect to pay for an ex trainer, on its first engine, that is about 1/2 TBO ????

[cscotthendry]

Skippy:

I think you need a lot more info than that.

1) How has it been maintained? Sure, training aircraft have to be L2 maintained, but there are L2s and there are L2s, if you know what I mean. The appearance of the aircraft, especially under the cowlings will tell you something about this.

2) Was it hangared or left outside? What shape is the paintwork and the glareshield top in? Is there any evidence of corrosion? How do the windows, especially the windscreen look? Scratches? Discoloration? Cracks etc?

3) What is the general condition of the interior?

4) How does the engine run? Does it use oil? What condition is the prop in WRT scratches, chips etc. Has the prop been repaired for stone chips? Has the aircraft ever had a prop strike?

I could go on pretty much all day with this, but I think you get the drift by now.

If you know a good L2 who hasn't been involved with the maintenance of the aircraft, get them to do a pre-purchase inspection and report. Then if it's a common aircraft like a Jab or a Tecnam (which most school aircraft are) have a look online to get a feel for the value of the aircraft. Then armed with the report, start negotiating with the seller.

The short answer is: there's no formula for discounting a used aircraft.

The right price is what the seller and the buyer agree on.

[BreezyLog]

Hi Skippy, cscotthendry is well on the right track.

Skippy:

I think you need a lot more info than that.

1) How has it been maintained? Sure, training aircraft have to be L2 maintained, but there are L2s and there are L2s, if you know what I mean. The appearance of the aircraft, especially under the cowlings will tell you something about this.

2) Was it hangared or left outside? What shape is the paintwork and the glareshield top in? Is there any evidence of corrosion? How do the windows, especially the windscreen look? Scratches? Discoloration? Cracks etc?

3) What is the general condition of the interior?

4) How does the engine run? Does it use oil? What condition is the prop in WRT scratches, chips etc. Has the prop been repaired for stone chips? Has the aircraft ever had a prop strike?

I could go on pretty much all day with this, but I think you get the drift by now.

If you know a good L2 who hasn't been involved with the maintenance of the aircraft, get them to do a pre-purchase inspection and report. Then if it's a common aircraft like a Jab or a Tecnam (which most school aircraft are) have a look online to get a feel for the value of the aircraft. Then armed with the report, start negotiating with the seller.

The short answer is: there's no formula for discounting a used aircraft.

The right price is what the seller and the buyer agree on.

The purpose of an aircraft maintenance schedule is to keep the aircraft in an "Airworthy Condition". What this means is that you will most likely never keep the aircraft in the condition it was the day it was built because of the aging process, coupled with normal wear and tear, accidents and incidents and the last is the owners attitude towards airworthiness. Lets look at these parts briefly.

 

AGING AIRCRAFT.

 

Since manufacture everything on this planet ages. Aircraft are no different. The Cessna SIDS program is one manufacturers process to help owners maintain airworthiness to address aging. CASA has some good information and some videos and DVDs on the subject. Look at your prospective purchase and check nuts, bolts, brackets and areas where water will accumulate after flight and check for corrosion or deformation. Types of corrosion will differ between the aircraft construction type. Composite aircraft fatigue different to Metal, which are different to wood, which are different to fabric. Check the Aircraft Maintenance Manual for any recommended Corrosion Protection or Inspection System. If there is not one, read AC43-13 about this subject.

 

NORMAL WEAR & TEAR

 

What the title says. The manufacturers aircraft maintenance schedule SHOULD provide a "Life Limit" or "Overhaul/Service Schedule" for individual parts that "WEAR". They typically wont do it for the carpet or the head liner or the windows but may provide limitations on parts of the aircraft that, If they fail, can place the aircraft in an "Un-Airworthy State". Items such as Fuel pumps, Engines, Propellers, Wing Attaching bolts and fitting on Aerobatic aircraft as given in the example used by Facthunter. Look at the ROTAX 5 Year Rubber Life requirement. Classic example.

 

Other parts or systems may not be listed in the AMM and are required by Legislation, such as CAO100.5 system checks. Does your Pitot/Static system work correctly, is your Transponder System calibrated correctly and so on. Also, associated are Airworthiness Directives and RAAus AN's. These mandatory requirements are derrived due to past accidents and incident and are there to help you maintain your aircraft in an "AIRWORTHY STATE".

 

ACCIDENT & INCIDENTS

 

If the aircraft has been damaged, then it needs to be repaired IAW (in accordance with) "Approved or Acceptable Data:. These should be recorded in the aircraft records.

 

OWNERS ATTITUDE

 

Like buying a used car, you can tell pretty quick if the owner has maintained their aircraft appropriately. Some people are anal and do things correctly (some to extreme and they do almost resemble the new aircraft) and some wont spend 5cents on their aircraft. Seen both and it shows.

 

OVERVIEW

 

I would think that a reputable flying school would have well maintained aircraft that keep them in an "AIRWORTHY STATE". Do your homework, download the prospective AMM (Aircraft Maintenance Manual) and get yourself a list of all the tasks associated with the aircraft, research AD,s AN,s and Service Bulletins for Aircraft, Engine, Propeller and installed components by the individual serial number. THEN, check the aircraft records. I mean REALLY checkout the aircraft records. Ask for a "Maintenance Run-out Sheet or Maintenance Due List" to find out when all the aircraft maintenance was last done, who it was done by and how long is remaining for each task.

 

The only thing I will suggest is DO get a Pre-Purchase Inspection. A proper one. DO NOT get the maintainer who has looked after the aircraft for the last 10years. He will be "Too Familiar" with the aircraft.

 

I have attached an article I wrote many years ago and it is still relevant. If you would like help, contact us as we can do the complete Maintenance Requirement list for you based on the aircraft and component serial numbers you provide.

BUYING A PLANE ARTICLE.pdf

[skippydiesel]

Great article Breezylog and you make many good points about purchasing an aircraft

BUT

again I think you miss the point of my question.

Its not so much about the pitfalls & shonky vendors, more about two theoretical aircraft - same make/model/ type, calendar age, engine hours - one has been used exclusive for private flying - the other for instruction and hire. They have both been maintained "by the book" have nil accident records, look equally great.

The number of TO/ landing cycles, for the latter, very much greater than for the privately used aircraft, possibly subject to rough handling (stress on landing gear ) and wear on engine due to many more starts, climb/descent cycles..

 

This question is about how much (if at all) you would mark down/devalue the training aircraft ,purely because of the type of work it has been performing.

[Flightrite]

Great article Breezylog and you make many good points about purchasing an aircraft

BUT

again I think you miss the point of my question.

Its not so much about the pitfalls & shonky vendors, more about two theoretical aircraft - same make/model/ type, calendar age, engine hours - one has been used exclusive for private flying - the other for instruction and hire. They have both been maintained "by the book" have nil accident records, look equally great.

The number of TO/ landing cycles, for the latter, very much greater than for the privately used aircraft, possibly subject to rough handling (stress on landing gear ) and wear on engine due to many more starts, climb/descent cycles..

 

This question is about how much (if at all) you would mark down/devalue the training aircraft ,purely because of the type of work it has been performing.

 

Nobody can give an answer there's no base, book, list or previous comparisons from which to work from?

You will have to draw from your own conclusions and gut feelings.

[BreezyLog]

Flightrite is correct. Its like buying a used car. High hours and hi useage is always a consideration, however if I maintain the aircraft IAW the maintenance schedule, and have a good attitude towards airworthiness, then all aircraft should be as "Airworthy" as each other regardless of their age. Try this process. Years ago there was an auction and part of the auction was an old Piper Pacer. It needed recovering and a new engine. The instrumentation was typical of the era and the interior was fair. I started looking at what the average price of similar aircraft were and then discounted an engine overhaul or replacement and the expected cost of a recover. The figure I arrived at was $5K. At auction, the bidding started on this "LOT" at $20 and it climbed up to......You guessed it..$5 and stopped dead. Everyone did the same math. (I dont know who bought it but thats the process. YOU have to determine what you are prepared to pay for it and the seller has to be prepared to let it go for that. Please do NOT forget to ensure "Airworthiness. Goodluck

[Bruce Tuncks]

Airframe life can have a big effect. My club here at Gawler had to write off 2 Grob Twins because they got to the 12,000 hour "life "of the airframe.

The 12,000 hour was complete nonsense but it was the law of the land. We maybe could have paid for an extension, but it was decided that this would not be profitable.

The science is that glass does not fatigue. But the law is not based on science.

I do not think that Jabiru's have a fatigue life, but metal aircraft sure do. The whole fatigue life thing for gliders started when an old Blanik had a problem in Europe. It was found that Blaniks had a fatigue life of 3000 hours.

[facthunter]

Not ALL hours are equal. The situations they are subject to vary. Aerobatic hours count for much more than normal hours. You could also overstress a new airframe. and make it useless except for a pole mounted exhibit. Nev

[Nico13]

More so if they are aerobatic They have a reduced service life and some spars are "lifed". Aluminium alloys "fatigue" and I don't know any way of determining the level of fatigue without strength testing and that's not very useful for small component in larger assemblies..Fatigue tests of whole aircraft are costly. Australia did the test of the Mirage fighter which is essentially a lot of highload reversed cycles. Nev

Funny you should mention the Mirage Nev, finding cracks and evaluating the repairs in the Mirage was my job for a number of years at GAF Avalon.

It was the ones in the main spar that slowed them up and basically turned a fighter jet into a taxi for the boss to fly around as the worst of them were limited to 3G

The best ten years of work I had I reckon working on the jets.

But yes the same things happen to the smaller lighter machines with a lot of hard work in some cases. How long has it been a flying school plane and who serviced it are questions to ask I guess.

[Steve L]

My Bulldog has a fatigue life with an index of 114 which is calculated annually from 8 individual windows displayed on an installed fatigue meter. I sent the readings every year to De Havilland UK, they then calculated the remaining airframe life. I purchased the Bulldog 2012 with 85.4 on the index, it now only has 86.7 in 8 years flying with occasional aeros. One year when de Havs received the calcs they called me and told me go fly and chuck it around as the calcs hadn’t changed since last year. I did and that re affirmed them the meter is still working, went on accusing me of flying like a granny :yikes:Anyway point of my post is, don’t be deferred with an ex military aircraft with a fatigue meter, it’s still possible to get a lot of remaining life.

[Bruce Tuncks]

I'm sure that none of us would lie about the hours, but it has been known to happen.

[Kenlsa]

Steve, any pics of your Bulldog in its new life "back home"? Ken

[facthunter]

IF you find yourself flying any plane that is used so much it's the oldest or highest hours plane of that type you are a TEST pilot. Many planes have extensive cracks they just keep an eye on. Eventually ALL planes reach a point where they cannot continue to fly except in some 3rd world counties( mainly in the past.) Aluminium and it's alloys are not as resistant to fatigue as some other metals are, but they are light.. Planes are built as light as is safely possible, but this very fact means it has a very finite life and an ultimate FAIL load. An OLDER airframe must have a reduced ultimate load factor due to fatigue. It may also have undetected cracks or Corrosion further affecting it's strength.. Inspections are devised in the light of experience to keep an eye on "known" suspect sites. This keeps older planes more safe as the AD's etc check known weak points. Not the "as yet undetected" ones. Nev

[Steve L]

I’ll have to ask Neil for some as I’m sure it’s flying again. I get the sads on whenever I think of it, would be even worse

seeing pictures. I think myself fortunate to have owned the Bulldog for 9 years. Im looking forward to RA- AUS now.

[skippydiesel]

COMPOSITE ! the way to go especially if combined with the original WOOD - Laugh at corrosion. Laugh at metal fatigue. Lower cockpit noise. Great for compound curves. Very very low maintenance requirement. Whats not to like? Sure it has its own issues but almost nothing compared with metal.

[old man emu]

Here's one bloke's story based on his own purchase;

https://www.youtube.com/watch?v=BxAlnPDi-xs:597

[facthunter]

There's metal and there's metal. A .015' skin won't have a very good rivet outcome without bonding to help transmit loads. In hard working aircraft a tube steel fuselage is easy to live with. What life do you expect.? Ease of inspection and repair is important also. The basic Taylorcraft /Auster can be kept going forever.. For anyone who wants a minimum care and attention situation the Jabiru airframe is sturdy and affordable and easy repaired.. Composite seem to be a Euro situation and aimed at the high cost end of the market and have the potential to be more efficient and lower weight. Nev

[Flightrite]

I'll take metal any day. Easy to repair, shows any structual issues easily, easy to work with?

[skippydiesel]

I'll take metal any day. Easy to repair, shows any structual issues easily, easy to work with?

 

Naturally I have a different view -Nil structural issues, Easy to repair. No brainier to work with.