Why does the PA-38 Tomahawk have a wing life of 11,000 hours?

[RTN11]

I've got a fair bit of time in Tomahawks, and love them. They're a great trainer, and a reasonable touring aircraft.

I've never had a proper answer from anyone as to why the wings are lifed at 11,000 hours, when I can't find another aircraft anywhere that has a similar restriction. Does anyone know why Piper decided on this restriction?

[ferrydude]

Can't find another aircraft with a similar restriction? Cirrus aircraft are Airframe life limited at 12000 hours. The PA-44 wing is life limited at 14, 663 hours. There are many other examples. ;)

[RTN11]

Are these structural limits arrived at as the result of tests, or simply plucked from the air by the legal team?

[Genghis the Engineer]

Many aeroplanes have big bits of structure lifed like that. The Twin Otter mainplane is another such example, so are many of the wing tubes in the Pegasus flexwings.

In a nutshell, the design and manufacture ensure a maximum size of flaw in the wing structure. It's then worked out the number of hours at a representative operating regime it would take for any of these flaws to turn into a critical and endangering crack.

This number of hours is then divided by a safety factor - typically around 3, to allow for errors in calculation or manufacture.

And this is then the maximum hours that the component is lifed to.

It makes a lot of sense in terms of long term economics, just frustrating if you find yourself owner of a late-in-life aeroplane.

G

[Big Pistons Forever]

The rules under which aircraft are certified evolve over time. The simple Cessna singles are all certified under the old CAR3 rules dating back to the 1950's, which did not require establishing life limits and grandfathered onto todays Part 23 regulations. The Traumahawk was certified as a new design under the rules that has been updated in the mid 1970's. One of the updates was requiring airframe life limits. I think Piper simply did not want to spend the money to do the required engineering work and testing to go past 11,000 hours.

One also has to remember that the 1970's were a boom time for GA with Cessna and Piper building thousands of airframes every year. Schools would routinely use a trainer for a couple of years and then replace it with a new one, so 11,000 hours probably seemed like plenty. I don't think that even in their wildest dreams, did the light plane designers of that era think that you would routinely see trainers still on the line that were 35 + years old with flight times in over 10 K hours. The highest time C 152 I know of has 24 K + total time, all as an ab inito trainer, and is still working every day

[ferrydude]

It is a conservative calculation for the purposes of meeting the certification criteria in lieu of actual testing. By the way, there is an FAA STC available for wing life service extension.

[Jim59]

Even gliders have airframe lives.

A Discus is initially 6,000 hrs, an inspection at that point raises it to 9,000. Further inspections at 10,000 and 11,000 hrs and then buy a new one at 12,000 hrs. That's a plastic airframe - mainly carbon.

Most Blaniks are now grounded (metal airframe) if over something like 3000 hours due fatigue problems in main spar. A mod exists to extend life - but costs more than the gliders are worth.

[A and C]

There is a life extension program for the PA38 that involves some wing modification, I think that this would be an option if Piper supported the aircraft in terms of parts. Five or so years back I was looking at buying two PA38's as they were cheap and then doing the life extension work. What did for the deal was the spake parts situation not the modification work.

The Buldog is another aircraft with an airframe life issue hanging over its head with the RAF getting withdrawing the aircraft from service because of the cost of doing the life extension work that BAe had proposed. As always BAe had gold plated the contract and pitched it at just under the cost of buying new aircraft. The RAF found a cheaper way of financing new aircraft and ditched the Buldog.

Buldog owners are now facing the choice of a very expensive modification or scrapping the aircraft if they get the work done individually, the last time I looked at the issue the problem was the cost of setting up the manufacture of the spar bolts, if all the Buldog owners got together they could drive the unit costs of the bolts down to something reasonable and each of them have a set of bolts ready for the day when the aircraft needs the work doing.

Things on the Buldog front may well have moved on in the last few weeks with the change in status of DH support and the chance to put the Buldog on a permit to fly, however I doubt if the cracks radiating from the spar bolts understand the difference certification management and are likely to grow at the same rate making the modification mandatory who ever provides the paperwork.

[peterh337]

Haven't Piper recently sold their spares operation? I vaguely recall reading something about that.

Can't be much left of Piper, without the parts business. Just the odd few Meridians, Malibus, Matrixes, miniscule numbers of PA28s...

['Chuffer' Dandridge]

Last time I flew a PA38, I was not impressed at how flimsy it all was... Like it was made out of the thinnest Alu they could get away with? Maybe the wings just fall apart after a few thousand hours..:E

[John Miller]

Rockwell 112s and 114 also have wing life issues. ;)

[A and C]

Take a look at the Sport cruiser it makes the PA38 look like a battleship !

[Pilot DAR]

I'm not quick to second guess experienced structural designers as to their choice in aluminum thickness. Indeed, ad good resign can be made bad by going one gauge thicker. There are many cases where the gauge of aluminum chosen for a skin, is more based in it's need to be stiff for ground handling loads (people leaning, and bumping things against the fuselage), rather that flight loads.

Consider the venerable, and arguably heavily built Cessna 206. Some of the fuselage skins are only .016" thick. You don't hear people saying that 206's are flimsy....

Similarly, those "well built" Rockwells, have have aileron skins, which are surprisingly thin, but it's what the plane needs to do the job, and be balancable. Just watch out for hanger rash!

The Twin Otter is one of many mid sized aircraft which have life limits imposed. deHavilland in the day, really was not expecting those aircraft to make it through to the limits, but imposed them, and the aircraft was largely intended as a military design. Most common is a 33,000 hour and 66,000 [landing] cycle service limit, though certain conditions could increase or decrease these values per aircraft. I believe these numbers were reached on analysis early in the designing, and then supplemented by testing, once the aircraft were in service. I have personally seen a wing strut strut/spar attaching fitting in which one of the two laminated aluminum plates was seriously cracked, and a definite safety concern. Happily, the wing had been removed from service already. I was aware of deHavilland engineers having informally said in the 1990's that had they to do it again, they would not have made the Twin Otter wing life as great as 33,000 hours. This supported the DH position of not endorsing extending it. There were other STC efforts to extend and relife the wings. "Extend" was a stop gap, which sort of helped, but the relife STC became the much more viable action, for a long term safe fix. In the late 1990's, the high time Twin Otter had more than 109,000 hours in service. This is much more than DH ever expected.

It is the continued use of aircraft, well beyond the manufacture's vision for the aircraft, whic his introduction thee concerns. The buzz word is "aging aircraft". It's not finding it's way down to our little GA types yet, but it will in the long term. Events like the Aloha and Southwest B737 upper fuselage skin failures are really a big motivator for this new policy. In those cases, like the Comet, it's cylced pressurization loads, but flight loads can be every bit as harmful. Piper PA-28's did have a wing attach AD decades ago, but it was eventually recinded, for lack of actually finding a problem, in any other than the one aircraft which started it all.

The ideal, is to assure that the design of the aircraft is such that detail inspection, or obvious external distress will indicate an impending structural failure, before it becomes a safety hazard. There after, the aircraft is a good repairable design if the repair or replacement of these vulnerable parts is easily accomplished.

It is this easy repair, which makes the much maligned Cessna spam cans an excellent choice for low cost longevity. The Cessna structural repair manuals are comprehensive, and simple. The majority of most light Cessna airframes are folded sheet metal (as opposed to extrusions (more often found in Piper low wings), homeycomb (Grummans), or non metallics of some of most recent GA aircraft.

When a maximum time in service for an airframe is expressed as a "limitation", take it seriously. This is akin to time/cycle limitations on dynamic components (mostly found in helicopters). These "limitations" are much more serious, that the "recommended" intervals for overhaul which manufacturer's state for piston engines



It has been said about structures: "Them that bends, don't break". Perhaps over simplified, poor grammar, but there it a worthy theme in there...

[Genghis the Engineer]

Last time I flew a PA38, I was not impressed at how flimsy it all was... Like it was made out of the thinnest Alu they could get away with? Maybe the wings just fall apart after a few thousand hours..:E

Yet strangely enough, the certification engineers come out with it being as strong as a PA28 or a C152.

Maths does beat pilot opinion, sometimes.

G

[RTN11]

I hadn't realised that wing limits were so much the norm. I had heard some old wives tale about the piper legal team demanding a life limit on the tomahawk for fear of getting sued years down the line, and the number had simply been plucked from the air so was just wondering what the real story would be.

It is kind of crazy that tomahawks are still flying now, 30+ years after being built, I'm sure surpassing all expectations of those who made them.

[mad_jock]

Have a look at DC3's thats really taking the piss :D

[Pilot DAR]

My two DC-3 ongoing approval projects are Balser conversions. The first, was built in 1944, and rebuilt 2006/2007 for it's current operator. They were so pleased with it, they bought a second, which entered service a few months ago. I suspect that the DC-3 will live on forever, as it should be :D

Basler Turbo Conversions, LLC Basler Turbo 67 Aircraft (http://www.baslerturbo.com/DEFAULT.aspx)

http://i381.photobucket.com/albums/oo252/PilotDAR/Aircraft/9169001.jpg

[pasir]

Further to Piper Tomahawks - was there not a problem involving spin recovery - or the tendancy to agressively spin and was this ever eventually sorted ?

...

[Mickey Kaye]

Flying school gossip - by schools that never ran them.

OK I'm a sample size of one but I've spin tomahawks dozens of times totally without incidence and I'm no ace of the base.

Personnel I think the Tommy is a lovely training aircraft and its a shame there isn't a few more of them about these days.

[abgd]

Piper Tomahawks were intended to stall properly and spin aggressively. As a student PPL on the Tomahawk I can confirm that the stall can be moderately alarming. Certainly far more so than on the PA28.

The controversy is due to whether some Tomahawks don't exit the spin as readily as they should. There's a story (that I don't know quite whether to believe) that production Tomahawks differed from the prototype and have less rigid wings. Some apparently spin more predictably than others.

I've never spun a Tomahawk, but both my instructors have. One says 'never again' whilst I think the other would rather enjoy the experience. Unfortunately, Tommies aren't certified for intentional spins any more.

[AdamFrisch]

I'm afraid we'll see a lot more of this in the future. There are a number of SID's (Supplemental Inspection Documents) in the works for Cessnas. They will start with the oldest and least supported models, like the 336 and the 337 Skymaster but will most certainly migrate to the older singles as well soon after. Cessna do not want to be responsible for old aircraft falling out of the sky. Plus, it doesn't hurt sales either.;)

Now, in FAA-land for part 91 operations (private flying), this inspection is voluntary. For part 135 it's not. In EASA-land you can bet they will be mandatory for all, so that will overnight make any Skymaster on the European register worthless (as the inspection is north of $60K).

I myself as an Aero Commander owner am in a similar bracket. I happen to own one of the few models in their range that doesn't have a wing inspection AD, but most of the models between the early 60's and 70's had this. There were some accidents due to a combination of cold extrusion of the main spar and galvanic corrosion from a strap. Now, with the spar modification in place, the AD goes away and many Commanders soldier on (still) with almost 20.000hrs on them (I know an operator with 30 of them, who regularly flies them beyond 15.000hrs).

But ultimately, and as I fly an aircraft from 1953 myself, one can't help to sometimes think about the structural integrity of an almost 60 year old wing. I certainly do. That's why I really ask them to check extra carefully for any type of corrosion or funny spots during my annual. But I'm also calmed by the fact that they many times overbuilt things back in those days, so everything just feels a little beefier.

[abgd]

It is kind of crazy that tomahawks are still flying now, 30+ years after being built, I'm sure surpassing all expectations of those who made them.

I don't know that it's so crazy - there are plenty of tiger moths and Piper cubs still about and they'd have been 30 - 50 or so back in 1980.

[AdamFrisch]

Plus, metal is easily inspected and repaired. Imagine years down the line when these old S-glass or composites have been flying for 50 years - nobody knows what lurks within those structures after such a long time. We have it good - it's only going to get worse.

[RTN11]

I have a spare set of fabric covered wings

Sounds a bit like trigger's broom from only fools. This plane is 50 years old, it's had 3 sets of fabric covers, and 2 main spar replacements :}

[abgd]

I don't know...

Older aircraft and engines are hugely inefficient compared to some of the newer types. I doubt if avgas/mogas are ever going to get cheap again and I expect this is going to get ever more important.

Secondly, aviation infrastructure is expensive - if it isn't well utilised, it's going to disappear.

[Dan the weegie]

It depends very much on what you want to do. I certainly wouldn't say they were "massively" inefficient. I have a 1952 C90 cub that does 18 l/h but doesn't go very far, it doesn't go as fast as a SportCruiser but it was also less than 1/5th the cost and wont depreciate, at all. Whereas the sportcruiser will depreciate by half over about 10 years. To get that money back I would have to do a boatload of hours. I can fix just about anything in my cub for relatively little money, the same cannot be said for the "more efficient" modern aircraft you talk about :).

I'm not saying they're not good, they are. But it's a blinkered opinion that the old stuff is worn out and expensive to run. It's not by a long shot.

The Tommie is even better, you can buy a servicable one for about £7k it burns 23 l/h of AVGAS and will take all the ****e that Ab initio training will throw at it without failing anything too expensive (except the bastard noseleg). It pays for itself in a matter of months.
Flying fast, for little fuel is only a portion of the game and while it's relevant it's not for training, which is the Tomahawks only mission, because PPL training is about the time you spend in the air, not how far/fast you go.
It will only be replaced when there is a hardy fuel efficient and cost effective alternative. The AT3, SportCruiser, Remos GX, SkyCatcher, are neither tough nor cheap and that is why we will see people training on PA28s from '76 and C172N/Ms for years to come.

[abgd]

I don't disagree with anything that Dan's said... And I never meant to imply that old aircraft were bad aircraft. However they were designed in different times - generally before the oil embargoes and concerns about global warming, and before ordinary Chinese started to buy cars.

Fuel already makes up about half of the Tommie's running costs (in the UK), and they certainly do seem to need a lot of maintenance. If fuel prices were to double... triple... quadruple... then older aircraft would become less and less economical.

I obviously don't know whether this will come to pass, but I wouldn't be surprised if it happens within the decade. If so, then I reckon it will be devastating for GA and particularly gas-guzzling types.

Also, is efficiency really mutually exclusive with durability? Many of the newer types have been heroically squeezed into the weight limits set by microlight or LSA specifications, and it strikes me that this may be a more fundamental reason why they tend to be flimsy in some respects (e.g. nosewheels). As Silvaire points out, there are plenty of old LongEZs about, so composite aircraft can be reasonably durable.

Anyway, the long and short is that I could already rent a C42 for an hour wet, for less than the price of an hour's fuel in a Tomahawk. I'm going to try it as soon as I get my PPL, and see how I get on with the aircraft. Perhaps I'll find it doesn't suit me.

[abgd]

Well, there's something special about the LongEZ. I grew up reading about them in the national geographical. Always wanted one. May get one, but not for a while yet...

[peterh337]

As regards efficiency, there has never been and never will be a free lunch - all the time you are burning hydrocarbons to get propulsion.

The old Lyco engines, when in cruise and running at peak EGT (stochiometric), are as efficient as the most modern car engines when running in similar conditions e.g. going down the motorway at 80mph.

Similarly there is no possible significant difference between a Lyco and a Rotax. The Rotax should benefit from a more modern combustion chamber design, etc, but it loses out by running at a high RPM which, as every Lyco owner with a VP prop and some decent instrumentation will know, is a great MPG killer.

The way to make a plane do more MPG is... wait for it ... to make it smaller :)

Reduce the cockpit volume and you get better MPG. Especially if you make it a tandem design so the cross section is small.

The PA38 probably does more or less the same MPG as any other plane with that size cockpit and the same or similar engine.

The total operating costs of a plane are not just the fuel, of course. Once an aluminium airframe goes past 10-20 years (depending on whether hangared, abused, etc) then you have to start replacing airframe parts, and these are universally expensive.

The reason every PA38 is a knackered old heap is because they are all around 30 years old and most of them were kicked around the flying school scene. I started my PPL in them and the ones I used to fly were the worst bits of crap ever, with an inch of water on the cockpit floor following a rainy night, stunk like a public phone box, one would drain about half a litre of water out of the tanks following some rain (perished filler cap seals), the trim was knackered, the yoke was just bare metal rusted up with decades of students' sweat (and everybody flying a PA38 seems to be constantly sweating because it gets hot and most of them are flying circuits :) ).

Very few people bought PA38s for private flying because it is not really suitable for going anywhere. It is too agile to give you any rest.

[Mickey Kaye]

"Similarly there is no possible significant difference between a Lyco and a Rotax"

So why does the AT-3 need 14 litres of fuel to top up after an hours instruction and the PA-38 needs 22 litres then?

[peterh337]

Stupid engine management in the PA38?

A slight difference in the MTOW - 580 v. 760kg.

Other reasons, probably.

[mad_jock]

It is too agile to give you any rest.

I don't quite get that to be honest I used to ferry them for mx and without the student annoying her she would sit happy as larry trimmed out with just an occasional squeeze of the rudder pedals to keep her pointing in the right direction.

I will admit I had over 10's of flights altered the trimming tabs so they were spot on for cruise. It just takes a bit of effort by a pilot and they just as good as anything else for flying in a striaght line.

[Dan the weegie]

The AT3 is lighter, more aerodynamic but nowhere near as tough, it also has more frequent and expensive tech issues. Not to mention being £100k to buy.

It's a good plane but it's been designed for a different job, not to mention that it needs full rudder on the take off roll in zero wind, which is wholly unacceptable for a trainer.

the CT and the C42 are the same except that they're microlights, so only good for NPPL (M) and PPL (M).

Those flying schools I spoke to that have been using the AT3 in anger, wish they weren't for the above reasons.

Mission is key. You can't compare apples and cucumbers ;) or oranges with potatoes :D

[peterh337]

needs full rudder on the take off roll in zero wind, which is wholly unacceptable for a trainer.

If true, it's unacceptable for, ahem, flying of any sort, because what if you get some, ahem, wind from the right?

[mad_jock]

Anyway the weegie is going to be flying another tough auld girl in a couple of weeks.

Congratulations of passing your first type rating LST. All those hours in the tommy put to good use. 700kg to 7000kg and 65knts to 130knt approaches in one hop. Oh and it has a limit of 31000 cycles but they have just got an extension up to 42000 cycles :eek: without any mods. Built like a brick ****e house.

[RTN11]

needs full rudder on the take off roll in zero wind, which is wholly unacceptable for a trainer. If true, it's unacceptable for, ahem, flying of any sort, because what if you get some, ahem, wind from the right?

It pretty much needs full rudder to be applied to keep it straight in nil wind. In the event of a cross wind I've seen people line up at an angle, rather than nose straight down the runway, that way any extra yaw puts you straight and you still have some directional contol left.

Truely awful design.

[abgd]

The way to make a plane do more MPG is... wait for it ... to make it smaller http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/smile.gifDon't disagree, but also compound curves, reduced weight, larger aspect ratio, winglets (when appropriate), smoother surfaces, and some consideration towards reducing parasitic drag. My understanding is that the Long-EZ is so efficient in large part because of its decrease in surface area, because the fuselage volume is so much better utilised.

As an example of how older aircraft simply haven't been designed with efficiency in mind, I always wondered at the sharp wing-root junctions on the PA38 and PA28. Sure enough, when I looked for a wing root fairing kit, the manufacturers claimed to increase speed by 2-3 knots - which probably counts for an efficiency increase of 5% or so if you kept the airspeed constant.

I still suspect that many of the drawbacks of the present offerings are due to the microlight and LSA design criteria. They are mandated to have comparatively low stalling speeds, necessitating larger wings. Top speed is limited, so they'll never be able to compete as tourers.

But anyway, where I live my renting options are essentially C42s or PA28s - why would I want to hire a 4 person plane for a solo or 2-person outing, which will make up the majority of my flying over the next few years.

[peterh337]

I don't disagree, but in your list are parameters which alone will give a better MPG by flying slower.

If you have a lower wing loading / a lower stall speed (a requirement on microlights and other "ultralight" stuff) then you end up with a plane whose optimal cruise speed is lower, and that alone will produce a better MPG.

The Long-EZ is a tandem, which will easily be hugely more efficient. It also does away with the elevator drag causes by the elevator pushing down in most traditional designs. Canards are more efficient due to this.

The rest, like wing root fairings, are little details which all help. My TB20 is covered in pop rivets and it's obviously cheaper to do that than flush rivets, and my guess is that Socata didn't think it is worth spending the extra money to get maybe a few extra kt.

It is a known fact that the retractable footsteps on the TB20GT are worth an extra ~2kt; Socata apparently did that to preserve the POH performance figures despite the taller roof, because any change to the POH creates a lot more certification work :)

Aerials can make a big difference too. If you have 2 x VHF, ADF, DME, XPD, that is probably 3kt down the drain.

[abgd]

It also does away with the elevator drag causes by the elevator pushing down in most traditional designs. Canards are more efficient due to this.

That's debatable. I don't fully understand all the arguments, but on the canard forums, people reckon that the efficiency of the canard is limited because it has to have a very high loading, and the inefficiency of this offsets the advantages of eliminating tail downthrust.

It's apparently not always true either that tandem seating is more efficient than side-by-side seating ('sociable', to borrow cycling terminology). What tandem seating loses in x-sectional area, it makes up for in wetted area. On the Long-EZ this is 'free' because the passenger is effectively sitting where the empennage would otherwise be, and this space is poorly utilised in most aircraft.

Other than that, I don't think we're disagreeing so much on matters of fact as emphasis. And perhaps not even on that - I agree that the best way to massively reduce an aircraft's consumption is to make it much smaller, but I don't agree that the rest's just icing.

Touring motor gliders (and derivatives) are another class of aircraft with a l/d at least twice that of most light aircraft. Again, most of them aren't designed to go fast, but when compared with aircraft in the same speed category (like the Tommie) they still come out very favourably in terms of fuel consumption.

[AdamFrisch]

Flap gap seals normally add enormously to most airframes. The Commander gains almost 10kts by installing them.

[mrmum]

Unfortunately, Tommies aren't certified for intentional spins any more.
Really? When did that happen then and why?

[abgd]

Really? When did that happen then and why?

I was told by my instructor - I would have been very keen to experience a spin, had I not read so many stories about the Tomahawk.

My understanding was that the aircraft wasn't certified to be intentionally spun, but it may be possible that it's the instructor who's not allowed to intentionally spin, or that it's a flying school rule.

[mad_jock]

They changed it you needed a 4 point harness the standard harness won't cut the mustard on G reg.

Or you have a yellow livered prat of an instructor who is **** scared of being in a tommie and shouldn't be flying one never mind instructing in one.

[abgd]

@Silvaire:

It's good to hear so much about canards - I had a bit of a fetish for them as I mentioned earlier - even went as far as buying the CDs of the plans.

What worried me was working through the NTSB reports of LongEZ crashes. As I recall about 1/15 of the LongEZs ever built had been involved in fatal accidents, often killing more than one person. The problem, as far as I could make out, was that the minimum flying speed was so high that forced landings were much more likely to be fatal than for other types. I figured that this may be acceptable in large areas of the states, but that in the British countryside this was simply not something I could live with. I eventually decided that I would only consider one if it became possible to fit a ballistic chute.

[abgd]

Or you have a yellow livered prat of an instructor who is **** scared of being in a tommie and shouldn't be flying one never mind instructing in one.

To be frank, I reckon my instructor would love it if I 'accidentally' spun the Tommie on every lesson, but is far too professional to say so.

[mad_jock]

Well thier knowlege of the aircraft they are teaching is quite frankly ****e, if they told you its not allowed any more.

What speed do they get you to fly the approach at?

[Big Pistons Forever]

What you can and can't do with any aircraft is clearly stated in the POH provided by the manufacturer and specific to the serial number of that airframe.

Since UK flying schools have the bizarre habit of hiding the POH in some obscure bookshelf still in its clear plastic wrapper, safe from the possibility of actually providing any useful information to pilots; it may take some convincing to actually look at it but that will definitively answer the question of whether your Tomahawk can be spun.

Now the club may have instituted a policy that the aircraft may not be spun, as they own the aircraft that is their prerogative, but it has nothing to do with whether or not a PA 38 is certified for spins.

[mad_jock]

The caa have put the 4 point harness in the POH due to some fanny ****ting themselves and causing an issue.

If they had just done the normal method of getting the student to sit on there hands for the first one it wouldn't be in the POH.

[A and C]

Yet more un informed rubbish spouted by flight instructors who should know better.

The truth of the PA38 spinning saga is that the UK CAA mandated that intentional spinning was not permitted unless a four point harness was fitted.

This CAA mandate was as a result on a fatal accident enquiry that had suggested that the crews efforts to recover the aircraft from the spin might have been hampered by them not being fully secure in their seats.

Having done a lot of spinning in the PA38 I would agree with this mandate as spinning in the PA 38 is a lot more ( shall we say) sporty than most other trainers in common use.

[Maoraigh1]

I hit a fence in a Jodel about 15 years ago. I hit one fence post with the engine. The prop tip broke backwards, and fence posts damaged the wing leading edge. After a days work by an engineer, I flew it out with a borrowed prop.
If there had just been fibreglass/wood between me and the post, I would probable been seriously injured at best.

[AdamFrisch]

Off topic canard talk:

There's nothing inherent in the canard design that would make it unsuitable for slow flight, but because adding flaps is more complicated on a canard, the manufacturers rarely do it or attempt a solution. It certainly can be done with some clever engineering. But since they often lack that, the approach speeds are much higher.

Also, IF, for any chance, you have managed to get a canard stalled, they're almost impossible to get unstalled. Which makes them a little bit more dangerous in extreme scenarios, perhaps.

[Cameronian]

I only flew a Tomahawk once, a long time ago at Glasgow, and it seemed to be exactly what one would expect. There was a young lady instructor there who came in as white as a sheet after spinning one with a student in the LFA. She said that absolutely nothing would bring about a recovery until, far too low, she opened the door and held it as wide as she could. That would be the last time, she said!

[abgd]

Yet more un informed rubbish spouted by flight instructors who should know better.

Um, I'm not certain that they should have known better, or whether I should have asked more probing questions, or whether I was perhaps even given the correct explanation but later forgot it. It was a while ago that I asked, and if I misremembered, mea culpa.

[RTN11]

Either way, the instructor was correct that the aircraft is no longer certified for intentional spinning, the fact he didn't know it was because of the lack of a 4-point harness isn't too important in the grand scheme of things.

I don't think anyone wants to spin a tommy so badly that they will take the trouble to fit a certified harness. They are hard work at the best of times, now they're 30+ years old, including all the rigging at the back, not sure I would put my life on that. Any repair work or anything over time that could contribute to an imbalance could mean that any spin in a tommy could well be your last.

[Big Pistons Forever]

Either way, the instructor was correct that the aircraft is no longer certified for intentional spinning, the fact he didn't know it was because of the lack of a 4-point harness isn't too important in the grand scheme of things.


I disagree. The instructor mindlessly accepted what somebody had told him without making any effort to find out why. The information is there with a bit of research. It is this attitude that causes so many ridiculous "flightschoolism" to exist.

[Pilot DAR]

Oh dear....

now they're 30+ years old, including all the rigging at the back, not sure I would put my life on that. Any repair work or anything over time that could contribute to an imbalance could mean that any spin in a tommy could well be your last.

"Any" repair work will have been done in accordance with approved data, or the airplane is no longer certified. If anything was affected by "balance", it will have been restored to a balanced condition, or the airplane is not longer certified. If the "rigging at the back" is not as per the approved design, the aircraft is no longer certified. "Anything over time" (corrosion?) has affected the airworthiness of the aircraft, it is no longer certified.

My plane is more than 30 years old, is still certified, and I spin it regularly. I'm more than 30 years old, and I spin regularly. Two weeks ago I flew a 67 year old plane, which had not flown in 7 years. (I did make sure I could glide back to the runway for the first bit though).

So presuming the Tomahawk you fly is maintained so as to be airworthy (and you check the airworthiness before you fly it), what's the real problem with Tomahawks?

If I had access to one, I'd spin it tomorrow, I remember them being excellent to spin!

[A and C]

I have to agree with DAR their is too much totally uninformed rubbish being talked about aircraft repair and maintenance.

All aircraft repairers or modifications have to be done in accordance with data from a design organization (normaly the manufacturer) and so the repair will not be any less safe than the original design.

We see far too much utter rubbish on these pages about aircraft damage and repair, this is not the motor trade, "cut & shut" is not an option with aircraft, with aircraft all repairs are tightly regulated so aircraft that are beyond technical repair simply will not return to flying.

When the repair is of a composite aircraft the rubbish talked throughout the industry goes up by a factor of ten, this is because there is so little composite repair knowlage within light aviation.

The bottom line is that I am more than happy to spin a thirty year old PA38 provided all the AD,s have been done IAW the maintenance data............come to think of it I have, usually following C of A renewal on an airtest or when instructing.

[A and C]

I think you are being a little hard on the European airworthiness system but this is probably understandable given that on these pages you will find everything from half truth to utter rubbish written.

AC43.13 is considered approved data as long as it says so in the manufactures repair manual and can be used as such. In fact one Europan company has a very small repair manual, apart from a small section on repairs to the spar area and other critical adjoining parts they state that all other areas of dammage can be repaired IAW AC43.13.

I just wish that all manufactures would take such a view.

[Pilot DAR]

'in accordance with approved data'

Well, sort of... "approved data" is appropriate for a "major" modification or repair. Approved data is obtained from the regulator (FAA, or Transport Canada, for example). The approval can come from FAA/TC engineering staff, or in the FAA, a "DER" or in Canada, a "DAR". "Approved data" of this type is most commonly used, where the manufacturer has not designed such a repair before (they did not think you'd do that to the plane, and want to fly it again!). Yes, DAR's have to live too, so "approved" data will have a cost - after all, it is custom to that aircraft!

The repair might also be accomplished in accordance with the manufacturer's "Acceptable Data", (usually a Structural Repair Manual (SRM)), or Service Bulletin. Though this "acceptable data" might not be literally "approved", it can, when appropriate, be used to support a repair, so the repaired aircraft will still be "approved". There is also "specified data" , of which AC43.13 would be an example. This would be for not major repairs.

Incidentally, my experience with Piper PA-28's has been that "Acceptable Data" is not abundant, for un-expected repairs. This has resulted in my having to develop and approve repairs for seemingly minor (hail, for example) damage. I'm glad I own a Cessna - they are well supported by an SRM. (I can't speak for the Tomahawk - 'never repaired one).

In any case, Pilots can be confident that if an aircraft is repaired by a qualified person, in accordance with the regulatory requirements, the repair will be "acceptable" or "approved". The handling, performance, longevity, or balance! of the aircraft will not be affected. The pilot need not worry, unless the pilot believes that work accomplished on the aircraft was not carried out legally.

[Pilot DAR]

Eventually that was resolved, and incidentally the fleet wide inspections never unearthed a problem in any other aircraft. The whole thing was an untempered overreaction

Piper had a similar situation with the PA-28 back in the mid 1980's. A lot of wings were pulled for inspection, for no good reason! AD eventually rescinded.

anybody involving themselves with any aircraft should take the time to understand what they're buying into

Oh yeah! Too often (and most recently with a Piper Arrow) an owner or new owner's maintainer contacts me for a repair approval. The aircraft was purchased cheap or easy, with the seller perhaps knowing something the buyer did not. A defect with the aircraft, which might seem very simple, can actually require a complex or too costly repair. There is a lot to be said for buying one of the maligned Cessna "spam cans", at least you can always repair it! More exotic types? Not always so easy!

I enjoy flying exotic aircraft when I have the opportunity, I relax in owning a simple Cessna!

[Sleeve Wing]

I personally have always been quite happy to spin a Tomahawk, provided the W&B was always checked beforehand.
The only thing that used to bother me was the amount of movement/distortion of the vertical surface and T-tail during the recovery. The whole lot flapping about is a sight to behold.
I suppose fatigue is a real concern if the aircraft is spun regularly and also whether the amount of distortion could reduce the opposite yaw requirement too much to stabilise the aeroplane.
Any comments from an airframe specialist ? A & C ? :confused:

[A and C]

You are right on the money with what you say about the T-tail movement.

The Fin and its attachments both at the top and bottom are the subject of a number of AD,s. Some of these require the inspection and replacment parts.

I have not worked on the PA38 for some years but seem to recall a lot of worn bolt holes in the front and rear fin spars that required the fin spars to be changed along with all the bolts.

The wise operators also installed (optional) inspection panels in the rear of the aircraft to enable easy inspection of the frames supporting the fin.

The PA38 is an aircraft with issues at the back end but these issues are well known and can be safely managed with good engineeing practice.

[Sleeve Wing]

Thx, A and C.
Now I know why I always choose to take a "spanner" when I'm testing...........if he's up for it !!

[cpl4hire]

O.K. I know this is an old thread but I used to fly a PA38 and I liked it (even after watching the Fin/Tailplane shake about during stall practice !) I have seen one that may be for sale and I want to know what the bottom line is regarding the Wing Spar?
My research so far points to its liffed at 11000 hours, that there is a mod which will give you 7660 more hours. I also remember being told by an Engineer that the Wing Spar suffered from corrosion and had to be subjected to a Boroscope inspection.
So whats the bottom line ?

[smarthawke]

Some info here:

http://www.pprune.org/engineers-technicians/502456-pa38-wing-spar-life.html#post7565700

[bonanza7]

I am a Flight Instructor, and worked at a school where we had both Tomahawks and Cessna 150's and 152's. All the instructors liked the Tomahawks better than the Cessnas, and regularly competed to use them as our trainers. None of us had any negative comments about the stalling characteristics of the Tomahawk, or any other flight issues. Until it came to spins. A couple of those, and we never did them again in the Tomahawks. On recovery, they would pitch inverted. Scared the you know what out of the students, and got the Instructors' pulse going up also.

[mad_jock]

The pitch only moved because you weren't keeping the ailerons neutral.

You can take them from vertical to flat and back again by using the ailerons.

centralise and hold them there nothing funny happens.

[bonanza7]

It wasn't a wing drop to inverted, but a straight forward pitch to inverted during spin recovery. Unfortunately, there are no more Tomahawks around here to experiment with. Not many planes at all, actually. Most are left to rot on the ramps. Pathetic sight.

[mixture]

Personnel I think the Tommy is a lovely training aircraft

They're a ghastly aircraft.

Did my spin/stall training in PA38s and then was glad to see the back of them.

Can't imagine having to endure cross-countries in one !

[mad_jock]

Its nothing to do with wing drop.

While your in the spin if you turn the controls one way it makes it go flat and then turn it the other it goes steep. But your still going down.

PA38's are like marmite some folk hate them and some love them. They do produce better pilots than C150/C152 trained.

[DX Wombat]

They do produce better pilots than C150/C152 trained. Not according to the examiner who did my test. Don't forget that apart from a couple of hours in Oz, your granny learned in a C152.

[mad_jock]

The examiners are just as bad as instructors with the marmite tendency's.

Some refuse to examine in Tommys and if they do they make the student add ridiculous addition to the approach speed so much so the student is completely out of the grove because they are flying 10-15 above the book speed.

[A and C]

Please tell me this is not true and you are having a joke at the expense of someone unknown to me.

[mad_jock]

Nope last one I encountered was 5 years ago. Wanted the approach flown at 80knts because of "known and well documented dangerous stall and spin characteristics" this is with a dirty stall of 50knts from memory or it could even be less.

Even briefed the PFL had to be flown at that speed as well.

Instructors using 70 or 75 knts arn't uncommon either and then wonder why the student struggles to go solo.

I had one to sort out that had been told to fly at 75knts when I was full time all I did was get him to fly at 65knts approach speed which is still a smidge fast and sent him solo 3 circuits later. The poor lad had been getting raped in the flare every time before that. Right speed the aircraft just sat down as the power came off.

The student just said "it just stopped flying when it was meant to and we didn't float down the runway"

"No****sherlock 10knts to get rid of in ground effect takes a bit of runway to get rid of it".

I demo'd a 55knt approach landing and stopped on the piano keys and he was just gob smacked.

[A and C]

It is sad to say that I have experiences that reflect yours but the most extreme was the owner of PA38 who had asked me to do the C of A air test and wanted to come along as observer.

He was ok until we got to the stall checks, this he was very unhappy with but we did them, the turning of the page to the spin recovery bit sent him into some sort of total panic when he demanded that we don't do the spin because we would likely be killed, at this point I decided to not continue the test as it had become pointless, as I reduced towards the approach speed he broke into some sort of histrionic rant as I reduced the speed past 80 KTS saying I was about to kill us, eventually I managed to gear the guy to agree to 70kts approach speed.

The debrief was interesting with the guy accusing me of all sorts of things and asked to see my licence because he wanted to report me to the CAA, when I produced an ATPL he calmed down enough to be shown the flight manual and see the numbers. I have doubt if he had ever looked at the flight manual.

Eventually he did agree to me flying the rest of the air test solo and I am told he sold the aircraft without flying it again.

I did wonder who had instructed him when he was getting his PPL.

[mad_jock]

Its not just one school out there, there are a few.

And there were more than one or two examiners that are at it as well.

The 80-85 knts thing though does seem to be a bit of a favourite.

The picture doesn't even look even remotely right at that speed and the power is way way up but of course they have the carb heat on as well for landing. As there is some rubbish about that as well even though they have just flown the approach at just under cruise rpm.

As a FI they weren't going to listen to me. I just didn't use them again and warned the students not to go near them and we would sort it out when the more sensible examiners were available.

You could show them all the accident reports which had a to fast approach as a major cause and they would still insist on 30knts above stall speed.

[Flyingmac]

You could show them all the accident reports which had a to fast approach as a major cause and they would still insist on 30knts above stall speed.
I see a lot of guys coming to grass strip operations from the 'Two miles of tarmac' environment. They almost without exception suffer from the '70 knot and partial flap' syndrome. They take some weaning off it.

I blame their instructors. Am I being unfair?

[A and C]

Regretfully I have to agree with you about the quality of instruction, I was very lucky in that apart from a few exceptions my instructors were all ex WW2 & ex airline pilots who we're doing the job for the love of flying, I at the time was doing an aeronautical engineering apprenticeship so I got quite a rounded aviation education.

Roll on ten years and I was instructing most of the guys instructing with me only wanted an airline job to be fair most did the ( unwanted) instruction job quite well when it came to the flying but the teaching of technical subjects including aerodynamics was not good ( as pointed out in a CAA report of the time) some of the guys were just useless and actually managed to teach the student very little as I found out when I occasionally had to fly with their students.

My view of the current PPL instruction state is that EASA trying to turn it all into a professional pilot system had had a detrimental effect on quality as it has edged out the keen part timers who fly at weekends who keep high standards because they are flying for the love of flight and it has populated the training system with budding airline pilots who will be off to follow the magenta line at the drop of a hat, not all of these guys are bad but the biggest failure is the quality control system that seems to be unable to weed out the bad instructors.

Of course the situation is not helped by the latest PPL exams from EASA..... Asking a PPL student to calculate the time of sunrise in Calcutta on June 12 by using the air almanac tables shows just how far out of touch with reality the Numpty who set the question is........... With oversight like that no wonder instructor quality is so variable.

[mad_jock]

Unfortunate fact that some people learn to fly in spite of the instructor.

[mad_jock]

And I just don't get this partial flap thing either.

Asked one pilot after being checked out in the C172 why he didn't use full flap.

Because there was a xwind.

Turned out he had been taught. Use partial flap when.

Strong winds which was apparently above 10knts.

Any xwind.

Any gusting.

Any turbulence reported.

Any windshear reported.

Any CU in the area.

So it turned out that the only time they could use full flap was when it was less than 10knts straight down the strip and cavok. So they had never used it since their PPL test 3 years before.

Give them their due though after they went for their flight with thier family while all the women went shopping they came out and did an hour of circuits in the tommy with 20knts on the nose and 10knts xwind with full flap. And concluded there instructor was full of :mad: and the tommy wasn't such a bad plane after all and it was actually quite fun.

[fireflybob]

I have flown and stalled the PA38 today and survived!

mad jock, A & C, flyingmac - agree with all your comments there!

Having returned to the fray of basic flying instruction (which I love) some of the BS and old wives tales one hears about the Tommie are fatuous to say the least.

Great little trainer!

[mad_jock]

well done Fire and I do hope you used the correct approach speed.

To note instructors I didn't try and retrain the guy who was on check. He was safe so I left him alone and it was only a debrief comment afterwards.

It was at his own request that we went and did circuits using full flap. Maybe being chilled about things being different even though they are stupid as long as they are safe. Actually encourages pilots to come in for more instruction.

[cavortingcheetah]

As I remember, from many years ago, when the PA38 was launched the aircraft was certified for spinning. Indeed, one of it's rationales was as a spinner trainer.
However, in the beginning the handbook called for a standard spin recovery as in releasing the back pressure on the control column. This rather half hearted action could lead to the spin tightening up or the aircraft entering an inverted spin. Several pilots in the US died as a result of PA 38s spinning in. The handbook was, I believe, subsequently changed to reflect control column fully forward.
In South Africa we took delivery of a couple of PA38s at FAGC and used to operate them at a pressure altitude of some 5,500ft in the summer with temperatures up at 30c. With a density altitude of around 8,500 ft (or whatever, no whizz wheel to hand) you simply couldn't climb to more than 7,500/ 8,000 ft.
We therefor used to demonstrate spinning to the student, through one turn only. If any student asked for more torture we'd do it again only this time ask the pupil to observe the tailplane at spin entry and rotation. No one ever came back for thirds.

[mad_jock]

They put rumble strips on the wing after the yank accidents.

And I have never needed to push the stick forward to get it to come out of a spin. Centralised the controls apply opposite rudder it will speed up initially then come out nicely.

If you do push forward even slightly when it comes out you get a spectacular bunt.

In the UK they had an incident which they put down to the student waving there arms round in the cockpit. So they made it you couldn't spin it unless it had a 4 point harness fitted. From my experience this is pretty much ignored if its even known about.

[cavortingcheetah]

http://www.snapflight.com/PA38-112_files/Piper%20PA-38-112%20POH.pdf

Section 4-24 et seq refers to spins and recovery with a couple of caveats if you get it wrong.

That doesn't really help in answering the OP question unless you regard the PA38 as a throw away or Meccano machine?

[Piltdown Man]

The Tomahawk was Piper's idea of a Joke. And the punchline was giving it such a huge life. 50 hours would have been better. It's a nasty aircraft because it had such pathetically poor performance. But slow in a PA38 was quick for other aircraft. Thing would stall in the high forties giving rise to an approach speed in the high fifties, early sixties. Only it's redeeming features were its spinning, stalling slow flying characteristics. This is because you can demonstrate and practice them properly. But I think what used to really worry people was seeing the tail shake and wobble in the spin.

PM

[mad_jock]

That's quite a bit different to the UK POH.

I don't have access to a UK POH. 2001 rings a bell for the latest update which I presume was the 4 point harness thing.

They changed it a bit, they also had there own TP's redo the spin recovery.

I never needed forward controls and recovered in the 1-1.5 turns.

62knts is the official final approach speed though.

And pit that's what the instructors said they wanted when piper surveyed them before designing it. Its designed as a trainer and has no real other function. And as a trainer it fills the job well and teaches people to fly properly. Its not really the aircrafts fault if the people teaching in them can't fly properly and have there heads full of old wives tales.

[cavortingcheetah]

That's just about it. Piper canvassed thousands of instructors and then produced this paragon of a trainer precisely as requested. It had no other function apart from the entertainment factor when the wings fell off at 11,000 hours.

[A and C]

To be more blunt than Jock I find those who don't like the PA38 are those who have failed to see it as a tool to teach people to fly well, in that it is much better than a C152.

The PA38 shows up the students faults very well and makes any inability to teach from the instructor very obvious, may be that is why some people dislike the aircraft so much.

I would far rather have two PA38's than the C152's that I do have but the lack of parts and airframe life make that a non starter.

[Lone_Ranger]

But I think what used to really worry people was seeing the tail shake and wobble in the spin

How odd............ I've never turned my head to look behind when spinning.........I've obviously been wrongly taught

[rustyflyer]

I know this thread started out about wing life but the discussions about stalling prompted me to post.
As someone who trained in Tomahawks I found them OK but the lack of payload was a joke. Luckily Hawarden has a nice long runway!
I found stalling uneventful but never experienced a spin and can't remember if they were allowed.
I learned at Hawarden with CFS, one of who's instructors was was teaching for a different school at that airfield until August 2012 in Tommys when he & a student tragically lost their lives in one. This really rattled me as he was a career instructor with masses of hours. The Investigation Report was published a year later and the cause was put down to a spin which was not recovered, probably due to insufficient altitude.
I'm posting this as the bit that I find truly chilling is that a new revision to the POH was received by the school a month after the accident giving advice on safe altitudes for stall training which were substantially higher than those used by instructors at that, and I guess other, flying schools. This amendment was based on a US NTSB Safety Recommendation from 1997!
Here's a link to the report for anyone who wants some further reading:

Air Accidents Investigation: Piper PA-38-112 Tomahawk, G-BODP (http://goo.gl/vDSo7p)

Just thought this might be worth sharing or reminding people of....

Russ Ware

RIP John & Karl

[fireflybob]

My father instructed on (amongst others) the Miles Magister during WW2.

Post war he continued instructing and was still examining when he was 81 years.

When the Tommie came on line and there was the odd spinning incident/accident he commented that it was like the Magister all over again and that it had a "reputation" for spinning which was quite undeserved so long as you knew the correct recovery etc.

In the days when I taught spinning on a/c like the Chippie I also made sure the student understood the "conservation of angular momentum" amongst other things wrt spin recovery.

When I was a (civilian employed) military flying instructor part of the course was "high rotational" spinning - with the "student" mishandling a recovery and the instructor taking over control to recover. Also part of the brief was action in the event of intercom failure.

That said I have a healthy respect for spinning any aircraft. Make sure you are within the weight and centre of gravity limits and that you have read and understood the recovery procedure as specified in the POH/FM. Also track down a competent instructor who knows what he/she is doing!

Sadly as the "oldies " retire these skills are being lost and are therefore not passed on and hence the old wives tales abound.

[mixture]

I find those who don't like the PA38 are those who have failed to see it as a tool to teach people to fly well

I see it as a tool to teach people about stalls and spins.

For the rest of your flight training, there's no need to subject to yourself to the discomfort and slow speeds, particularly when you start doing navex and cross-countries !

I dislike it for the correct reasons. :E

[Mickey Kaye]

There still a few of us around who knew you old man.

looking back I was perhaps a little foolish. Coming out of a spin downwind was perhaps something that I would not recommend in a Tomahawk these days. But back then it was my standard join.

And cfi Harris never found out either. Which gives a little added satisfaction - he had my arse for pretty well everything else.

Great times and I don't care what anyone says I think its a great training aircraft.

[Genghis the Engineer]

I see it as a tool to teach people about stalls and spins.

For the rest of your flight training, there's no need to subject to yourself to the discomfort and slow speeds, particularly when you start doing navex and cross-countries !

I dislike it for the correct reasons. :E

So how many types would you use in a PPL course? I've generally felt that allowing a student to get to know one type throughout was best.


I like the PA38 - it has excellent ergonomics and good visibility out, bites a bit at the stall, flies like it's slightly out of forward CG thus requiring good trimming and attitude control. I've flown it for various reasons over my career, and would be very happy to be asked to instruct on it.

I can't see why being slow is a bad thing for nav - it both gives a bit more thinking time, and makes it more susceptible to drift, forcing good navigational practice. 85 knots or so is a good enough speed to learn at for the purpose.

On net I think it is a bit better training aeroplane than the C152 - it teaches fuel management better than the 152, creates more respect for the stall, and requires a bit more attention to handling and trimming.

Both can be spun - but I decline to deliberately spin anything I can't jump out of.

G

[mad_jock]

I can't really answer your post without being disrespectful of the dead.

I suspect he had never spun one before as you can normally recover in 1000ft. The spinning up when applying full rudder before slowing down was usually the fall over point for Cessna instructors. They usually released the rudder when it started to speed up rotating.

So it was more than likely nothing to do with the aircraft behaving strangely.

And there are other things you can get with students. If they are big lads they can lock on the controls. If you not strong yourself and quick about it you can get into trouble in any aircraft type. Standing on one pedal as if its the brake on a car with the force of an elephant on cocaine happens occasionally. And you would be surprised what adrenalin does to even the small ones as well.

I can't see how you can say its uncomfortable compared to the other two seat trainers. Its roomy you don't have play the closing door game. You can reach the fuel valve. The seat goes right back. Good visibility from both seats. 90knts is a very good speed to be teach nav at. Decent ventilation at leg and face level. Heater works a treat even in -10 degs at MSL in Scotland.

[A and C]

The PA38 uses the same engine as the Cessna 152 flys at more or less the same speed in the cruise burns the same amount of fuel and is easy to climb into. It is more comfortable to fly in with much better visibility than the Cessna 152.

So why don't people like it ?

It's because they know what they know and don't want to be confused with the facts.

It is a very good trainer that is economically handicapped by the spar life... That is fact not flying club folklore or prejudice and delivered from the owner of two Cessna 152's who would be operating two PA38's if the finances were equal.

[cavortingcheetah]

The training merits of the PA38 notwithstanding, I can assure you that, on a cross country, down here around 23S and in summertime, there's no comparison in the comfort stakes between a Cessna and the aforementioned aircraft. Ridiculous as it may sound, but highly apposite under the circumstances, bubble domes in this part of the world combined with long time exposure to a high altitude sun may, or might not, be an inflammatory agent in malignant melanoma of the neck and face.
One further small point. Down here in summertime, we started flying at 06.00 and often finished at 18.00. Six hours in the circuit in a PA38 followed by a Navex is a tad more wearing than the same in just about anything else. No doubt the same sort of complaint would apply in Arizona in the equivalent season?

[mad_jock]

That might be fair point. In Scotland when it rarely got into those sorts of temps its way more comfy than a Cessna equiv type.

[cavortingcheetah]

Of course, that was in the good old days when barnstorming still existed and I numbered, among my pupils, industrialists, surgeons and a bishop whose pre flight checks left more in the hands of his god than I was prepared to leave in the hands of mine.

[mixture]

So how many types would you use in a PPL course? I've generally felt that allowing a student to get to know one type throughout was best.

Just two types !! :eek: Base type (e.g. PA28) and the PA38 for spins and stalls.

You don't need to get to know the PA38 type in order to get the most out of doing a few hours stalls (and spins if you want to), all you need are basic flying skills and a half-decent instructor.

Rest of the time can be spent getting familiar with and enjoying the base type.

[mad_jock]

The price difference between the two puts the PA28 into a different group.

Also as well the PA28 isn't really suited to be teaching people to land in. Yes you can do it but as an instructor you have to be very protective of the landing gear. PA38 with its sprung gear you can afford to let them screw it up quite spectacularly and the only thing hurt is the students pride.

The there is the thing with only having one door. Personally I like the idea of being able to get out both sides. Fuel selector unless you have a thing for sticking your face into students crotches on trial flights is much better on the PA38.

These days you can do your PPL in a PA38 for about 5500-6000 if you do it in a PA28 your 7000-8000. I wouldn't say that you get any real benefit from a training point of from flying a touring aircraft. Just gives you a false sense of stability as everything is designed damped to death.

[A and C]

Ten years ago I would have wholeheartedly agreed with Mad Jock but things have moved on and my agreement with the Scotsman in the subject has fallen to 60%, the fuel burn of the PA38 is it's big advantage with it being £26/ hour cheaper to operate than a PA28.

Maintenance is the rapidly growing problem for the PA38, parts are becoming harder to source and due to the airframe life issues PMA suppliers are not willing to invest in parts production for a type that they see only having a limited life. The aircraft also has some limited life items in the back end with fin support frame and fin spars being the usual suspects for replacement, this work is quite labour intensive and so expensive. You can offset some of this cost by buying cheap aircraft from those who are withdrawing the aircraft from service but the chances are these aircraft will have the same worn items as the aircraft you own.

The best game in town for training from the economic point of view is the Cessna 152, the aircraft is a very "sorted" Cessna 150 having evolved from a good aircraft it has all the major problems of the 150 addressed and the same fuel burn per hour as the PA38.
The Cessna Supplemental Inspection Directive checks (SID's) is a major cost issue and only the penny pinching low hours group owned aircraft owners will ignore these checks as doing so will save them money in the short term while turning the aircraft into a worthless asset. Those who operate the C152 on a commercial basis would be wise to take heed of the SID's program as if it is fully implemented it will guarantee another 10-15000 hours working life from the airframe, something that the PA38 can't offer even if you do the spar life extension modification.

Right now I can hear the Rotax engined light sport brigade muttering things about over weight Lycosorus powered antiques that should be pensioned off, the problem with the new breed of light sport aircraft is they lack the robustness required of a training aircraft, I am seeing the same issues in terms of landing gear & exhaust cracks, pulled rivets and general wear and tear on 150-200 hour Sportcruisers that I see on 15,000 hour Cessna 152 aircraft. The fact is that these aircraft are built down to a weight and what gives is the robustness required to endure the training environment. From what I have seen most light sport aircraft are unlikely to see the other side of 2000 hours and that is why Piper & Cessna have dropped the idea of being involved in this end of the market.

So the conclusion of all of this is that the PA38 regrettably has not the airframe life to warrant much in terms of investment, the light sport aircraft are too fragile to re-pay the capital investment over their relatively short life expectancy so for the task of training the Cessna 152 is the only game in town that makes any sort of financial sense.

[Fostex]

On the subject of SIDs, the CAA ratified their own interpretation of the Cessna 100/200 series SIDS at the beginning of September.

The new SID checks are now no longer mandatory although one may need to make a formal declaration as to why one has chosen not to carry them out. However the cost of owning a 152 as a trainer just went down considerably, i.e. no potential SIDs to break the bank shortly.

IN-2013/138: The Cessna Aircraft Company Supplemental Inspection Documents (SIDs) ? 100/200 Series Aircraft | Publications | About the CAA (http://www.caa.co.uk/application.aspx?catid=33&pagetype=65&appid=11&mode=detail&id=5720)

"Cessna have published SIDs for its 100/200 series aircraft.
They are not included in the airworthiness limitations sections
of the Cessna Instructions for Continuing Airworthiness (ICA),
and are not subject to any Airworthiness Directives.

Therefore, Cessna SIDs for 100/200 series are not mandatory
inspections from a regulatory point of view, even though they
may be designated "mandatory" by Cessna."


"The Owner/Operator must consider the relevance of any new or
revised ICA, taking into account the type of operation being
undertaken, the aircraft utilisation, age and general condition.
Before making a decision not to incorporate the new material
into the Maintenance Programme, careful consideration should be
given to the potential airworthiness and safety consequences of
this course of action. If it is decided not to adopt the new
ICA, an entry should be made in the aircraft’s maintenance records
that the ICAs apply to their aircraft, but have not been adopted.
If it is decided to carry out the inspections, then the
Maintenance Programme must be amended to include the relevant tasks"

[Genghis the Engineer]

Right now I can hear the Rotax engined light sport brigade muttering things about over weight Lycosorus powered antiques that should be pensioned off, the problem with the new breed of light sport aircraft is they lack the robustness required of a training aircraft, I am seeing the same issues in terms of landing gear & exhaust cracks, pulled rivets and general wear and tear on 150-200 hour Sportcruisers that I see on 15,000 hour Cessna 152 aircraft. The fact is that these aircraft are built down to a weight and what gives is the robustness required to endure the training environment. From what I have seen most light sport aircraft are unlikely to see the other side of 2000 hours and that is why Piper & Cessna have dropped the idea of being involved in this end of the market.

Sportcruiser really hasn't done well on numerous levels.

But, the microlight schools have shown massive and successful use from the C42 and various Thrusters, as well as in much smaller numbers the Medway SLA, numerous similarly constructed flexwings, and older types such as the AX3/2000. There are aircraft in that category which will provide that sort of robustness - of which the C42 seems to be current best of the bunch. There are plenty in flying schools flying 400++ hours per year with fantastic reliability.

Of course the C42 mysteriously has about the same sex appeal as a C152 - it's just a similarly excellent training aeroplane which unglamorously does exactly what it say on the tin (albeit at about half the running cost of a C152).


Back to the PA38 - yes, it's proven to be a poorly engineered aeroplane for long life, but that doesn't in my opinion detract from it being an excellent training aeroplane for any given flight or course - for all the reasons Jock explains so well.

G

[A and C]

You are 100% correct from the regulatory point of view and the unwise are delighted that the SID's are not mandatory.

Having done the SID's on one airframe and almost finished a second one ( both in the 10-13000 hour range) I can tell you that the SID's program is a well reasoned and necessary program for aircraft of this age and flight hours. If you have an aircraft that lives in a heated hangar and has flown only 1500 hours the it is a bit over the top but few aircraft meet this description.

If you are a wise owner of a 152 you will have a good look at the program and start doing the bits of the SID's that you think are the most likely to be needed, then the bits that can be done on a low cost opportunity basis while other inspections are being done but you ignore the program at your peril because things will come along to bite you in the wallet............. Or far far worse !

There was nothing on my aircraft that would have resulted in any airworthiness issues in the next 1000- 1500 hours but the early detection of light corrosion and the treatment of these areas will have undoubtedly saved me a lot of money in the medium term when combined with the recommended corrosion control program. Reliability is also an issue that the commercial operator need to consider the aircraft that has had the SID's program done has had no unscheduled maintenance done over the past eight months of club flying, maybe this sort of reliability is not required for a flying group but for some of us it is.

Quite frankly I think that it is foolish to ignore the SID's but from a commercial point of view I am quite pleased that some take this view as these aircraft will provide a rich haul of cheap spare parts for those of us who have taken the trouble to keep the airframes in good order.

[mad_jock]

A and C I was speaking from a Student point of view not an owners.

[A and C]

In an ideal world I would totally agree with you but in a practical world the state of play with PA38 maintenance and parts supply is approaching the time when it will be imposable for training providers to achive a reliable service using the PA38.

No one regrets this more than me but it is the way it is.

[mixture]

Its roomy

The traumahawk is roomy ? What are you on ? Are we talking about the same aircraft ? :}

[mixture]

I wouldn't say that you get any real benefit from a training point of from flying a touring aircraft. Just gives you a false sense of stability as everything is designed damped to death.

The stability makes it much less tedious to fly, which is great on navex.

Also as well the PA28 isn't really suited to be teaching people to land in.

Actually, it is actually quite useful in that if you don't get it right, it'll happily float half way down the runway.

It is also more manageable for gusty crosswind landings than a PA38 which would be all over the place.

[mad_jock]

I am an ex front row rugby player when teaching in a C150/152 I have one arm over the back of the seats and my hips twisted through an angle. Just so I am not sitting on the students and they have a clear space to fly the aircraft. Door shutting is a game of doors, one side closes the other side pops open. The seat is always max travel back.

Tommy I can sit straight and my shoulders don't touch the student or the side of the aircraft and I don't have the seat at max travel. I will grant you the PA28 is similar but I comparison to the other two seater's it is roomy.

[A and C]

I it would seem have a stature much the same as Mad Jock and find that my experience with the PA38 is much the same in terms of comfort.

The cross wind thing and landing thing mentioned by Mixture I simply don't understand unless an approach speed of greater than 1.3Vs is being used.

About twenty years back when I was instructing almost full time we had a bunch of budding airline pilots as instructors who had swallowed the whole airline thing hook, line & sinker. The result of this was hugh circuits so as to accommodate the very long so called stabilized approaches with airspeed increments added to the Vref ( as they called it ). All this resulted in landings that aimed for just inside the numbers at the threshold and actually happened nearer to the other end of the runway.

As most instructing is done at below MTOW just flying the flight manual 1.3Vs as an approach speed is enough as the real Vs for the weight is lower than that quoted in the flight manual and that provides you with a little airspeed margin. If you are at MTOW and you have a very gusty day you might want to add 5 KTS but no more as all that will result is the floating just above the runway described in a number of posts above and the inconsistent landings that hamper student progress.

Roll on twenty years from working with the big circuit and long "stabilized approach" brigade and I find myself flying a B737-800 into Chambray, no long straight stabilised approach but a speed stable approach with a constant rate of turn and decent onto a short runway, this from a visual circuit that would fit inside some of the efforts from my former employers instructors. The one thing all of these landings have in common is that they are flown at the correct speed.

Fortunately I now find myself instructing PPL students at a Military flying club were we can as the student progresses introduce the standard military curcuit with a curving final approach, the students thrive on this achiving very good control coordination and speed control with the time to solo usually 10-12 hours.

The instructing staff are all from professional aviation and all long in the tooth with nothing to prove and who ensure the aircraft is flown in accordance with the flight manual Not in accordance with any of the Folklore that seems to inhabit some flying clubs.

[fireflybob]

A & C, excellent post!

The only suggestion is to remark that 1.3 Vs is Vat ie speed At Threshold - as you say maybe an extra 5 on a windy day.

On certain single engine aircraft I have even calculated 1.3 Vs for different weights (allowing for airspeed position error at both stall speed and 1.3Vs) which is revealing and interesting!

Am also with you all the way about those bomber circuits and like you have also done tighter circuits on circle to land in B738.

[Fostex]

Agree on the circuits, tighter circuits require better energy management of the aircraft and are safer in case of a fan stop.

This sums it up perfectly:

A Sarcastic View of Pattern Flying - YouTube

[A and C]

First class video ! But as with all good humor it has a firm basis in truth.

[mad_jock]

Actually, it is actually quite useful in that if you don't get it right, it'll happily float half way down the runway.

It is also more manageable for gusty crosswind landings than a PA38 which would be all over the place.

Well the first is excess speed again. And more exposure to getting raped very close to the ground. More than likely the reason why PA28 have a high number of nose gear incidents every year.

And PA38 isn't all over the place if you have full flap and the right speed. And as we are talking about a trainer then fact that the student can control a more difficult aircraft than the more sedate touring aircraft means that they are pretty much set up for life. And the two seater tommy has done its job as a trainer.

Now we just need someone to produce a modern equivalent of the tommy. Nothing that's come out gets anywhere near the usefulness of the tommy for teaching people to fly.

[RTN11]

Now we just need someone to produce a modern equivalent of the tommy. Nothing that's come out gets anywhere near the usefulness of the tommy for teaching people to fly.

Looks like the PS-28 is set to be the one, a lot of flying schools seem to be testing them out right now.

They're affordable new, and they claim that they've solved the nose leg problems, so you should still be able to teach someone how to land it. Nothing will ever be as robust as a Tommy, but they've had their day and it's time to let go.

They have a rotax engine, so won't need to carry as much fuel, so the 600KG MTOM shouldn't be a problem, might actually be able to do a mass and balance and have it work, unlike a PA38 or C152.

All in all a very comfortable aircraft, with great vis, I just wonder how that massive screen will hold up to flying school use and abuse.

[mad_jock]

but they've had their day and it's time to let go.

That's very true and to be honest most of us would be more than happy to if there was something which was even just nearly as good.

But its only a tool to do a job, the major part of the quality of pilot produced will still be sitting in the RHS.

[Big Pistons Forever]

Speaking of trainers, albeit of the multi engine variety, Perimeter airlines in Winnipeg recently decided to close their flight school. They ran 3 Beechcraft Travel Air twins. The low time one has 19,000 + hrs but incredibly the highest time airframe is just short of 40,000 hrs :ooh:

There is no way spam cans like the Seneca/Seminole/Duchess would ever make it to those times. Ditto for the Tupperware specials like the DA 42 and the high wing Rocrap powered toy whose name escapes me. They don't build them like they used to !

[Fostex]

In fairness, longevity of an airframe all depends on the maintenance organisation.

Despite all passing certification there can often be marked differences in the quality of the work.

[Mickey Kaye]

I love to see a mark 3 rotax powered pa38

[baron_beeza]

I have worked on PA38 aircraft for many decades. The newest one I can recall working on had 400 hrs TT.
I have worked alongside LAME and IA types that have also maintained them since new. These guys generally have a CPL as well as the engineering qualifications. The type is well liked and very popular. They were subject to a range a SB in the early days and this was at a time when GA was booming.
Yes we all threw the banter about, the ratchet hatchet and traumahawk etc but it was all just bar talk and joking.
I think of the clubs that had fleets of PA38 aircraft and how those training hours paid all the overheads effortlessly. The Tomahawks paid the hangarage, wages, and all other overheads with ease. The hourly rate not only paid the operating costs, maintenance, office staff etc but also allowed many organisations to operate a range of less 'profitable' aircraft on the line as well.

It was equally obvious from within the hangar to see which aircraft were profitable for the clubs. Inspecting and maintaining the PA38 was a breeze in comparison to the similar 'C' brand machines.

The Tomahawks are brilliant little machines. It is interesting to see the backgrounds of the guys commenting. In my experience the knockers were the ones that knew least about them.
I am pleased to see so many positive comments here.

[India Four Two]

I did a few hours in a PA38 in Jersey in the 80s. I thoroughly enjoyed it, much more so than the 152 I flew a couple of years later.

Prior to flying it, I had plenty of spinning experience in various types, mainly Chipmunks and Blaniks, but I have to say, I found the PA38's spin-entry characteristics impressive to say the least. I can see why a low-houred student might have been frightened by the rapidity of the entry.

Having said that, the recovery was always benign and by the book.

[wsmempson]

I was taken flying in a PA38 some years ago, where the owner spun it and told me to look at the tail, which wobbled and shook like a loosely made blancmange. Genuinely scary...

[Genghis the Engineer]

I was taken flying in a PA38 some years ago, where the owner spun it and told me to look at the tail, which wobbled and shook like a loosely made blancmange. Genuinely scary...

Particularly if you have no basic understanding of the concepts of aeroelasticity.

G

[Beethoven]

I'm a Tomahawk flyer and love it. I have stalled it and found it not much different to most other types I have flown but I have never approached a spin. I would be interested to see any videos of the "tailshake" if they exist. There is one on You tube but to be honest that could just as easily by the camera shaking. Does anyone have any links to a clear video of this "phenomenon"?

[wsmempson]

Gengis, I understand the concept of elasticity perfectly well; I just don't particularly care to see it in action as I spiral towards the ground.

I did my first five hours training in a Tomahawk and I very definately fall into the camp that considers the PA38 to be a meritless piece of sh1t. A chacun son gout, as the French say.

[A and C]

You opinion of the PA38 says more about you than it does about the aircraft type.

The aircraft was built to train pilots and so was not the most pleasant to fly but it made sure that the tyro pilot was well equipped with the skills required to fly most other GA types with little or no extra training.

In short for the mission it was built the PA38 is a superb aircraft.

[cavortingcheetah]

Had the PA38 been flown solely by armed forces as an ab initio trainer then I doubt much trouble would have arisen with the machine. Tomahawk design instability was a little more electrifying than had been the case in civilian trainers, especially in a wing drop situation. Air Force training and instructors are designed to cope with snappier machines than the lazy old leisure flyer and all that was missing in the early days of the PA38 was a more carefully thought out flight profile manual and some experienced acrobatic instructors to train others in the aircraft.
Although it's not a good idea to pick up a dropping wing on a PA28 or a C150 with aileron, it can usually be done quite safely and effectively. That action though, of jerking the control column in a lateral direction through full deflection, is often the student's first reaction to deep stall wing drop. Try that little trick in a PA38 and you can flick into a spin over easy. You couldn't emphasis that sort of recovery in a POH some thirty five years ago, probably any more than now. You'd scare the punters.
I certainly didn't enjoy flying the machine in the hot and high African veldt but the aircraft certainly did what it was designed to do and students did benefit from it and enjoyed the 'luxury' of their CCs in the C172s or PA180s we used.

[Big Pistons Forever]

The PA-38 and the C 152 were introduced at the same time but look at how many schools still use the C 152 vs the PA-38 ?

For every PA-38 still being used commercially I bet there are 25 C152's.

The market has spoken......

[cavortingcheetah]

The corollary to that true comment is that the market doesn't train people to be pilots any more. It trains them to get right hand seat jobs in commercial jets with 200 hours. You don't need to be able to fly (by the seat of your pants) to be primarily a systems operator. This is just as it should be in twenty first century aviation until there arises a situation which calls for basic flying skills and decision making. Then one suspects, there is sometimes a rather large accident.

[A and C]

The market has spoken but not about the flying qualitys of the PA38..... It is all about the spar life and parts availability that I talked about much earlier on this thread.

If the PA38 had the same spar life & parts support as the C152 I would be operating the PA38 not the C152.

[Mickey Kaye]

"The corollary to that true comment is that the market doesn't train people to be pilots any more. It trains them to get right hand seat jobs in commercial jets with 200 hours"

Which is fundamentally wrong. They have the privileges to work commercially in GA. Therefore they should have the skills.

[gordon field]

The number of brand C or P still in service today is largely the result of the marketing policy of each manufacturer. At the time they were built C had 1000+ dealers and probably 800 Cessna Pilot Centers and if you make each of them take 1 aircraft a year then that is 1500+ sold. That is what they did in the mid 60s to kick start the Learn to Fly program and over the years that led to pilots moving up to 172, 182 and then Citations.

Pilots, students and engineers may prefer the Piper but now it is a question of parts availability in the area of operation. I've enjoyed flying both.

[A and C]

Following the post above and some of my comments I should make it clear that the problem with Piper parts is ONLY with the PA38, other Piper aircraft have a parts avalblity no better or worse than Cessna and a lot better than some other aircraft manufactures.

[BeechNut]

I had a Beech Skipper for a while and it too had time-limited wings, I think 12k hours if my memory's not too far off. It was a contemporary and competitor to the Tomahawk. I'm glad my current plane, a Beech Sundowner 180, doesn't have such a limit as it has 10.5k hours on the airframe :eek:

I come from an era and country that mandated spin training and have never been afraid to spin an aircraft if it was certified to allow intentional spinning. But that Skipper was quite violent as well compared to a Cessna or even compared to my Sundowner (I have a rare aerobatic model with the spin kit), and I only spun it once. I can say however that I've spun all the aircraft I've ever owned (C150, PA28-140, Beech C23 and Beech 77, currently own the C23, others long sold).

BTW I don't know if anyone's looked at aircraft values in Canada lately but they've sunk something awful. My Sundowner is now only worth about half what I paid for it 10 years ago. So much for all the jokes about "flying my retirement fund". Granted my engine is high-time (1750 hrs on a 2000 hr TBO), but it's basically worth no more now than a C150. I had been thinking of trading back down to a 2-seater now that the kids are grown but I think I'll hang onto it a while longer. Sorry for the rant/thread drift.

[Genghis the Engineer]

Gengis, I understand the concept of elasticity perfectly well; I just don't particularly care to see it in action as I spiral towards the ground.

I did my first five hours training in a Tomahawk and I very definately fall into the camp that considers the PA38 to be a meritless piece of sh1t. A chacun son gout, as the French say.

Perfectly, gosh. I'm jealous - I can think of three Engineers in Britain whose understanding I'd call "good", and I'd put myself at "mediocre". What's your issue with using displacement to reduce structural peak loads ?

G

[Fostex]

Agree Genghis,

Next time this chap is flying any sort of aircraft he should look out to his left or right and monitor the flex in the wings. How un-comfortable is he with elasticity now?

My father is a retired chief eng in the merchant navy and has some fantastic footage of being down in the bowels of the hull whilst looking down a long corridor. As the hull distorts in response to the motion of the ship upon the waves the view down the corridor becomes visible and obscured. Quite remarkable, and much better than the alternative of the hull snapping into pieces and spilling the black stuff. The same applies to wings or any load bearing part of an airframe, provided of course that the behaviour is elastic and within design limits.

[BPA]

Video of spin testing in the PA38 from 1979 here;

P-28 Tomahawk Spin Test - YouTube

And a video of spin training in the PA38 from a school in the USA here;

Training spins in the Piper Tomahawk PA38 - YouTube

Back in the 90's I was an instructor at a flying school in Sydney Australia that operated 2 C152s and 4 PA38s. By far the PA38's were the most popular, with larger or taller students and instructors appreciating the wider cabin of the PA38.

Most students would use the PA38 for their first few NAV's to save money, before moving onto the PA28 or C172. Hardly any students used the C152 for NAV's as they found it lacked the space for them to use a folder or kneeboard.

For me after spending 4 years flying the PA38 and the C152 I preferred the PA38, not only because of the extra space inside, but I found it produced a better pilot as it wasn't as docile as the C152.