Bulldog

[ZoomZoom]

Dear all,

I wish to pick your brains regarding the Bulldog.
Can anyone offer advice regarding the following

Maintenance costs (annuals , 50 hour checks etc) Fuel burn
Handling ( heard spin recovery can be a pig)
Would it make a good group aircraft?

I have spent all my time on touring aircraft so I have very little knowledge regading this type. Any views / opinions are gratefully received..........

Many thanks ZZ

[BroomstickPilot]

ZoomZoom,
Old Sarum Flying Club operate two Bulldogs. From what I can understand, the big problem with the Bulldog is spares, which are both difficult and expensive to source. Hence, hire charges on the Bulldog are very high.
The person to talk to at Old Sarum is Mr. Simon Burt, their ops manager. I'm sure he will be able to fill you in on the joys and tribulations of operating a Bulldog.
Personally, as a group aeroplane I would have thought a Slingsby T67M would be a better option. You'd get much the same kind of performance and spares should be much less of a problem.
Broomstick.

[ZoomZoom]

Thanks Broomstick will give him a ring.

[A and C]

Looked at the "dog" as an aerobatic aircraft for a flying club but I could not make the numbers work due to the fatigue index thing.

Untill someone gets to do the spar re-work and finds out how to get the cost down to something realistic the "dog" is a non-starter, this is a bit of a shame because it would be an ideal club aerobatic aircraft.

[airborne_artist]

Ultimate High (http://www.ultimatehigh.co.uk/index.php) operate some as well, so they must have an idea on the pluses and minuses.

Anything ex-MoD is bound to be expensive, over-complicated and hard to source spares for :}

[ACL]

My own Bulldog experience reveals that you get a lot of aircraft for the money, with maintenance costs comparable with any other 200HP injected Lycoming engine aircraft. Spares don't seem to be a problem for the Bulldog specialist maintenance orgainisations, and I suspect the buy price of a Bulldog + the mod to extend fatigue life (which will reduce in price once owners start getting it done) will still be less than a T67. For private ownership, even one at 95% of its fatigue life will give many years of typical PPL-type use, before you are faced with the decision on the modification. (Swedish, etc ones are lifed on hours rather than Fatigue Index). I would agree with the thoughts that if one were used a club aerobatic trainer, the fatigue life could be quickly consumed, though. However, doing 40 or so hours per year with gentle aerobatics sessions once or twice per month seems to have little impact on the fatigue index. I have been told that there is a market for fatigue-life-expired Bulldogs in the USA where they can continue flying under the 'Experimental' category, but haven't verified this.

When not doing aeros, you can put 100kg of luggage and stuff in the back, and go touring with decent range and speed.

Handling is delightful, if a little heavier than a Chipmunk for example. Visibility is great, so nice views - especially looking up at the ground, and it's difficult to make turns of less than 60 degree bank angle. Spin recovery is no problem - just learn how to do it with a suitably qualified instructor, and plenty of altitude. In reality even screwed up aeros don't seem to result in a spin - just hold everything central and you recover from an incipient spin into a nose-down attitude.

It's difficult to fault the Bulldog. If you're tempted by the type of flying it enables you to do... go for it!

[greeners]

ZZ

Bulldogs IMHO much under-rated. Super piece of kit, lovely handling, great viz, strong if heavier than ideal. Unlike a T67 it will actually roll and has far more room inside. Spin faff not an issue if flown properly, whether by CFS or AC recovery technique.

Come along to Aero Expo this weekend to have a look at one of ours and I'll happily discuss costs. Spares not ideal but not as bad as many make out either.

[Dan Winterland]

The poor reputation for spinning came from it's introduction into the RAF. At first, the spin recovery used was similar to the Chipmunk's. The problem with this (and a problem which didn't occur on the Beagle Pup from which it was developed) was that the very large canopy partially blanked the rudder during the recovery. A couple of aircraft were lost. A change in technique resolved the problem and there are no recovery problems. However, the aircraft may go 'high rotational' in a spin. It looks dramatic but is easily recovered.

[greeners]

High rotational spin only occurs (very occasionally) if stick is not held firmly back against the stops whilst applying pro-spin controls.

Incipient spin recovery in any case works very well in practice if inadvertently starting to spin.

[high voltage]

go in with your eyes open and beware the high maintenance and running costs. A superb aircraft nonetheless, built like a brick sh*thouse!

[Mercenary Pilot]

The Bulldog is a fantastic aircraft, I totally agree with the other comments regarding the sweet handling! I think I used to pay about £120 per hour to rent it so I dont think the maintenance costs could have been that bad?

[A and C]

I can't fault anything that ALC says but my usage was based on a minimum of 300 hours a year, so untill the spar thing is sorted no "dog" for me !

[MEON VALLEY FLYER]

I thought the RAF had one dog re-spared just before they sold them, to drawings and cert ? should be to hand.
As for cost, could it be a case of they need it so lets set the prise to milk them.
I remember a Beech sundowner had a new spar fitted aboutn 4-5 years ago (due to corrision on a 1700 hrs airframe) by airtime EGHH for about £ 3k, as part of a CofA issue.
Then again the dog was built strong, lots of easy to get at parts !!! so hours to complete works take longer and thats the main reason mx costs ate high.

[airborne_artist]

Handling ( heard spin recovery can be a pig)

Can't think where you got that from - we span them regularly on RN EFTS and I don't recall any issues, ever.

[hugh flung_dung]

ZZ: I'd reinforce what others have said about the handling, the Bulldog is a lovely aeroplane. We've operated them successfully at Old Sarum Flying Club for nearly 10 years - mainly for aerobatic training. Superb in roll, a little heavy in pitch, not terribly fast for the power. They have a "proper" spin when induced but are unlikely to spin from manouevre unless seriously provoked, spin recovery is standard.

The engine is standard Lycoming IO-360 (same as Arrow, Seneca and many more) so spares are very easy. The propeller is Hartzell. Fuel flow is roughly the same as an Arrow (10-14 gph leaned for best power, 8-10 when leaned for best economy). Engine is lifed at 1800/2000 hours.

Airframe spares haven't been too much of a problem. Batteries are expensive.
The stub spar needs a major mod around 5000 hours which extends the airframe life to 9760 hours (based on memory!); the estimate for the spar mod was £20k but I don't think anyone has done it yet.
Some aircraft have fatigue meters fitted and I believe the spar mod is required at F.I.114, but none of ours have had fatigue meters so someone else can confirm this. Most of the ex-RAF Bulldogs were sold with high FIs.

It would make an excellent group aircraft; easy to fly and with no vices. Some of the 'dogs on the market have basic panels and very high FIs and engine hours, others have an "airways" fit or dual panel and relatively low hours - prices vary accordingly.

Pop down the M3/A303 to Salisbury if you want to fly one.

Edited: oops, forgot to add:
DeHavilland support Ltd are the font of all technical knowledge http://www.dhsupport.com/beagle/index.html
Old Sarum are at 01722-322525, PM me if you want more details

HFD

[ZoomZoom]

Dear all

Great advice, I appreciate the time.....

I might just make that trip down the M3....

Thanks ZZ

[A and C]

You are quite correct that BAe did do the spar mod on one aircraft, and quoted the MoD a price per airframe that approached the level of the national debt of Bolivia.

So the MoD went off and found another type of aircraft to do the job, it is my contention that BAe was of the opinion that the MoD was over a barrel and would pay to have the work done but this backfired on them!

I have no doubt that when the time comes the UK GA industry will find a way to do the spar job at a fraction of the BAe price but I am told that a number of special bolts have to be made and it is financing the manufacture of these bolts that is the sticking point at the moment. Untill there is enough demand for a production run of these parts the total cost of the job is only speculation but I would not want to be footing the bill for the first aircraft spar re-life.

[MEON VALLEY FLYER]

So can anyone explain the real issue with the spar. Did SA just decide because the RAF were going to throw it around, they would give it a life limited to be safe, or was a problem found along the line.

As for expense of it. I have never flown any SA products and am not familiar with the design detail. But could someone explain the spar detail and why it costs so much to replace, hell I don't even know if we are taling about a wing spar or a ctr carry through ? After all its just a little ally fixed gear single !

[A and C]

The RAF dogs have box that measures the stress (or fatigue) that is put on the airframe and the life of the spar assembly is lifed acording to the mesurments from this box, so if you fly only S & L the readings will be low and the aircraft will last a long time.

The snag is that aerobatics is what the dog is all about and it is a very good aerobatic trainer and so is often mis-handed this all amounts to the fatigue life getting used quite quickly if you use the aircraft for what it is good at (it is not a good touring aircraft!).

I looked at a dog for the leaseing business that I have and talked to DH support about the re-life of the spar and it requires the replacment of a lot of bolts with oversize items and the reworking of the bolt holes, the problem is the manufacture of the bolts requires a production run to make it economicly posable, so without an order for say thirty bolt sets the price of the bolts exceeds the value of the aircraft.

The dog is not the only light aircraft with a fatigue life the PA38 has a 13000 hour spar life and some of the UK fleet of PA38,s have already been scrapped as they have reached the spar limit.

It's all very well trying to get around the fatigue issue and if it is your aircraft and only you fly in it then you take the risk of it coming apart in the air and except that risk.
For me with a business I have to provide a product that meets all the requirments of a public transport C of A afterall if I did not the lawers would have a field day with me in case the of an accident even if the spar life had nothing to do with the accident.

The bottom line is how much is YOUR life worth to you?

[ACL]

Interestingly, the hours life on Bulldogs not fitted with a fatigue meter must be based on worst case usage, as typical ex-RAF ones will have 8,000 to 9,000 hours, at 90 to 95% fatigue life. Straight and level flight adds nothing to the fatigue reading (but each landing is logged and has a tiny effect on FI), so with gentle flying, airframe life should not be an issue.

The current estimate on the spar mod cost is a similar order of magnitude to an engine replacement - TBO 1,800 hours. We all mentally or physically allocate an 'engine fund' - say £10 per hour, so another £10 per hour towards the spar mod isn't a huge deal... for a private owner for whom all this is some way off in the future. As a business proposition, it's clearly a different matter, as time to mod will be much shorter, down-time while it's being done means no income, etc.

Once done, the mod extends the FI from 114 to 200, so almost doubling the airframe life. I hope Bulldog owners can pull together and take advantage of economy of scale when it comes to commissioning a run of bolts, etc. That way the cost will be reduced for all of us.

[stevef]

The engine TBO is reduced to 1400 hours with the aerobatic inverted oil system. Something to bear in mind regarding operating costs.

[hugh flung_dung]

SteveF: where did you find "engine TBO is reduced to 1400 hours"? The AEIO-360 has a reduced TBO but (AFAIK) not the IO-360 fitted to most Bulldogs.

HFD

[stevef]

HFD - sorry, I couldn't remember the AEIO-360 designation at the time, that's why I wrote 'aerobatic inverted oil system'. As you say, the IO-360 has the standard TBO.

We have a Bulldog in our hangar at the moment and a very solid bit of kit it is, too!
Steve.

[TwoDeadDogs]

Hi all
What's so special about these replacement bolts? Is there no way that a standard MS or NAS bolt can be used? I've encountered this kind of thing on another aircraft and smelt a rat from the word go.I had no choice but to use the "special" bolts, which turned out to be metric bolts on an Imperial aircraft, at 50 quid a shot.There has to be a way around it.
regards
TDD

[A and C]

I don't have the full details but these are oversize close tollerance bolts that have to match the re-worked holes.

I am sure that the guys at DH support are smart enough to know the difference between a standard bolt and what is required for this job.

[Mandator]

TDD: The bolts are special because they are 64th inch oversize on the standard AGS diameters. This allows for reaming the exisiting bolt holes and hopefully taking out all the nasty little cracks which have already started to form by the time 114 FI is reached. The reaming also makes sure that the exisiting holes in the spar and the newly drilled holes in the reinforcing straps are in perfect alignment. Failure to use the right bolts and the right techniques will invalidate the subsequent fatigue testing which was carried out after the fatigue test specimen was repaired by embodiment of the modification; it will jeopardise the future ultimate life of 200 FI if the mod is not done correctly. The answer to getting the cost down is to run a programme of say ten aircraft at a time, which will make it economic to produce runs of reinforcement plates and fasteners. Also, the learning curve of doing what is a serious dockyard job can be spread over the whole batch of aircraft; the turnround time will also drop sharply as the team gains experience. This job is not one to be tackled by every M3 on a little airstrip doing just one aircraft.
To pick up an earlier post, there are no Bulldogs without a fatigue life limitation to when modification BH193 must be carried out. The ex-RAF ones still using a fatigue meter can run to 114 FI, which can exceed as much as 10,000 hours if the aircraft is flown carefully. However, all the rest (ie, those without a fatigue meter) are lifed very much on the safe side at 5,000 hours before the modification must be carried out. All Bulldogs - ex-RAF or not - then encounter a tailplane attachment limitation at 15,000 hours, but that is far enough down the pike not to be a concern at the moment. In answer to Meon Valley Flyer, the real problem with the spar is that during the full scale fatigue test it bust. Therefore, not doing modification BH193 is not an option for Bulldog owners if they want to fly (safely) beyound 5,000 hours (or 114 FI on an ex-RAF aircraft).

[TwoDeadDogs]

Hi there,
I'm not doubting you,but it smacks of the Chipmunk/Tiger Moth saga all over again.Aircraft that are sold to the public and suddenly require major mods to make them "safe", after years of rugged military service.:rolleyes: Either they're fit for flight or they're not.The bolts I had to put in mine were also close tolerance oversize.
regards
TDD

[Mandator]

TDD - you could hardly expect the RAF to dispose of its Bulldog fleet with all of them freshly modified and ready for 50 years of effortless life in the hands of their new civilain owners, especially with the current Government holding the purse strings. Buy a Bulldog, either ex-RAF or ex any of the other military forces and you are buying military surplus kit - its the law of the jungle, buyer beware. Some of the RAF Bulldog disposals represented a really good buy, especially for the person who got the one aircraft which had Mod BH193 embodied. On the other hand, other Bulldogs were clapped out and in need of serious cash to be made fit for purpose. Most of these seemed to find their way to the States where they fly as Experimental and their owners ignore the fatigue lives - until the first one claps hands like the Beeches did, that is. The fatigue life issue was made quite clear at the time of the RAF disposals and to those who did their research it came as no sudden surprise that a big modification was in the offing. Indeed, when the first batch of aircraft was sold the ex-RAF Bulldog Series 120, Model 121 did not have any form of civil certification and it could not be flown on a CofA; that situation was sorted out quite quickly, but at great cost in time, effort and no doubt hassle for the people involved. In fact, British Aerospace went so far as publishing a letter which advised their forecast of costs to purchase and embody the fatigue modification. It seems to me that the bottom line is that if you want an aircraft which holds together with standard bolts, has a relatively long fatigue life and is cheap and easy to maintain then you have to buy what might be a rather bland US aircraft designed and built for the civil market - a characterful British aircraft designed to meet a military requirement, such as a Bulldog, or a Chippie or a Tiger for that matter, does not fit the bill.

[A and C]

First I would like to thank Mandator for puting flesh on the bones of what I had said, my reseach into this matter only went deep enough to decide that the Bulldog was not the aircraft for my business because of the spar issue costs.

What seems to be a very worrying train of thinking from some of the posts above is a hint that "someone is ripping the poor pilots off" and no doubt "they" whoever "they" are are getting rich and stoping the fun.

This is the type of thinking that I would expect from the likes of Ann Robinson and the rest of the BBC's Wachdog team.

I do think that the BAe price to fix the Bulldog spars was aimed at the MoD with a veiw to them not looking at it to hard at the price before saying "yes" to the work. I also think that the "real world" engineers in the GA industry can bring the price down BUT there is no getting around the techincal issue of the fatigue life of this wing structure.

This is not a "consumer issue" it is not an industry "rip off" it is about keeping the wings firmly attached to the aircraft and it is not going to be cheap, the RAF did the sums on this and that is why they replaced the aircraft.

[MEON VALLEY FLYER]

I second that thanks to mandator. That clearly says whats what. Like most I thought of a Bae rip of attempt. But you really need to look at it as 'military surplus'.
The bulldog was bought to do a job with a finite life span in mind, as with most military kit, and without any future value in mind at the end of this.
It was tested to ensure it was suitable for task and a weakness found. but this was within the scale of use and life the mod needed so nothing was done. If they wanted them to last longer SAL could have redesigned them and huge cost and removed the issue. It wasn't needed, so the fatigue issue is here now.

Sensible answer. buy them at the right price, enjoy them and all get together at the end and sort it our for less £.:D

[gyrotyro]

Hi

The French seem to take a more pragmatic view.

There are some Bulldogs operating here in France and when operated on the "F" register they come under a permit to fly situation and the fatigue index does not matter.

[MEON VALLEY FLYER]

But surery whatever registration its on won't stop the wings folding !!!!!!!!!!!

[Mandator]

MVF - Got it one, good buddy! A crack in the main spar cannot tell the difference between the registration letters or whether the aircraft is on a CofA or a Permit.
The Yanks ignore the airframe lifing also, as they did on the Beech whatsits - until they clapped wingtips.

[TwoDeadDogs]

Hi all
I stand corrected....I thought the Beechs that crashed were all involved in regular aerobatics and mock dogfights and subject to greater stress than most of their breed.Also, the operators of those Beechs have come up with solutions to the spar problem (at least three available) without delay, gross expense and official handwringing.
regards
TDD

[Mandator]

TDD
There is no delay with the Bulldog answer - modification BH193 is ready to rock and roll right now. If you buy the bits and do the job on an individual aircraft basis then costs will be high. However, set up a programme and run say ten or twenty aircraft down the same line then costs will be contained. I don't think there is any official handwringing going on - you ignore the life limitations at your peril.