Interesting story for anyone who flies IFR in a single!

[ForkTailedDrKiller]

I have flown nothing much other than the FTDK for the last 500 hrs, so I for the first time in 35 yrs of flying I am pretty much in tune with this one aeroplane.

I normally use a 1200 rpm idle, and at that the suction warning light is not illuminated.

Last week, taxying in from a flight from "The Curry" I noticed the suction warning light illuminated at 1200 rpm and I thought "that's interesting". Had to increase rpm to 1300 to extinguish it.

"Its never done that before I thought to myself!"

Today, about half way into a flight from Townsville to Atherton while in VMC in top, the suction light illuminated, suction guage went down to zero.

Scratch one vac pump - and I only have one!

Fortunately I do have an electric standby AH and a couple of GPSs to steer by.

I have had some harsh words to say about Cairns ATC in the past, but I would like to thank the Centre controller on 120.15 and the CS Appr controller who was on late this afternoon for your help. Good one guys!

A couple of vectors and a descent to radar lowest safe got me safely down through the overcast.

B*gger it! Now I have to grope my way home tomorrow VFR.

Moral of the story is: if your vac pump needs higher than normal rpm to extinguish the low suction light - it may be about to sh*t itself.

Always carry a couple of covers for the AH and Gyro Compass. I was wandering around a bit until I wacked sticky covers (which I carry) over these.

Dr :cool:

PS: Anyone have any experience with the new "super dooper" long life vac pumps (see Global Aviation) over the standard garden variety?

[training wheels]

Thanks for the interesting headsup, sir. You seem to be doing a lot of single engine IFR flying. Is it all commercial operations or private?

[CHAIRMAN]

FTDK,
I'm on my third one in 300 hours. Seems they had a problem with the mk1 and mk2 versions. Hopefully the mk3 version will go the 2000 hr guarantee!
My son had one of them fail on a Angelflight in IFR. The electric AH (Castleberry bought at Oshkosh last year) made life easier, but as you said, it was disconcerting without the u/s instruments blanked off!

[ForkTailedDrKiller]

training wheels

All of my flying these days is private ops - for business. I will do about 200 hr this year, 99 percent on an IFR flight plan.

Dr :cool:

[VH-XXX]

The new "piston" style vac pumps are apparently the go nowdays as everyone is pushing them, however I'm yet to see anyone operating one.

[Peter Fanelli]

Anyone remember back in the 80's when auto pollution equipment on many cars included a vane type air pump to pump air into the exhaust manifold to allow combustion to continue....... blah blah blah

How is it the the japanese can make an auto air pump which NEVER has to be replaced during the life of the car and yet aircraft are stuck with these stupid dry vacuum pumps?

There's gotta be many better ways to get a source of pressure or vacuum in the cockpit.

[Jabawocky]

Just a thought for those with single vac pumps etc. I know of a few IFR machines that have a non TSO'd instrument for backup, some actually fly off this instrument and carry the others for legal obligation.

The recent flight into space by the Rutan Spaceship One was done with the Dynon D10A.

I have one and its brilliant.

CASA have also approved them for fitment as a backup in IFR a/c.

I would strongly urge anyone not having one as a backup that flies IFR to consider them. They are not expensive at all, and are very reliable. Ours has seen over 500 hrs run time and nil defects. If you want the compass function to be accurate I would suggest fitting the external mag flux compass though.

Model D10A
http://www.dynonavionics.com/docs/D10A_intro.html

News from CASA http://www.dynonavionics.com/docs/news_australia_casa.html

J

[ForkTailedDrKiller]

Jaba

The Dynon is a great bit of gear, but unfortunately it would not have helped me much.

I have a TSO's electric 2nd AH, so which way is up was not an issue. Also I can fly around quite happily on partial panel anyway, although doing it for real may have got a bit of adrenaline flowing. I would however not recommend to anyone flying IFR in a single that they rely on partial panel to get themselves out of strife.

The GNS430 and the GPSMap296 were both still functioning so I could still find my way around OK and would have flown an Appr if necessary.

The biggest issue for me is losing my co-pilot George! He is a great mate and I would much prefer to sit there an watch him fly the aeroplane.

I do recurrent training with an ATO every 6 months or so between renewals. He makes me hand fly all the approaches for my renewals.

Dr

[185skywagon]

How is it the the japanese can make an auto air pump which NEVER has to be replaced during the life of the car and yet aircraft are stuck with these stupid dry vacuum pumps?


They are mostly wet vac pumps especially in the case of diesels, where these pumps provide the vacuum for the Brake systems. They are usually on the back of the alternator. They appear to run forever without intervention.

I have had wet vac pumps on my 185s. They can be as unreliable as dry pumps. They give no warning when they are about to fail and are very expensive to O/H.

[flywatcher]

The Cessna Pilots Association has a long running thread on their forum detailing the problems and associated short operating life of the piston vacuum pumps. Some are only lasting a few hours, some about sixty, and that includes the C revision.

[squawk6969]

And they are damn unreliable when the engine stops, which is a bugger if you are on top of cloud!:eek:

Pays to have a Lecky one too:ooh:

SQ

[bushy]

I remember one C206 that kept blowing dry vac pumps. Some only lasted abour 50 hours, and no-one could figure out what was going on, until one day a clever LAME re-balanced the prop, and the problem went away.

[ForkTailedDrKiller]

Its this one that I am particularly interested in.

The Sigmatek AEON dry vacuum pump is a radical new design, warranted for a full 2,000 hours or 5 years. The problem carbon vanes and rotor found in other pumps have been replaced with a piston pump that runs significantly cooler than older designs, thus ensuring long life.

Dr

[tinpis]

What was the last thing that went through the single engine IFR pilots head ?

His duff vac pump. :hmm:

[flywatcher]

FTDK, before you buy one of those check out the forum in Cessna Pilots Association or PM me.

[Counter-rotation]

I've often wondered why these a/c seem to have the "primary" instruments (the AI and DG) powered by air, and the T&B is electric (not allowed to be powered by the same source).
Why not the other way around. I have had more failed vac. pumps than I care to remember, but only ever two failed T&B. And while I'm at it, why these pin head sized suction gauges (Cessna), hidden behind the co-pilots control column. :ugh:
And if the "electric" instrument fails, it is usually the instrument itself at fault, not a failure of electric power supply. When you drop a vac pump, you now (typically) have two perfectly good instruments deprived of vacuum, thus rendered useless. Both of them.
Does it go back to the days of venturi derived suction (almost impossible to fail) when electrics also probably weren't what they are today?
I once had a vac pump replaced, then taxied away, took off, got no more than 20 miles away and had to turn around - the "new" pump had just failed. Less than one hour. But wait - I told the LAME when I pulled up that it had just crapped itself, and his remark? He had one he'd just fitted fail in the runup bay yesterday...
Also once saw the vac gauge the second it dropped to zero. Day VMC, so I flew along casually watching the AH and DG. After a few minutes they went ABSOLUTELY HAYWIRE BEZERK. Spinning and toppling and carrying on. To fly in IMC with that happening in front of you would have to be impossible. That aircraft was due to be dispatched the next day on night freight... Thank God it didn't last one more day or someone would've had an interesting time.
CR.

[Brian Abraham]

FTDK - Just talking to a maintenance organisation today who specialises in the Bonanza and owner was running around checking all the dry vac pumps on the shelf, as some notice has come out about non overhaulable pumps being overhauled and put into the market. Can chase up exact details if you wish.

[Chimbu chuckles]

Hey FTDK....I recently sent an email to my maintenance org to check whether my vac pump is wet or dry type...it has never let me down in 7 years and wet vac pumps were commonly fitted to 60s Bonanzas and other aircraft...and commonly last indefinately.

Wet vac pumps lost out to dry vac pumps because dry were so cheap and OEMs favoured them...so they died a death in the 60s...there is a company in the states manufacturing wet pumps again.

Seems the only downside to wet vac pumps is an oily belly...hence an air/oil seperator is also perhaps desirable. My Bo's belly gets a little oily so perhaps I have a wet vac pump.

While NOT cheap they seem to me to be good value for money.

If my vac pump turns out to be a wet type I'll be VERY happy.

[ForkTailedDrKiller]

Chuckles

My Bo gets "dirty belly" but definitely has a dry vac pump. Doesn't use much oil but seems to blow enough oil vapour to ensure an oily underside.

The wet vac sounds interesting, will look into it.

The dry pump that quit yesterday was at least 3 yrs and 500+ hrs old. Don't have the books here to check when it was installed

I have had many vac pump failures over the years, including one on a pitch black night (due smoke) while on NVFR test nav.

Have had one electric AH fail (in this aeroplane) and two total electric falures (not this aeoplane).

I have my bases pretty well covered, but can you really have too much redundancy?

Brian A - would appreciate the details thanks.

Dr :cool:

[qtn]

We used to have the same problem with vac pumps until we got the prop balanced. I remember some aircraft fitted with a venturi style vacuum system. This would get rid of any failures of the engine or pump type.

[MikeJulietHotel]

This video reviews both dry and wet vacuum pumps. It may be of some interest.

M

http://www.youtube.com/watch?v=pJC0SScgQyw

[Chimbu chuckles]

This article in the latest Aviation Consumer is interesting...and is what led me to see what kind of vac pump is installed in my Bonanza.

In free markets—or so the theory goes—good products rise to the top like cream and bad products are weeded out and tossed aside to wither and die. In the real world, it’s messier than that, thus we have VHS instead of BetaMax, PCs dominate Macs and the overwhelming majority of airplanes have failure-prone dry vacuum pumps instead of bulletproof wet pumps. What happened here? The precise details seem to be lost to the sands of time but the short version is this: Dry pumps appeared in the mid-1960s, they were substantially cheaper than wet pumps and by the time owners realized how unreliable dry pumps were, the aircraft manufacturers had established them as the defacto standard. And because the OEMs could get away with that, the two wet pump manufacturers—Pesco and Garwin—got out of the wet pump business and eventually disappeared entirely.

In the interim, owners who have always preferred wet pumps over dry pumps have simply retained them, finding shops to overhaul them or in many cases, just letting them perk merrily along without so much as a friendly swipe from a 9/16th-inch wrench. That sort of thing gives some mechanics the willies, but vacuum is vacuum and owners are understandably reluctant to fix what ain’t busted. As far as we know, there’s only one manufacturer of new wet pumps, the Airwolf Filter Corp., an Ohio-based company best known for add-on aircraft oil filter systems and, lately, wet vacuum pumps. At least one company we know of, Airpower, overhauls Pesco and Garwin pumps and markets these through Aircraft Spruce and Specialty. A third company, M-20 Turbos, made a run at the wet pump market with overhauls and a proposed new wet pump, but the company informed us recently that it’s no longer in the pump business.

Buy Or Not?

The economic ascendancy of dry pumps complicates the wet-pump purchase decision for most owners. Diehard owners of wet pumps tell us they’re not interested in converting to dry pumps. But having suffered through multiple failures, many owners of dry pumps are contemplating a walk on the wet side. But it’s not so simple. Any airplanes manufactured after the demise of wet pumps—early to mid-1960s—are usually approved only for dry pumps, so even though a wet design will bolt to the same accessory pad, the installation wouldn’t be legal without an STC. For any owners interested in converting, Airwolf has a long approved model list (AML) for virtually everything flying. As attractive as wet pumps are and even though Airwolf makes the conversion process easy, we suspect many owners pass on wet pumps because of the hassle and cost. It’s just easier to buy a rebuilt Rapco or a Tempest, bolt it on and go flying. At $1599, the Airwolf pump is nearly six times more expensive than the price-leader Rapco overhauls and more than four times as much as top-of-the-line Tempest dry pumps. Moreover, dedicated air/oil

Airwolf’s pump is an improved derivative of the original Pesco, found in thousands of light aircraft.

Separators for the wet pump are must-have equipment and if you don’t have one installed, plan on another $400. Bottom line: Budget $2200 to $2400 to convert from a dry pump to a wet pump. But realistically, wet pumps appear to be so reliable and durable that most owners may never have to replace or even overhaul one. Airwolf, for example, offers a generous 2000-hour/10-year warranty.

How They Work

Wet pumps have such a superior service reputation over dry pumps that you’d assume that they’re radically different in design. In fact, they aren’t. And a better description of a wet pump may be "oil misted" rather than wet, since they are anything but submerged in oil.

As shown in the photos at left, wet pumps and dry pumps share a fundamental design similarity. Both pump or compress air by spinning blades or vanes inside a sealed bore. Both types also use graphite for the vanes, but at this juncture, the two designs diverge.

A wet pump’s vanes are three times thicker than those found in the typical dry pump and they’re composed of a softer graphite. While the dry pump’s vanes bear and seal against a polished bore inside the pump, they run dry, relying on powdered graphite from the wear process for lubrication.

Wet pumps, on the other hand, are lubricated by a light misting of oil metered into the pump through accessory case inlets. In addition to lubing the vane-to-bore contact surface, the light oil film also seals better, which improves pumping efficiency. In the Airwolf pump, the vanes seal against a cast iron insert, a material that naturally contains embedded graphite, further reducing friction.

In part, this is why wet pumps are more durable. But there’s more to the story. Wet pumps are more robustly made than are dry pumps, which accounts for their higher prices. Note that the Airwolf pump has a heavy, precision machined rotor which rotates on a pair of ball bearings, one sealed and one constanly lubricated by engine oil.

Airwolf Pump

Airwolf sent us two pumps for trials, one of which arrived disassembled so we could examine its innards. We were impressed with the overhaul quality of the machine work on this product. The pump body is machined from a single billet of 6061 aluminum and nicely anodized a striking gold color. The body, end cap and sleeve seem to be similarly well machined for perfect fits.

Airwolf’s John Kochy told us the company’s pump is a direct descendent of the original Pesco pump, whose plant was in Bedford, Ohio, near Airwolf’s Middlefield, Ohio headquarters. He makes no claims about reinventing the wheel.

"Our specialty is not inventing something from scratch, "Kochy told us, "but making something better." Those improvements include the billet body rather the original cast aluminum, plus a handful of minor proprietary changes Kochy declines to reveal. He explains that the largest challenge in building a wet pump—which drives cost upward—is the requirement to hold exceptionally tight mechanical tolerances. For example, all of the clearances in the pump are in the 0.0001 to 0.0003 inch range. "It would be a lot easier if we could open those tolerances up, but if we do, we lose performance." (This leads us to wonder how efficient overhauled pumps are compared to Airwolf’s new models, but the company doing the overhauls didn’t respond to our queries.)

Trying It

From our previous test of pumps, we know that all of the dry pumps and Sigma-Tek’s new Aeon piston pump deliver adequate vacuum through the entire RPM range, although their output falls off at idle speed. (See Aviation Consumer April 2007 for the full report.) We wondered how the wet pump would compare.

The Airwolf clearly moves more air than the dry pumps do, probably due to the oily seal between the vane bearing surfaces and the inner bore of the pump. As the lowest possible idle our pump motor could deliver—about 600 RPM—and lower than the typical engine would be idled, the pump was easily delivering 3 CFM at over 5 inches of mercury. At these low RPMs, dry vane pumps typically deliver marginal vacuum, although the Aeon pump did better. We weren’t surprised that the Airwolf pump was working harder to deliver more vacuum. Our DC test motor drew 9.9 amps when running the dry pump, but nearly 25 amps when the Airwolf pump was running. Apart from high cost, one glaring weakness of wet pumps is their reputation for spewing oil, which finds its way onto the belly of the airplane. The OEMs used this as a selling point in the conversion from wet to dry pumps. And while it’s true wet pumps are messier than dry pumps, we think the argument is overstated. In running the wet pump on our test stand, we placed a sheet of clean white paper in front of the exhaust vent and collected a barely detectable misting of oil. The exhaust smells warm and oily, but it’s hardly spewing oil. (Admitedly, it might exhaust more if the pump were being oiled by engine oil.) Airwolf’s Kochy told us the pump consumes less than 3 cc’s of oil every 10 minutes, which equates to 0.02 quart per hour. That may vary with installation—some owners do complain about an excessively oily belly—but a properly installed air/oil separator catches most of the oil. Just know this: A small number of owners still report serious oil issues.

Conclusion

We have no reservation in saying that a wet vacuum pump is right for every airplane—it’s just better technology than the dry pump. But it’s not right for every owner, chiefly because of cost. We think an owner who flies a Cessna 172 or a Piper 180 50 hours a year and never ventures into IMC is better off retaining a dry pump and replacing it as necessary with an overhauled Rapco pump, the value leader in dry pumps.

But for hardcore IFR pilots or those who worry about dry pump failures—and it’s a question of when, not if, a dry pump will fail—a wet pump is as close to a lifetime component as any of us are likely to get. Backing up instruments is always a risk tradeoff. The belt-and -suspender approach is costly and not always necessary for owners on a budget. We think wet pumps are reliable enough to install in lieu of any other kind of backup, such as electric gyros or electrically driven backup vacuum pumps.

[Centaurus]

Watched a wealthy businessman pilot practicing IFR in an Elite Synthetic Trainer. He flew beaut ILS's and wonderful holding patterns on the autopilot. Even his hand flying with a flight director was spot on. After all, isn't that what a flight director is for - to make instrument flying easier because there are less instruments to scan? It was suggested to him perhaps he should also practice hand-flying on limited panel - in other words no artificial horizon. He disagreed saying his aircraft (a new sophisticated single) never needed such manoeuvres.

A few minutes later an instructor quietly failed the artifical horizon without the pilot being aware of anything gone wrong. It took less than 45 seconds for the graveyard spiral to occur and the bloke didn't have a clue what was going on - nor how to recover on instruments. He was more pissed off with the instructor for failing the AH than with himself for his lack of skills.

Moral of the story? If you can afford the money to practice instrument flying on a synthetic trainer, make sure the money is well spent by improving your skills on limited panel flying. One dark night you may need to use those skills to save your life.

[ForkTailedDrKiller]

Good one Chuck!

We can always rely on you to have ALL the info!

Centaurus - I'll second that! However, if you can afford to own and operate a new sophisticated aeroplane, why bother with a simulator (unless its full motion). Go fly the aeroplane. My Instructor/ATO really works me over!

Dr :cool:

[Captain Nomad]

One option that has not been presented is installing a standby electric vac pump. One aircraft in our fleet has one and it is a great thing to have for peace of mind. Activated by a flick switch and hey presto - vac restored. Every so often we give it a run for internal lubrication even while the engine driven pump is operating (will boost the suction reading a bit when on line - also audibly a bit noisy). I think for a SE IFR aircraft it is money well spent. In FTDK's case when your engine pump desides to quit at least you have an instant backup which will at least get you out of trouble until you get home for maintenance! :ok:

[ForkTailedDrKiller]

Capt - for the same money (from my enquiries) you can install a wet vac pump and pretty much eliminate the issue. I have a lecky AH so I already have instant backup.

Has anyone tried simulated IFR on the flight instrument display on a Garmin GPSMap 296?

Dr :cool:

[Captain Nomad]

Yes, I noticed you mentioned you have an elec AH but the standby elec vac pump will give you George back if he needs the DG to fly for ya!

[ForkTailedDrKiller]

'Since the 1970s, when cheaper dry pumps were introduced, they have been made with thin, brittle carbon vanes which usually break before 500 hours. Dirt in the line, solvents, water, reverse propeller rotation from backfiring or even backing the prop by hand - all can cause catastrophic disintegration of the vanes.'

Did you know this?

I didn't until told by a LAME a couple of years ago!

Dr :cool:

[UnderneathTheRadar]

Great in theory but my only experience with a loss of primary instruments was the AH itself dying and the standby VAC pump didn't do anything to contribute to the situation.

On the downside, it was my first IFR trip after being let loose with a rating.

On the plus-side, I'd emerged from the clouds less than 30 seconds earlier.

UTR

[das Uber Soldat]

DR: Re Garmin 296 backup instruments: Yeh, there is a good few seconds delay when using them. Not the best alternative.

[ForkTailedDrKiller]

das U S - the 296 is my last ditch effort to stay alive when all else has failed!

Dr :cool:

[Wheeler]

FTDK and others, how often should you change a standard vac pump - IFR or otherwise?

No so long back I bought an IFR single with a vac pump that had over 1200 hours on it, working perfectly, with both the owner and his LAME saying it was pefectly safe and legal. I changed it. Some LAME's seem to say if its working its OK, others say 500hrs no matter what, others say 500 hours unless its the Tempest type and you can check its not worn beyond limits.

Another of my aircraft had a stanby electric vac pump - probably only ever ran for about half an hour. One Australian Cessna dealer said both vac pumps were fine and signed out a new 100 hrly. Another (whom I had the misfortune to 'visit' immediately after same 100hrly) said the aircraft was illegally maintained and both must be changed immediately because they could find no record of either being changed during the last 500hours.

Yeah yeah yeah, it depends, its a matter of interpretation, its whether you are working to Shed 5 or manufacturers scheme etc etc - so who knows?

On related matter, I now have an aircraft with one of those standby vac thingys that works on manifold pressure. It seems to work quite well, but are they any good when the real thing happens and will George keep going?

[ForkTailedDrKiller]

Dunno Wheeler!

Maybe there is a LAME sticks his head in here can shed some light on it. I have had the FTDK for close on 500 hrs and it hasn't come up so far. My LAME is a stickler for "by the book".

But I got a new one today !!!!!!!

You gotta love VFR. Sitting round YATN waiting for the fog to lift. Can't get over the cloud without going into IMC so spiral down through a hole north of Tully and down the Hinchinbrook Channel at 800' with the terrain alert in the GNS430 going ga ga!

Dr :cool:

[...still single]

'backing the prop by hand...can cause catastrophic disintegration of the vanes.' -I back the prop(s) by hand every pre-flight (to check the blades), never had a vac pump fail on me since I was a student pilot.

Maybe good luck rather than good management, but I reckon this one can be added to the huge list of Old Wives Tales that pervades aviation.

Btw, there's two mounting pads on the back of the donk, why not put on TWO cheap and nasty vac pumps? (Oh no! Twice the chance of a pump failure!)

[Wheeler]

FTDK - sounds like you had fun! Those times are hard to beat.

I dunno either. I believe there was case a few years back of a crash where the cause was deemed to be vac pump failure(?). Case was lost because it was found that the component had not been changed according to manufacturer's recommendations. Maybe its perfectly OK not to change a vac pump - unless you crash? - Just shows how rediculous our regulator can be?

[corowacomet]

"Has anyone tried simulated IFR on the flight instrument display on a Garmin GPSMap 296?"
Hey forky have a look at the US Flying magazine website (www.flyingmag.com (http://www.flyingmag.com)), Richard L Collins has written an article about using a 2/3/496 garmin for last ditch back up. It makes for interesting reading, he seems to be of the opinion that it isn't that useful unless you had made an effort to practice it and even then the update rates (1sec or so) made keeping the wings level quite a task with reacting to longer trends being the only option. I think it is in the latest edition but you may have to have to do a bit of a search for it.
The Comet

[Wheeler]

MJH/Chimbu - fantastic info... those guys at Aviation Consumer do a brilliant job.

A couple of things though - Just looked at Spruce/Chief etc and the cost of the Airwolf is about US$1600. I guess if your plane is certified with a dry pump you would need an STC and they seem to be a fairly substantial piece of kit so guess they would weigh a bit more and maybe need to ajdust the w and b schedule a little? Wet pumps would obviously be a much better option and with 2000hour 10 year life virtually eliminate the worry of those crappy dry pumps - but which are only about A$350. You could get a few dry pumps change them at recommended 500 hours and still be better off (financially), which is probably why the manufacturers changed to them in the first place.

[Brian Abraham]

FTDK - Service letter Number 66 from Parker Airbourne dated 31 Jan 07 model numbers 211 to 216, 241, 242, 441, 442 which are more commonly fitted to Bonanzas. The pumps are stickered by Parker as not to be overhauled but companies such as RAPCO have been overhauling them and putting them back into the market. Organisation recommended Tempest ($500, manufacturer says 1000 hour life) as a dry pump, but wet as being the best of the best.

[Centaurus]

but I reckon this one can be added to the huge list of Old Wives Tales that pervades aviation.


I presume you are referring to "backing" the prop by hand "to check the blades", hmmmm?

[Jabawocky]

Forkie.......Gotta luv VFR

I do, and when faced with a heap of time over the top, I turned around and went coastal......got me five hours in a FTDK!......where is the downside there?

Nothing like flying at FL-Tree Tops occasionally!:E:ok:

J:ok:

[tinpis]

You dudes have got too much money. :hmm:

[ForkTailedDrKiller]

Wheeler - The FTDK could do with a bit of weight in the nose!

Jaba - You're a cheeky beggar! Unfortunately there was no Good Samaritan (?) to come collect me in his TBM700.


Got m' new pump installed - and its sucking 5.4 something or others. George is back at work and flew me to Coffs today. Its a tough life but I guess someone has got to do it.

Its good to see that Oz is right on top of airport security. The security gate outside the Coffs Aero Club is designed to keep would-be terrorists OUT!

At least short ones!

Its just a tall pool gate. Provided you can reach the latch, you are in - but then I guess any terrorist who breaches our brilliant security that way will likely perish hiking from the GA area at Coffs to the main apron.

Thank God for the folding lecky bike!

Dr :cool:

[YoungAggy]

FTDK
Does your bonanza instrument air system work on vacuum or is it a pressure system (as most beech systems are).Have you had it modified/changed at some stage. regards aggy:)

[Chimbu chuckles]

work on vacuum or is it a pressure system (as most beech systems are)

Huh?

Do tell us more.

[ForkTailedDrKiller]

YoungAggy

To tell you the truth I have no idea (apparently!), but I will go get the POH and see what it says. The FTDK is NOT modified.

I would have said the V35B has a vacuum system cause people call the thing bolted to the engine a "vac pump". There is a dial labelled "suction" on the panel, and a light that I think is labelled "low suction".

Will go check and get back to you!

Dr :cool:

[Codger]

Dry pumps used to last all winter and then die every summer when things got warm and dusty. Found that the air inlet pipe just above the footwell was the perfect size to stick a standard inline fuel filter in to. Same pump has now been through 4 years and a thousand hours or so. Just a SWAG but maybe being particular about keeping the air super clean as its flowing in to the dry pumps is the way to go.
No, I have no idea if there is an STC or any such paperwork on this. Check it out yourself before you do such..... Perhaps there is already an inlet filter on yours that just needs to be checked frequently....

[bushy]

I believe the pnuematic system was driven by suction so that the "wet" pumps did not blow oil mist into the instruments. When the dry pumps came along, some aircraft came with a pressure system, but I do not think that lasted very long.
Instrument LAME's used to say cigarette smoke was harmful to gyros.
It would probably not be a good idea to fit a wet pump on an aircraft with a pressure system to drive the gyros.

[ForkTailedDrKiller]

My excuse is that I was a "Cessna man" before getting the V-tail!

The POH for my Bonanza (1977 V35B) says:


"INSTRUMENT PRESSURE SYSTEM

Instrument pressure is supplied by an engine driven pressure pump"


The filter is attached to the "In" side of the pump. The pipe from the "Out" side of the pump goes through the firewall, presumably to the instruments.

The guage that I had always considered to be a suction guage, is labelled "Instrument Air" and the warning light is labelled "Low pressure warning light".

This would tend to suggest that the air is flowing from the pump to the instruments as in "blow" rather than from the instruments to the pump as in "suck"!

It is filtered twice before it gets to the instruments so it should be pretty clean.

Dr :cool:

The Mad Dr throws YoungAggy a lollipop!

[Wheeler]

Ah Dr so you work on more air instead of a lack of it - didn't know you could do that - come back to us Cessna boys, get weight in your nose, the right number of parts in your tail - and work under lower pressures!

No-one has told me how often I should legally change a dry vac pump in an IFR single. - Bugger it, I'll rely on a sby vac and leave it till it dies, which apparently could be anything between 10 and 10000 hrs. Rediculous things those dry pumps. The advice on brushing up on limited panel seems sensible!

[YoungAggy]

FYI - Main reason i posted is I was asked about this during a recent instrument renewal in Bo by ato.Fortunately i have done time on both bonanzas/ barons,in the air and in the maintainence hanger and could answer the question straight away,set the mood for a good renewal flight.Although i do believe some early v tails had wet pump vacuum system as stated by someone else.
FTDK I too was a cessna man but am now converted beech man for life.
Flew a 210 recently IFR and did not like it at all,couldnt wait to get back in the Bo.
By the way (no vac/press pump to worry about in the old agwagon/agtrucks.Had hydraulic pump mounted on accessory case pad to run spray system)

Keep up the good work - I enjoy reading your posts.:ok:
regards Aggy

[the wizard of auz]

for not a lot of $$$ you can by a solid state electric AH, and fit it up in a spare hole in the dash. you can have the best of both worlds then. :ok:

[ForkTailedDrKiller]

"come back to us Cessna boys, get weight in your nose, the right number of parts in your tail - and work under lower pressures!"

Wheeler

It will take a bit to drag me back! Now that I have my head around blow-not-suck, after 500 hrs in the Bonza camp, I am starting to feel at home!

Its a while since I have flown a Cessna that will climb to A100 in 12 min, and true 160 kts on 48 l/hr.

Dr :cool:

[Jabawocky]

WOW, does it really? Thats pretty quick, is that at full load?

New G36 says 14 min, and even the light weight go fast Jabawocky would be about that climb!:E

Have to say though....the Bo is the Go in serious singles!

J:ok:

[Chadzat]

Its a while since I have flown a Cessna that will climb to A100 in 12 min, and true 160 kts on 48 l/hr.


Lightish-medium weight 210N (N/A) with Gami's and LOP will romp those figures in. :p

[ForkTailedDrKiller]

Chadzat

I have more than a few hours in the C210, including one of the last new N models sold in Oz.

I stand by my statement!

I understand that the Scimitar prop knocked a couple of kts off the FTDK in cruise but it climbs like its on rails.

I suspect that with an all cylinder engine monitor and LOP I could safely get it back to <45 l/hr at the same power setting (2300/22 at A100).

Dr :cool:

[Wheeler]

'ere we go again.... The 210 beats the Bo... the Bo is more fun etc etc

Hey Doc, I thought the 35B would do a bit better than that - could come close in the 182RG, on a lot less neddies and a Lycoming of all things! (BTW did you mean 160kts TAS during the 12 min climb? If so, OK you win. If not, come on, you're wasting your time, come back to aircraft that suck!)

Hey, whilst we are on it, isn't the S35 the best and fastest FTDK ever made?

Getting back to the single vac pump in IMC issue, when it packs up in the poo I'd rather be in the Cessna - keeping an FTDK straight and level without George in tip top condition is challenging to a mere Cessna driver like me at the best of times!

[ForkTailedDrKiller]

Wheeler - you bin smokin that weed again?

"I thought the 35B would do a bit better than that - could come close in the 182RG"

Been a while since I have flown a 182RG, but my recollection is I flightplanned 150kts. My FP program says 145 kt TAS at 50 l/hr.

"BTW did you mean 160kts TAS during the 12 min climb"

Not without a PT6 up front! I climb at 110 kts.

"isn't the S35 the best and fastest FTDK ever made?"

Certainly one of the fastest! The best (?) - dunno. The V35B carries more but has greater CofG issues.

"Getting back to the single vac pump in IMC issue, when it packs up in the poo I'd rather be in the Cessna - keeping an FTDK straight and level without George in tip top condition is challenging to a mere Cessna driver like me at the best of times!"

Yes, the aeroplane has neutral lateral stability. It will easily peel off into a spiral dive if your scan is not good. While I seem to be able to fly it around quite happily on partial panel during renewals, I would not launch into serious IFR without a functional AP.

Dr :cool:

[Wheeler]

OK Doc, its a fair cop, didn't think the weed would be that obvious to someone with a confused vac pump that blows..

As I said, not THAT far behind in a 182RG, don't know where your numbers come from but try fully loaded 14 mins to A100, 154 kts 47 litres per hour - and oh yes, on 50HP less. I can easily be at 10,000 by Richmond taking off from Camden (26nm) and still be climbing at 500fpm. A decent TR182 would beat that by a bit. Imagine looking up from the Killer and seeing an old high wing biscuit tin, with all 3(!) feathers correctly placed in the tail above you, struts and all - and a decent 210 might be in front of that...

(Actually I'd love a V35B or a F33A but don't tell the buscuit tin club I have those terrible secret desires - its only the weed.)

[ForkTailedDrKiller]

Don't know about the TR182. Only flown one. Bloody thing used 65 l/hr at my usual 9 - 10 k and only managed 155.

Maybe "decent" is the key word. It was that aeroplane that got me onto the FTDK. I figured I had to get a better aeroplane to fly before my luck ran out.

On my last trip in the TR182 - the oil leaked out of the compass; the A/H rolled upside down (not vac pump failure) and then I had a total electrical failure.

Dr :cool:

[Jabawocky]

On my last trip in the TR182 - the oil leaked out of the compass; the A/H rolled upside down (not vac pump failure) and then I had a total electrical failure.

Makes ya wanna walk:eek:

J

[Tmbstory]

The discussionon vac pumps (both wet & dry) & suction or pressure air systems has been around for a long, long time, giving much good information to pilots. It shows the value of knowing the systems in the aircraft that you fly.

The Beech 60 & 70 model Queen Airs used in the early commuter days in Australia, were fitted with the instrument pressure system & it worked well. The aircraft also had an "augmenter exhaust system", which in certain circumstances could cause an engine cowling fire / smoke problem during the start-up phase. The discharge of the ground fire extinguisher into the cowling, gave the ground engineer attending the start-up, much heart ache , cleaning & rectification work because of the extinguisher substance contaminating the instrument air system.