Dornier Seastar

[mag check]

Trust me aileron stall is not a control problem with the PBY,

Furthermore to get into a position where aileron stall is experienced requires one to really be aggressive with the ailerons at a high angle of bank and a high G load in the turn....

Perhaps it is not a problem for a guy like you Cat, but maybe the stories that told of PBY's being lost to aileron stall were new low time pilots during the war, in which case they would have been at low level, pulling g's, and likely not experienced enough to have explored the entire flight envelope of the pby over 50 years like you.

I've never looked into the numbers, but I would suspect that many PBY's were lost out over the ocean while circling a sub at low level, high g's, and a 200 hr pilot at the controls.

[Driving Rain]

The OMNR's 7 ex-military Otters hand that hand crank thing too. I always thought it was a great idea for a bush plane until they installed a radio stack where the handle was inserted.

[Cat Driver]

Perhaps it is not a problem for a guy like you Cat, but maybe the stories that told of PBY's being lost to aileron stall were new low time pilots during the war, in which case they would have been at low level, pulling g's, and likely not experienced enough to have explored the entire flight envelope of the pby over 50 years like you.

For sure that is a possibility, aileron stall could cause a loss of control, if it is not centered to un-stall it.

What can cause a total loss of control is rudder over center lock which can be induced in that condition by excessive rudder input and crossed controls.

I have had it happen to me while practicing for the air display routines and it was one of the most heart stopping experiences I have ever had in an airplane, fortunately when I found that the two of us could not over power the rudder lock I yarded back on the elevator and snap stalled the thing and after one turn of the spin I had rudder control back and premature gray hair.


It was a Cat with the Davis tail but the standard PBY will also over center rudder lock if the wrong control inputs are used as the Navy pilots found out during the war.

It is my belief that the loss of the flying fireman's tanker 1 and the crew was due to a rudder over center lock and insufficient altitude to recover. Witnesses described the classic scenario of such an event.

I am only alive today because I was doing the edge of the envelope exploring at a high enough altitude to recover from the spin.

I've never looked into the numbers, but I would suspect that many PBY's were lost out over the ocean while circling a sub at low level, high g's, and a 200 hr pilot at the controls.

I have to agree with you.

and likely not experienced enough to have explored the entire flight envelope of the pby over 50 years like you.

Hey, easy there I only flew the PBY's from 1968 to 2005 when I retired, believe it or not I did fly a few other types as well.

_________________

[mag check]

Cat.

Wow, that doesn't sound like a fun situation.

It would seem to me that is a serious design issue with the aircraft.

Was this aerodynamic lock, or mechanial lock caused by control interferance?

If it was aerodynamic, it would seem that the original flight test pilots didn't fully test the full flight envelope.
It is, and as far as I know always has been, a test condition to ensure that control forces increase all the way to the stops, with NO reduction in force. Controls are not allowed to go "over center".

Perhaps the military doesn't have the same testing protocol that the rest of the industry does.
But you would think that when the PBY's went civilian, more testing to the current standards would have been accomplished.

Glad you are still with us after that flight

[Cat Driver]

Was this aerodynamic lock, or mechanial lock caused by control interferance?

It is an aerodynamic lock.

It only happens when the rudder is fully deflected in a slipping configuration, therefore it is seldom experienced.

I asked the TSB people who were investigating the flying fireman crash why they did not add a caution to the PBY AFM.

They refused to accept my description of what I had experienced and never did put a warning in the PBY AFM.

Please do not ask me why they ignored my suggestions during that accident investigation because I do not have the faintest idea of why they did not.

Maybe they just felt that I was relating a story that was not plausible?

Then there is the question of why the same problem was experienced by the Navy crews during WW2, maybe they also were just imagining it?

Having been involved in two high profile investigations of PBY accidents with the TSB shall we say my admiration for some of their conclusions as to cause for some accidents is rather shallow to say the least.

Then there is the position that some in aviation take that I am just a crack pot who really doesn't understand anything about flying, therefore it is easy to ignore my advice.

You probably would not believe this, but there are a few in the government side of aviation who have actually accused me of being anti authority.....

.......so therefore to be ignored.

[Liquid Charlie]

aerodynamic locking of controls also raises it's ugly head in several other types as well -- DC-3 - rudder and HS748 -- ailerons

Experience level did give a few aircraft a bad rep -- Beech 18 for one -- it was a great airplane on wheels and could take a good xwind -- like the DC-3 it could handle 40 kts. but when the beech was used as an initial twin engine trainer -- no wonder the reputation was born.

[skybaron]

WTF.

I thought this post is supposed to be for a Donier Seastar!

Why the hell is all the attention going to the cheesy PBY for - cuz its a flying boat??
Different engines, design, blah blah blah.

[Cat Driver]

Why the hell is all the attention going to the cheesy PBY for - cuz its a flying boat??
Different engines, design, blah blah blah.

Excellent question skybaron so why don't you start bringing this thread back to the Dornier Seastar by explaining to us why that design is so superior to older flying boats.

Maybe you could go back and read this thread once more and you may find some interesting discussion regarding the behavior of airplanes when they are flown at their limits and something goes real wrong.

[xsbank]

Well, I'm going to take it one step past the limit and say the Grumman/Dehavilland Tracker also had a frightening rudder stall - 40+ knot x-wind and the rudder would suddenly go to the stop and it took 2 legs to centre it. Military designers danced to a different tune than boring old civilian a/c....


Nya nya nya

[skybaron]

Excellent question skybaron so why don't you start bringing this thread back to the Dornier Seastar by explaining to us why that design is so superior to older flying boats.

Maybe you could go back and read this thread once more and you may find some interesting discussion regarding the behavior of airplanes when they are flown at their limits and something goes real wrong.

A little sensitive there chap. Don't get your wiskers all twisted up.

Why the Donier or PBY or whatever, when a Van or Otter can do the job with much more versatility?

[Cat Driver]

A little sensitive there chap. Don't get your wiskers all twisted up.

Sensitive, naw far from it, it was the use of the word " cheesy " that made me wonder what you were talking about.

Why the Donier or PBY or whatever, when a Van or Otter can do the job with much more versatility?

Well I guess it all depends on what job you want to do, for instance will a Van or an Otter lift ten thousand pounds, or will either of them fly non stop for over twenty hours?

Why do you think a PBY is " cheesy "?

[xsbank]

I looked at the Dornier at CBAA and it seems way too expensive to ever be an aircraft that you can earn a living with. It also seems delicate with its composite sponsons. I asked the salesman about docking with it and he said you needed to hang boat fenders off the attached cleats! My first thought was somebody in a hurry bogging off with the fenders attached, flapping about and finally going through the rear prop....

Docking against tires will leave black streaks along the side of your shiny plastic hull - a rogue boat swell will surely fill the thing with water through its low door. I forgot to look but I don't think there is a front door for the pilots to get out of. Besides, it would be right in front of a spinning prop, perhaps. That same swell might bang the wing on the dock. Looked like a PITA to service the engines - even PT6s need care.

I nearly got checked out on a Mallard once, it was close... I would love to be checked out on a Cat. By Cat, for that matter! Both of the last-mentioned aircraft need flight engineers to climb on the wings for servicing because pilots are too clumsy for that type of work.

[Cat Driver]

Xsbank you obviously have poor ideas about waht a real airplane should be wanting to fly something that looks this cheesy.

http://i43.photobucket.com/albums/e353/ ... wImage.jpg

[Shiny Side Up]

With all due respect wabano you have been getting some very flawed information.

Late to the game, but you're right, though I'm suprised you didn't point out one flaw to his position. Being bored today with the rain and all, I have ample time to find such things.

As for the aileron down deflection aggravating a high speed stall in big wing airplanes,
like the canso and B-52,

The B-52 doesn't have ailerons, it only has spoilers for roll control.

Anyhoo, back on topic. I personally don't have any experience with larger amphibians, flying boats and float planes. Aside from the arguement above on which might have better handling characteristics, on air or on the water, I always have to give kudos to anyone out there making the attempt to put a new craft of this type on the market. If the Germans can be reasonably sucessful in selling the thing it might pave the way for that sector of aviation to make a resurgence - One has to wonder why when a good portion of the world's waterborn airplanes are put to use in Canada, why there isn't more impetus in this direction. We're content apparently to keep using and reusing the same airfames, and not that they aren't good airframes that do an excellent job, but it seems to be a bit of a lack of foresight on our part. Someone already mentioned a factor that the expensive Seastar has in its favor - its composite construction. Is the saving in maintenance (with corosion issues) worth the higher ticket price?

Forget about the Seastar though, I'm always hoping someone with a lot of money will bring one of those Black Sea Monsters over.
Jeebus! They got more of them on there!

[xsbank]

Hi ., yeah, that's just gross! Yuk!

I think the composite thing is great until you damage one, hit a log or pound a dock with one, then the repairs are difficult yet with metal you just slap on a patch. Ramp-to-ramp only, perhaps. Where can you find a ramp nowadays?

That's why everyone on the coast went to Navajos - not only were they cheaper than a Beav, the runways didn't move, unless they were part of a road like in River's Inlet, then all bets were off.

Less than half a mil for a deluxe Beaver or 5.5 million for a Dornier? And you have to ask why we use old airframes? The pilots are already paid little enough, give 'em a new airplane and they would probably have to pay the employer to fly it.

Umm, wait, I.... never mind.

[1000 HP]

Can't compare a Dornier to a Beaver, more like a twin otter. Except the 13 foot floor would make it tough to haul 16 foot lumber. Price seems similar to a new Twin-Otter. The center-line thrust would likely make it a much-less capable dock airplane. I'm still trying to figure out how to tie a boat on.. I like it though. If anyone wants to buy one, and let me fly it, I'll work for Goose-pilot wages, more if I have to wear a white shirt and tie...

[1000 HP]

http://i43.photobucket.com/albums/e353/ ... wImage.jpg

Nice...

[CLguy]

Wabano I was agreeing with a lot of what you were saying until you threw out the Norseman/Twin Otter comparison,...Please!!!! A Twin Otter will do circles inside a Norseman.

As far as the PBY goes and Cat know this as well, is that with the shallow step and hull design it is very easy to get into a porpoise with it compared to deeper hulled boats such as the 215/415's. Allowing it to get into a porpoise and not dealing with it properly or quick enough is where most guys got themselves into a mess and yes that is when the prop usually came thru the cockpit. Rough water usually aggrevates the chances of a porpoise hence the reason most people say it can't handle rough water.

[golden hawk]

As the guy who started this thread, I don't consider it hijacked at all - it's one of the most interesting discussions I've seen on here. It feels like we're sitting around a table at a pub with a few pitchers of Molson Canadian. (Diet Coke for Cat, of course)

[wabano]

Again, twenty years ago, the older guys at Marignane(Marseilles) had flown
all three types and their opinion was that if the PBY(Canso) had limits compared
to the CL 215, they had NOTHING good to say about the German flying boats.
Had great fighters maybe, but since most airplanes are actually built by
politicians, the Jerries' luck was that their boat builders where lousy
and Dornier well connected(DO X and all that).
The amazing thing is that some suckers are going to buy into this again!

The last time I flew the 215, there was this old fart (who you all know)in a Canso flying
circles around us!(Of course, he was going full throttle...)
He saw the French all do the same in Marseilles and
must have decided to teach us a lesson!



As for Norseman VS DeHav, with the high winds last week,
we seriously where thinking of bringing the company Norseman up here,
as operating the otter was a skin of the teeth job,
while a Beech 18 or Noorduyn is practically unaffected!

[Cat Driver]

I never got to fly the Canadair's so I can't really compare them to the PBY except to say that I was on a fire with a 215 from Quebec many years ago and they asked me to change lakes because they were having trouble with the cross wind, I was flying a Cat with the square Super Cat Tail.

The only flying boats I have flown are the Sea Bee, Grumman Widgeon, Grumman Turbo Goose and the Cat.

I must have about six thousand hours on flying boats and still have a lot to learn.

[wabano]

The 215 does require muscle in a crosswind, but if you have it, no problem.

I'd think it would be one problem for the less strong, as with women or smaller folks...
in France, they had a crude power jack setting on the ailerons, caused many crashes when it locked
in steep turns. (It felt as if the wheel was connected to nothing,
except in the middle, where you had a hard block to overcome.
you could make the huge ailerons flap like an overweight duck...
the weirdest airplane I ever flew!)

I'd think the 415 has powered ailerons as well as nosewheel steering,
but I.m not too sure there, got to get something for all these millions.

When the 415 design engineers asked me, I told them the 215 was already overpowered,
but who care when taxpayers foot the bill...

[Cat Driver]

The 215 does require muscle in a crosswind, but if you have it, no problem.

I'd think it would be one problem for the less strong, as with women or smaller folks...

I never flew a 215 is it heavier on the controls than a Catalina?

Maybe I was to small to fly one and that is why no one asked me to.

[Driving Rain]

I think the slab sides of a 215 make it almost like a flying billboard.
A x wind technique I've used in the 215 made cross winds much easier. If the lake allows, scoop into wind at first as the 215 takes on some load use the rudder to turn it cross wind. It's very easy no matter if the wind is from the left or the right. The 215 with a right cross wind in a narrow lake can be a real handful for all but the strongest copilots. Part of the problem is the throttle pedestal makes for a long reach from the right seat. I remember helping some of the guys with the power while they hung on to the control column with both hands.

[wabano]

Canadair first designed the 215 with spring tab controlled ailerons
just like their CL-44(i.e. with only a loose spring but using the
tabs to actually move the ailerons, like all airliners at the time.)
The DC-8 move it's elevators this way...very powerful!
It would have made the ailerons light and balanced with the elevator and rudder.

But the cretins at TC would have none of it, so, if fairly light
in normal operations, ailerons can be a bear with cross controls in a crosswind.

Did you know that Canadair's original proposal was to fit a Grumman Duck type
of central float to the Douglas Skyraider?

Alas, the Chicken Little you know where screamed bloody murder
and DEMANDED it be built square!!!(What can you expect from forestry engineers!)

That would have been kollossal fun to fly!!!