Scudrunners

Following is a link to the Pratt & Whitney
"Manual of Engine Operation" for Radial
Engines:

https://dl.dropboxusercontent.com/u/165 ... Radial.pdf

It's a 47MB PDF - not small.  But grab a
copy, and read it when your insomnia gets
too bad.

If you're never, ever going to operate a
piston engine in an aircraft again, you
probably don't need to read it.

But even if you operate a flat Lyc or TCM
engine, there is good stuff to be learned
from it.

For example, did you know that you can
hydraulic lock a flat piston aircraft engine
with fuel, and bend a connecting rod?  It
doesn't fail at the time - no, it fails later,
in flight.

Great link Colonel!

Now, has ANYONE seen first hand a hydrolic lock on let's say a R-985?
I know I haven't, and would assume that it would take a long.... (Read "LONG") amount of time sitting parked on the ramp/dock before it happened!

Colonel, you know more about this than I do... On the same subject but with LCM/CONT engines; Are they any different than a radial whom is apt to pool oil in the lower jugs?

All the best,
TPC

Chuck and Doc and Leadsled all have thousands
of hours more radial engine time than I do, so I
hope they speak up ...

The worse radial engine I know of for hydraulic
lock is the chinese copy of the russian engine in
the Nanchang CJ6.  I know a guy, blew the bottom
jug off his CJ6.  Twice.

The R-985 is much, much better in this respect.
One particular R-985 that I know of, in a Stearman,
is absolutely phenomenal in this regard - I swear
you could leave it all winter, jump in and crank it.
You never would, of course.

To the best of my knowledge, the quality of the
rebuild and how much wear the rings have, determines
how much oil is going to pool in the bottom jugs.

This is certainly applicable to the Ranger and
Gypsy inverted inline engines, where every
cylinder is a "bottom jug"!

I should mention that some shops will intentionally
build an engine "loose" to allow oil to get past the
rings, into the cylinders.  An aircraft piston engine
that doesn't use any oil between 50 hr oil changes
makes me nervous.

A friend of mine, the legendary Freddy Cabanas,
delivered a Spad (Douglas AD-1 Skyraider) from
France to Arkansas, and he was oil consumption
limited, not fuel limited.  It was rebuilt that way
intentionally.

I gave him shit and he shrugged and said he didn't
have time to set up a 55 gal drum and a wobble
pump and a rubber hose to the oil tank, to refill it
in flight.  Freddy knew all the tricks.

The 985 is almost immune to hydraulic lock in my experience.

But the R1830 can and does sometimes in a short time period.

As to oil consumption I used to fly some C117's that burnt and leaked so much oil you could follow the trail back home.

Chuck Ellsworth wrote:I used to fly some C117's that burnt and leaked so much oil you could follow the trail back home.

More reliable than an ELT, I guess...

The C117 was an interesting airplane.

It really performed compared to the DC3 except in X/wind landings, the rudder effectiveness was no where as effective as the DC3.

And those Wright engines were no where as reliable as the P&W.

While this is many years back in my aviation history and I have only ever had experience with P&W power but I have flown most variants from 985 to 2800 and for any chance of hydraulicing I was always told to roll the engine through with the starter and never pull through by hand -- thoughts by company was pilots are just too ham fisted and with all that leverage on the prop damage was likely -- starters had clutches and would stop turning before they created the damage -  as long as you didn't have the switches turned on -- which you shouldn't until appropriate number of blades counted -- that was my experience -- other might preach just the opposite 

That is a good point which I take for granted ...

Starting a radial engine, it's mags off until
it spins a while on the starter, then mags on.

It's aggressive to have the mags on when
you hit the starter with a radial.  You can
do it, but sooner it later it might cost you.

I've never heard this before

Sigh.  This is as essential to operating a radial
engine, as pulling it through by hand before
getting in.

Two thoughts:

1) there is so much knowledge being lost, as
the "old breed" disappears.  It cannot be easily
replaced, as Harrison Ford can tell you about
his carburetor jets in his PT-22.  Oddly the
obnoxious youngsters like to sneer at the old
guys - they have nothing to learn from them.

2) this is the really hard thing about instructing -
not forgetting really important stuff.  This sounds
stupid, but one of the hard things about instructing
after flying so many decades, is that there is so
much stuff that you just take for granted.  It can
be hard to relate to the newbies, sometimes, and
is one of the advantages of a low-time instructor,
actually - he remembers learning to fly, a couple
years ago.