MD or Bell
Steve
>
> And the Bell 407 is a total different story. If the word tail is used in the
> description of a component, there is an AD, ASB or TB dealing with it.
>
> Hope I didn't burn you out,,,,,? Any more questions,,,,,,,just ask.
> Brad, aka,
> RotorHead
Please tell me all the 407 problems in detail. Ive heard its a pain in the ass.
Steve
Rotor Head
I'm kinda new at this message board stuff, but I like the aviation info
talk.
Well I will give you a little background about myself, if you have any
questions that I might be able to answer. I have 17.5 years Army (3 active)
9.5 years as an A&P. I worked at a MD and Schweizer at a repair/service
center. I am currently the sole maintenance person of a Bell 407.
In the Army, I maintained OH-58's and was trained on Blackhawks, but am back
on OH-58's again. I like the OH-58's, this product had more thought put into
it.
Maintenance, Bell uses hyd. to assist the pilot in flight and ease his work
load. 500 has about 1.5 ounces of hyd. It uses springs, cam and natural
forces. Less parts to break or leak. And just as responsive, no, more
responsive.
The M/R head: Bell is greased, has bearings, and is overhauled regularly. MD
uses stainless steal straps, no grease and a much higher TBO. Less moving
parts, no 50 hour lubes.
Engine. SAME ENGINE. Allison 250-C20B. 420 shaft hoarse power but the MD can
lift approx. 800lbs more. Bell eng. is horiz. giving access to both sides.
The MD is at a 45 degree up. tilt. giving quick access to the eng. except
for the compressor area. But the MD you area working on the ground and not a
ladder, plus the eng. removal in a MD does not require a chainfall or hoist.
Just a small block and tackel that fits in a zip-lock bag. MD eng removal
time 30min. You have to wait on the oil to finish draining. Bell, 1.5 hour.
cowlings, induction fairing, more oil lines, more heater lines, etc.
T/R and T/R drive; Bell has several, 7 bearing on the t/r drive. MD "0", no
lubes, no mess quick removal. Bell T/R; the improved one is greased every 25
hours. MD nothing. Plus easier to balance.
M/R Blades. MD has expandable pins that hold the 4 or 5 blades on. All
blades can be removed from the head (without affecting track or balance )
with two people in 15 min. Bell; just think about that one.
Main xmsn. Bell; it sit on the cabin roof, you must remove the m/r head to
remove the xmsn. MD is suspended in the pax area. You only need to remove
the interior. But this makes the MD louder in the acft than the Bell.
In short, the MD requires little to no maint. between 100 hr insp. while the
Bell has grease services every 25 or 50 hours.
Shaber CJ
>description of a component, there is an AD, ASB or TB dealing with it.
>
>Hope I didn't burn you out,,,,,? Any more questions,,,,,,,just ask.
Can I ask you to expand a bit on the maintenance problems with the 407 and the
AD's. We are considering a purchasing a 407.
Craig
Walter Hawn
>
snipped
> T/R and T/R drive; Bell has several, 7 bearing on the t/r drive. MD "0", no
> lubes, no mess quick removal. Bell T/R; the improved one is greased every 25
> hours. MD nothing. Plus easier to balance.
Isn't the boom life limited vs on-condition for 206 and kin?
180 Walt
Shaber CJ
>180 Walt
MD 520N boom is on condition.
Craig
mr_rot...@my-deja.com
The MD 500 is a maintenance disaster. I'm not sure what the aircraft
you were maintaining were being used for but in my past experience;
Rotor Head. Full of fiddly little parts that wear out. Strap pack design
is subject to regularly cracking, requiring either replacement or
continual inspections. MRH overhaul can only be accomplished by the
factory. Plus lots of AD's.
Engine. The engine suffers continual oil leaks. Must be why the engine
is designed for quick removal -it's always coming out. It's an Allison,
so it's always subject to a random hot start whenever, for whatever
reason.
Tail Rotor system. Poor accessibility, cheap and nasty parts, horrible
design for tail rotor system and gearbox. Use's loads of parts, all wear
out rapidly. Continually in need of balancing. Plus (what else) plenty
of AD's.
Main Rotor Blades. Again MD wins with the quickly removable blades. Just
as well, as they come off a lot! Guaranteed delamination of abrasion
strips requiring replacement. Cracks, reducing life limits and again
loads of AD's. Additionally the 500 is the most hopeless helicopter to
track and balance - often taking days with experienced guys. Fortunately
there are now PMA blades available (with no AD's).
The 500 is a maintenance disaster, requiring never ending maintenance
and tuning to remain Airworthy. It has continual AD requirements that
mean lots of Mandatory inspections between scheduled maintenance. It is
still suffering from the same problems it experienced 30 years ago. If
it has MD written on it, it has an AD on it!
Plus their parts supply system is useless. Nuff said.
Bell OK. Eurocopter better. There's a reason that everyone is buying
A-stars!
Sent via Deja.com http://www.deja.com/
Before you buy.
Shaber CJ
>uses stainless steal straps, no grease and a much higher TBO. Less moving
>parts, no 50 hour lubes.
>
MD also uses a static mast which is MUCH safer design. Inever could figure out
how the Army could justify the switch from OH-6's to OH 58A's. Just the safety
factor of the OH-6 as compaired to the OH-58 would justify keeping the OH-6
(until the Comanche is operational).
Craig
John Bicker
mr_rot...@my-deja.com wrote on 5/6/00 12:21:
> Please remember this is my opinion only...........
And this is no defence, I have worked on them all from about Serial No.99
thru 600N.
>
> The MD 500 is a maintenance disaster. I'm not sure what the aircraft
> you were maintaining were being used for but in my past experience;
>
> Rotor Head. Full of fiddly little parts that wear out. Strap pack design
> is subject to regularly cracking, requiring either replacement or
> continual inspections. MRH overhaul can only be accomplished by the
> factory. Plus lots of AD's.
Granted although most strap and droop stop problems are a ground handling
problem, if you see a ship running on the ground without the tip path
perpendicular to the mast, aim a warning shot between the eyeballs.
>
> Engine. The engine suffers continual oil leaks. Must be why the engine
> is designed for quick removal -it's always coming out. It's an Allison,
> so it's always subject to a random hot start whenever, for whatever
> reason.
The oil leak dilemma is associated with poor airflow around the exterior of
the engine IMHO AS 355's are worse. Seals are cheap and easy with the right
equipment. But that's no defence. The C30-C47 unfortunately doesn't come out
easy anymore.
>
> Tail Rotor system. Poor accessibility, cheap and nasty parts, horrible
> design for tail rotor system and gearbox. Use's loads of parts, all wear
> out rapidly. Continually in need of balancing. Plus (what else) plenty
> of AD's.
Ask Frank Robinson he designed it and the R22-44 is not much different.
>
> Main Rotor Blades. Again MD wins with the quickly removable blades. Just
> as well, as they come off a lot! Guaranteed delamination of abrasion
> strips requiring replacement. Cracks, reducing life limits and again
> loads of AD's. Additionally the 500 is the most hopeless helicopter to
> track and balance - often taking days with experienced guys. Fortunately
> there are now PMA blades available (with no AD's).
They are all essentially only 300 blades.
>
> The 500 is a maintenance disaster, requiring never ending maintenance
> and tuning to remain Airworthy. It has continual AD requirements that
> mean lots of Mandatory inspections between scheduled maintenance. It is
> still suffering from the same problems it experienced 30 years ago. If
> it has MD written on it, it has an AD on it!
Exactly!
>
> Plus their parts supply system is useless. Nuff said.
Agreed
>
> Bell OK. Eurocopter better. There's a reason that everyone is buying
> A-stars!
Funny I think a few years back EC were kicking themselves a bit because the
old A-Stars wouldn't go away hence no new sales and they even starting
buying them back to stabilize the market. Blink! The light went on, lets
build better of the same hence BA,B1,B2,B3. It pays to know a few little
tricks which any experienced operator will tell you and also having a supply
of hardware which is not widely available like AN or MS stuff is. Otherwise
couldn't agree more. The flight manuals are comprehensive and honest and
performance as documented is easily achievable. No smoke and mirrors.
A mild swap of the frontal lobes so you can think like a grenouille will
always help and it doesn't hurt much.
>
>
>
>
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
--
Rotor Head
All note worthy, and some true. But beauty is in the eye of the
beholder. (i.e.) Ford lovers and Chevy lovers. This could be an excellent
"bar" argument, with neither of us winning over the other.
As for A-stars, I have little experience on them, and the lack of
metric tools to prove that.
Thanks for the reply , RotorHead
<mr_rot...@my-deja.com> wrote in message
news:8hgk23$7ee$1...@nnrp1.deja.com...
> Please remember this is my opinion only...........
>
> The MD 500 is a maintenance disaster. I'm not sure what the aircraft
> you were maintaining were being used for but in my past experience;
>
> Rotor Head. Full of fiddly little parts that wear out. Strap pack design
> is subject to regularly cracking, requiring either replacement or
> continual inspections. MRH overhaul can only be accomplished by the
> factory. Plus lots of AD's.
>
> Engine. The engine suffers continual oil leaks. Must be why the engine
> is designed for quick removal -it's always coming out. It's an Allison,
> so it's always subject to a random hot start whenever, for whatever
> reason.
>
> Tail Rotor system. Poor accessibility, cheap and nasty parts, horrible
> design for tail rotor system and gearbox. Use's loads of parts, all wear
> out rapidly. Continually in need of balancing. Plus (what else) plenty
> of AD's.
>
> Main Rotor Blades. Again MD wins with the quickly removable blades. Just
> as well, as they come off a lot! Guaranteed delamination of abrasion
> strips requiring replacement. Cracks, reducing life limits and again
> loads of AD's. Additionally the 500 is the most hopeless helicopter to
> track and balance - often taking days with experienced guys. Fortunately
> there are now PMA blades available (with no AD's).
>
> The 500 is a maintenance disaster, requiring never ending maintenance
> and tuning to remain Airworthy. It has continual AD requirements that
> mean lots of Mandatory inspections between scheduled maintenance. It is
> still suffering from the same problems it experienced 30 years ago. If
> it has MD written on it, it has an AD on it!
>
> Plus their parts supply system is useless. Nuff said.
>
> Bell OK. Eurocopter better. There's a reason that everyone is buying
> A-stars!
>
>
>
>
>
Rotor Head
I am fairly new to the 407, and I am dealing with early s/n.
Bell is changing alot of their seals,
t/r input.....with a new input adapter $$
freewheeling unit.....with new adapter and nut modif. $$$
main xsmn oil pump seal $
T/r p/c mech........a mod. to the gearbox, but that mod. is not
out yet.
The ship has oil leaks, but so do others, oil leaks don't bother me as
much as they do the pilots. But you stop one and another starts it seams.
The word "tail" is followed by TB, ASB, or AD.
The tailboom has a 50 hour AD& revised ASB for cracking on the L/H side top
but the bearing mounts and around the horiz. stab.
t/r d/s bearing are failing, fairly easy to catch prior,,,but at $800 a
bearing. I'm on my 5th bearing. This is a 25 hour insp and lube AD.
T/R d/s disc packs are cracking,, another AD. But I haven't seen any cracked
yet.
The T/R system is having an airspeed activated peddle restricting stop
installed to prevent the tail rotor from striking the tailboom causing the
separation,,,,,,??????????? The jury is still out on that one. But it is an
ASB and it being installed on acft now. And Bell is crediting people with
{If I remember right} $4400 credit towards just the labor. Not an easy ASB
to do??
The ECU is being changed and the throttle redone to prevent pilot error when
the ECU fails and goes into the manual mode. This ASB is a honestly a good
one.
But in all, the acft has a lot of power and is comfortable inside. I seats 4
well and 5 tightly in the pax. The new composite head is fairly maintenance
free, changed a couple of bearings. the elstomeric is holding up fine. The
engine runs fine. No problems with the FADEC. And when we had an HMU
failure, the FADEC acted as advertised. This is good, because I spend all my
time at the engine looking aft.
RotorHead
Steve <Ke...@STP.com> wrote in message news:393B3468...@STP.com...
> >
> >
> > And the Bell 407 is a total different story. If the word tail is used in
the
> > description of a component, there is an AD, ASB or TB dealing with it.
> >
> > Hope I didn't burn you out,,,,,? Any more questions,,,,,,,just ask.
Rotor Head
I won't claim to be an expert on the 407, but my ship flies about
75-125 hours a month. This might be a consideration for you. Depending on
how much you fly it.
This has been a good ship, excluding the "tail" items. And the never
ending battle over oil leaks. I get about a month before another leak
starts. We have not gone to the "new" type seals yet. Mostly due to the
parts or the TB has not been approved as of yet. But it is just a matter of
time.
I expect you read what I wrote to Steve. If you want the total detailed
story Bell does have a site to down load the ASB's and TB's. It's
bhti.com look
under "customer support" and downloads.
That will give you the hole story from the beginning. But I would look at
other acft. too, each has its own nitch. I favor MD, {Ford} and now I'm
working on a Bell {Chevy}. Oh.......don't forget to look at those A-star
{BMW} also.
If I missed something or another question, Ask. RotorHead
Shaber CJ <shab...@aol.com> wrote in message
news:20000605092319...@ng-ft1.aol.com...
> >And the Bell 407 is a total different story. If the word tail is used in
the
> >description of a component, there is an AD, ASB or TB dealing with it.
> >
> >Hope I didn't burn you out,,,,,? Any more questions,,,,,,,just ask.
>
John Bicker
bralb...@enter.net wrote on 6/6/00 0:04:
> Craig,
>
> I won't claim to be an expert on the 407, but my ship flies about
> 75-125 hours a month. This might be a consideration for you. Depending on
> how much you fly it.
> This has been a good ship, excluding the "tail" items. And the never
> ending battle over oil leaks. I get about a month before another leak
> starts. We have not gone to the "new" type seals yet. Mostly due to the
> parts or the TB has not been approved as of yet. But it is just a matter of
> time.
>
> I expect you read what I wrote to Steve. If you want the total detailed
> story Bell does have a site to down load the ASB's and TB's. It's
> bhti.com look
> under "customer support" and downloads.
>
> That will give you the hole story from the beginning. But I would look at
> other acft. too, each has its own nitch. I favor MD, {Ford} and now I'm
> working on a Bell {Chevy}. Oh.......don't forget to look at those A-star
> {BMW} also.
Sorry the truth is omit BMW insert Mercedes Benz - The Daimler Chrysler
Aerospace connection.
>
> If I missed something or another question, Ask. RotorHead
> Shaber CJ <shab...@aol.com> wrote in message
> news:20000605092319...@ng-ft1.aol.com...
>>> And the Bell 407 is a total different story. If the word tail is used in
> the
>>> description of a component, there is an AD, ASB or TB dealing with it.
>>>
>>> Hope I didn't burn you out,,,,,? Any more questions,,,,,,,just ask.
>>
>> Can I ask you to expand a bit on the maintenance problems with the 407 and
> the
>> AD's. We are considering a purchasing a 407.
>>
>> Craig
>
>
--
Please reply to either
"johnb...@earthlink.net" or "JohnG...@compuserve.com"
Ph. +39 335 465 742
Arnold B. Christensen
Then you say that you changed a couple of bearings and the elastromatic
is holding up fine. If the elastromatic bearings are holding up fine why
did you have to change a couple of bearings in the m/r head? Actually
the m/r head is very old. It is basically a 406 (Kiowa Warrior - OH58D)
head painted grey.
Chris the Bigfoot
Rotor Head
Correct on the OH-58D head, that is were it came from. The bearings I was
talking about are on the M/R P/C links. Sorry about the confusion.
Rotor Head
Arnold B. Christensen <ab...@mindspring.com> wrote in message
news:393D75EA...@mindspring.com...