MONTY THE ANSWER MAN ARCHIVE
Swift Landing Gear Emergency Extension
FEDS APPROVE...
(050100)
Subject: Landing Gear
From: Dennis Mee <jmmee@nh.ultranet.com>
Hi Jim, The fed's finally showed up today, they inspected the installation
but did not care to see it operate, they took my word for it. I've mailed
you a copy of the approval just to keep with your records, the final package
was about six pages with pictures, and a copy of your approval. The good
news is that my new PMI will be a lot easier to deal with then the present
one. I checked the LG adjustments IAW SB #7 & #28. Item #9 of SB #28,
for s/n prior to 3501, (N3812K is s/n 3501) calls for a gear-up pull down
cable tension of 90 -100 lbs. AD 51-11-4 (every annual or 100 hrs) applies
to all s/n, so I backed off on the pull down cable tension a little and
that solved the up-lock problem. Now all I have to do is get the strips
painted and she will be ready to fly!!! Thanks again for all your help,
sometimes the paper work is the most difficult part of the job! -- Dennis
Mee
DO IT ON THE JACKS...
(050200)
Subject: Re: Hydraulic Pump Motor
From: Phil Howell <POPPAPOU@aol.com>
Jim: Question: Is it a no-no to test the emergency system in the air now
and then in addition to the tests on jacks? Thank you for your help. Phil
>>
Phil,
I wouldn't say it is a no-no but I wouldn't do it. If something malfunctions,
you probably would end up with a belly landing. It's better to test it
on jacks, where any error (human or mechanical) is easier to correct.
-- Jim
PULL DOWN CABLE ADJUSTMENT
STOPS GEAR PUMP MOTOR CYCLE... (060300)
Subj: Electric Gremlins
From: Peter Kailey <kailey@sunri.com>
Monty,
I am a rookie Swift owner and am learning much already from the group.
My Swift has a panel mounted Apollo GPS that was pronounced to be "intermittent"
by the previous owner. In monitoring the unit in flight, the problem does
not seem to be in the GPS, but rather in the power source. What happens
is that every few minutes in flight, the "gear pump" light comes on for
a split second. At the same moment, the ammeter shows a very large drop
in voltage, again for just a split second. The "gear up" light does not
flicker during this moment, however. As soon as this occurs, the GPS goes
into it's startup sequence, just as if it had been turned on. (The digital
Nav/Com is not affected.) This event occurs more often in rough air, and
I must confess I have not noticed if it occurs when selecting "Gear Down"...I
seem to be too busy to look just then. While I suspect that the answer
may be to add the filter or capacitor you mentioned concerning the fuel
totalizer problems of another member, I also am wondering why the pump
light should come on for that split second. It doesn't seem to come on
long enough to actually do anything...is there some adjustment in the
switch that could be a simple fix? Peter Kailey
Peter,
I think you have the answer to your GPS problem. All we have to do now
is figure out why the pump motor comes on in flight. Obviously, the gear
is falling out far enough to activate a microswitch. With the airplane
on jacks and the gear up, turn off the circuit breaker switches. Make
sure there is no pressure on the hydraulic system by operating the flaps.
Place the gear selector down. If one gear comes out, or can be pulled
out, the actuator arm may be mis-indexed with the gear in the actuator.
(one tooth off) Or the pull down cable may simply be too tight. Read the
service bulletins. Perhaps you can get by adjusting the microswitch so
it doesn't click. (providing the gear doesn't come all the way out
of the well) Dennis Mee had some gear problems recently, maybe he has
some hints for you. -- Jim
WELL... IT JUST SO HAPPENS
THAT WE DO INDEED HAVE SOME HINTS FOR PETER FROM DENNIS MEE... (060300)
Hi Peter, Monty copied me in on your gear problem, I had a very similar
problem with the pump coming on in flight causing a voltage spike on the
radios. I determined the problem was with the left gear by turning the
hyd pump motor off in flight and letting the speed build up in a shallow
descent then with a gentle pull up the left gear came out, I have the
external "curb feeler" indicators on the gear doors so I was able to see
it was the left gear, after slowing to 80 mph I retracted the gear and
pressed on with my flight. The same thing can be accomplished on the ground
with the airplane on jacks by following Monty's directions:
Make sure there is no pressure
on the hydraulic system by operating the flaps. (manually - with the hyd
pump motor off). Place the gear selector down. If one gear comes out,
or can be pulled out, the actuator arm may be mis-indexed with the gear
in the actuator. (one tooth off), Or the pull down cable may simply be
too tight. Read the service bulletins.
I followed Monty's directions
and found that with a hefty pull the left gear would come down, but it
took a good pull. I had already replaced seals in any actuator that had
the slightest leak in the entire hyd system, and the travel on the gear
actuator looked ok so I focused on the pull down cable. Following the
advice of Monty and Steve Wilson this is what I did: with the Swift on
jacks and the gear down I loosened the pull down cable turnbuckle in the
left wheel well until the cable had no tension on it, (about five or six
turns). I then retracted the gear, when the gear is up and locked take
the hyd pressure off the system as Monty previously described and try
to pull each gear down, if they both stay up, then extend the gear and
tighten the turnbuckle one turn and try it again. You may have to do this
several times, tightening the turnbuckle until it is just loose enough
to keep the gear locked up. Once you have the correct cable tension set
so that the wheels cannot be pulled down you will have to check the operation
of the emergency gear extension system. Caution never retract the gear
unless you are sure the pull down system has been reset, (cranked back
up)! With the gear up and the hyd pump motor off place the gear selector
lever to down, crank the gear down (about 52-54 turns), when you have
finished cranking check the over center side brace links and the hyd down
locks IAW AD 47-06-01 (due every 100 hrs or annual inspection) and Swift
service bulletin # 7, if this is ok, with the gear lever down turn on
the hyd pump motor and gear switches to check for proper light indications.
This would be a good time to reset the pull down system, (crank it back
up if you haven't done so). AD 51-11-04 (due every 100hrs) and Swift service
bulletin # 28 address the pull down system, don't forget to check for
the spacer, I was recently helping someone annual a Swift and found that
did not have one installed, this was a very well maintained and documented
Swift. You may want to charge the battery before you return the Swift
to service. This solved my problem and is not as complicated as it sounds.
I've sent a copy of this to Monty so he could make any corrections or
additions, he knows far more about Swifts then I do, but if I can be of
any help just let me know. Good Luck, Dennis Mee
EMERGENCY PULL DOWN CABLE
SHOULD BE TIGHT AS A "G" STRING... (100400)
Subj: Pull down cable
From: Sheridan Owens <Sandb12345@aol.com>
My emergency pull down cable broke during a gear swing. was rusted a little
bit. put in new cable and pulled the gear up the cable is tight as a "G"
string adjusted to pull the locks at turn and a half as per blue book.
but still seems tight. is this normal??? thanks. Sheridan Owens N80776
sandb12345@aol.com
Sheridan,
Yes, when the cable is adjusted right and the gear is cranked down it
seems VERY tight. -- Jim
HOW ONE SWIFTER SOLVED
THE EMERGENCY EXTENSION CABLE TENSION PROBLEM... (100500)
From: Porter Houston <phouston@erols.com>
Subject: Emergency cable G String Problem
I solved the cable tension problem many years ago with two very minor
modifications to the original design of the gear emergency extension system.
The original design, as a concept, is good except the design cable travel
is actually less than what is required for gear up/ gear down positions.
Basically the jack screw is too short. Also, a spacer at the bottom of
the jack screw( required by AD) reduces travel even more. Therefore, the
correct cable adjustment is so critical there is even and AD note on how
to do it. Also, the tension on the cable has to be excessively high because
just as it goes into down lock there is alot of extra force required.
This translates into very high cable tension in gear up position. The
modifications address these two problems.
(1.) increase the available
cable travel. (2.) decrease force required (read cable tension) to pull
into down lock position.
Mod #1 : To increase available
cable travel cut the cable groove in the pulley deeper by 1 cable diameter.
I used a wire saw blade available from local hardware stores and using
a shoe shine action to deepen the groove. The side benefit is that the
cable rides deeper in the groove and doesn't pop out and therefore the
original simple cable guard bracket is all you need. I also adjusted the
up stops and micro switches as far out as required so gear doesn't over
center in up position and gear doesn't fall out of gear well in flight.
Mod#2: .To reduce the force
required to pull into down lock I replaced the AN315-3 nut that locks
the #10 socket head adjustment screw with a AN365-1032 elastic stop nut
installed backwards. The extra thickness (use washers as required) of
the AN365 nut eliminates the space between the head of the socket head
and the old nut. Originally the down lock lever would fall into this space
and the extra force was needed to raise the down lock lever over the head
of the screw into position. Plus the AN365 nuts tapered diameter creates
a ramp for the down lock lever to fall into position almost on its own.
These two mods allows you
to significantly reduced the gear up cable tension and still guarantee
gear down lock when you need it. -- Porter Houston
SWIFTER DON ON THE EMERGENCY
EXTENSION CABLE...(010502)
Subj: Gear extension cable
From: DON THOMSON <swifterdon@attbi.com>
Hey Monty:
I was reading your response in the GTS newsletter to Jack Gladish about
the tension on the emergency gear extension cable. I thought it would
be worth sharing the experience I had with Charlie Hopkins when we did
my last annual. During the gear emergency extension check we found that
the left gear leg fell from the wheel well immediately after placing the
selector in the down position, but before we started cranking on the handle.
I remember you telling me that the condition was a symptom of the cable
was too tight. We continued to play with the tension until we could place
the selector lever in the down position, with the circuit breaker pulled
and the gear would stay in the wells. We found that the difference between
being "right on" or being too loose or too tight was not more
than a 1/4 to 1/2 of a turn on the adjusting turnbuckle. Charlie and I
had a blast getting it right, but once we figured it out, the satisfaction
made the effort justifiable. The extension worked with the customary 51-52
turns to get the green lights on the panel, and the gear down and locked.
After reading your advice about setting the tension between 90-100 pounds,
I got curious and went out to the airport to measure mine. It was exactly
95 pounds. Good call on your part. About the only other thing I remember
doing was checking to see that the gear cable didn't rub excessively on
the wing ribs in the wheel wells. Minor adjustments corrected that problem,
and I was sure to polish the opening in the rib with a small Dremel stone
to avoid any unnecessary wear on the cable. Well, it's clear here today,
so I'm going to go out and warm of the oil with a flight around the valley.
Oregon gets so few beautiful days in the winter, but when they come, they're
usually spectacular. Keep up the good advice, we all depend on it. Thanks,
Don T.
LEAKING HYDRAULIC FLUID RESERVOIR...(030102)
Subj: Emergency Pulldown
From: Brian Silcox (briansilcox@harbornet.com)
Hi Monty,
I am doing my annual on N46GS, had a strange thing happen when I pulled
the gear down with the cable this time. I have been doing this each year
since I got the plane ten years ago, and never had this: As the second
(left) gear is reaching the stop limit, the reservoir over fills and squirts
several ounces of hydraulic fluid out the cap vent. Thinking it was a
transient anomaly, I reset the cable, refilled the reservoir and recycled
the gear up and down.... no problems. fluid level remained at the proper
level. I once again pulled the gear down manually (cap off, cowl open)
and watched the gusher a second time. I repeated the above one more time
to ensure I wasn't seeing things, and once again same! It works fine in
both the normal, hydraulic powered cycle, and extends fine manually. I
am suspecting a port problem in the powerpack... return fluid is moving
back to the reservoir, but not vice versa through the down lines during
the pulldown. When the overflow occurs, the reservoir is absolutely full,
and stays that way till you activate the system hydraulically, and then
it indicates the fluid loss on the stick. Ever seen this one? Thanks,
Brian Silcox
Brian
Unusual? No, that is a very USUAL happening. This is the first time in
10 years that that happened? You must run very low levels of hydraulic
oil in your reservoir. Ordinarily, when the gear is cranked down it is
quite common to have hydraulic oil spray out the vent and over the windshield.
Rather than repeat myself, go to the "Monty the Answer Man"
archive and read about "Landing Gear - Emergency Extension".
I think Charlie Nelson even talked about that same thing in this months
newsletter. Jim
MANUAL LANDING GEAR EXTENSION...
Subj: Swift gear cable question
From: Larry Owen <Larry.Owen@Tenethealth.com>
Hi Monty
A few years ago, the gear cable was replaced during annual because "it
needed it" by a inspector I never used before or since. I was doing
some prep work for an upcoming annual and found something "odd",
that I have not noticed before. On the ground, the emergency retract cables
are "just short of slack", or VERY light tension. The retract
spring is all the way up and lose enough to move around with your fingers.
When I do a retract test (on jack stands) and retract the wheels using
the hydraulics, the tension on the cable is serious, VERY serious. The
retract spring is compressed all the way down and the cable will pluck
like a violin string !!! I can easily adjust the cable tension, using
the cable splice turnbuckle in the left wheel well, but I am concerned
that by doing that, I will put too much slack in the system during wheels
down. Does the retract spring need replacing to keep the wheels down tension
"normal" after backing off the cable turnbuckle? The pulleys
all test good, free and smooth turning. Thanks ! Larry Owen N78287
Larry
I don't think you have a problem. The cable is "almost slack"
when the gear is down. The cable is very tight after cranking the gear
down. Also, with the gear up the cable gets very tight. If you read S/B
#28 you will see they call for 90 - 100 lbs. I presume you have done retract
and emergency extension checks at annual inspection. DON'T back off the
cable tension because it "feels" too tight! -- Jim
PORTER HAS A SENIOR MOMENT... (OCT 02)
Subj: SB 28
From: Porter Houston <porter.houston@comcast.net>
Monty,
Ref: Emergency gear extension. I seem to remember, or maybe I'm having
one of those senior moments, but is there a special lower casting used
on some late model Swifts that does not use the spacer per SB#28. Fact
or Fiction? I've never seen anything in print about this. -- Porter
Porter
Yes, s/n 3501 to 3760 had a different casting which does not require the
spacer. The s/b requires some interpretation to deduce this - since it
is not required to have the spacer on s/n 3501 and later, the casting
is different. However, the parts catalogue only shows one p/n -- 11-532-2894.
When I used to have all the Swift parts around, I remember comparing two
brackets and they were a little over 1/4" different in height. --
Jim
OOPS... (JAN 03)
Subj: Gear emergency pull down cable
From: John Ewing <jonewing@bellsouth.net>
Jim:
I broke my pull down cable the old fashioned way, by raising the gear
with the system wound down after maintenance testing. Is it difficult
to thread a new cable in? I can easily remove the sheave bolts in the
gear wells, but how do you thread the male threaded end around the pulleys
in the crank down apparatus itself. I say this not yet having removed
the panel to look at the piece itself, but only looking at the drawings
provided in normal swift manuals. Please advise if the are any "swift
secrets". Thanks for your help, hope to see you at "Sun n' Fun.
Over, Jon Ewing
Jon
I haven't installed that cable in a few years but I don't recall anything
very hard about it. The right side (long) cable must be routed thru the
three pulleys at the c/l of the airplane. To hold the screw at the outboard
end of the cable at the actuator clamp a short Phillips bit in a small
vice grip and then ratchet the 10-32 nut off. (unless someone has put
in a slotted screw!) I don't remember if it is necessary to remove the
pulleys or not but it was not a hard job as I recall. -- Jim
SHARING A "GOTCHA"... (AUG 03)
By Larry Owen
Was doing a retract test this last weekend. Things were normal enough,
but was not quite smooth. Cleaned everything and did several more tests.
Couldn't find a problem but..... Did a manual test with the hand crank,
worked but not well, not smooth, something as "almost" not working.
Took the rest of the day to find it. In the left wheel well is the splice
joining the two gear cables together. It of course, has safety wire on
it. The safety wire was no longer "perfectly wrapped". Tight
and solid but not neat and uniform. It had been dragging on the Phenolic
block used as a guide in the wheel well. The block was slightly beat up,
the safety wire was "not straight and pretty". A chicken or
egg type of question of which problem came first. Removed the cable, cleaned
and smoothed out the block, re-installed the cable and redid the safety
wire, (verrrrryyyy carefully) ! Manual crank down is much smoother, electric
pump sound is much more even. Have to remember to look at the safety wire
separately and not just look at the gear wire during pre-flight. ( And
I didn't even have to break anything to learn something this time!)
Larry Owen
N78287
El Paso, Texas
915-577-6832
Larry.Owen@tenethealth.com
CABLE CONCERN... (FEB 04)
Subj: Pull down cable problem
From: Harry Fenton <gippsaero@charter.net>
Hi Jim,
On pre-flight today I found that the pull down cable has jumped out of
both of the big cable guide at the actuator and has gotten wedged between
the guide and actuator. It looks like a relatively simple fix of fishing
the cable out and re-installing in the guide. Must have happened on the
last flight as I check for this condition before every flight thanks to
Mark Holliday's instruction. My question- is this a common experience
and is their a fix or maintenance that I should do to keep this from happening?
To be honest, the cable is wedged in pretty tight and if I were out on
a wind swept ramp, this could be a real hassle. I'd just like to avoid
this as a continuing problem. Otherwise, the Swift is flying great! The
Hanlon Wilson mufflers really put out the heat!! Too bad they don't sound
as good as the straight stacks.I should have checked first, but found
some answers out on the Swift website in the answer archive. Sounds like
this is a common problem. I've been going through each system, bit by
bit, but my shop isn't heated, so kind of tough to do any real maintenance
in the winter. And when the weather gets warm, I want to go flying! It's
a vicious circle, but safety first. I'll knock my bird down for a month
or so when it gets warm and really go through it. Harry
Harry
You have already found the answer but be sure you read the Commings Hydraulic
Manual Pg. "Hints and Tips From Here and There" Also I believe
the blue book covers it. Like Mr Commings says -- you can drill #60 holes
in the crank down pulley and safety wire the cable to the groove. Univair
used to sell a kit which did essentially the same thing in a more elaborate
manner -- it kept the cable in the groove. -- Jim
CABLE CONCERN. THE PLOT THICKENS...(FEB 04)
Subj: Pull down cable problem
From: Harry Fenton <gippsaero@charter.net>
Hi Jim,
Well, what seemed like a simple fix has become a bit more complicated.
The right cable is back in place, but the left is firmly wedged between
the cable guide and the shaft extending from the actuator. I've tried
wiggling the pulley to get the cable loose, but no luck, the cable is
pinched really tight. It looks like I could loosen the bolt at the scissor
link to which a support bracket from the cable guide attaches to get some
freeplay . My concern is the down lock and if I can trip it loose with
my fiddling. I don't have a set of jacks yet, so I'm trying to do this
work without. Is it a bad idea to be trying to fix this without putting
it on jacks? -- Harry
Harry
You usually can insert a screwdriver and pry the pulley enough to get
the cable out. You will need jacks or jackstands sooner or later. If you
don't want to pop for jacks right now just make some fixed height jackstands.
Make them out of car jackstands or 2x4's just about 2" higher than
the distance from the jack points to the floor with the struts fully extended.
Raise the tail, put the jackstands in place and lower the tail. (You will
need a helper to put some weight on the tail) If you do get it jacked
up by some means, take a big straight screwdriver and push the downlock
in and partially fold the gear. It may be necessary to put the selector
in the cockpit "up" or in an intermediate position. The cable
will not be too tight and by manipulating it you should be able to break
it free. On jacks, you can remove the center bolt in the retract linkage
and then the pulley will be loose on the retract arm. The cable should
come free easier then. When up on jacks, the gear should be checked per
the reoccurring AD notes and the gear door fit should be checked. -- Jim
p.s. You can do this with just one side jacked up. That way the airplane
will not have such a tendency to nose over.
WHAT A JOB! (FEB 04)
Subj: Emergency gear fixed- finally!!
From: gippsaero@charter.net (Harry Fenton)
Hi Jim,
I finally fixed my jumped cables- what a job! The cable for the left gear
had developed a small loop, and then this loop was wedged between the
landing gear housing and the cable guide. I had to disassemble a bunch
of components to loosen the cable guide, disconnect the cable anchor end
from the guide and pulled on it like crazy until it came loose. It probably
took me four solid hours to get it finally worked loose. One significant
condition that I have noted is that the emergency cable is pretty loose
in tension. I have read in some of the discussion on this topic that the
cable tension should be pretty tight. A second observation is that there
is an adjusting turnbuckle that is positioned right in the middle of the
grommet in the center rib in the left wheel well. This turnbuckle seems
to be hanging up on the grommet as the cable pulls through. Finally, the
kink in the cable caused by the pinch bent the cable and the cable tends
to keep jumping out of the guide. I'm going to tension and lube the cable,
and drill the guide to install safety wire as described in the Swift maintenance
tips book. A final mod is to replace the Phillips screw that anchored
the cable with an Allen head machine screw. The Allen head is much easier
to work with than a Phillips in that tight environment. -- Harry
Harry
I use the Phillips head screw, I clamp a Phillips bit in a small vice
grip and that works fine for loosening/tightening. The cable tension is
only meaningful after the gear is cranked down. (about 100 lbs) Normally,
there is only spring tension on the cable. The cable tension should be
just enough to pull the gear to the down position. Too much and you may
have retraction problems or the gear may come unlocked in flight. You
are on your way to becoming an expert! -- Jim
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