 Savvy
Owner Notebook:
Why Didn't I Listen?
Airplanes have a way of telling you when something’s wrong, and
usually
they give you plenty of warning. Ignore such warnings and bad things can
happen...as I found out the hard way.
by Mike Busch,
A&P/IA (mike.busch@savvyaviator.com)
 I've
been an aircraft owner for most of my adult life. I'm a tech rep for
the world's largest aviation "type club" and have helped thousands
of aircraft owners solve their thorniest maintenance problems. I
hold an FAA mechanic certificate with airframe and power plant
ratings plus an inspection authorization. And yet I'm just as capable of screwing up as the next guy.
A few years ago, I had a mechanical failure on my Cessna T310R. It wasn’t serious or
life-threatening, but it was inconvenient, annoying and embarrassing. It
occurred away from home base, at night, with my wife as a passenger. (She’s a
white-knuckle flyer who doesn’t leave the ground if she can possibly avoid it.)
It occurred 200 miles from the "comfort zone" of my hangar and toolbox, so I had to throw myself on the mercy of a local
mechanic to bail me out of trouble.
Worst of all, it was my fault. It shouldn’t have happened. I screwed up.
Routine mission
Thursday morning was bright and clear on the California coast. A high-pressure
area over the Nevada desert brought strong northerly winds that blew the usual
marine layer well out to sea, resulting in exceptional visibility. I was looking
forward to some excellent aerial sightseeing during the 50-minute flight from my
home base of Santa Maria [SMX] to John Wayne Airport in Santa Ana, [SNA], where
my wife Jan and I were to have lunch with a good friend.
The DUATS briefing suggested that the flight would be quick and bumpy, due to
strong winds aloft and the rough terrain we’d be traversing. I warned Jan (a nervous flyer
who hates turbulence), and secretly hoped that the forecast
would be wrong so she could be spared the anxiety.
 We arrived at SMX about 10 am. I pulled the plane out of the hangar while Jan made her mandatory pre-departure potty
stop. My preflight revealed nothing interesting, so we climbed into the airplane
and belted up. I started engines, called for my IFR clearance, taxied out, ran
up, and launched right on schedule.
The forecast turbulence never materialized. With “George” doing the flying and Garmin
doing the navigating, I relaxed and enjoyed the spectacular view. Jan sat in back, pulled the
curtains, read a book, and tried her best to pretend she wasn't airborne.
John Wayne was landing to the north, a fairly unusual situation that only occurs
a few times each year during these northerly wind conditions known to the locals
as “Santa Anas.” I made a visual approach behind a Boeing 757, stayed high and
landed long to avoid its wake, and turned off about two-thirds of the way down
the runway, leaving me a long taxi to the Newport Jet Center on the southeast
corner of the field where we’d arranged to meet our friend.
Three decades earlier, I had based my very first airplane (a new 1968-model Cessna 182) at
this airport, and it was a delightful general aviation field with relatively few air carrier
operations. Nowadays, SNA is Big Iron City, and the taxiways are a
regular zoo. I found myself trapped in the middle of a conga line of air
carriers waiting for release. It was 15 minutes after we landed, and I’d still
not made it to the FBO. We were late, and I visualized our friend glancing at
his wristwatch in the FBO, wondering why we hadn’t arrived.
Finally, the Brasilia that had been blowing kerosene fumes into our cabin vents
got released, clearing the path for us to taxi to Newport Jet.
Do you hear that?
As I taxied to the FBO, probably just a bit faster than my usual “brisk walk”
taxi speed, I thought I heard something funny. Sort of a scraping sound, perhaps
a dragging brake.
“Do you hear that?” I asked Jan.
“Hear what?” she replied, reluctantly looking up from her book.
“That funny sound ... sort of a scraping sound.”
“No, I don’t hear anything.”
I listened again, and now I wasn’t sure I heard anything, either, other than the
usual growl of the two idling Continental engines.
“Probably nothing,” I said.
Jan returned to her reading.
A lineman directed our 310 to a parking spot. I shut down the engines, and we
climbed out of the airplane and headed for the FBO lobby. Our friend wasn’t
there. I decided I better call his office and find out why. Which is when I
realized I’d left my cellphone in the airplane.
I trotted back to the airplane to fetch my cell. While there, I decided to get
down on my hands and knees and have a very close look at the main landing gear, just to
see if I could see any evidence of a dragging brake or bad wheel bearing.
Everything looked fine, and the wheels and brake disks were cool to the touch.
Had the brakes been dragging, I figured the disks would still be warm. I felt
reassured that all was okay with the airplane.
I called my friend (who had forgotten our lunch date). He met us at the FBO a
few minutes later, and we had a lovely lunch that turned into an afternoon of
conversation. By the time we got back to the airport to head for home, it was
5:15 pm. While Jan made her obligatory potty stop, I checked the weather on
the FBO’s DTN terminal. Still clear as a bell, and the turbulence AIRMETs had
expired. We walked out to the airplane, strapped in, and fired up for the flight
home. The sun was just disappearing below the southwestern horizon.
Decisions, decisions
I picked up the ATIS and our IFR clearance, then called ground for a taxi
clearance to the mid-field runup area. Halfway there, I became aware that
something didn’t sound right again. This time, it sounded less like a draggy
brake and more like someone had sprinkled sand in the wheel bearings. And then I
heard a high-pitched squeaking sound, like fingernails on a blackboard.
I turned to Jan and could tell by the look on her face that this time, she’d
heard it, too.
“What’s that sound?” she asked.
“I’m not sure,” I answered, trying to conceal my worry.
I brought the airplane to a stop on the taxiway. The noise stopped. I started
taxiing again. The noise returned. Definitely the landing gear, I thought.
By now, I’d reached the mid-field runup area. I tried making sharp turns to the
left and right, trying to determine whether the sound was coming from the left
or right main gear. I couldn’t tell.
It was dark. I was tired. All the mechanics on the field had undoubtedly gone
home for the night. How serious was this problem? Could I fly home with it and
sort things out in the morning in the comfort of my own hangar and my own
toolbox? The siren song of get-home-itis was strong and sweet.
But what if a wheel froze up on landing? I visualized my airplane crippled in
the middle of the SMX runway in the pitch dark. In my mind’s eye, I saw the
collapsed main landing gear leg, three curled prop tips, and an engine going through
a sudden-stop teardown inspection.
After debating with myself for what seemed like a half hour but probably was
actually no more than 30 seconds, I made my decision. “Sweetie,” I said to Jan,
“I don’t think it would be a good idea to take off until we find out what’s
making that noise.” Jan offered no argument.
I called ground control, told the nice lady that we had a mechanical problem and needed
to return to the ramp to shut down and investigate. She said she’d extend the
P-time on my IFR flight plan, and cleared us to taxi to Signature Flight
Support, the nearest FBO.
Taxiing to Signature, the noise sounded really awful—now more like ground glass
in the wheel bearings instead of just sand. I was feeling more worried about the
airplane, and more confident about my decision not to take off.
I shut down on the Signature ramp, got out, and explained to the lineman that
I’d heard a funny sound that I thought might be coming from the landing gear and
wanted to check it out. The lineman replied that he’d heard the sound himself as
we taxied up (over the roar of the engines!) and wondered what it was.
I rolled the airplane back a few feet on the ramp, and the problem was
immediately apparent. The sound was coming from the nosegear. And it was loud
and awful-sounding.
Who ya gonna call?
“I don’t suppose there are any mechanics on the field at this hour?” I asked the
lineman.
“I think they all go home by 5 or 5:30,” he said. It was now about 6 pm.
Isn't that the way it always works?
I told Jan we might be stuck overnight. Neither of us had a change of clothes or
a toothbrush. Jan was worried about who would feed our dog back home. I was
worried about the airplane.
As Jan and I were pondering our fate, a lanky fellow waked up, introduced
himself as a local pilot and CFI, said he couldn’t help overhearing our
predicament, and said he might be able to get a hold of a local mechanic via his
beeper. “That would be wonderful,” I said. The pilot sent the page, got a call
back on his cellphone, and told me that the mechanic would be there in about 15
minutes.
Almost exactly 15 minutes later, a fellow drove up in a pickup truck and introduced
himself as Saeed Pourzandjani, proprietor of Starcraft Aviation Aircraft
Maintenance. Saeed listened to the sound of my nosewheel as we rolled the aircraft
back a few more inches, and suggested that we tow the aircraft to his
maintenance hangar not far away. The Signature lineman volunteered his snazzy $100,000 Lektro tug for the job, and soon my 310 was parked outside of Saeed’s hangar
with the nosewheel jacked up off the ground. The sound it made when we rotated
it was simply horrible.
A fine mess
The nosewheel assembly components were so badly frozen
that they had to be forcibly separated using a mallet and
wood drift.
(Click on image for higher-resolution photo.) |
As we pulled the axle bolt and tried to remove the nosewheel from the aircraft,
it quickly became apparent that we were dealing with more than your
run-of-the-mill bad wheel bearing. One of the cups that retains the tube axle to
the nose gear fork didn’t want to come out, and had to be driven out with a
drift and mallet. Then the nosewheel assembly came off the fork, but the axle
wouldn’t slide out of the wheel and had to be driven out with a hammer and a
block of wood. And even after we got the axle out of the wheel, one of the
magnesium spacers wound up being severely frozen to the axle and only came off
after heating it with a torch and some more vigorous hammering. Normally, all
these parts slide smoothly and effortlessly on and off the axle.
Both of the Timken tapered roller bearings and their races looked awful, and one
was absolutely destroyed. Neither appeared to have a speck of grease left,
although I knew they’d been thoroughly greased at the annual 11 months earlier. I
was certain of that because I’d packed those bearings with grease myself.
Clearly this assembly had gotten terribly hot. Hot enough to liquefy all the
grease in the bearings and let it run out of the bearings. Hot enough to distort
the spacer and cause it to seize to the axle. Hot enough to cause obvious metal
smearing on one of the wheel bearings.
Yuck! What a mess!
Teamwork
Saeed said he wasn’t sure if he could come up with two new bearings before
morning, but said he’d phone some friends and see what he could find.
After striking out on the first couple of phone calls, he finally located the
necessary bearings at a shop in Costa Mesa, about 30 minutes drive away.
While Saeed was off policing up the bearings, I tried my best to clean up the
other parts of the nosewheel assembly so that they could be fit back together.
The tube axle had significant deposits of transferred metal from the frozen
spacer that I polished off with a wire wheel. The ends of the axle had been
severely beaded from all the hammering required to get it separated from the
wheel bearings and spacers, and those had to be cleaned up with a motorized hand
grinder. I cleaned up the inside diameters of the tube axle and spacers with a
ball hone chucked into an electric drill. The spacer flanges were all torn up
where they rotated against the nose fork and had to be reground flat with a disk
sander. It took me an hour, but I finally got all the parts cleaned up to the
point that they would slide together relatively smoothly.
By the time Saeed got back to the shop with a pair of new bearings and races, it
was 9:15 pm. I showed him the results of my axle and spacer field overhaul
efforts, and he agreed the parts were airworthy (albeit not exactly pretty). Saeed removed the damaged
bearing races from the nosewheel, pressed in the two new ones, greased the new
bearings, and reassembled the nosewheel and spacers to the axle.
We took all this stuff out to the airplane on the now pitch dark ramp, and
reinstalled the nosewheel onto the nosegear fork using flashlights to see what
we were doing. By the time we were done and the aircraft was down off the jack,
it was 10:35 pm. Saeed and I had been battling this problem for four and a half
hours, but victory was finally in hand.
Getting out of Dodge
To my shock, I realized that I faced one more hurdle that might prevent us from
getting home. I remembered a NOTAM during my morning DUATS briefing, saying that
the airport would be closed for runway construction starting at 11 pm local
time. I called the tower on the radio and they confirmed that the airport would
be closing to all operations at 11 pm sharp ... just 25 minutes from now. Yikes!
I phoned Signature (where Jan had been cooling her feet in the pilot’s lounge,
watching TV) and asked them to tell Jan to hustle over to the airplane right
away. When Jan arrived a few minutes later, I asked her to start settling up the
paperwork with Saeed while I worked on getting a clearance to depart. I called
the tower on the radio and asked for a tower-enroute IFR clearance to “anywhere
north of LAX ... I’ll sort out the rest in the air.” The nice lady gave me a
canned clearance to Santa Barbara. Close enough!
Jan quickly settled up with Saeed for the parts and labor—about $300. He
apologized that the bill was so high, and we said, “don’t be silly, you’re our
hero!”
Once more time, Jan and I climbed into the airplane and belted in. It was now
10:50 pm, and it was going to be close. I started engines, told ground control
I’d forgo the runup and would be ready for IFR release when we reached the
hold-short line. Happily, the taxi-out was blissfully free of funny noises.
We lifted off at 10:54 pm, six minutes before the airport closed. I think we
were the last plane out of Dodge. The flight hope was uneventful, and by
midnight the plane was in its hangar at SMX and Jan and I realized we were
famished, having eaten nothing since our lunch 12 hours earlier.
Fortuitously, the local In-and-Out Burger didn’t close until 1 am. We munched on
burgers and fries on the drive home, fed the dog, and then collapsed into bed.
It had been a long day.
I should have listened
It wasn’t until the next day that I started asking myself some hard questions,
and realized that the minor mishap at John Wayne could have been avoided if I’d
been paying proper attention. There had been warning signs but I’d ignored them.
The airplane had been trying to tell me something, but I didn’t listen.
The side of my nosewheel was unusually greasy and
dirty. Had I investigated further, I'd have most likely
discovered the bad bearing well before it self-destructed.
(Click on image for higher-resolution photo.) |
More than a month earlier, for example, I’d added air to the nosewheel tire and
noticed that the side of the wheel was unusually greasy and dirty. At the time,
I’d just grabbed a shop towel and wiped off the grime without much thought. In
hindsight, I realized that the wheel was greasy and dirty because the wheel
bearing had been throwing grease and metallic particles.
Grease and grime don’t come out of nowhere. I should have asked myself where it
came from, and not just wiped it off. The airplane was trying to tell me it had
a problem. Why didn’t I listen?
Not long after that, I flew up to the Bay Area with a pilot-friend. After
landing back home at Santa Maria, I thought I heard a funny noise as we were
taxiing in. I asked the other pilot whether he heard it, and he said no. I
couldn’t hear it anymore myself, so I figured I must have imagined it. I even
briefly considered jacking the airplane and listening critically to the wheels
as I spun them, but never followed through.
It wasn’t my imagination. The airplane was talking, but I wasn’t listening.
Had I been paying attention, I could have caught this problem earlier. I could
have fixed it in the comfort of my own hangar, using my own toolbox. It would
have taken me about an hour and $20 worth of parts to replace the bad bearings.
My wife would have been spared the inconvenience, and I would have been spared
the embarrassment. (And my Savvy Owner Notebook article this month would have been on a
different topic.)
It could have been a lot worse. Had I succumbed to get-home-itis and flown home
without repairing the nosegear, I now believe—after seeing the devastating
condition of the nosewheel assembly—that I very well might have had a blown
tire, damaged nose gear fork, or even gear collapse when I landed at SMX. A
replacement nose gear fork would cost $2,000 from a salvage yard, and a gear collapse would have cost a whole lot more (not to mention the
impact on next year’s insurance premiums).
I was also lucky that Cessna decided to make the nosewheel axle spacers out of
magnesium rather than aluminum. The soft magnesium spacers bore the brunt of the
damage, and the nose gear fork (made of harder aluminum alloy) came out
relatively unscathed.
Coda
About three weeks later, I downed my airplane for its annual inspection. I
decided to replace all the nosegear components that were traumatized during
forcible disassembly at SNA: tube axle, magnesium spacers, and grease seals for
the nosewheel bearing. I brought the old scarred-up parts home and to keep as a reminder to pay closer attention
in the future.
| Do you have a maintenance-related
"war story" that you'd like to share with fellow
aircraft owners? If you do, I'd
love to hear from you. The most interesting stories
I receive each month will be rewarded with highly prized Savvy
Aviator coffee mugs, so please include your
shipping address. Also be sure to let me know if you'd like
me to "change the names to protect the innocent"
when sharing your story. |
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