Tales from the Log of the Ruptured Duck | Page 16 | SouthernPaddler.com

Tales from the Log of the Ruptured Duck

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
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Okemos / East Lansing Michigan
Best Glide

Other pilots reading this will recognize what I'm writing about here. It's something you have to learn.

When training for emergency landings, "engine out" is one of the situations that we train for. If the engine quits, pucker factor will increase - sharply. So, we practice what to do. One of the first things you learn is best glide speed. It's the speed, and rate of descent, where the plane will glide the furthest before contacting the ground. In the newer Cessna 172s that I started training in, it was 75mph.

When I bought the Ruptured Duck, I read the owner's manual cover to cover. Nowadays, they're called the Pilot's Operating Manual (POM), but in the early 60s, still thought of similar to cars, it was still known as an owner's manual. And, nowhere in there did the term "best glide speed" show up. So, I conferred with the FAA Designated Examiner. We decided that whatever it was, it would be pretty close to 75. Actually, I suspect that it is a smidgeon higher, because the newer plames have a slightly improved wing.

But, the Duck now has a much better wing than the new 172s. So, best glide should lie a bit south of 75. How much? Well, that's what I will do some test flights to determine. Terry, a friend of mine who is now retired from being a test pilot for Airbus, talked it over with me. There are at least two regimens for determination of best glide. I'll probably do both.

Method 1 is to Make a series of measured, timed descents, record the data (indicated airspeed [IAS], rate of descent, and time to descend at this constant rate through a 500' drop), draw a graph, and select the optimum point along the speed curve. Method 2 is to climb high, slow to, say, 80mph, start the descent, trim to maintain speed, look for the spot on the ground shead that "stands still". In a glide, the point ahead that stands still is your contact point. Nearer than that point, the ground appears to move down; you will overfly that. Beyond the still point the ground appears to move up; you will not get that far.

It's necessary to have a safety pilot, riding along with me to keep an eye outside, issue warnings, and record data. It's too easy to get either task saturation or target fascination, and an additional pilot will prevent that.

So, in a glide, stabilized at 80mph, locate the contact point. Run trim to raise the nose and slow to, say, 75mph. If the contact point moves further away good! Trim nose up to descend slower in small increments. If the contact point continues to extend, go slower yet. If it gets closer, trim nose down to speed the glide. At each speed, record indicated air speed, rate of descent, and "lift reserve".

This lift reserve is actually angle of attack (AOA), and I suspect that information will be more predictive than IAS. As a plane flies in different configurations and conditions, it requires more or less lift. That lift increases with airspeed and angle of attack - within limits. At a given airspeed, the wings can develop more lift (to hold up a heavier aircraft) by increasing angle of attack. At a given angle of attack, the wings develop more lift at a higher air speed. Thin air (high altitudes above sea level, or high density altitude) develops less lift than does thicker air (low density altitude, as at low levels and/or cold weather.

All this being said, I suspect that what I'm really seeking is the best angle of attack to achieve the longest glide distance. I expect AOA to vary less under widely changing conditions than will airspeed. We'll see. I'll do the tests at heavy weights, and then at light weights. Comparing the data will tell me what I want to know.

We'll see.
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
171
86
Okemos / East Lansing Michigan
Best Glide - First Shot

This morning, we climbed to 5,000 feet MSL (Mean Sea Level), about 4,100 feet AGL (Above Ground Level). First off, with low relative humidity and high density altitude we could see clear into next week. We had at least 25 miles of visibility in every direction except down. So, we're looking at a 50 mile diameter circle out there!

After calming down from that exhilaration, we got to work. Slow down to 80 mph, do a clearing turn to ensure there are no other aircraft (planes, balloons, unmanned drones, etc.) nearby, and set up for a slow, controlled descent. Carb heat ON, throttle FULL IDLE, trim FULL NOSE UP then back off 1/2 turn. Observe indicated air speed (IAS), adjust trim so it stabilizes at 80mph. Check for other aircraft. (We had already established Flight Following, so Air Traffic Control was also watching out for us, but primary responsibility for avoidance of a mid-air is still mine.) Julie had her eyes on outside the cockpit too.

Time to record data; Julie was ready.
IAS 80, Lift Reserve 4.2 (an arbitrary number unique to the specific set up on the Duck). Vertical Speed negative 500 feet per minute (FPM)

Run trim back to full nose up, speed slows to 75mph, and flight stabilizes again.
IAS 75. Lift 3.6. Vertical Speed negative 495.

Pull back on the yoke to raise the nose a bit more. Speed slows to 7O and stabilizes.
IAS 70. Lift 2.8. Vertical Speed negative 495.

Well, analyzing this data gave several insights. First, the trend is inconclusive. Our glide was better at both 80 and 70mph than it was at 75. Probably, this is due to sloppy technique. I probably need to keep tighter control of conditions, and also let it glide longer at any given speed.

Second, the rate of descent seemed much more constant than I expected. The difference between 495-500 FPM is only about one needle width on the gauge. Frankly, error of measurement could easily account for that difference.

Third, the one, consistent reading was Lift Reserve. This is really an Angle Of Attack reading. It accurately reflects that as I slow down, I had to raise the nose.

Lastly, when running the numbers, this new wing generates about a 12:1 glide ratio. The original wing had only a 7:1 glide ratio. THAT IS ABOUT A 70% IMPROVEMENT! Even if I screw it up - the plane will glide wayyy further than ever before.

Upshot is, we will work some more on this. For one thing, winds were in a different direction at 3,000 feet than at 5,000 feet. Also, trusting my Vertical Speed Indicator (VSI, also called the "climb and dive dial"), may not be the wisest thing to be doing.

Anyway, we glided nearly all the way back to the traffic pattern, landed, and went for coffee and lunch. Cheated death again.
 

Wannabe

Well-Known Member
Apr 5, 2007
2,645
2
on the bank of Trinity Bay
A 70% improvement is a whopping lot. Congrats. Back to your last pose about watching tour spot on the ground and seeing if it moves up on down on a spot on tour windshield. Your windshield is a valuable flight instrument. Any time you see another airplane and it stays on the same spot on your windshield you are on a collision course. If you see another aircraft glued to the same spot on your windshield, alter your course a few degrees (time it so you can get back on track) to get him moving across the windshield. and out of Harms way.
Bob
PS. Thanks Mike. I should of done this three years ago.
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
171
86
Okemos / East Lansing Michigan
Best Glide

After several flights, we narrowed it down. I have some math yet to do, but we have it bracketed at about 70mph, and a specific Lift Reserve reading. (This Lift Reserve reading is unique to my, specific aircraft. More specifically, it is unique to how this instrument is calibrated on this plane. It is an easy condition to replicate in flight.)

As we recorded vertical speed - rate of descent - and later corrected for measurement error, it became obvious that the plane actually does have a very improved glide ratio. Originally 7:1 - 7,000' forward for every 1,000' down - it is now about 11.7:1. Several runs confirmed this.

We had also tried to glide at 65mph. The Duck wasn't very happy there, so we aborted the test and came home. Job done.
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
171
86
Okemos / East Lansing Michigan
Michigan Fall Colors

Today, the Ruptured Duck turned 53 years of age. She has a few wrinkles, but the waist line is just as trim as when she was a young lady. We didn't do a celebration this year; I just taxied her down to the fuel pits and filled her up. Tomorrow, Julie and I are taking her for a ride.

Michigan has four seasons. In my opinion, fall is the best one. While fall colors are a bit slower coming this year, so tomorrow's soirée will be lunch instead of viewing autumnal splendor. In a few weeks, I'll be waxing enthusiastic about golds, reds, blazing orange, and large vee formstions of Canadian geese.

Some fellas go fishing; others watch them from overhead.
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
171
86
Okemos / East Lansing Michigan
And Then, There Were None

Yesterday, with the best of intentions, we planned a trip to Hillsdale KJMY for a coffee stop. Then Charlottee KFPK for lunch and to get the nose wheel shimmy dampener serviced. The road to Hell, it is said, is paved with the best of intentions. Yesterday, our intentions became a paving stone on that road.

With high pressure dominating the entire Great Lakes area, I was pretty confident of a favorable weather briefing. Surprise! Wind wer 10 knots, gusting to twenty, and forecast to be gusting to 26! I looked out through the hangar door at the flagpole across the road. "Doesn't look that bad. Hmmm." So, we pulled the Duck out onto the taxiway, and cranked'er up. As always, she ran sweet and smooth. BUT, the N'ly wind coming down through the row in between the hangars was a wind tunnel. Though we were stiing still, the wings were rocking. Quietly, a little, yellow caution light blinked on in the back of my head.

"Nawww, I think it'll be OK." So we taxied out to runway 10, lined up into the wind, locked the brakes, mixture full rich, RPM1600, and did the mag check to ensure that both magneto systems are operational. We radioed our intenrions and took the runway. I'd turned full left ailerons to counteract the stiff crosswind, held it on the ground so the nosewheel and rudder could reinforce esch other, then lifted off. About 20 feet into the sir, a bright red csution light was blinking. As we gained air speed and rose to about 80 feet above ground level, a loud horn added itself to that red light in my head.

The weather guy was right, and I was wrong. "Mason traffic, Skyhawk 2111 Yankee, remaining in the pattern for full stop." On the intercom - not transmitted out - "Honey, we're returning." A tense voice beside me agreed. The wind was so strong that I couldn't come around into the downwind leg of the pattern. We had to reverse the turn to gain room to reenter the pattern. After turning base leg, it was then difficult to get lined up with the runway.

As we descended, the wind weakened closer to the ground. Touchdown on the upwind main, three on the ground, flaps up (I'd used minimum flaps in the strong crosswinds), let it roll out, and then braking to turn off and exit the active runway. We'd cheated death; time for coffee. We'll wait for better weather.
 

Wannabe

Well-Known Member
Apr 5, 2007
2,645
2
on the bank of Trinity Bay
We all get these little quite warning signals and oft times they are ignored. Life would be a whole lot simpler if we would listen to these small warnings. Being 9 st. tall and bulletproof will get you bd hurt. Glad you came through it ok. As I learned long ago, Excitement if not Fun.
Bob
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
171
86
Okemos / East Lansing Michigan
Bob, you are sure as heck right. Through experience, we learn to recognize both patterns and anomalies. Some bode good - others signal or hint in the other direction. I expect that, folks who walk around in dry brushy country or in wet mushy country, soon learn to recognize and avoid certain areas that could be snaketory. In other locales, a guy learns to recognize stuff that could be bearatory, or pumatory.

Flying the same plane all the time, I've learned to listen to her when she talks to me. A different feel, a different sound, an unexpected dip or buck tells me she isn't happy here. "Take me OUT of here - right now! Please!" Other times, she settles in, purrs, and is as contented as a puppy dog with a full tummy, curled up near the fire. She communicates, and you listen. It's a two way street, because I communicate to her too. And, she listens.

We learn, as experienced drivers, to recognize potential accident situations. Often, while they are still in their formative stages. Sometimes, it's a specific pattern that alerts us. Other times it may be an anomoly that interrupts a general pattern. Over the years, if we've survived, we've learned. We listen to others and lesrn from them too. We often label this collection of learned knowledge as "common sense".

Situation is, though, that our common sense is pretty personalised to our own, personal collection of experiences. Each of us has a pretty unique collection of personal experiences. What is common to one of us, will be uncommon (read "strange") to another.

Sometimes, common sense just ain't all that common.
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
171
86
Okemos / East Lansing Michigan
AARRGGHH!!

A couple of weeks ago, I wrote of flying over Michigan's beautiful, fall colors. Since then we've tried three times to get aloft to see them. Three times now, we've been weathered out. Gusty winds, lowering clouds, towering clouds, blowing rain, and ripening mist have all conspired to keep us on the ground.

So, three times now, we've retreated to the coffeeshop. Today, we joined a group of friends there. Ken, who was on a supply ship in WWII. Rollie, a young Marine on Iwo Jima. Alisha, a present day young lady struggling to make her way in today's world. Harold, who was in the Navy from '54 through '60, all over the Pacific and Antarctica. Sue, Ken's cultured wife. Kay, a dedicated grandmother and wry wit. Julie and I enjoy being with and around them. Others come by our table, dropping in, passing greetings, moving along with their own day.

Pretty quick, it's lunch time. "Hey - let's walk down the street to Los Tres Amigos. Is that OK?" Julie and I have a handful of restaurants that are favorites. Los Tres is on top. Not only is the food good, it's healthful. Seven of us trek off down the street to a relaxing time together.

We didn't have to cheat death today.
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
171
86
Okemos / East Lansing Michigan
Persistance Pays Off - Finally!

After having been weathered out four times, we got airborne today. We were able to see some fall colors today, the first after one or two frosts. (Insert a medly of blaring trumpets here; add snare drums playing ruffles and flourishes; and now - fifers are sent a piping along the village square!!! )

One morning this week, we awoke to unexpected sunshine and blue skies. Hurrying, we gathered our gear and drove to the hangar. When we stopped the car and got out, we realized that clouds had blown south faster than we'd driven. Winds swirled around, clouds stacked higher and fell lower. Back to the coffeeshop. But today - today the good weather held. A bit of turbulence from surface to 18,000' was only a series of chop that didn't deter us.

This morning, while on the way to the airfield, Julie called her brother, and arranged for them to meet us at Marshall's Brooks Field KRMY. In the meantime, we flew an angular, dogleg-route to get there so we could go over more territory and more colorful woods. Here, we saw reds, yellows, and banks of amber. Lakes of deep blues, turquoise, bordered by green mosses and filds of brown, ripened soy beans.

Along the way, we skirted wide to the south around Napoleon Airfield 3NP where an aircraft with three skydivers was getting ready to call out, "Jumpers away! Jumpers away'". Doing that, we flew over the Michigan International Speedway that roars to large engined race cars.

About 15 miles out of Marshall, Air Traffic Control (ATC) released us from flight following, and we changed radio frequencies to the Common Traffic Air Frequency (CTAF) for Marshall. Immediately, we heard three aircraft enterring - or already in - the traffic pattern already at Marshall. Holy mackerel! Lots of folks coming here today. But, by the time we got there, flew past so we could double back on the downwind leg, all other aircraft had completed landing, and were parked on the ramp. We were all by ourselves, and taxied to a nice spot, shut down, and secured the Duck.

Ken and Ginger were waiting for us. We elected to go to Schuler's Restaurant. Here is an elegant restaurant that I've mentioned before. Folks come in from all over. One of those planes that landed just ahead of us, had flown in from Indiana. Today, we partook of a large, multi-layered buffer. Shrimp, prime rib, breads and cheeses, varieties of super potatoes, and veggies galore were on the dinner tables. Simultaneously, a breakfast table offerred eggs, potatoes, bacon, etc. etc.

Exhibiting absolutely no self control whatsoever, I dug right in. About 8-10 pounds later, I began to slow dow. Tallyho! There's also a dessert table. Well, it would be impolite to ignore the efforts of those folks, so we fastidiously partook. BURP!

Later, we walked around the iconic downtown, in and out of antique shops and boutiques. An hour or so of that pursuit served to settle the meal, so we strolled back to the car and returned to the field. Julie and I got the Duck ready, cranked it up, and took off. Duck Lake slid by on our left; and then the village of Springport on our right. Then, ATC informed us of approaching traffic dead ahead, altitude unknown. Neither Julie or I could see it. A minute later ATC revectored us from our 60 degree heading to 140 to get us around the approaching traffic. Still, we could not spot any approaching aircraft. Then, they were able to let us know that the traffic was no longer a factor, and we could proceed directly to Mason.

"Thank you for the help, Lansing. We appreciate the it." In fact, they had helped by removing us from the area of a potential midair collision. No small favor, that.

Back at home base, we had an uneventful landing. Cheated death again.
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
171
86
Okemos / East Lansing Michigan
Blue Skies - Orange/Red/Yellow Leaves

Again, we took to the air and drank in fall colors. In some areas, the bright colors are already fading to a dull yellow, and even some dingy browns. But - LOOK, OVER THERE! See that bright red tree! And look at how it sets off that brick home next to it. See the whole, southerly side of the woods is glow.

Large, clumsy combines waddle along in fields, gushing out a steady stream of soy beans into the hopper, and belching dust trails for over a quarter of a mile, out across the field and over the fence. Corn fields that have already been picked, are being fertilized. Next, comes the plow.

Later, over sandwiches in the Bestsellers Coffeeshop and Book Store, folks are gathered in little gaggles of friends and family. Aged mothers accompany middle aged daughters. Young moms guide little ones from 2-3 years of age up to 12-13. Most are new to us, some are old acquaintances. Midwest, small town, Americana, over a cup of coffee.

Silently, and to myself, I say, "Thanks, God, for giving me another year to see this miracle of the fall. Marvelous!"
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
171
86
Okemos / East Lansing Michigan
On A Sunday Afternoon

Weather here for both today and tomorrow, is dominated by high pressure systems. Beautiful flying weather! We motored on over to the hangar, preflighted the Duck, and called for a weather briefing. After 15 minutes of listening to fuzzy background music that was punctuated by a few announcements about experiencing a high workload - I gave up. I'd originally planned to fly north, and then WNW'ly along the Maple River. But that's too far away without a legal weather briefing. So decided to fly just around the flagpole (remain in sight of the field).

As we were pulling the Duck out of the hangar, I got a call. It seems that my friend, who was a young Marine on Iwo Jima, is going downhill. And, his driver's license was revoked. DAMN! This is going to be tough on him. Next, a neighbor dropped in. When he plugged his air compressor into his extension cord, there were sparks and smoke. "Darned extension cord needs a new receptacle on it. But for now, do you have an extension cord I can borrow?" We finally got into the air.

Sadly, last night's rain had washed out most of the color. Muddy brown seems to be in the majority out there in the hinterlands. So, we wandered back and forth, running along a railroad, follwing up a tiny stream, watching a WWII Srearman trainer take off. Dave says it takes off at 80, cruises at 80, and lands at 80. His company, Yesteryear Aviation, sells rides. Further on, we circled a golf course, but saw no one on the links. Next to it is a lake with no fishermen out on it. How can people stay inside on such a pretty day??!!

Back at the field we taxied up to the fuel pumps. Two ladys were refueling their Cessna ahead of us. They pulled off, and we pulled on. FAA rules are that when traveling, you have to have a half hour's fuel when landing at your first stop. For the Duck, that would be only 3 1/2 gallons. Well, my personal limit is to not fly below 10 gallons. I don't mind hauling around a few extra gallons of gas - and hope it's always a waste.

Back at the hangar, Tom drove up with the extension cord. We'd all been at the same hayride and party last night, so had no trouble finding stuff to talk about. After Julie and I got the bugs washed off of the windscreen and wings, we headed for the coffeeshop. We'd cheated death enough for todsy.
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,976
171
86
Okemos / East Lansing Michigan
Costs and Benefits

I have written about some of the benefits of flying in the Duck. And, there are many of them. As each of us is proud of - and in some cases we're probably in love with - our boats, planes are every bit as wonderfully addictive. And, there are costs for those benefits. Recently, I was forcefully reminded of that.

While flying an older plane is often cheaper than a new one, once in a while, they can still jump up and bite you in the hip pocket. I'd noticed a crack forming in the upper door hinge on the pilot's side. If one of you looked at this hinge, holding it in your hand, you would likely estimate a purchase price of $8-15 dollars. And, at the corner hardware, you would be right. In this case, not so much. A new hinge from Cessna was $600, plus freight. Then, of course, I have to fly to the mechsnic, have the old hinge removed, and replacement installed. OUCH!

I contacted an aircraft salvage yard, and found used hinges for $36 plus tax. Great! Oops, first hinge was also cracked in the same place as mine. Second hinge was too badly corroded to be air worthy. I retreated to mull it over. Then called a friend who repairs aircraft at another field. Jim directed me to another salvage yard. Wow - only $145 plus freight. Gee, what a bargain. Well, it finally arrived. We flew to the next field, and the Duck now has a "new" used hinge.

All in all, it was about $325 plus or minus pocket change. This time, I think death took a nip out of me. sigh
 

Wannabe

Well-Known Member
Apr 5, 2007
2,645
2
on the bank of Trinity Bay
Take a common automotive part and repackage it as marine and you can get twice as much for it. Repackage the same part and label it as aviation then the sky is the limit on price. Pun intended.
Bob