MONTY THE ANSWER MAN ARCHIVE...

WEIGHT and BALANCE (page two...)


PETE KING GETS WEIGHT AND BALANCE MOMENTS ADVICE...  (10299)
In the last update Swifter Pete King, <peetking@earthlink.net>, wrote:
Subject: It's gone !!!!!!!!!!!!!!!!!!!!
Every time I read your newsletter I wonder what I am about to reminded of that I need to go check -- Oh Dred! This time its weight and balance -- but I can't find the list of moment arms for the calculations -- It's gone!!!!!!! Would ask someone to tell me where I saw them or print a set in next weeks letter. I need pilot, 9gal. aux baggage tank, main spar, etc.

Pete;
For shame! The weight and balance information you want is right on the Swift Home Page! All you have to do is click up the original type certificate and print it! I shouldn't do your work for you but.......
Engine oil (GC-1A)@ -14.5 (GC-1B)@ -20.3
Pilot & Passenger @+42.5
fuel 28 gal @ +47
Baggage GC-1A 50 lb, GC-1B 100lb.@ +60.5
Aux. Fuel also @ 60.5 or the tank itself is given as 61 all the factory equipment is given there, props, starter, generator etc.

SWIFT GROSS WEIGHT INCREASES...  (11399)
Subject: ???????????????
To: Pete King <peetking@earthlink.net>
Hi, Jim,
What do you think the long lower wing fitting would add to gross weight capacity if the upper helped to get to 1710? High regards, Pete

Pete:
The Merlyn GW increase is to 1970 lbs. with the big engines. They also have a GW increase for the 145 and other smaller engines to 1835 lbs. They send you some paperwork, including revised CG limits and operation limitations. They send a strap, approximately 6" long, which must be riveted in place in the outer wing panels extending the lower wing attach fittings effectively to the same length as the long fittings. Several Swifts have gotten field approvals to install the 11-010-3554 fittings on the lower attach point instead of the upper, and have been allowed the same gross weights. -- Jim

SWIFTS EVERYWHERE!!!  (010200)
From: Steve Wetherbee <wasinc@northpro.net>
Dear Monty,
I have most of the bugs out of this plane now but am getting some kind of side to side yaw at speeds above 160mph. I wonder if it is CG related after reading all the books. My last wt/bal shows 28.6 empty with an empty wt of 1386. I put it on the scales today and have 1720 full of fuel, it has the small tanks in the belly and the tank in the baggage compartment. That should be about 1440 empty. I flew with a bag of sand in the baggage compt. yesterday and the swaying stopped and picked up about 5mph and did not have to adjust trim after take off. I have checked all surfaces for rigging and did correct the horizontals and ailerons quite a bit but it still flies hands off. Do you have any opinions on this? It cruises at 172mph at 25/25 is this typical or slow for that power setting? Steve Wetherbee

Steve,
It sounds like your Swift has too fwd. a CG. When they got the GW increase to 1970 lbs. they limited the aft CG to 33.5, which is kind of bogus, they only did that to avoid spin testing. A Swift flys best at about 34.7 -- just don't spin it. Your speed seems about par. -- Jim Montague

THAT'S REAL HEAVY MAN... (050300)
Subject: Weight
From: N80730@aol.com
Jim,  How heavy is heavy for a empty weight for a GC-1B just weighed mine and it is 1329 lbs. -- Lee Davis

Lee,
Quick answer: Too heavy! Longer answer: Most Swifts are too too heavy. Mine is 1224 and that's too heavy. I had a 150 Lycoming powered Swift and it weighed around 1250 -- too heavy. I had the old HC-82XL prop and a full gyro panel. I wrote a piece for the EAA which they published in their Vintage Airplane Magazine two years ago, did you see it? It had several tips on reducing the empty weight. -- Jim

210 SWIFT EMPTY WEIGHTS... (050400)
From: David C. Barker <dbarker@interpath.com>
Subject: Dry weight of modified swift
I have a 210 swift with full avionics, auto pilot, fiberglass tips replicas of the original, new interior, sticks, canopy, new fibeglass cowling, Merlin long range tanks. Slots have been removed and 032 D section on leading edge of wing and horizontal, new vertical spar with .032 skin, lights in wheel well, & mooney spinner. My empty weight is 1,440 pounds. How does this check with the other superswifts, weight wise ????? I don't believe there is anything I can cut to reduce weight. Suggestions?????

The following from Don Bartholomew, MSM...
One thing the message does not mention is whether the plane is painted or polished. This can add as much as 30 pounds. At initial glance, the plane sounds heavy until you start looking at everything. I am sure the fiberglass tips and cowl are heavier than original. The electronics and auto pilot add a lot of weight. The aux tanks are about 14 pounds, sliding canopy is heavier than stock, sticks are a wash. The increased skin thickness adds about 10 pounds. Here are some examples:

--- Miguel Nelson's, 210, glass cowl, canopy, sticks, polished, wet center section, 1 radio: 1409

--- Mike Sweeley, 180, glass cowl, original canopy, sticks, painted, aux tanks, 2 radio: 1416

--- Jim Roberts, 210, metal cowl, original canopy, polished, 1 radio: 1375

--- Bill Merwin, 210, metal cowl, org canopy, polished, aux tanks, 1 radio, 3 blade prop: 1382

To reduce weight:
Check weight of cowl, original is about 12 pounds. Interiors are heavy, depending what was done, easy 25 pounds in carpet, side panels, and headliner. Get rid of interior and paint the inside of the metal. (Look at Rick Scott's plane, it looks good and is light.) Check weight of wing tips, fiberglass usually heavier than metal. Get rid of the auto pilot and all unnecessary radios. Check for dirt in hidden areas of the centersection, wings, and fuselage. If it is painted, strip and polish. Hope this has been a help for you. -- Don

(Editor's note: MSM = "Master Swift Mechanic". New term...)

GROSS WEIGHT INCREASE FOR SWIFTS DEFINED...  (060100)
Subj: Gross Weight Increase Kit
From: Brian Cumpston <n78320@hotmail.com>
Jim,
It was a real pleasure to meat you in Athens. At the banquet they were auctioning off gross weight increase kits, what is a gross weight increase kit, and what does it contain? Brian

Brian,
The normal gross weight of a Swift is 1710 lbs. Merlyn Products of Spokane, WA has a kit to raise this to 1970 lbs. for the big engined Swifts. (210 Continental, 200 Lycoming, 220 Franklin) They also were offering a kit for the smaller engine Swifts, like the 145 which allowed 1835 lbs, but I don't know if they sell that kit anymore. I think the kit sells for around $800. What you get is primarily the paperwork. The hardware consists of a pair of aluminum straps about 6" long which must be riveted in at the lower wing attach point. -- Jim

HEAVY SWIFT... (100401)
Subj: Gross weight limits
From: Jim Shosted <Jim2swift@aol.com>
Hi Jim, I have heard it said the Swift is a strong overbuilt airplane. Is there a real hazard in flying at 2000 lb. vs 1710. assuming the plane is properly loaded ref CG. and has the engine to haul it into the air. I would think if you simply reduced the intentional g loading by .5 g you would have the same load safety margin as a plane weighing 1710? Does a gross weight increase kit add safety or just add weight? Your thoughts. Jim Shosted N3854K 1710 x 3.5 g = 5985 lb. 1996 x 3.0 g= 5985 lb

Jim
I think you are thinking in the right direction as far as structural loads go, but there are many other factors such as higher stall speed etc. The gross weight straps at the wing attach points can't hurt! They only weigh a few ounces. I think most of the Swift is overbuilt but there are a few weak points, like the seam below the windshield and the horizontal stabilizer spar. I am not an engineer, so I won't try to tell you what to do about it! The new AC 43.13-1B stresses not trying to beef up structure by installing heavier skins and doublers etc. They are concerned the airplane will just break somewhere else. A good example of that was the D'arcy Swift N90379, with a 250 hp engine and beef ups on the wing attach and other places, it still came apart during a high "g" pull up at way over design weight. I've been preaching weight reduction for years. I think a lightweight engine weighing no more than an O-200 but with 125 hp or more would make a nice airplane. -- Jim

SAM'S GENERAL CURIOSITY ABOUT EMPTY WEIGHT...(NOV 02)
Subj: Swift Empty Weight Question
From: Sam Swift <flyboycpa@aol.com>
Jim,
I have a general curiosity about most folk's empty weight and their horsepower. I would like to pose this question on the internet newsletter: What is your Swift's empty weight and what engine do you have? (and VFR or IFR?) I would love to hear from as many Swifters as possible. Thanks, Sam Swift

Sam
I have weighed a few dozen Swifts over the years. I have not seen one under 1200 lb. for a long time. The lightest I have seen recently is 1224 lb. Most 145s run about 1225 to 1275 lb. I believe my old 150 hp Swift was around 1250 but that is from 30 year old memory. Dennis Gehring's 210 Swift weighed in recently at 1302 lb. Most 210 Swifts are between 1300 and 1400 lb. I have seen EW as high as 1500 lb. which is too much! -- Jim

WEIGHT AND BALANCE TRICK... (JAN 03)
Subj: Request for your opinions
From: Jim Kissick <swift328@aol.com>
Have noted some weight & balance questions lately on the newsletter, but have not seen anything regarding a tidbit of info going around about the time I obtained my Swift back in the '70s. It had nothing to do with weight, but offered the concept that one could put a bubble level on the cockpit edge angle and jack up the tail on a scale until the bubble was centered and read the weight of the tail at that point. There were low and high limits, believed to be something like between 45 and 70 pounds, and if it were in the area, the balance was OK. The 2nd deals with the elevator trim control. Could you comment on the replacement of the overhead crank with an older model C-172 elevator trim tab wheel-and-spool with an indicator mounted aft of the fuel gage between 2 C-150 seats? Thanks. Jim K.

Jim
I have never figured out an exact figure but I have weighed enough Swifts to know if the tail weight is around 40 pounds with the airplane level the w&b will be Ok. The 172 trim system works fine but it's not STCed. Fette got some field approved I believe but most are just "in there". It should be approvable but nowadays you would have to get an STC. -- Jim

TARE WEIGHT DEFINED... (JULY 03)
From: William Roberson <attywfr@yahoo.com>
Subject: Answer Man Question
Hey Answer Guys,
I'm working on my weight and balance. Can you give me a definition of "Tare?" At the moment, it has been suggested that "tare" refers to the non-aircraft "stuff" that is on the scales during the weighing process. Problem is, looking back at my original GC-1A paperwork, my tail weight was 81, the tare was 34, and the net weight was 47? If that definition is correct, the there was 34 pounds of "stuff" on the scales (maybe to level the tail?) and that seems like too much extra "stuff" for that definition to be correct. Please let me know if this is the correct definition. Will Roberson

Will
That's right - tare is the stuff on the scale, 34 pounds of stuff and a tail weight of 47 sounds reasonable. They probably had a steel tripod that weighed 34 pounds on the scale to level the airplane. I looked at my original weight and balance and the tail weight was 65 pounds less 25 pounds of tare for a tail weight of 40 pounds. -- Jim

WEIGHT AND BALANCE...(FEB 04)
Subj: Swift wt and bal
From: Cody Coombs <ccoombs@bellsouth.net>
Monty,
I've got a stupid question for you. Can you tell me who is authorized to certify a Wt and Bal sheet? Can an A&P or does an AI have to sign it? Thanks, Cody Coombs

Cody
The A&P that does the wt & bal. Doesn't have to be AI. -- Jim

C OF G...(MAY 04)
Subj: Swift C of G limits
From: Alan O’Gorman <dvp@mweb.co.za>
Hi Monty
I have just completed major repairs to my Swift GC1B serial 1358 and need to complete new forms for re issue of certificate of airworthiness. I need to know the centre of gravity limits to complete the application. This info is not in the owners or maintenance manuals , can you help . Many thanks, Alan O`Gorman South Africa

Alan
If you go to the Swift site, on the left hand margin you will see "Swift Type Certificate Data" -- click on it and then print the Type Certificate. You will see the CG limits are 29.6 to 34.7. -- Jim