PROPS  (page three...)

HARTZELL A.D... (040300)
Subj: PROP. A.D.?
From: Bill Doty <wdoty@seidata.com>
Jim, N80572 has a Hartzell C/S propellor that I want to have serviced and an A.D. complied with.. Do you have a source for looking up the A.D. ? -- Bill Doty

Bill,
Do you have a HC-82XL prop? That is a steel hub prop which needs to be inspected per AD 97-18-02. Every A&P IA is required to have an AD note library with all the AD's. Yes, I have read the AD many times, and can tell you its not something you can do yourself. I have seen prices quoted from $600 to $2,000 for the inspection and then the time until the next inspection is not very great. For that reason many owners have purchased a newer replacement prop. I have one I removed if you need parts, the blades look ok. -- Jim

AN OPINION IN FAVOR OF AEROMATIC PROPS ON SWIFTS FROM DAVE JEWELL... (040300)
Subject: High Cruise Aeromatic Prop for C145-2H
From: Dave Jewell <jewell@crcwnet.com>
Monty,  I have been following with interest your comments regarding the Aeromatic Propeller. After reading the latest issue of the GTS Internet update I feel I have to make a few comments. I have a C145 -2H Continental engine in my Swift. I purchased the Swift with an Aeromatic prop with 73E blades. I found this propeller to be very satisfactory. We consistently cruised between 135 and 142 mph. I was lucky enough to find a high altitude Aeromatic with 74E blades. I took the propeller to Aero Prop at Hemet airport in California for overhaul. Their price to overhaul a standard Aeromatic prop is $1600.00. Aero Prop specializes in Aeromatic props. The installation of the propeller included the pressure regulating unit, which is controlled by a vernier prop controller. I would be glad to send additional information after we fly the Swift North from Arizona sometime in May. Our Swift is currently in Arizona and I was unable to complete theadjustments to the propeller before we had to come North for business purposes. The reason we changed to the high altitude prop was to be able to obtain the 2700 RPM, that as you know, the C145-2H is rated for on take-off. I feel that not only will this propeller be of some advantage to us because of the extra blade length but will allow us to adjust the prop in flight, much the same as you would a constant speed prop. This propeller will allow for full power take-offs. We are anxious to take our first cross country trip with this prop because if it performs as advertised we will be able to get maximum performance out of our C145. -- Dave Jewell 1948 GC-1B N1948J

HARTZELL PROP OVERHAUL... (040400)
Subject: PROP.
From: Bill Doty <wdoty@seidata.com>
Jim,  Thanks for the info.. Yes, it is a HC82XL-2C propellor. Was rebuilt by Sensenich in 1967. Had two reconditioned blades at that time and full inspection. Plane has only flown about 300 hrs. since, but been out of service since 1984. I will check with local prop. shop for A.D. and have it rebuilt along with the governor. Is this an acceptable prop. for the Lycoming 0-320 at 150 H.P.? -- Bill Doty

Bill,
If there is no corrosion present, your prop may check out OK. Regardless, the AD note has to be done. I might remind you, 1967 was 33 years ago! That is the prop called for on the STC for the 150 Lycoming installation. You should wait until you are near back to flight status before overhauling that prop. They may come out with another AD note before you ever fly it if you overhaul it now! I was annualing an airplane with that type of prop once. When greasing that prop, you must remove the grease zerk on the opposite side of the hub to give the grease someplace to get out of the hub. (instead of blowing out the grease seals at the blades) When pumping in the grease, water came running out. When overhauled, nothing was salvageable from that prop, not even the blades. BTW -- the grease to use is AeroShell 5. -- Jim

BUT WAIT, THERE'S MORE... (040400)
Subject: PROP.
From: Bill Doty <wdoty@seidata.com>
Jim, The prop. shop is telling me $2200----$5000 for service and A.D. ..... Probably nearer the $5M price !! Is there any other prop. STC'ed for the 150 HP Lycoming ? -- Bill

Bill
You mean $2,200 to $5,000? Don't put anything near that amount of money into an old steel hub prop. Yes, there are later model props available, I can't give you a number off hand, but I can get it if you need it. Even if you get that old HC-82XL thru the inspection, it needs to be done again in very few hours to my recollection. You probably could put a fixed pitch prop on it. Look for something off a TriPacer or Cherokee 72 or 73 inches in diameter about a 59" pitch. For $6,000 you can buy a brand new aluminum hub Hartzell. Hartzell can advise which model prop you can use for a replacement. It can be installed without a STC if they furnish enough data that FAA engineering can give you a field approval or issue a one-time STC. Contacting Hartzell is the route I would take. The return to service must be done on a 337 form. Make sure Hartzell furnishes all the data required. Tell them you have the same engine/prop as an old Mooney-- Jim

BILL FOSCHAAR HAS STC FOR AEROBATIC HARTZELL PROP... (040500)
Subj: Hartzell Prop
From: Bill Foschaar <swift@yosemite.net>
Jim, I have a one time STC for a Hartzell c/s prop. on my 150 Lyc. the prop number is HC C2YL-4BF-FC7663-4. Also for Hartzell spinner #835.23. This is an aerobatic prop with counterweights.In case of oil pressure failure the blades go to high pitch. I have a letter from Hartzell stating the counterweights do not affect the certification. The FAA engineering accepted this letter. I yould be happy to share this STC if anyone wants/needs it. -- Bill

C-125 IGNITION SYSTEM CAUSING POWER LOSS??? (050100)
Subject: SWIFT W C-125
From: Bbrut55@aol.com
Jim,  I believe I have a mag problem with my new Swift. I had a significant loss of power on takeoff. After returning to airport I found compression to be great, mag timing was at 28 degrees left and 26 right, should have been 30 and 28 per manual. On examing the SF-6 mags I found a huge amount of build up on the mag pick ups and on the plug wire cigarettes. The right mag points were pitted ( cleaned and reset to .015). I also cleaned the mag pick up points and the cigarettes. It appears the cigarettes brass ends are wearing down and probably need to be replaced. Could these conditions cause a loss of power? The darn thing just barely cleared the trees at the airport I was taking off from. In flight the rpm came up to 2600 Help. Is there a source for the cigarettes for the SF-6 mags? -- Bill Bruton, Tacoma, WA SN#254

Bill,
Yes, you can still get parts for those old mags and the harness. Aircraft Spruce has them, or Fresno Airparts. (559-237-4863) The complete harness was available from Voltair, if they are still in business I couldn't say. There address was: Voltair, Box 13004, Fresno, CA 93794. Having said all that, why bother? Those old mags never were much good and after 50 years it's time for a rest! If you belong to the EAA, every month there is an ad near the back of Sport Aviation Magazine from Mattituck. You can get two brand new Slick Model 6364 mags from them for about $700.00, with a new harness. Ask for the kit for an O-300. Those mags are strictly speaking not approved on the C-125, but a field approval is no problem. Slick just never bothered to include the C-125 on the approval list because there are so few C-125's still around. If you ever install a 145 the mags can be transferred over. A Swift is valuable enough now these days it's foolish to risk the airplane (and your own skin)! With a mag that was designed in 1926.   --  Jim

ON THE OTHER HAND... (050100)
Bill,
I reread your letter. Its sounds like your mags are definitely tired, but if you get 2600 rpm in level flight maybe you have some other factor also. What weight are you operating at? The gross weight is 1710 lbs. What length and density altitude is the runway? The Swift is not a short field airplane unless you have optimized it for takoff. (climb prop, well tuned engine) For a short runway I would recommend a McCauley !A170-DM7356 prop, turning the max. allowable static rpm. -- Jim

TAKEOFF PERFORMANCE... (050200)
Subj: Take-off Performance
From: Richard Aaron <raaron@pica.army.mil>
Jim,  I just read your comments in the newsletter to Bill Bruton about take-off performance. This is one of my concerns. I'm use to the Lyc 150 with a constant speed which was never any problem. When I flew N2405B back from Athens it was very hot and humid and I followed Charlie's advise to accelerate to 100 mph and hold it for the climb: at times this was a lot flatter than I was use to. Of course it does better in cooler weather. I haven't built up a lot of time in it yet and have read numerous articles on how to achieve the best angle of climb on take-off (I'm not interested in best rate; I'm not in any rush to hit an obstacle). I'm not sure that I agree with all of them though and it's hard to make precise comparisons. What's your opinion? The prop is a McCauley DM7355 (changed from DM7354): would changing the pitch to 56 make a substantial difference? The engine is a C-125. What about take-off flaps? Sussex is 3500' long @ 420 msl and has a hill about ¼ mile past the end of runway 3.

Dick,
The 55' pitch prop should be better for takeoff than a 56'. I was thinking Bill might have MORE pitch than that. For best takeoff performance, you want the lower pitch number. I don't like using flaps for takeoff. Yes, I understand that if done correctly, a slight reduction in takeoff distance can be gained by using flaps. But there are pitfalls, when the gear is retracted, if the flap selector is "up", the flaps go up, and the airplane settles, perhaps onto the runway on its belly.  I like 90 mph for climb, it gets the engine rpm up to where it does its best work and produces a good climb rate. I suppose the best solution would be to install a 145 hp engine, but a 125 will do if you don't ask the airplane to do something it can't do. The biggest reason I switched to the O-300 was with my medical condition I often fly with a friend who is a CFI. He weighs 300 lbs. The little 125 just didn't have enough guts to get us in the air safely. -- Jim

WANTS TO "OUT RUN DENIS IN CRUISE"... (050400)
From: Larry Rengstorf <swiftair@pacbell.net>
Subject: Props
Jim - I am trying to get a good prop for the Swift Don B is building up for me. I took a 1A170 DM7355 to the prop shop, had a slight curl in the blades, But the shop rejected it- bent too close to the hub, so now I have another one there. It is a 1A170 DM7653. Here is my headache = The prop shop book states - (GC-1B) DM7355 is a climb prop for a C-125-2, & DM7359 is cruise, & DM7357 is Std prop.-------- Next the book states, C-145-2 & 0-300-A calls for =Std prop - DM7458 or DM7359, Cruise prop = DM 7460. On C-145-2 & 0-300-A & -B (MY ENG)= Std prop is DM7361 & Cruise prop is DM7460. The prop shop says they can cut the prop to 74 or 73 with 53 pitch, OR -cut it and re-pitch it also to 60 or 61. Should it be cut to 74 or 73, fully understanding if it is cut to 73 - (it can't grow back to 74) & what pitch?? 53 ?, 60 ? or 61 ?   Note - I want to out run Denis in cruise - HaHa. If you can shed some sense on this, I would greatly appreciate it. You can answer me on the GTS Internet page, if you like.  Thanks Again, Larry Rengstorf

Larry,
If you are using the Swift Assn. STC it calls out a McCauley 1A170DM7359. I presume you are installing a 145, but a 7359 is legal on a 125 also, providing the engine is strong enough to turn the static rpm called out in the Aircraft Spec. A 59 pitch will work just fine. With a strong engine, sometimes 2900 rpm can be turned in level flight at full throttle, but a few minutes at that rpm won't hurt anything. A 73 diameter will be several mph faster than a 74. Go with the 7359.  --  Jim

NOVICE NEEDS PROP NUMBERS... (060600)
Subj: Props
From: Dennis Friedrich <dennisd@crcwnet.com>
I have a DM7359 McCauley Kliptip prop which came off my C-125 and a stock prop I bought with a 300A. (Off a 172) Don't know the numbers on it as yet. Being a total novice at this.... can either of these be used and/or repitched to use on my Swift with the 300A? If not what will work best? Thanks.

Dennis,
Regarding the stock O-300A Cessna 172 prop, it would probably have numbers ending 7653 or 7651. The Swift Association STC calls for a diameter of 73 and a pitch of 59. Most of those C172 props can be cut off and repitched to that. Regarding the prop that came off your C-125, a 7359 is the EXACT prop called out on the Swift Assn. STC. So you don't have to do any repitching - just bolt it on. Call Swift and buy the STC paperwork - I think it's only $25.-- Jim

LOTTA TORQUE ABOUT PROPS...  (070400)
Subject: Prop bolt torque
From: Marvin Homsley <marvin@accesstoledo.com>
Jim, I have read the maintenance manual for the swift, looked thru the web site, and I cannot find what I am looking for. I had to remove the prop from my swift to comply with an AD and am trying to put it back on today. I need the torque value for the prop bolts. I have a C-145 with a McCauley on it. It has the 8 bolt pattern. Do you know what I should torque it to. I know this info must be available in a book somewhere but I have not been able to find it. Marvin Homsley N80740

Marvin,
Well, right off the top of my head I know it's 25 foot pounds. I will look it up, BRB. ------ I looked it up, and the book figure is 23 to 25 foot pounds. That's for a 3/8" prop bolt. ou can find the torque info on the web... <http://www.mccauley.textron.com/home.html> This is the McCauley site. Torque is in SB 227A - it actually calls for 30 -25 foot pounds, but I don't believe in over 25. <http://www.sensenich.com/> This is the Sensenich site. It calls for 23 - 25 foot pounds.-- Jim

GOODBYE AEROMATIC HELLO SENSENICH... (070600)
Subj: sensenich prop 337
From: tj3368k@mmcable.com (T. J. Johnson)
Monty - After reading all the good stuff on props from the Swift website I am interested in replacing my Aeromatic prop on N3368K (O-300-A) with a Sensenich 74DR-1-62....Given your recent experience with our friendly FAA gang I would appreciate a copy of your 337 if its not too much trouble....if the prop limits the engine to 125hp output do you ever get the full 145hp capability?? Thanks, TJ Johnson tj3368k@mmcable.com

TJ,
You can't get over 125 hp with that prop unless you are at or below sea level. I have applied for the multiple STC to use the 74DR-1 prop at any pitch, but haven't heard anything back from the feds yet. I can shoot a copy of my 337 and mail it to you if you let me know your address. -- Jim

WANTS MONTY'S PROP PAPERWORK... (080100)
Subj: Re: sensenich prop 337
From: TJ Johnson <tj3368k@mmcable.com>
Jim, I would greatly appreciate a copy of your 337... Thanks for the hp info..... I am at 1193 ft at HSD and still learning what to expect from an engine/prop combination.

TJ,
It's in the mail! Our field elevation is 932, very close to what you've got. I feel I get excellent performance, although I've got my McCauley on at present, my Sensenich was pitched to 59" and turned up too much rpm. I had it repitched to 62". Caution: the tips must be narrowed to near the repair limit, or it won't perform. -- Jim

HOW TO "HOTROD" A SENSENICH PROP... (080300)
Subj: Re: Speed
From: Jerry Swartz <JSw7211963@aol.com>
In a message dated 8/9/2000 4:48:33 PM Central Daylight Time, Monty747 writes: << and get a Sensenich Prop. >> Here we go again. Back on Aug 2, you advised me to get a Sensenich 74DR-1-62, however it needed to be reworked by narrowing the chord to near the repair limit. So now I have another question. My McCauley (near new) is a DM/74-58, which actually works very well both on takeoff and in cruise as long as I run it in the 26 to 2700 rpm range, at 24 inches. Would it make any sense to replace my present McCauley with a STOCK Sensenich 74DR-1-62, or would it have to be modified to really make a difference??? Jerry S.

Jerry,
You can make a McCauley "go" too. a 74 x 58 won't cut it. First of all, if you are using the Swift Association STC, (old Piedmont) the maximum diameter is 73". The STC calls for a 73 x 59. I would hesitate to cut your "near new" prop down, but then again, it isn't doing the job as it is. Call a prop shop and see if they might have a prop from a Cessna 170 or 172 that started as a 76" dia. and can be cut to 73". A prop like this is not worth a premium price, like maybe $300 to $500, expect to pay $300 to $500 additional to have it reworked. Have them cut it to 73" and reduce the chord and blade thickness to near the repair limit and round the tips. They should make sure the pitch angle at the tip stations is the maximum allowable. You could have your present prop reworked in this manner, but bear in mind, if you "ding" it, it's probably scrap. A new Sensenich, out of the box, won't perform much, if any, better than a McCauley. -- Jim

IS THAT YOUR FINAL ANSWER??? (080300)
Subj: Re: Speed
From: Jerry Swartz <Sw7211963@aol.com>
O.K., that answer's my question for now. According to the paper work I have, the 145 engine was installed in 1958 with a repair and atlteration form that states per attached copy of ACA 337 dated 4-30-52 covering identical alteration to GC-1B ser. 1111, N80918. and per attached copy of letter of authorization dated Feb 4, l952 from W.A. Klikoff, 6th region. Nothing Follows. The engine was installed with an Aeromatic propellor, at that time. The prop that is now on it was installed in Jan 1989 and there is a letter from Maxwell that states that the correct propeller for our Customer's aircraft N77759 is a 1A170/DM7458. And that prop came with the airplane. So legal or not, that is what I am stuck with. Flew it today and put another hour on the new cylinders. At 3500 ft., 24 " of mp produced 2650 rpms. A four way check on the GPS gave me an average of 145 mph. So I guess I am a little confused, when you say that the prop is not working. Is 2650 too many rpm's for 24"??? It doesn't bother me to run it at this rpm or even higher, but maybe it should???? The bottom line is, if I am going to throw another grand or better at this airplane to obtain better performance, I want to be darn sure I will ACTUALLY get better performance. Right now I have nothing to compare it with, so don't know how another prop would work, no matter what the cut might be. I am not dissatisfied with 145 mph, but then again, maybe I should be. Keep leading me, as I definitely do need help on this.

Jerry,
So you do not have the Swift Association STC. So your prop should be legal on your aircraft. I really think your performance is pretty good. What I meant, when I said your prop was not doing the job was, if your cruise speed was off, a shorter prop with narrower tips would do better. There is nothing wrong with 145 mph! 2650 rpm at 24" is a little high power for cruise, maybe a little over 80%, but there is nothing wrong with using over 75% if temps are within limits. If you have a 125hp placard, and most 145 conversions do, that is 86% power and cannot usually be exceeded except at sea level. 75% power on a 145 is 24 square or 23" and 2500 rpm, whatever your fixed pitch prop allows. hint - the number should total "48". 24" and 24(00) = 48, get it? I would be happy with what you've got! -- Jim

PORTER ON PROPS AND HOW TO GO FAST... (080400)
From: Porter Houston <phouston@erols.com>
Subject: Props
Dennis,
On the subject of props and how to make a stock Swift go fast I offer the following. If you want to go fast put in the big engine, that seems to work the best. I have tried 2 different pitched Sensenich, 2 different McCauley, and the original wood Senenich 73BR54. Except for the incredible smoothness and vastly improved landing characteristics of the wood prop, the only thing different with all 5 props was take off and climb performance. The cruise and top speed was essentially unchanged. Weight doesn't even seem to make a top speed difference in my swift. Oh sure it's probably there but not that you'd notice. Now there are some airframe mods that will give you a mile here and a mile there. ( reduce the drag). The testing with the wood prop proved the viability of rear CG on improving landing characteristics. The wood prop is 15lbs. lighter than a metal prop and gave me an instant 1" shift in CG to the rear when I installed it. I am currently using a Sen 73DR60 and have adjusted the empty CG to the exact factory setting. Bottom line, if you have a smooth running prop stick with it. -- Porter Houston

MONTY SAYS THIS IS A JOB FOR DON BARTHOLOMEW... (090300)
Subj: Propeller
From: Bob McKay <n2345b@calweb.com>
Hi,  I know you have been down this road many times. Swift 78034 has a O300D engine. The prop was a 1C172/EM7655. It worked OK but probably was not really legal at that length. I recently sent it into a prop shop to have it cut down to 74" and wanted them to set the pitch at 57 or 58. They were sticky about paper work and found a 337 that let them set it to 59 pitch. That is the way it came back. It works well and improved the performance about 10 miles per hour. I get 130 mph at 22" mp and 2500 rpm at 3500'. It will turn about 2675 rpm at full throttle. Not Bad. Static rpm is about 2000 rpm. It is sluggish on take off. I do a lot of my flying in the Sierras and wonder how it will work out at density altitudes of 8000'. I haven't tried this yet. I think I would be happier with a 57 or 58 pitch, and give up a little speed. Is there paper work that will let this be done? American Propeller in Redding Calif. are sticking to the letter of the law. Bob McKay n2345b@calweb.com

Bob,
I doubt if changing your pitch down to 57" or 58" will give you what you might be expecting. For high altitude you should have stuck with the 76 x 55. I would be very cautious with the prop you've got at high altitudes and high density altitudes. I have gotten a 76" prop approved on a one-time basis by checking the installation per FAR 23.925(a) and referencing it on the 337 form. That process is not for beginners, but an experienced mechanic like Don Bartholomew might be able to pull it off. For best performance with an O-300D you should get a Sensenich 74DC series prop. Some 172's from the '60's had this prop, but most are found on Beech Musketeers with the IO-346 engine. I would suggest you use a 74DC-1-60 or 62 for speed and a 74DC-56 or 58 for altitude performance. -- Jim

GC-1A PROP APPROVAL... (100200)
From: Jose Ocampo <Planemex@aol.com>
Subject: Obtaining Prop Approval
I'm currently working in Globe GC-1A that has a McCaulley 1A105-SCM7150 fixed pitch metal prop. This prop is not listed in the Aircraft Type certificate and I do not find anywhere in the aircraft records where the prop has been approved for use in the GC1A, If anyone has any information about STCs or other means of obtaining approval I would really appreciate hearing from you. Thank you, Jose Ocampo

Jose,
I got that same prop approved on Charlie Hoover's N80905 which is also a GC-1A with a C-90 engine many years ago. I didn't keep copies of 337 forms then. The 337 form is in the aircraft file of course. I could get a copy and snail mail it to someone. So the prop was never approved on N80505, that's too bad because all prop changes have to go to FAA engineering now, which is another bureaucratic hoop to jump through. I also got a Sensenich prop approved on that same airplane a couple of years ago, so it can be done! Charlie has since gone back to the McCauley SCM because he likes it better. -- Jim

WOODEN NOSTALGIA...(120400)
Subj: Wood Prop
From: Joe Murphy <jmurphy@whitakerbank.com>
Jim, Where would I go to find a wood prop and hub for a C-90? What is your recommendation, leave the metal prop on or convert to a wood prop. I am looking at it from a nostalgia point of view. Thanks, Joe Murphy, NC80505

Joe,
For a wood prop contact Sensenich. <http://www.sensenich.com/> I would suggest about a 72x50. A wood prop will not perform as well as a metal prop. You need a field approval for either one. I have gotten several McCauley 1A105/SCM props approved on GC-1A Swifts and had copied a 337 last time I heard from you. I never heard back from you, so I don't know what happened to that copy. The Swift Museum GC-1A in Athens has a C-90 and a prop that I got approved, maybe they can copy the 337. -- Jim

PS You don't need a hub for a C-90, which is a flange shaft engine. You do need a front plate with a wood prop.

On to page four of props...

back to the index