Adding the 10 degree flap setting to a 170B

How to keep the Cessna 170 flying and airworthy.

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russfarris
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Joined: Wed May 15, 2002 2:25 am

Adding the 10 degree flap setting to a 170B

Post by russfarris »

Hi George! I noticed that you have mentioned a few times that adding the 10 degree flap notch to an earlier model 170B was not legal, unless done on a 337. On the type data certificate for the 170, A-799, on page 5 it clearly states that all serial numbers from 20267 and up are eligible for O, 10, 20, 30 and 40 degree flap settings (it also states that s/n 20267 through 26504 were delivered without the notch.) So, if the TDC states that s/n 20267 and up are eligible, why is a 337 needed? I agree it can't hurt, but if it's on the TDC, why would it be illegal?...Russ Farris

P.S. N8143A, my beloved '52B, has the 10 degree notch, with no paper work... 8O
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GAHorn
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Re: Adding the 10 degree flap setting to a 170B

Post by GAHorn »

russfarris wrote:Hi George! I noticed that you have mentioned a few times that adding the 10 degree flap notch to an earlier model 170B was not legal, unless done on a 337. On the type data certificate for the 170, A-799, on page 5 it clearly states that all serial numbers from 20267 and up are eligible for O, 10, 20, 30 and 40 degree flap settings (it also states that s/n 20267 through 26504 were delivered without the notch.) So, if the TDC states that s/n 20267 and up are eligible, why is a 337 needed? I agree it can't hurt, but if it's on the TDC, why would it be illegal?...Russ Farris

P.S. N8143A, my beloved '52B, has the 10 degree notch, with no paper work... 8O
The eligibility statement on Pg 5 of the TCDS is in reference to which aircraft serial numbers are eligible for that TCDS A-799,....NOT the flap setting mentioned in the previous paragraph.
Reading the paragraph regarding flap settings, notice that there are two section, SN 20267 through 26504, and SN 26505 and up. Only the latter serial ranges qualify for the 10-degree flap setting. I also have a copy of a letter from Cessna (obtained via Tom Hall) that specifically addresses this issue. Cessna states categorically that the later flap sector is not legal to be installed on the earlier serial numbers. (This would be their legal positon, of course. An owner might obtain his own approval via field approval or other authorized modification methods. Hence, my statement that a Form 337 would be required.)
russfarris
Posts: 476
Joined: Wed May 15, 2002 2:25 am

Post by russfarris »

Hi George...that's not the way the copy I have of the TDCS reads at all.
It says, Wing Flaps, immediately below that, UNDERLINED, "all serials S/N 20267 and up eligible". To the right of this statement are the flap settings, listed by degree and notch, 0, 10, 20, 30 and 40. Your copy of the TDCS may not be the same as mine...go to the old Yahoo site, and look in the the files section by Low and slow. TDCS A-799, revision 51, July 15, 1998 is the date. I noticed a vertical line next the area in question, as you know this normally indicates a change from the previous version. Anyway, check it out and report back! Russ Farris
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GAHorn
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Post by GAHorn »

russfarris wrote:Hi George...that's not the way the copy I have of the TDCS reads at all.
It says, Wing Flaps, immediately below that, UNDERLINED, "all serials S/N 20267 and up eligible". To the right of this statement are the flap settings, listed by degree and notch, 0, 10, 20, 30 and 40. Your copy of the TDCS may not be the same as mine...go to the old Yahoo site, and look in the the files section by Low and slow. TDCS A-799, revision 51, July 15, 1998 is the date. I noticed a vertical line next the area in question, as you know this normally indicates a change from the previous version. Anyway, check it out and report back! Russ Farris
Interesting point, Russ! I was actually referring previously to my copy of Revision 50. Revision 51 has at least one error, maybe more. Notice that in the same section as you mentioned, it states that earlier serial numbers had the 20-degree setting omitted. Maybe that is a clue they've messed up. I've got a call into my FSDO to get to the bottom of it. (But it sure would make a lot of sense that if the earlier airplanes were allowed to fly while passing through the 10-degree setting, and if later aiplanes were allowed the 10-degree setting with no other significant changes, then earlier airplanes should be allowed the mod. :roll: )
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flyguy
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10* er ded

Post by flyguy »

TALK BOUT MAKIN A MOUNTING OUTA A GOFER MOUN!

THERE ARE PROBLY 47 THAANGS THET ER GONNA GET YOU BENT UP MORE QWICKER THAN HAVIN A LIL 1/4 INCH NOTCH IN YER FLAP THINGY! PROLM IS, WHETHER IT IS A REWPLACEMENT PART OR A PLACEMENT OF A LIL GROOVE IN THU ITEM, THU EXTRY NOTCH AINT EVEN MARKED ON THE ONES THAT HAS IT LEGGALY.

SKWEEKY WHEELS GIT NOTICED!!! SO IFN YU DO THE DIRTY DEED DONT TALK ABOUT IT :twisted:
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