I just took out my headliner to find what looks like the bolt holes that would be used for the shoulder harness in the wing carry through. The hole and threads look kind of small. I thought this started in later B models. Problem is my fuselage is supposed to be a 1950. If these are indeed the harness bolt holes then I must have a later model fuselage with L-19 wings and B model elevator with a 1950 A model data plate! The mystery behind the history of this aircraft might have taken yet another strange twist.
How could I positivily identify what year fuselage I have?
I do have all the holes in the bulkheads for the A model cables running to the back of the baggage area. They are not used of course cause I have L-19 wings and B model flaps. I've looked these holes over pretty good and it doesn't appear any were ever used. Are they still found in B models? My interior, instrument panel and heat sytem and lack of defrost is consistant with 1950 but also early 1952 B models. I have A model landing gear but that could have been what was availabel when this parts plane was assembled. What is the likely hood that someone installed a B model carry through in the A fuselage. Would this have to be done to install the pulleys and associated hardware for the B model flaps?
Boy I wish my plane could talk
Any ideas
CAUTION - My forum posts may be worth what you paid for them!
Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
No. There are no holes in the top of the cabin and there were no harnesses installed, just the holes. Also the thread (lug) uses flush rivets to hold it in place on the inside of the carry through spar which looks like they could have only been installed before the spar was installed in the aircraft.
CAUTION - My forum posts may be worth what you paid for them!
Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
Have you looked through your logs to see if the rear spar carry-through has been replaced?
As you've already suspected, there are many cases in which wrecked airplane's data tags have been "liberated" and the airplane re-constructed using parts completely unassociated with the original data tag. Such airplanes frequently bear little or no relationship to their maintenance logs.
L-19 wings are virtually identical to the B-model, with the exception of hardpoints. (Many B-model parts are merely re-numbered L-19 parts. PN's beginning with 06xxxxx are L-19, and 05xxxxx are 170. Be careful, however, as there are exceptions to interchangeability. For example, the elevator tips {counterbalance} are identically numbered except for that prefix, and they appear identical to the naked eye. But the lead counterweights are different on the right side from that req'd for the B-model due to a larger trim-tab and heavier elevator used on the L-19. Simply installing a L-19 right elevator tip on a B-model can result in destructive flutter, even though it's a perfect fit.)
Last edited by GAHorn on Sun Dec 21, 2003 8:59 pm, edited 1 time in total.
Yes George I have looked in the logs and there is no mention of any work on the rear spar carry-through or the wings and elevator for that matter until 2000 when an alert IA noticed the wrong wings and rectified the paperwork with a 337 and FAA approval.
So I ask again. What year did Cessna start putting in the shoulder harness bolt holes and do B models have the holes in the center of the top rear cabin bulkheads where the A model cables would have traveled to the back of the cabin area?
CAUTION - My forum posts may be worth what you paid for them!
Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
My 170A SN 19853 built Dec 1950 has two small, perhaps AN3 or AN4, holes drilled in the rear carry through spar. Each hole is about 2 to 3 inches from the sidewall, they look like drain holes to prevent water accumulation. There is no nut plate and the holes are not threaded.
N9149A wrote:Yes George I have looked in the logs and there is no mention of any work on the rear spar carry-through or the wings and elevator for that matter until 2000 when an alert IA noticed the wrong wings and rectified the paperwork with a 337 and FAA approval.
So I ask again. What year did Cessna start putting in the shoulder harness bolt holes and do B models have the holes in the center of the top rear cabin bulkheads where the A model cables would have traveled to the back of the cabin area?
The nut-plates for shoulder harnesses were factory-installed starting witht the 170 B-models. Previous aircraft did not have them from the factory.
The B-model bulkhead assy. PN 0512121, made up of bulkhead PN 0512121-3 (sta. 108) had four large lightening holes, and 3 small fairlead (cable) holes across the top.
The A-model PN 0512112-9 is the sta. 108 counterpart. It is constructed similarly but when assembled into a complete assembly it has a pair of vertical brackets that traverse from the bottom to top of the bulkhead to support the upper and lower flap cable pulleys. Without that bracket it would appear the same, including the 3 small and 4 large holes at the top.
I installed Hooker Harness in my 1950 170A serial number 19810. As I recall there were small holes in the spar that looked to be drain holes. Some harness installation require vertical holes which go through the top of the cabin. Hooker installation holes are horizonal and a little tricky with a regular type drill.
