If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Tow hook max wt marking
Simple question, but why are tow hooks marked, "1200 lbs Max weight",
like the Schweitzer type release, towing big heavy 21M ships, ships with water, Grobs and others over 1300 lb gross weights? Actual pulling weight? Is there an FAR? Thanks. |
#2
|
|||
|
|||
Tow hook max wt marking
On Thursday, June 28, 2012 9:43:36 PM UTC-5, Karen wrote:
Simple question, but why are tow hooks marked, "1200 lbs Max weight", like the Schweitzer type release, towing big heavy 21M ships, ships with water, Grobs and others over 1300 lb gross weights? Actual pulling weight? Is there an FAR? Thanks. 1200 lbs on the towhook refers to the maximum rope strength, not the maximum glider weight. |
#3
|
|||
|
|||
Tow hook max wt marking
On Jun 29, 7:20*am, Tony wrote:
On Thursday, June 28, 2012 9:43:36 PM UTC-5, Karen wrote: Simple question, but why are tow hooks marked, "1200 lbs Max weight", like the Schweitzer type release, towing big heavy 21M ships, *ships with water, Grobs and others over 1300 lb gross weights? Actual pulling weight? Is there an FAR? Thanks. 1200 lbs on the towhook refers to the maximum rope strength, not the maximum glider weight. And if you trace it back far enough, it probably stems from an old NACA study on glider towing loads from the 1930s where they said "We don't think there is ever a case where you could apply more than 1200 lbs load to a glider tow hook." And thus, we in the US are saddled with a tow hook limitation from the days of 800 lb max weight two seat gliders from the 1930s. |
#4
|
|||
|
|||
Tow hook max wt marking
On Jun 29, 9:25*am, Steve Leonard wrote:
On Jun 29, 7:20*am, Tony wrote: On Thursday, June 28, 2012 9:43:36 PM UTC-5, Karen wrote: Simple question, but why are tow hooks marked, "1200 lbs Max weight", like the Schweitzer type release, towing big heavy 21M ships, *ships with water, Grobs and others over 1300 lb gross weights? Actual pulling weight? Is there an FAR? Thanks. 1200 lbs on the towhook refers to the maximum rope strength, not the smaximu glider weight. And if you trace it back far enough, it probably stems from an old NACA study on glider towing loads from the 1930s where they said "We don't think there is ever a case where you could apply more than 1200 lbs load to a glider tow hook." *And thus, we in the US are saddled with a tow hook limitation from the days of 800 lb max weight two seat gliders from the 1930s. Thank you. So there is no FAR, just various 337's and field approvals? |
#5
|
|||
|
|||
Tow hook max wt marking
On Friday, June 29, 2012 2:13:42 PM UTC-5, Karen wrote:
On Jun 29, 9:25*am, Steve Leonard wrote: On Jun 29, 7:20*am, Tony wrote: On Thursday, June 28, 2012 9:43:36 PM UTC-5, Karen wrote: Simple question, but why are tow hooks marked, "1200 lbs Max weight", like the Schweitzer type release, towing big heavy 21M ships, *ships with water, Grobs and others over 1300 lb gross weights? Actual pulling weight? Is there an FAR? Thanks. 1200 lbs on the towhook refers to the maximum rope strength, not the smaximu glider weight. And if you trace it back far enough, it probably stems from an old NACA study on glider towing loads from the 1930s where they said "We don't think there is ever a case where you could apply more than 1200 lbs load to a glider tow hook." *And thus, we in the US are saddled with a tow hook limitation from the days of 800 lb max weight two seat gliders from the 1930s. Thank you. So there is no FAR, just various 337's and field approvals? from what i've seen the max load allowed on the towhook is usually specified in the documentation for the installation. so yes, no FAR. |
#6
|
|||
|
|||
Tow hook max wt marking
On Jun 29, 12:43*pm, Tony wrote:
On Friday, June 29, 2012 2:13:42 PM UTC-5, Karen wrote: On Jun 29, 9:25*am, Steve Leonard wrote: On Jun 29, 7:20*am, Tony wrote: On Thursday, June 28, 2012 9:43:36 PM UTC-5, Karen wrote: Simple question, but why are tow hooks marked, "1200 lbs Max weight", like the Schweitzer type release, towing big heavy 21M ships, *ships with water, Grobs and others over 1300 lb gross weights? Actual pulling weight? Is there an FAR? Thanks. 1200 lbs on the towhook refers to the maximum rope strength, not the smaximu glider weight. And if you trace it back far enough, it probably stems from an old NACA study on glider towing loads from the 1930s where they said "We don't think there is ever a case where you could apply more than 1200 lbs load to a glider tow hook." *And thus, we in the US are saddled with a tow hook limitation from the days of 800 lb max weight two seat gliders from the 1930s. Thank you. So there is no FAR, just various 337's and field approvals? from what i've seen the max load allowed on the towhook is usually specified in the documentation for the installation. *so yes, no FAR. The FARs only specify the weak link requirements. |
#7
|
|||
|
|||
Tow hook max wt marking
A tow hook installation done in accordance with AC 43.13-2B section 807 will
include a PLACARD stating the maximum tow line strength (1200 lbs for Schewitzer). The installation paperwork for my Tost hook says 750 daN (1686 lbs). FAR 91.9 says no person may operate a civil aircraft without complying with the operating limitations specified in the approved Airplane or Rotorcraft Flight Manual, markings, and PLACARDS, or as otherwize prescribed by the certificating authority of the country of registry. So there is an FAR. The POH for many glliders includes a maximum rope breaking strength, which must be adhered to according to FAR 91.9. 4RL wrote in message ... On Jun 29, 12:43 pm, Tony wrote: On Friday, June 29, 2012 2:13:42 PM UTC-5, Karen wrote: On Jun 29, 9:25 am, Steve Leonard wrote: On Jun 29, 7:20 am, Tony wrote: On Thursday, June 28, 2012 9:43:36 PM UTC-5, Karen wrote: Simple question, but why are tow hooks marked, "1200 lbs Max weight", like the Schweitzer type release, towing big heavy 21M ships, ships with water, Grobs and others over 1300 lb gross weights? Actual pulling weight? Is there an FAR? Thanks. 1200 lbs on the towhook refers to the maximum rope strength, not the smaximu glider weight. And if you trace it back far enough, it probably stems from an old NACA study on glider towing loads from the 1930s where they said "We don't think there is ever a case where you could apply more than 1200 lbs load to a glider tow hook." And thus, we in the US are saddled with a tow hook limitation from the days of 800 lb max weight two seat gliders from the 1930s. Thank you. So there is no FAR, just various 337's and field approvals? from what i've seen the max load allowed on the towhook is usually specified in the documentation for the installation. so yes, no FAR. The FARs only specify the weak link requirements. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Compare/Contrast: CG hook on aerotow vs. CG hook on winch | son_of_flubber | Soaring | 37 | June 4th 12 10:40 PM |
Marking sheetmetal | Michael Horowitz | Home Built | 41 | September 23rd 06 05:25 PM |
CG Hook for SGS 2-33 | Rusty | Soaring | 0 | November 23rd 05 12:15 PM |
Wire marking | Scott Vetter | Restoration | 1 | December 1st 04 03:23 AM |
CG hook & Low Tow | Ray Lovinggood | Soaring | 2 | July 25th 03 06:20 AM |