172driver
Well-known member
- Joined
- Apr 4, 2002
- Posts
- 744
I am under the assumption that there are no takeoff minimums for aircraft operating under Part 91. Correct? Several of us have been discussing takeoff mins for 121, 125, 135 and we really opened up a can of worms. Eventually, people were trying to convince me that the 1/2 and 1 SM rule applied to turbojets operating under 91. I shook my head and left the discussion, seeing that we weren't getting anywhere.
OK. Now, what are the rules for departure under 121, 125, 135? I just need the takeoff mins, not the alternate reqs. From reading, I gather that std mins are: 1 or 2 eng= 1 SM and 3+ eng= 1/2 SM. Am I correct so far?
The next thing that got me was the back of the Jepps, which list the std mins as stated above. They also state that with adequate visual reference, required vis drops to 1/4 SM for all operators. I understand the definition of adequate visual reference but 1/4 SM seems like a pretty big drop from 1SM. Also seems like it makes the std mins pretty much obsolete. Why would one ever use 1 SM when they could just as easily use 1/4? Seems like you would always have adequate vis ref if you had 1/4 SM vis...
Why isn't the adequate vis ref discussed in the FAR's since it seems it is probably more widely used than the std mins?
Don't all 121, 125, 135 operations have ops specs anyway which supersede the regs? Are they more or less restrictive?
Also, why are the t/o mins for 121, 125, 135 operators discussed in Part 91 of the FAR's rather than the appropriate chapters?
Help! I know I came to the right place and that this stuff is probably pretty elementary to most of you but it's got me chasing my tail. Thanks in advance.
OK. Now, what are the rules for departure under 121, 125, 135? I just need the takeoff mins, not the alternate reqs. From reading, I gather that std mins are: 1 or 2 eng= 1 SM and 3+ eng= 1/2 SM. Am I correct so far?
The next thing that got me was the back of the Jepps, which list the std mins as stated above. They also state that with adequate visual reference, required vis drops to 1/4 SM for all operators. I understand the definition of adequate visual reference but 1/4 SM seems like a pretty big drop from 1SM. Also seems like it makes the std mins pretty much obsolete. Why would one ever use 1 SM when they could just as easily use 1/4? Seems like you would always have adequate vis ref if you had 1/4 SM vis...
Why isn't the adequate vis ref discussed in the FAR's since it seems it is probably more widely used than the std mins?
Don't all 121, 125, 135 operations have ops specs anyway which supersede the regs? Are they more or less restrictive?
Also, why are the t/o mins for 121, 125, 135 operators discussed in Part 91 of the FAR's rather than the appropriate chapters?
Help! I know I came to the right place and that this stuff is probably pretty elementary to most of you but it's got me chasing my tail. Thanks in advance.