tag:blogger.com,1999:blog-4982873379095996006.post8444979758760925350..comments2023-06-16T09:49:27.651-04:00Comments on Russ Roslewski, CFI/CFII/MEI: 0/0 takeoffs for Part 91?Russhttp://www.blogger.com/profile/06271438246152236864noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-4982873379095996006.post-43775253532363516482020-12-04T15:09:54.906-05:002020-12-04T15:09:54.906-05:00Hi Steve! While I don't have any great insight...Hi Steve! While I don't have any great insight into the "why" of this regulation, I can speculate. In my opinion, the takeoff minimums aren't an issue of "navigation" - the airplane and avionics don't know the weather, and you can navigate the same regardless of the ceilings and vis. Rather, it's from an "emergency" perspective, and primarily an "engine failure" one. <br /><br />In a single-engine aircraft, obviously if the engine fails, there aren't many options, you are going to descend, and having a little bit of visibility is going to help with trying to make a safe landing. <br /><br />In a multiengine aircraft, of course, in many cases you will be able to keep going, however the concern there is going to be any initial heading changes as you deal with the control forces changing. Asymmetric thrust, etc. Although my experience tops out at light twin-engine jets, I would guess that the more engines an airplane has, the less of a concern this is - for a B-52 with 8 engines, losing one of them probably isn't going to result in much control difficulty.<br /><br />Since we are visual creatures, having that added visibility requirement for single- and twin-engine aircraft probably helps with being able to control it in the event of an engine failure on takeoff roll or just after takeoff.<br /><br />That's my guess!<br /><br />Thanks for reading.<br />RussRusshttps://www.blogger.com/profile/06271438246152236864noreply@blogger.comtag:blogger.com,1999:blog-4982873379095996006.post-43018849526720717772020-12-04T14:29:23.890-05:002020-12-04T14:29:23.890-05:00Recently had a student ask “why is the minimum vis...Recently had a student ask “why is the minimum visibility different depending on the number of engines?” Given that both aircraft are operating under IFR, what is your take on this question? CFIISTEVEhttps://www.blogger.com/profile/13492733837345008933noreply@blogger.comtag:blogger.com,1999:blog-4982873379095996006.post-80791708815500189472016-01-09T22:11:30.129-05:002016-01-09T22:11:30.129-05:00Peter, thanks for reading! The accident report you...Peter, thanks for reading! The accident report you linked is sobering, and unfortunately we'll never truly know the source of the pilot's spatial disorientation. However, it is well known by IFR pilots that one of the most difficult moments in a flight is that first moment you enter IMC - the transition as you switch from visual to instruments. That's why it's a good idea to get on instruments before you actually enter IMC - so you're already "in the groove".<br /><br />With a 0/0 takeoff, you don't have that option. You have to be visual as you roll down the runway, and as soon as you lift off, you're instantly IMC. Dangerous stuff those next few seconds.<br /><br />Approach RVR as a minimum at least gives you a little time to get "on the gauges".<br /><br />Glad you're completing your instrument rating! It's a tough one but a very worthwhile rating to have. Good job!Russhttps://www.blogger.com/profile/06271438246152236864noreply@blogger.comtag:blogger.com,1999:blog-4982873379095996006.post-67538545545474952942016-01-09T14:03:55.249-05:002016-01-09T14:03:55.249-05:00Thanks for the blog.
At my old airport (KPAO) a fa...Thanks for the blog.<br />At my old airport (KPAO) a fatal accident occurred with a C310 as the pilot attempted a departure in 0/0. <br /><br />https://eesmog.files.wordpress.com/2011/11/ntsb_e11232011120000.pdf<br /><br /><br />As I complete my IFR rating now, I always wondered about the legality of 0/0. My CFI thought at least Approach RVR was required but the KPAO tower allowed the 0/0 departure at "pilots risk". My own personal minimum would always be enough visibility to land again if there was a flight issue. Hence minimum approach plate RVR makes sense.Peterhttps://www.blogger.com/profile/10854231647325322509noreply@blogger.comtag:blogger.com,1999:blog-4982873379095996006.post-51754410006651378522015-02-27T09:22:59.706-05:002015-02-27T09:22:59.706-05:00MikeM, thank you for the comment.
I see where you...MikeM, thank you for the comment.<br /><br />I see where you're coming from - you're right, 91.175(f) isn't very well worded, and it could be inferred that since it's in Part 91, it applies to Part 91 operations in addition to the other parts listed. However, this isn't the case. In addition to the FAA's own Instrument Procedures Handbook explicity stating that takeoff minimums do not apply to Part 91, I refer you to the following Regional Counsel letter from 1999:<br /><br />http://www.faa.gov/about/office_org/headquarters_offices/agc/pol_adjudication/agc200/interpretations/data/interps/1999/landis%20-%20(1999)%20legal%20interpretation.pdf<br /><br />Your concern on wording was identified as early as 1967, and the current wording is apparently the "clarified" version!<br /><br />Thank you for reading my blog, and please let me know if you have any ideas for topics for future articles. Good flying!<br /><br />RussRusshttps://www.blogger.com/profile/06271438246152236864noreply@blogger.comtag:blogger.com,1999:blog-4982873379095996006.post-61506977048015457542015-02-26T20:24:00.173-05:002015-02-26T20:24:00.173-05:00In your explanation, you state 'this subparagr...In your explanation, you state 'this subparagraph only applies to "persons operating an aircraft under part 121, 125, 129, or 135'. However, the word 'only' does not appear in the regulation. Instrument Procedures Handbook notwithstanding, I contend that 91.175(f) DOES apply to Part 91 operations. Other subparagraphs in Part 91 don't say that they apply to Part 91 operations, it's implicit. Why should this subparagraph have to say that it applies, it's published IN Part 91. Legally speaking, and parsing the words, I think that it does apply..... MikeMhttps://www.blogger.com/profile/14629038695348023187noreply@blogger.com