According to 91.169, airplanes need 2,000-ft elevation while helicopters need 1,000 ft. Airplanes also need three set miles visibility while helicopters only need two. Is this because helicopters fly lower and slower than airplanes?
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$\begingroup$ Would you please clarify your question? IFR alternate minimums (in the title of your question) for an airplane are 800-2 or 600-2. For a helicopter it is 200 feet above the minimum for the approach to be flown and 1 mile vis. In the body of your question you are saying 2000-3 for airplanes and 1000-2 for helicopters, which is actually the criteria for whether or not an alternate airport is required and not the minimums required at the alternate airport. I think you are mixing 2 different sections of FAR 91.169. Thanks $\endgroup$– user22445Feb 17 at 15:50
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$\begingroup$ @757toga sorry for the late response. I assume there's a mix up with 91.169 part B and part C. My original question was referring to part B. But it seems that in both scenarios helicopters have the lower minimums. I was just wondering if that anything to do with the fact that helicopters fly lower and slower than airplanes. Sorry again for the mix up. I greatly appreciate your time spent researching. $\endgroup$– Boeing787Feb 18 at 18:35
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$\begingroup$ No problem. Thanks for clarifying. $\endgroup$– user22445Feb 18 at 20:02
2 Answers
The reason/rationale for why helicopter alternate weather minimums are lower than airplane alternate weather minimums can be found in this Federal Register addressing 14 CFR 91.169 - IFR flight plan: Information required.
Here is a pertinent excerpt from the Federal Register (Titled: Flight Plan Requirements for Helicopter Operations Under Instrument Flight Rules), specifically "A Rule by the Federal Aviation Administration on 01/21/2000" (Final Rule):
(Below is an excerpt from the linked Federal Register paragraph shown above titled "Alternate Airport Weather Minima")
"The commenters stated that helicopter operators should not be subject to the same restrictions imposed on operators of other types of aircraft by the use of nonstandard alternate minimums. ... Due to the ability of helicopters to fly any available instrument approach, regardless of wind direction, and to land at the approach threshold regardless of runway length by pivoting into the wind, if necessary, just before touchdown, the commenters asserted that helicopter operators should not be restricted by these non-standard alternate minimums. They further stated that helicopter operators therefore should be allowed to use lower-than-standard alternate weather minima, regardless of whether standard or nonstandard alternate airport weather minima are specified on part 97 approach plates.
The FAA agrees with these comments. ..."
(emphasis is mine)
Yes. The Helicopter can slow down enough to better avoid obstacles, even stop if it's within its Out Of Ground Effect hover ceiling, so credit for this is taken in defining minimum visibility conditions.
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2$\begingroup$ How timely, I came across this video the other day.youtu.be/RxpYTByTHB8?t=499 $\endgroup$– GastonFeb 16 at 18:48