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Part 91 REG Clarification

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Well-known member
Feb 24, 2002
I have two questions that pertain to part 91 operations. The first is in the area of SIC currency. The way I read the regulation, they state that as long as the SIC meets the part 61 requirements for SIC the only currency requirements is that the SIC have 3 T/O’s and landings in a year. The question is, as long as the PIC meets all the necessary requirements, does the SIC need to by night current to act as the PF and make night T/O’s and landings?

The second question has to do with T/O mins. If the departure runway has a required ceiling and visibility minimum due to say obstacles or noise abatement, does a part 91 operator have to adhere to that limitation? Stated differently, let’s say runway X has a MIN climb gradient listed on the approach plate. If you cannot meet that gradient you need say 2000/1 to takeoff. Does that apply to the 91 operator or can he T/O when it’s 0/0?


Since 61.55 does place a night landing requirement upon a SIC, it can be assumed the SIC is legal day and night if they meet the 3 landing per year requirement of the reg.

Part 91 operators can only use the 0/0 take off rule if standards take off minimums apply, i.e. no restrictions upon vis or ceiling. If teh departure runway lists no minimums you can go 0/0, if their is a listing of 1 miles vis, you must have 1 miles vis in any airplane to takeoff from that runway.
14 CFR 61.55, a second-in-command need only meet the annual requirements as spelled out in the FAR. The SIC is not acting as pilot-in-command, and does not need to meet he recency of experience requirements set forth in 61.57 with respect to 90 day landings, night landings, instrument experience, etc.

Weather the SIC is manipulating the controls or not has no effect, as the issue is one of pilot-in-command. So long as the SIC will not be designated the pilot-in-command, then he or she is subject to 61.55, for all operations conducted under Part 91.

If an instrument proceedure has non-standard minimums, the pilot using that proceedure is obligated to adhere to the proceedure as cleared. If I understood your question, you asked if an operator who can't meet the minimum climb gradient would still be obligated to observe the minimum visibility and ceiling requirements.

An operator who couldn't meet the minimum climb gradient would be very foolish to depart in zero-zero conditions. The purpose of appending ceiling and visibility restrictions to a departure proceedure is to ensure adequate ability to maintain terrain separation or obstacle clearance.

Until given guidance in the form of a heading or radar vectors by ATC, the PIC is responsible for terrain separation. The only way to do this is either visually, or by flying a charted proceedure. Can the pilot depart in conditions less than prescribed under 91? Yes. However, he or she had better be able to fly the departure as charted, or be prepared to receive guidance from ATC in the form of vectors. Until those vectors are given, then the pilot is on his own. Not a good time for guesswork.

91.175(f) states that takeoff minimums are restrictive to operations under 121, 125, 129, or 135. A Part 91 opreator may takeoff without regard to the visibility restrictions or takeoff minimums...but is it really a good idea? A part 91 operator has every bit as much right and ability to hit a hillside as the next guy, and generally makes just as big a fire.

Thanks for your responses. The SIC answers are what I expected and how I read the regs as well so I’m glad to see that I’m reading them correctly. As for the T/O question I’d like to see if I understand AVBUG’s answer correctly. In your answer you refer to “what’s the smart thing to do” as I call it and then at the end, state that the 91 guy can ignore the published visibility and ceiling requirements and go anyway. If I am understanding you correctly, part 91 allows me to depart say Aspen even if I don’t have the visibility and ceiling requirements. Which I don’t think is right.

The way I see it is if there is a MIN climb required off a given runway, I have to be able to make that climb single engine whether I’m 91, 135, or 121. The reason is that the climb required is there for noise abatement or to keep me off the side of a hill. Part 91 doesn’t give me a license to steal so to speak.

Your thoughts?

Hogdriver, as I stated before, it's legal, but not necessarily safe. Under strictly Part 91 operations, 91.605 dictates that takeoff weight limits, and accelerate/stop distances must be observed, but does not speak to climb gradients. The only portion of part 91 which does speak to climb gradients is found in 91.611(c), which deals specifically with flight tests to determine single engine aircraft performance.

Under Part 91, pilot may takeoff without regard to published visibilities. If a pilot is departing using a proceedure as part of the clearance, the pilot must adhere to the proceedure, as cleared. If cleared via the proceedure with changes, then the pilot must still adhere to the clearance. For example, the pilot may be given a departure proceedure, but have ammended altitude instructions, or may be changes to the proceedure. The pilot must fly the clearance. If the clearance includes the departure proceedure, then the pilot must comply.

Takeoff visibility minimums are not included as part of the restrictions to part 91 ops. This isn't "stealing," any more than failing to declare a takeoff alternate or have one available, is "stealing." It's the way the regulation is written, and enforced.

The FAR does not require you to comply with minimum climb gradients with an engine inoperative. However, wise flight planning dictates that you understand weather or not your aircraft can meet the minimum climb gradients in the event of a powerplant loss, and plan accordingly. It's well to remember that failure to do so may be met with enforcement proceedings under 91.13, and 91.103, assuming that one survives the failure.
If the approach plte has a black "T" and in front of the publication it lists 300-1 then you must have 300-1 to takeoff. Approach plates are a regulation-PART 97. Unless you have an OPSPEC saying otherwise then you must follow what the approach plate says.

No, an approach plate is not a regulation. Part 97 is the regulation that specifies how approach procedures are designed and published (read the applicability of Part 97) Part 97 includes the current revision of the TERPS by refernce, so that the TERPS become regulatory (for designing approaches). It is important to point out that Part 97 and the TERPS are regulations for designing approaches, NOT regulations for flying airplanes. Nothing in Part 97 specifies how someone should fly an airplane.

The regulations for flying airplanes are PART 91. Other parts may apply, depending on what kind of flying you're doing.

Now, the rules for flying airplanes (Part 91) require you to use an approach designed according to the rules for designing approaches (Part 97)

>>>>91.175 Takeoff and landing under IFR.

(a) Instrument approaches to civil airports.

Unless otherwise authorized by the Administrator, when an instrument letdown to a civil airport is necessary, each person operating an aircraft, except a military aircraft of the United States, shall use a standard instrument approach procedure prescribed for the airport in part 97 of this chapter.

Notice that the regulation is very specific who must use a part 97 approach procedure; pretty much anyone flying a plane in US airspace, except the US military.

Now, on to takeoff minimums. The rules for flying airplanes (Part 91) specify who must comply with the takeoff minimums derived according to part 97.

91.175 (f) Civil airport takeoff minimums. Unless otherwise authorized by the Administrator, no pilot operating an aircraft under parts 121, 125, 129, or 135 of this chapter may take off from a civil airport under IFR unless weather conditions are at or above the weather minimum for IFR takeoff prescribed for that airport under part 97 of this chapter. If takeoff minimums are not prescribed under part 97 of this chapter for a particular airport, the following minimums apply to takeoffs under IFR for aircraft operating under those parts:......

Notice that the regulation is very specific who must comply with the takeoff minimums; pilots operating under part 121,125,129, or 135. No one else is mentioned. If they had intended for everyone to comply with the takeoff minimums, they would have specified everyone, like they did in 91.175 (a)

Nowhere in the regulations does it specify that a pilot NOT operating under 121, 125, 129, or 135 must comply with published takeoff minima.

Disclaimer, I'm not saying it's wise, I'm just saying it's legal

Hogdriver, I'm curious, the local FSDO has a different spin on which aspect of this discussion??

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part 91

First of all, thanks for all the well thought out comments. This discussion started during a Part 135 check with the Feds. During the oral we discussed T/O mins for Part 135. We were looking at the runway 19 takeoff mins. at MKC. Because this topic had come up in discussions at my own company I asked the examiner about T/O mins. under Part 91. His answer was that the ceiling and visibility limits if you can not meet the climb gradient apply to part 91 operators as well. His example was to use Aspen and ask if you could take off out of Aspen part 91 if it’s 0/0. I went along with him because it’s best not to start a pi$$ing contest with a Fed. on a checkride. The difference is that Aspen’s limits are part of a published departure procedure and MKC’s is a runway limitation for obstacle clearance not part of the SID. As stated in a previous post, if you depart RW 19 with an assigned heading of 210/230 you ovoid the obstacles.

My concern is that if a Fed. witnesses you departing 0/0 at a similar airport can he violate you under the reckless operation of an aircraft section of Part 91?

a New twist


Here is a new twist on this issue straight from a FAA inspector. He said that Part 91 only requires you to be able to meet the climb gradient with all engines vice single engine under 135. Which, under most situations makes the visibility and ceiling requirements N/A. So you can legally depart 0/0 but there is a catch. The FAA uses a term for part 91 called highest level of safety. They consider that to be part 135 limits. So if you were to depart under the circumstances described and have any problem that causes the FAA to do an investigation they would look at the highest level of safety. So even though you are not required to meet the single engine climb, that information is still available to you in the AFM for a jet aircraft and their view is that you should have used it anyway to make your T/O determination. So they can violate you under the reckless operation rules.


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