'Normal' rate of descent using 'normal' maneuvers

meritflyer

Well-Known Member
91.175(1)

I believe I've seen some sort of un-official definition of normal per this regulation. Does anyone have an official FAA document or LOI defining normal?
 
I could be wrong as I often am but I doubt that you'll find one since it's so dependant on what type of aircraft you're flying. The normal descent rate of an Airbus would be excessively high for a Skyhawk. The FAA's 8900 document does set forth **some** things that are acceptable during certain phases of flight but I don't believe it says "Normal rate of descent = xx" and "normal manuevers = yy". I'll spend some time reading thru it next time I need to look busy at work.

Jason
 
I"ve always known a "normal" decent to be less than a 1000 ft/min and stabilized. I don't have a reference for that however.
 
I could be wrong as I often am but I doubt that you'll find one since it's so dependent on what type of aircraft you're flying.

Merit,

I guessing Jason is on the right track here. Even the FAA was confused on this subject when the new FAR was written. In Part 91, Amendment 91-173, adopted December 30, 1980, they said: "Commenters suggest, and the FAA agrees, that a further clarification is necessary for terminology previously used in 91.117(b)(1) and proposed under [ some meaningless sections of Part 91 that don't relate to your question] regarding a normal descent to the runway."

In typical FAA fashion, they were writing FARs that didn't provide the user enough guidance to be of complete value in every case. If they put out anything for Part 91 after that, and perhaps they did, I didn't notice, probably because I was paying any attention. :D

I tried contacting my source (you know, someone who actually knows what he's talking about) regarding the pure Part 91 answer to your question but haven't heard back.

I did some checking from the Part 121 side and found that compliance with normal maneuvers/rate of descent requirement of the FAR is satisfied by being in conformance with stabilized approach criteria laid out by the FAA (in the FAA Air Carrier Inspector's Handbook [8400.10] ). This is likely the same stuff published in company manuals. Of course, this doesn't specifically address a pure Part 91 case, which was your question.

For any Widget Worshipers, my source is: "Up Front-4th Quarter, 1990", in "The Pat Answer" section, page 11, written by the late Pat "Mother" Malone herself...answers you can believe in.

Hope this helps.
 
Only place I've seen written a reference for standard descent rates is for HI-approach jet penetrations, which are based on a 4000-6000 fpm rate of descent. On non-precision IAPs, I use a rule of thumb of 1000-1500 fpm descent between fixes and/or down to the MDA.
 
What do you normally do? If you 'normal'ly wouldnt bank over 30 degrees around the airport at a low altitude and you now would have to bank 50 degrees to get to the runway, well, that's not 'normal'. If your a quarter mile final and still 1000' agl your not going to be able to get down to the runway as you 'normal'ly do on your 3 degree glide path.
 
What do you normally do? If you 'normal'ly wouldnt bank over 30 degrees around the airport at a low altitude and you now would have to bank 50 degrees to get to the runway, well, that's not 'normal'. If your a quarter mile final and still 1000' agl your not going to be able to get down to the runway as you 'normal'ly do on your 3 degree glide path.

I believe the term "normal", implies "generally accepted". Normal won't do anything for you when you don't set yourself up for success in the first place, whether your fault or not.
 
A power-off 180 is normal for me, and I consider it normal for any GA airplane that is also used normaly as a trainer.
 
To maintain a 3 deg glide slope. Some approaches are Alpha because the FAF is less than 3nm from the MAP, not allowing for a "normal descent to landing" Look at the approach into Marathon to see a prime example of this.
As you all know, faster you go, the greater descent rate needed to maintain that 3 deg glide slope...
 
91.175(1)

I believe I've seen some sort of un-official definition of normal per this regulation. Does anyone have an official FAA document or LOI defining normal?
FAA-H-8083-16A Instrument Procedures Handbook
pg. 4-37 "Maximum Acceptable Descent Rates"
1,000 fpm during final stages of an approach is considered 'abnormal'
 
If your a quarter mile final and still 1000' agl your not going to be able to get down to the runway as you 'normal'ly do on your 3 degree glide path.

Ever flown a Pitts or other high drag airframe? Granted I've never seen an IFR equipped Pitts.
 
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