Minimums?

[Cessna172]

Hi everyone!

Dave, nice work on the new layout!

The other night, Tuesday night to be exact, I was looking through one of my friend's Operations Manual. He's a 737 pilot for Continental based out of KIAH. Very interesting with all of the normal and non-normal (that's what they call it) situation checklists. The COA Ops Manual for the 737 covered the -300, -500, -700, -800-, and -900 series. He answered some of my questions that I had for him, but I didn't get to ask one of them because of time (it was Tuesday night, after all). So, maybe someone here can help me: what are minimums? This question came about while looking at the procedure charts for what the PM and PF (Pilot Monitoring and Pilot Flying, respectively) should say when shooting any type of approach. The PM (or was it PF?, I can't remember) is supposed to say "Minimums" when they are reached. I believe this has to do either with altitude or airspeed or both, but I'm not sure. Being a GA pilot of a single engine piston aircraft, this term isn't used at all (or at least I wasn't tought to do so; regardless, only one pilot is required to fly the C172). Can anyone help??

Thank you in advance for your help! It is greatly appreciated!!

[Jason]

Hi everyone!

Dave, nice work on the new layout!

The other night, Tuesday night to be exact, I was looking through one of my friend's Operations Manual. He's a 737 pilot for Continental based out of KIAH. Very interesting with all of the normal and non-normal (that's what they call it) situation checklists. The COA Ops Manual for the 737 covered the -300, -500, -700, -800-, and -900 series. He answered some of my questions that I had for him, but I didn't get to ask one of them because of time (it was Tuesday night, after all). So, maybe someone here can help me: what are minimums? This question came about while looking at the procedure charts for what the PM and PF (Pilot Monitoring and Pilot Flying, respectively) should say when shooting any type of approach. The PM (or was it PF?, I can't remember) is supposed to say "Minimums" when they are reached. I believe this has to do either with altitude or airspeed or both, but I'm not sure. Being a GA pilot of a single engine piston aircraft, this term isn't used at all (or at least I wasn't tought to do so; regardless, only one pilot is required to fly the C172). Can anyone help??

Thank you in advance for your help! It is greatly appreciated!!

Cessna172, "minimums" in the situation you are using it here refers to the minimum altitude a pilot may descend to on the approach until the "runway environment" is in [visual] sight. 

You will see these minimums described as minimum decent altitudes on a non-precision approach or the decision height on a precision approach.  You will find these minimum altitude (and visibility) restrictions on every terminal approach chart for the different types of approaches and category aircraft. 

For example, the minimums for category A aircraft shooting the ILS 8L at IAH are 296 feet MSL (200 AGL) and 1/2 mile visibility.  The pilot may descend on the glideslope until reading 296 ft. until s/he sees the runway environment in sight.  If s/he does, s/he may proceed on the approach and land, if not, s/he must go around.  (An exception to this is a CAT III (specifically CAT IIIc) approach which basically has no minimums).

In the pilot/controller glossary, the definition is:

MINIMUMS- Weather condition requirements established for a particular operation or type of operation; e.g., IFR takeoff or landing, alternate airport for IFR flight plans, VFR flight, etc.

Also, the way I've learned it is that the two terms used are PF (Pilot Flying) and PNF (Pilot Not Flying) but maybe COA words the two meanings differently.

Hope this helps,
Jason

[KSYR-pjr]

If s/he does, s/he may proceed on the approach and land, if not, s/he must go around.

A minor correction:  A go around is a visual maneuver normally flown by VFR aircraft or IFR aircraft cleared for a visual approach. 

If the runway environment is not in sight by the decision height or MAP (depending on aircraft's approach category and approach being flown), the pilot must execute a missed approach, or, by the slang term that you might be recalling, go "missed."   

[Jason]

If s/he does, s/he may proceed on the approach and land, if not, s/he must go around.

A minor correction:  A go around is a visual maneuver normally flown by VFR aircraft or IFR aircraft cleared for a visual approach. 

If the runway environment is not in sight by the decision height or MAP (depending on aircraft's approach category and approach being flown), the pilot must execute a missed approach, or, by the slang term that you might be recalling, go "missed."   

I guess that's what happens when you post while doing 6 other things.  I meant "missed approach" not go around.

I also forgot to include the MAP in my explanation.  Thank's, Peter!

Jason

[Cessna172]

Jason and KSYR-pjr,

Thank you so much for your thoughtful explantions! That makes a lot of sense now!

Also, the way I've learned it is that the two terms used are PF (Pilot Flying) and PNF (Pilot Not Flying) but maybe COA words the two meanings differently.

Yep. That's how I learned it as well. But, according to the COA Ops Man. for their B737 aircraft, COA uses PM and PF. Different airlines think differently, I suppose! Another one of the things that my friend and I talked about was Autobraking on the 737. He says that, and I do not totally agree with this, being a SWA fan, Southwest Airlines does not use Autobraking while landing because (and, again, this is the only the opinion of my friend ) they are always in a hurry. I don't quite see the reasoning in that (wouldn't you get to the gate faster if you used Autobrakes?). Anyway, thanks for the help!

[Cessna172]

Oh, and by the way...he says that the "sliding off of the end of the runway" incident at KMDW wasn't the pilot's fault. Reasoning: MDW has short runways, the weather was awful, the runway was slick from the snow, etc. The pilot DID use autobrakes, and in fact he set the dial to about 3, I think. The breaking action just wasn't good enough. He also landed too far down the runway. The only thing that is still up in dispute concerning the pilot is: why didn't he divert?

Cessna172

P.S. It is COA's policy to set the Autobrakes to RTO in all T/O runs. Also, it is their policy to use the Autobreakes on all landings (setting is pilot's discresion).

Second P.S. I'm going to try doing an aborted T/O with RTO set at MDW with snow today just to see what happens (I'm curious). 

[Jason]

Oh, and by the way...he says that the "sliding off of the end of the runway" incident at KMDW wasn't the pilot's fault.

See the quote from your above post below:

Reasoning: MDW has short runways, the weather was awful, the runway was slick from the snow, etc. The pilot DID use autobrakes, and in fact he set the dial to about 3, I think. The breaking action just wasn't good enough. He also landed too far down the runway. The only thing that is still up in dispute concerning the pilot is: why didn't he divert?

1) Midway's longest runway is 6500 feet.  This isn't all that short for a B737 in normal conditions, but the pilot tried landing there in a snowstorm on a wet runway with a below normal breaking action (I can't give you an exact because I can't remember what the breaking action was reported as).  The plane landed on 31C, MDW's longest runway.  Also be advised that as soon as the pilot initiates manual braking, the autobrake system kicks off.  If, in fact, the pilots pressed as hard as they could, the autobrake system would have been found in the reset position and no autobraking would have been used after that time.

Your reasons basically state how it WAS the pilot's fault.    He landed on a runway that was much too short for him in the conditions that were present at the field.  I have no idea why the pilot did not divert, and I'm sure he won't be flying a Southwest trip anytime soon.

I'm not sure what SWA's Ops specs state, but they don't seem to like to divert to non-SWA airports.  For example, when PVD/G90 closed [on Wed.] at 12AM and a SWA 737 claimed they needed them to safely land at Providence, they diverted back to their orgin; BWI.  Although they service BDL (a short 57nm distance away), they decided to go back to Baltimore.  I don't know why the decision was made to go back all that way, but it may have something to do with Southwest's ops specs.  It beats me....but I know that if there was not a specific rule that stated SWA couldn't divert to a closer airport, then the pilot pretty much made a poor judgement call to return to BWI.  I understand though, that I can't make such a bold statement with such limited knowledge of the situation.  If anyone has any info on that one, feel free to post it.