Captain Toolbox (WARNING! LONG RANT!)

[TonyC]

That's exactly right. The threshold crossing height data and main wheel contact point is now based on an aim point of 1000'. The contaminated analysis is based on touchdown point of 1000'. Definitely a difference between aim point and touchdown point and one I definitely meant to distinguish between.

Thanks for clarifying - - no, it was clear before, I just was skeptical - - thank you for confirming that. That leaves me with this question: What do you use as an aimpoint to ensure a 1,000' touchdown (for your contaminated runway data)?

Absolutely no "duck under" going on here. I would never use those words at any time under any situation. The verbage is "runway in sight" "taking over visually".

I'm not sure why you're reluctant to use the terminology, because it accurately describes the maneuver you're presenting, When you go below the glidepath to land at a point priior to the normal touchdown point, that is a duck under. Since you have data for it, why not call the spade a spade?

I believe the CFR's you quoted give the latitude to maneuver as I described. It is now necessary to land...I will be leaving the electronic glideslope for a visually performed landing. There is nothing unusual or unsafe about maneuvering for a new aim point to acheive the required touchdown point objective. Especially when you are given approved data for such a maneuver.

AS a matter of fact, such manuevering is required to acheive the necessary stopping distance as stated in the engineering analysis.

IF one has valid manufacturer data and a proscribed normal procedure to descend below glideslope to accomplish a normal landing, then it's hard to argue against it. Until this discussion, I had never heard of such data, or of such a "normal" procedure, or of formal training of such a maneuver. I have run across a good number of "common" practices throughout my aviation career which were not "normal." One particular "common" practice involved moving the thrust reversers to interlock shortly before landing for a "short field" landing. A very experienced and talented pilot scraped a pod and wound up explaining the practice at the end of that long green table. The common procedure was not normal.

Of course, an important distinction between my example and your procedure is the former was not an approved procedure. I take it from your posts that you are describing a manufacturer and company approved procedure.


Since my curiosity is piqued, let me pile on a couple more questions. You described data that assumes an aimpoint and then a touchdown at 1,000' (no flare) and you said the mains touchdown at 650'. Do you really NOT flare, or do you flare and touchdown beyond the 650' point? IF so, how far?

A typical glideslope provides a threshold crossing height in the neighborhood of 50'. (We require a minimum TCH of 47' for an autoland.) Your described procedure stipulates a TCH of 25', roughly half that normal height. How much of that do you suppose might be consumed by a deviation due to a wind gust, or simply a change in winds, in direction or velocity, due to local terrain features?


You described in an earlier post the requirement to annually demonstrate proficiency in a visual landing maneuver without the aid of electronic or visual glideslope aids. Except for the requirement to land 1,000' down the runway, the maneuver sounds like typical Appendix F training. Is the maneuver requirement you described, specifically the requirement to touchdown at the 1,000' point, part of your airline's Ops Specs?



Now... it's coffee time.





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[mtsu_av8er]

I don't like some of what I'm hearing here. Does this have anything to do with guys being hired with no experience? Possibly,the 6 month captain upgrade?

I think maybe we've got captains out there that don't know how to be captains and first officers who don't know how to fly. It may not be the norm...but if it fits 10% of the population...that's a heck of a lot of this stuff going on.

I'm pretty sure that's exactly what's going on! 500 hour jet drivers and 6-month upgrades look good on paper, but I guess it does take time to build experience!

 

[davetheflyer]

"once we had visual, dipped below glideslope once the field was assured to make the most of the runway, "

Do NOT go below glideslope.

As to the FFDO comment, think about it. The cockpit is most vulnerable when the door is open. It would be easy for a terrorist to see the preparations for opening the door in flight and be ready to strike. It would be much better if you simply heeded the call of nature on the ground, if possible.

As to the captain's nature, everybody has flown with jerks. I had one recently. He touched the controls in a descent when I was flying, as well as doing a couple of other things that really ticked me off. On the ground, we had a heart-to-heart discussion and he didn't do it again.

I also agree with the comment above about briefing any increase in landing speed.

It seems that there were attitude problems on both sides of the cockpit.

 

[derg]

Doug? What do you do in the -88 on a wet runway?

Wet runway in a mad dog? Once the runway is in sight, I'll consider "slightly adjusting my glidepath" to maximize runway. Medium (or max) autobrakes depending on the amount of contamination, triple-check that the spoilers are armed and mentally remind myself that a firm landing with the throttles at idle is worlds better than a smooth landing, halfway down the runway with the throttles out of idle is going to send me into the weeds.

 

[Mr_Creepy]

Been watching this one for a while and half to jump in.

There is no such thing as a "Touchdown Point"

The aiming point is the center of the fixed distance markers, 1000' from the threshold.

The touchdown zone is defined as the first 3000' of the runway or the first half, whichever is smaller.

It is completely legal by FAA regs to land on the numbers in any aircaft.

Can't believe how many captains had this wrong though, back in my airline days.

 

[CapnJim]

Well, as to the glideslope issue, folks seem pretty evenly divided between the camps of "Never!" and "Sometimes!" I'm in the latter category, and will stay there. Here's why:
The argument against going below glideslope, on the face of it, seems sound: You no longer have obstacle clearance, and you're picking up airspeed. As I noted, "the field was assured", and by "assured" I meant we were over the displaced threshold. Obstacle clearance at that point was moot, and as I also noted, I fully intended to carry a small margin of extra airspeeed for the gusty conditions. Had I carried that extra airspeed to the 1000' markers, I would have been much farther down the runway than I would have been comfortable with given the winds, gusts and runway length, consistent with "a lower altitude for safe landing" Did I need it? Not really. So why did I do it? Because the margin of saftey extra runway and airspeed gave me outweighed the risk of obstacle clearance or "changing the physics of the touchdown".
As it was, I landed within a few feet of the 1000' markers. It was only at that point, with the mains on the ground and the nosewheel descending, that the Captain jerked the controls to full aft. I'm hard pressed to imagine what he saw at that point that made him think the flight was in jepoardy.

However, and as I noted in my original post, I allowed the actions of someone else to affect my performance: My pride was bruised and my ego got in the way of what I knew was the right thing to do. This in no way absolves the Captain of his actions, and in point of fact highlights that his poor leadership abilities were what created the hostile CRM environment in the first place. To those who wish to beleagure this point, feel free to do so as long as it makes you feel good about yourself. I've already admitted in my first post that I had failed in this regard, so it's an easy target for those who need one.

My compliments and thanks to those of you who were professional enough to give objective opinion devoid of condescention and pretention, your time spent at the keyboard was appreciated and well spent. To those of you who weren't, well, better luck next time!

 

[DE727UPS]

Has anyone mentioned what you're flying might make a difference? A widebody, I don't think it's a good idea. A 737, you could probably duck under a little. An RJ, I wouldn't think it wouldn't hurt to put it on the numbers.

 

[derg]

Aircraft type makes ALL the difference in my opinion. Plus, for the 'duck under' crowd, it also depends on how much as well.

 

[BobDDuck]

Not really related, but keep in mind in many cases that a VASI will not be the same as a glide slope and it is perfectly legal to switch to the VASI once in visual conditions. I think it's one of the runways at ATL where if you follow the G/S down you end up right on a big hump. If you switch to the VASI you get some nice some concrete. Or maybe I have it backwards. Either way, if I drop below the G/S to catch the VASI I'll announce it if I think about it, but either way it is legal.

 

[cime_sp]

In the CRJ it is actually very difficult to fly the glideslope down to the runway and put it down near the fixed distance markers. The thing comes in at 3 degree nose down..lands about 3 degrees nose up...and LOVES to float. 5-10 extra knots can eat up 1000-2000 extra feet of runway in a hurry. Just come to ATL and watch a few landings. Yes there is plently of runway so it is not much of an issue, but you will routinely see touchdowns 3000-4000 feet down the runway. Not the norm, but not uncommon either. In order to put it down "on the markers" you just about have to pull it to idle VERY early (about 120-150 feet) and also dip below the glideslope a little....which is perfectly legal inside the marker. But this is also a technique that is not really recommended in gusty conditions for obvious reasons...(unspooled, gusty winds, super-critical swept wing, etc...) When you're going into Naples FL at max landing weight into a 5000' runway and a final approach speed of 147 knots...and now you need to add a few extra for the winds, you better believe I'm going to try and put it down as early as I can. Runway behind you in that case doesn't help you one bit!

 

[TonyC]

There is no such thing as a "Touchdown Point"

I may have missed it, but I don't recall either of us putting capital letters or quotes on the touchdown point, and we didn't assign an acronym to it. The touchdown point (no big letters, no quotes) is simply the point at which the airplane touches down. It's important when it comes to calculating stopping distance, because the brakes can't be applied until the airplane touches down. As I explained before, the only landing data I have available (a laptop computer) assumes a touchdown at 1,500' down the runway. For the computed landing distance to be valid for my landing, I can't float to the end of the Touchdown Zone (TDZ).

Apparently, B767Driver has data that assumes a touchdown at 1,000' down the runway. His data would not be valid if he were to touch down 1,500' down the runway.

The aiming point is the center of the fixed distance markers, 1000' from the threshold.

Since we're splitting hairs here, the Fixed Distance markers can be used as your aimpoint. They BEGIN 1,000' from the end of the runway. (Perhaps it was unclear wording, but I inferred from your sentence that you believe the center of the fixed distance markers to be 1,000' from the end of the runway.)

The touchdown zone is defined as the first 3000' of the runway or the first half, whichever is smaller.

It is completely legal by FAA regs to land on the numbers in any aircaft.

Ah, yes, the numbers. DO you know how far "the numbers" are from the end of the runway?

500 feet?

750 feet?

650 feet?

How about less than 500 feet.


If you'd be so kind as to explain to me how take a 747 from on-glidepath at 200' AGL (the Middle Marker) and using normal descent rates and normal maneuvers plant the main landing gear less that 500' from the end of the runway, I'd certainly like to hear it.


Even B767Driver's data only touches down at 650' with no flare - - that's still well beyond "the numbers."

Can't believe how many captains had this wrong though, back in my airline days.

Maybe you could educate me.




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[Mr_Creepy]

Show me the regs that show it's not legal.

 

[TonyC]

Show me the regs that show it's not legal.

I already did. Post #37.


OK, here. I'll do the work for you. Here's a Cut & Paste:

CFRs are replete with the phrase, "normal rate of descent using normal maneuvers," as in, "[N]o pilot may continue an approach below the authorized DH unless ... [t]he aircraft is continuously in a position from which a descent to a landing on the intended runway can be made at a normal rate of descent using normal maneuvers and where such a descent rate will allow touchdown to occur within the touchdown zone of the runway of intended landing." It would be my position that the glideslope signal broadcast by the ILS system would be "normal," and the angle projected by the VGSI (PAPI, VASI, etc.) would be "normal." It would be my position that a 1,000' aimpoint using a 3 degree descent gradient is "normal." I submit that going below any of these would not be normal.

CFR 91.129 Operations in Class D airpsace includes the following:

(e) Minimum Altitudes. When operating to an airport in Class D airspace, each pilot of--
(2) A large or turbine-powered airplane approaching to land on a runway served by an instrument landing system (ILS), if the airplane is ILS equipped, shall fly that airplane at an altitude at or above the glide slope between the outer marker ... and the middle marker; and
(3) An airplane approaching to land on a runway served by a visual approach slope indicator shall maintain an altitude at or above the glide slope until a lower altitude is necessary for safe landing.
Paragraphs (e)(2) and (e)(3) of this section do not prohibit normal bracketing maneuvers above or below the glide slope that are conducted for the purpose of remaining on the glide slope.

Explain how you'll take the 747 from on glideslope at 200' to touching down less than 500' down the runway using normal rate of descent and normal maneuvers.


Come on - - you said any airplane could do it.






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[taildragger173]

3) An airplane approaching to land on a runway served by a visual approach slope indicator shall maintain an altitude at or above the glide slope until a lower altitude is necessary for safe landing.
Paragraphs (e)(2) and (e)(3) of this section do not prohibit normal bracketing maneuvers above or below the glide slope that are conducted for the purpose of remaining on the glide slope.

If you read a little more it says to maintain glidepath until a lower altitude is necessary for a safe landing. I take that to mean that Mr_Creepy is correct.

 

[Mr_Creepy]

CFR 91.129 Operations in Class D airpsace includes the following:

(e) Minimum Altitudes. When operating to an airport in Class D airspace, each pilot of--
(2) A large or turbine-powered airplane approaching to land on a runway served by an instrument landing system (ILS), if the airplane is ILS equipped, shall fly that airplane at an altitude at or above the glide slope between the outer marker ... and the middle marker; and
(3) An airplane approaching to land on a runway served by a visual approach slope indicator shall maintain an altitude at or above the glide slope until a lower altitude is necessary for safe landing.
Paragraphs (e)(2) and (e)(3) of this section do not prohibit normal bracketing maneuvers above or below the glide slope that are conducted for the purpose of remaining on the glide slope.

TC you don't think they used this argument on me? LOL

I can hear them now - "If you descend below the glideslope only at the middle marker - you are no longer doing a stabilized approach."

We used to argue about whether it was legal to continue from a VDP on a non-precision approach at the MDA without the runway in sight, for the same reason.

And the answer to both questions, given by my chief pilot at the time was, "what if you have a 30 kt head wind?"

Since most of the time you are landing with a headwind it is perfectly safe and stabilzed to slightly increase your rate of descent at the MM, thereby touching down prior to the aim point.

By the way the AIM says the "Aim point" is indicated by fixed distance markers which are "approximately 1000 feet" from the threshold. There is a diagram which appears to indicate that the aim point is at the beginning of the FDM, so I give you that one.

Good discussion here. Brings back my "pilot lounge" days

 

[Kingairer]

Just curious how long this runway was. I cant think of one that you actually need the mains to touch down on the numbers. Ill said it again, its all about the briefing.

 

[FlyChicaga]

Even after being based in MDW for a year, landing on short, contaminated runways in low visibility and heavy winds, I have never found it necessary to land "on the numbers" of any runway. In both regional aircraft I have flown, you could land safely on 5000-6000 foot runways by aiming for the beginning of the fixed distance markers and touching down soon after that.

You can quickly create a dangerous situation landing on a short runway by having too much speed, floating, or being too high. The same can be said for being too slow, too low, or letting the airplane bounce high on touchdown.

I have very limited airline experience, but from the beginning of my career in the airlines I was taught that you must land in the touchdown zone--this means nosewheel on the ground as well as the mains in the first 3000 feet--and anything outside of that was unprofessional.

I hold the belief that if you must duck the glideslope or land on the numbers to land safely on a runway, you probably should pick a different runway, or different airport. Of course, aircraft type plays a large part in the decision factor here. My opinion of a safe runway in an RJ or turboprop will be much different than an MD-11 or B777 pilot. Also, our approaches will be much different to the same runway.

Something to point out: I have a friend who flies F-16s for the US ANG, and they fly a 2.5 degree glideslope rather than a 3.0 degree glideslope. Different strokes for different folks.

 

[TonyC]

TC you don't think they used this argument on me? LOL

I have no idea what argument they used, nor do I really care. I was simply answering your challenge to show you the reg.







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[Mr_Creepy]

I have no idea what argument they used, nor do I really care. I was simply answering your challenge to show you the reg.







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So when are you going to answer it?

 

[TonyC]

So when are you going to answer it?

I answered it twice, now, and you have failed to address it.

You have also failed to answer my question.



Just saying it's legal because you say so doesn't wash.




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