CRJ operators, what is YOUR definition of "touchdown zone?"

Re: CRJ operators, what is YOUR definition of "touchdown zon

Dugie8 said:
I've been playing with this the last couple of flights in the Citation. To make the "1500" foot mark it takes either of two techniques. Being slightly below the GS and throttles "briskly" moved to idle just prior to the threshold and hold the nose in the landing attitude and "thud" or duck under the glideslope when over the approach lights by about a dot, on Vref and ease the throttles out to come to idle right at touchdown.

The first way gets a more consistent impact, the second way is easier to grease on but you are coming over the end of the runway at 25 to 30 feet (really flat).

If I fly on speed on GS to the threshold, pull the power out over the threshold (at 50 feet) I usually end up about 2000 feet down the runway still with a thud, try to smooth it out and we get into the 2200 or so range.
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just curious- at what speed (roughly) and pitch attitude do you cross the threshold? I always heard the citations had refs around 100 and they landed like a 172...

If you look at the vast majority of landings though by everyone they are typically in the 2000-3000 foot area, 1500 is just a rough landing...
 
Re: CRJ operators, what is YOUR definition of "touchdown zon

seagull said:
In what respect?
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We come down (like Ken said) at about a 4 degree nose down angle. To my knowledge, the GS is designed for a 3 degree descent all the way down to the runway. If that's true (and I could be wrong) you're changing your descent in the last 30 feet. Most airliners from what I see from the outside change their nose down attitude slightly in the flare. Not the CRJ -200. It goes from nose down to nose up. If we had leading edge devices on this thing and could come in slower, I wouldn't see it as that much of a problem.

My main problem is that it seems that our touchdown zone has been re-defined from not only what most carriers use but what the AIM has defined as the "touchdown zone."
 
Re: CRJ operators, what is YOUR definition of "touchdown zon

Landing at 1500' from the ILS G/S, I don't believe, will ever win any awards for a smooth touchdown.

To get a nice, soft touchdown, you need to be 2 to 5 knots above landing reference speed which will promote a bit of float. To land at 1500', you really need to be right at Vref or the aircraft's 1.3Vso. I don't see very many pilots fly right at these speeds...simply because you know you are in for a firm touchdown.

On long dry runways, I'll fly 2 to 5 knots above Vref and accept a touchdown at 1800'. It does make for a nice touchdown.

I would suggest to everyone to pull out their landing performance data and review them. I found some interesting stuff in ours. Specifically non-normal landing data and contaminated runway landing data. The assumptions are different from the normal FAR landing data. For example, contaminated runway performance assumes a landing at 1000' and requires maximum reverse thrust. The difference in landing distance without reverse and max reverse for a 767 is approx 4000'.

Kell,

I believe it when you say the CRJ has a long flare. That thing looks like it has to make quite a pitch change during the flare maneuver. I would ask your standards department how they are training pilots to fly the flare maneuver to remain within your defined standards.
 
Re: CRJ operators, what is YOUR definition of "touchdown zon

You could consistently touch down at 1500' by doing one of or combining all of the following techniques: Ducking below the GS/PAPI/VASI, bringing the thrust to idle at around 100-200 feet, approaching the flare in a low airspeed/low energy state, planting the airplane on the runway with a high sink rate, or deploying the flight spoilers in the flare (a CA did that to a buddy of mine).

I wouldn't reccomend any of the above. If you begin the flare on speed, on sink, and on the glideslope you're probably not going to touch down before 1500' goes past. 3000' can be done, and that's my definition of the touchdown zone.

EDIT: If they're really writing people up for this I have a feeling a large increase in fuel use due to go arounds might change things a bit.
 
Re: CRJ operators, what is YOUR definition of "touchdown zon

higney85 said:
just curious- at what speed (roughly) and pitch attitude do you cross the threshold? I always heard the citations had refs around 100 and they landed like a 172...

If you look at the vast majority of landings though by everyone they are typically in the 2000-3000 foot area, 1500 is just a rough landing...
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Ref speeds from 114 to 90 knots or so. Definately easier to make the 1000 foot markers at the lighter weights. Nose attitude about 3 or 4 degrees up. The problem with this thing is how much it really starts to fall out from underneath you when you get below Vref and how high the nose goes. You can get behind the power curve real fast and a CE550 ain't exactly winning any power awards.

Now the King Air, I will put that down on the 1000 foot markers all day, crossing on speed, on GS, etc. Just have a natural breaking action from the props allows you to steepen that descent angle abit without having to lower the nose so much and keep your Vref speed.
 
Re: CRJ operators, what is YOUR definition of "touchdown zon

kellwolf said:
We come down (like Ken said) at about a 4 degree nose down angle. To my knowledge, the GS is designed for a 3 degree descent all the way down to the runway. If that's true (and I could be wrong) you're changing your descent in the last 30 feet. Most airliners from what I see from the outside change their nose down attitude slightly in the flare. Not the CRJ -200. It goes from nose down to nose up. If we had leading edge devices on this thing and could come in slower, I wouldn't see it as that much of a problem.

My main problem is that it seems that our touchdown zone has been re-defined from not only what most carriers use but what the AIM has defined as the "touchdown zone."
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I will grant you that you have a large pitch change on the round-out, if you are indeed at 4 degrees down on final (contrasty that to our 3-4 degrees up on final, with a touchdown attitude of about 6 degrees), however, I still don't see what that has to do with your glideslope antennae on the nose?

Ours in the radome with gear up, and then just above the nose gear when the gear is down -- which is typical of a widebody to help prevent dragging the mains through the dirt. As it is, on glideslope I believe our mains are only 20' or so off the ground as they cross the threshold.
 
Re: CRJ operators, what is YOUR definition of "touchdown zon

Watched the GS on my CA's landing yesterday. It went from dead center to fully deflected on the high side during the flare. That's why I say it has something to do with it being in the nose.

As for standards, there's really not any here for teaching the flare. The sim guys tell the new hires to keep the thrust in until 50 ft AGL and chop the power. Works great in the sim, not so much in the realy plane. If you're gunning for the 1500' mark and chop the power at 50 ft, you're not gonna make it. You'll be well past the mark before you even know it. Best thing I've found is start slowly reducing the power at 100 AGL, and be at idle around 50 ft. I can consistantly get a smooth touchdown around 1500-1800 ft in this beast, which is good enough for me and every CA I've flown with.

It's still in the early stages, and we're not totally sure if the TVC incident triggered all of this since the facts haven't come out yet. If they start writing guys up for it (rumors are, of course, already out that they are), I'm betting we will see a lot of go arounds.
 
Re: CRJ operators, what is YOUR definition of "touchdown zon

kellwolf said:
Watched the GS on my CA's landing yesterday. It went from dead center to fully deflected on the high side during the flare. That's why I say it has something to do with it being in the nose.

As for standards, there's really not any here for teaching the flare. The sim guys tell the new hires to keep the thrust in until 50 ft AGL and chop the power. Works great in the sim, not so much in the realy plane. If you're gunning for the 1500' mark and chop the power at 50 ft, you're not gonna make it. You'll be well past the mark before you even know it. Best thing I've found is start slowly reducing the power at 100 AGL, and be at idle around 50 ft. I can consistantly get a smooth touchdown around 1500-1800 ft in this beast, which is good enough for me and every CA I've flown with.

It's still in the early stages, and we're not totally sure if the TVC incident triggered all of this since the facts haven't come out yet. If they start writing guys up for it (rumors are, of course, already out that they are), I'm betting we will see a lot of go arounds.
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If you've followed the glideslope until the round-out, then the signal is obviously unreliable as you pass that point and go into the lobe area. It's not indicative of anything.

If it's before the round-out, sounds like you may be ducking under a bit. The size of the airplane isn't enough for that to be noticeable, even if you are at 4 degrees down, and even if you lower the nose to that point as you go into the flare (which seems unlikely). If the body angle as already at negative 4, then it wouldn't be changing the relative position of the glideslope as you approach the runway.
 
Re: CRJ operators, what is YOUR definition of "touchdown zon

It would seem there was a serious misunderstanding between the people that write the manuals and the people that fly the airplanes. A key word, "useable" was left out. And here's the official word on it: the first 1000 ft of runway is not usable due to the 50 ft crossing height. So, the company was saying "1000-1500 ft" but leaving out a key phrase. Turns out, it's 1000-1500 ft PASSED the 1000 ft markers (since if you crosee the threshold at 50 ft, that's where your useable runway starts anyway). That is totally within reason. Honestly, if you're landing more than 2500 ft down the runway, you're floating it anyway. That's only taking 500 ft away from the touchdown zone, and it's 500 ft we shouldn't be using anyway. I'm cool with this new interpretation. Now, if only the FAA will say "Oh, now THAT makes sense....."
 
Re: CRJ operators, what is YOUR definition of "touchdown zon

kellwolf said:
As for how do they know, FOQA plays a big part in it. Not sure if they download FMS data as well. If they do, then they can pretty much tell where you touched down on the runway.
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FOQA probably won't know the difference between 1500' and 2000'. You're traveling at 200 ft/sec, with a parameter acquisition rate of not more than 1 Hz for stuff like the glideslope and air/ground switches, and normally 1/4 Hz for Lat/Long, plus 300 ft uncertainty in the highest-quality position available (much more for non-GPS aircraft), plus ±2 ft uncertainty in the radio altimeter, etc.

I have yet to see a way of consistently knowing exactly where an aircraft touched down, based on the recorded data. Someday, but not for small tolerances, so far.
 
Re: CRJ operators, what is YOUR definition of "touchdown zon

Hopefully that is all cleared up now. I rode up front with a PCL crew this morning and they certainly had a few things to say about it.
 
Re: CRJ operators, what is YOUR definition of "touchdown zon

One of the ASAP guys said the best way they could figure it out is using the speed you were at at 50 ft AGL and then using data collected between there and the touchdown, they can ballpark where you touched down. Basically, it's not an exact science, and unless you wind up 1000 ft passed where you SHOULD have touched down, they really can't tell.
 
Re: CRJ operators, what is YOUR definition of "touchdown zon

kellwolf said:
As for how do they know, FOQA plays a big part in it. Not sure if they download FMS data as well. If they do, then they can pretty much tell where you touched down on the runway.
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I wouldnt worry about FOQA. only a small number of planes get their info downloaded. and even then its too much of a hassle to find out who the crew was. FOQA serves a great purpose, but its not to catch people who land more than 1500 feet down the runway.
 
Re: CRJ operators, what is YOUR definition of "touchdown zon

blee256 said:
I wouldnt worry about FOQA. only a small number of planes get their info downloaded. and even then its too much of a hassle to find out who the crew was. FOQA serves a great purpose, but its not to catch people who land more than 1500 feet down the runway.
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True. I think they might be concerned with the guys getting low and slow as a result of the revised FOM policy now. :)

Honestly, I'm not as worried about it anymore. If I get called in for a carpet dance, they'll have to tell me a) which reg I broke and b) how the 1000 ft behind me can be defined as "available" when the feds want us to cross the threshold at 50 ft. If they can change the laws of physics (BTW, Ken, thanks for the well written physics arguements on the other forum) then I'll take my slap on the wrist and go about my business. Otherwise, I don't think this will last very long. It might even go the way of the "every delay is gonna require a meeting with the ACP" deal......
 
Re: CRJ operators, what is YOUR definition of "touchdown zon

blee256 said:
I wouldnt worry about FOQA. only a small number of planes get their info downloaded. and even then its too much of a hassle to find out who the crew was. FOQA serves a great purpose, but its not to catch people who land more than 1500 feet down the runway.
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I promise I'm not just trying to be contrarian :) , but its not a hassle to identify and contact the crew. However, almost universially in all LOAs, the flight data is owned by the union, and only union gatekeepers are allowed to identify and contact crews about anything that was observed as abnormal.

Those crew contacts are usually made in the framework of fact-finding (what was the workload?, were there external factors?, etc., and is definitely non-punative ... its a union representative talking to a pilot). If a trend is observed and is warranted, that information then gets turned into a 10-7 page (for example).
 
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