POLL: Max Touchdown Rate Allowed

[Dave Blake]

SunAir Express prides itself with having experienced pilots that should be able to land an aircraft with a touchdown rate under -500 ft/min.

There has been a number of flights recorded to the POC lately with some very hard touchdown rates that in real-live would have require major repair and maintenance to aircraft systems and possibly personal injury.

The SAX officers have been considering setting up the POC to not accept flight logs with landing rates over a set touchdown rate like -700 ft/min.

This poll is to see if the SAX pilots think if it would be fair if the POC would not accept flight logs with an excessive touchdown rate.

Your comments are welcomed.

[Rich]

Fellow Pilots,

As I don't have the time to fly as much as I would like to, the approach and landing TDR's can sometimes be a bit confusing. Allowing for my limited flight time experience, I'm still having a difficult time adjusting the aircraft to a safe and minimal touchdown rate (TDR), which I sometimes disagree with. I can fly a smooth and easy '"touchdown" on the runway, yet my approach descent might be higher than expected.
Any assistance here would be welcome, but I agree that in the "real world", we would be in deep guano with some of our TDR's.

All the best and let's remember all those who gave their all so we could be free! Remember what Memorial Day is all about!!

Captain Rich G.
Tampa

[airifr]

To Rich,
I would agree with Dave (but no offense Rich ), that is a very good idea to limit the TDR for flight logging, and not to -700 but -550/-600, -700 wouldnt make sense. If SAX wants to keep its standards high, which will distinguish from other VAs, putting the limit just under the already high -500, ie -550, would be more than enough.But this is just me, I dont know what you guys think?

And the good TDR is down to passing the threshold at the right height (around 50ft agl) and the right speed (for the aircraft weight, meteo, etc) , if you pass the threshold at the right height and the right speed then you re good for a nice flare provided you re on the standard 3deg slope.
So if you say, that your approach descent might be higher than expected that means you re obviously not on a 3deg slope but on a maybe 5-6deg slope, in that case, you will pass the threshold at a higher height meaning your TDR would be greatly increased if you were to touchdown at the same spot than the 3deg slope, or the flare would take much longer, leading to maybe overshooting the touchdown zone.

Remember, you set your TDR in your pitch, so set your pitch early in the approach and stay it( throttle is for speed not for pitch), you pitch with the yoke.
Then when flaps and gear, pitch has to change, thats why landing config (landing flaps and gear down) early, approach and time permitting, is always a good practice at the beginning, then as experience come you could delay the landing config til "the last minute".

You could try that:
Offline, you set FS weather to Fair Weather, choose an airport with any ILS, take off, climb to 3000', fly away from the airport about 20miles, then set the autopilot to capture the LOC and GLIDESLOPE, then come back to the airport to land, with the autopilot flying the ILS , and watch during the approach, the way it interacts with pitch, speed, how stabilized it is, what is your altitude at OM, MM, IM, compared to your distance to runway, etc.When landed, go to replay, and replay it, so you can observe again and again, until you re good with it.

When done , do the same flight again, except that this time , YOU will fly manual and try to copy what the autopilot showed you.

So that, when flying online with SAX with real crosswind weather, etc, you ll have a base.

I hope this helps,

[sax767]

Hi Dave!
I see this issue with mixed emotions.

First, I applaud the incorporation of the TDR statistic on the POC. However, you can get carried away if you take that too far.

I think a lot of people join VAs to have some sort of organization to their "hobby". Some of the younger folks probably achieve significant training
associated with any real-world pilot instruction. More power to them. I, for one, have been in VAs for thirteen years but it is still a hobby, not a job. I
try to fly responsibly but, if I make an occasional bad landing or bad approach then so be it - it's a hobby, not a job. If you make a particularly good landing
then great - you get a gold star on the POC. Those folks who want to treat this activity as top priority can reward themselves with strings of gold stars and
I applaud them and their dedication.

I cringe at the thought of someone, after flying a perfectly fine five hour flight, not being allowed to log the time because of an unfortunate hard landing.
Disallowing filing of flights ending with a hard landing is the first step in making SAX a job and not a hobby.

For those who aspire to the hightest professional standards, the TDR is there for them to improve upon. Go to it and God Speed! However, don't close
the door to many who climb into their respective cockpits to get away from today's problems and dream a dream. Remember, it''s a hobby, not a job!

Bud
SAX767

[Marty_Becker]

From Jan 2006:

viewtopic.php?f=32&t=255

My thoughts:

A proper touchdown starts with a stabilized approach, which consists of proper speed for the current aircraft configuration. For every airspeed and aircraft configuration, there is a power setting that will produce that airspeed. Going back to the basics of learning to fly on instruments in a small Cessna or Piper, flying constant speeds and power settings is the first thing one learns. For a Cessna 172, a power setting of 2100 rpms produces a trimmed speed of 90 knots. Reduce the power by 100 rpms, one gets a -100 fpm descent at 90 knots; Increase the power by 100 rpms, one gets a +100 climb rate at 90 knots, etc. No trim adjustment is needed as the aircraft will find the stabilized position. Flying an ILS in a 172, typical localizer intercept is done at trimmed 90 knots. When intercepting the glidepath, the power is reduced to 1600 rpms to produce a -500 fpm descent rate at 90 knots. No trim adjustment is needed. The aircraft will stabilize in a nice -500 fpm descent at 90 knots which is perfect for a 3 degree glidepath. MINOR adjustments are made with pitch and power to remain stabilized.

Scaling that up to an airliner, the principal is the same. For example, landing the PMDG B737, an N1 power setting of in the mid 50% with gear down and 30 degrees of flaps will produce a speed around 120 knots and a descent rate around -650 fpm on a 3 degree glidepath. This will vary depending on aircraft weight. A lighter aircraft will have an approach speed in the one-teens, a heavier aircraft will have an approach speed in the mid one-twenties, maybe approach one-thirty. Determining the proper approach speed for the aircraft weight is a MUST. The N1 power setting will vary slightly with these variances in approach speeds, but somewhere in the mid 50% is something to shoot for. At about +50 feet, the power is brought back to idle, and the nose is raised, decreasing the descent rate from around -650 fpm to some alot less at touchdown.

Hope this helps.

[Pylet]

I completely aggree with everything that Marty said, only addition I do is that after smoothly pulling power to idle I slowly pull the nose up until I get my "Sight Picture" which is having the end of the runway approximately 2 inches above the instrument panel. Once I have that picture I keep slowly pulling back on the yoke to maintain that 2 inch spacing. By doing it the same way every single time keeps my TDR fairly constant in the 120-180 fpm range. I have a couple of smoother ones and I have had a few hard ones. The hard ones mostly came from an unexpected gust of wind or a small windshear on short final with little time to recover. I also hardly ever use full flaps. Most of my landings are with 30 degrees of flaps. I only go to full 40 when the weather/visibility is close to minimums. By going to a full 40 it allows me to lower the nose more with a slower airspeed thereby giving me a better chance of seeing the runway environment to complete my approach to a landing. Since a lot of pilots here fly many different airframes, they have to realize that the "Sight Picture" in one will look different in another. I only fly the B737-700.

My thoughts of a corrective action would be to rather than delete the flight data forever, but to reduce the Pilot's ranking or restrict them from flying that airframe after 3 hard landings in a row. If a pilot is constantly doing carrier landings, maybe the aircraft is too big for them. I hate to say it but by removing the data from the POC report seems like a way for the "Bean Counters" to keep the data looking better than it is rather than fixing the problem. I'm not sure if our outstanding programming folks could maybe make it happen but that is the route I propose.

[airifr]

Hi Dave!
I see this issue with mixed emotions.

..... However, you can get carried away if you take that too far......

I think a lot of people join VAs to have some sort of organization to their "hobby"......
.......unfortunate hard landing.
Disallowing filing of flights ending with a hard landing is the first step in making SAX a job and not a hobby.

..............
Bud
SAX767

There is no issue here, it is simple concern being raised by the company, like the concern for pilots who might want to X4 the sim to build hours quicker, they re told to look for another virtual airline, it is the way the company see it, like a policy.There is so many virtual airlines, and none is working or having the same policies.Some dont mind the sim X time, some rather not having it, like some dont mind the TDR(?), some see it as a value of their pilots, etc.So nothing is being taken too far or carried away, it is just SAX call.

If some pilots want to make their virtual airline a hobby, it is down to them but they still need to adhere to the VA POM, NOTAMS, IFR Rules, RVSMs, Aircraft Operation Procedures, etc, etc, etc, etc, .....otherwise what is the point joigning a VA? People join a virtual airline for fun?And why take the entrance exam, the checkride flight especially when it is said that a TDR greater than 500fpm would mean a FAIL. We all see that SAX made it clear right from the beginnning

People need to remember or realise that a VA is to reflect REAL operation as much as possible, depending of the VA, and REAL include good TDRs.
And there is no unfortunate landing, that doesnt exist, nor a fortunate landing (in normal conditions of course, Im not talking in an emergency or something like this where it is obviously a complete other story, and not going to debate over it), no matter after a traffic pattern or after a 20 hours or 100hours flight, this is no luck, this is skill, a landing is the pilot skills, not a good luck charm, that is why there is decision point before landing (minimums!), to decide if landing is possible safely, ie when a pilot say "land" after the decision point, he doesnt say it hoping that luck will be on his side, he says it because all conditions are met to land safely (right approach path, speed, stabilized, etc, ..) even if he 's really exhausted after a 11h flight.

Beside, I dont think SAX would like to be seen as a hobby VA, otherwise this TDR poll wouldnt be, and I wouldnt be writing this.


And for Marty, small corrections:
stabilized 3deg slope approach, means a 5% slope approach, so just time your GS NOT your IAS by 5, ie for the cessna 172 GS=90kt on a 3deg slope >>90x5=450fpm and not 500 fpm, and the 737 GS=120kt >>120x5=600fpm and not 650fpm.
So for instance,if on final you have a headwind of say 12kt gusting 20kt, and VREF=120kt, your approach speed would be VREF+1/2WIND+FULL GUST, in that case 120+6+20>>146kt but that would be the IAS not the GS, the GS would be 146-12=134 then the VS should be 134x5=670fpm and NOT 146x5=730fpm.

A good rule is to get your IASx5 value and always take some fpm off that value as we always land in the wind, ie if you have an approach VS(from IAS) of 650, use say 630-620, if you have headwind, if you have tailwind, you d use 670-680, but as we normally land into wind, it would normally always be lower than the IASx5 value, after how much to deduct is down to appreciation, depending on the IAS and wind speed, and as everybody say it s all down to experience, no matter if hobby, real or simulation.

And also, we do not iddle at +50ft on an airliner, not even on a light aircraft.
At +50ft(15m), we just pass the runway threshold(when following ILS or VASI lights), I am sure you do not iddle when passing the threshold, you side watch as you pass the threshold to evaluate your slope to flare the aircraft.
When you pass the threshold(around +50ft), you start reducing your rate of descend NOT the power, and certainly NOT iddle, or you will land way under VREF(VREF as everybody know is the touchdown speed,havent you wondered why V2=VREF or VREF=V2?) ,ie if your fpm was 640 before thresh bring it down to say 450 by gently pulling the yoke, that s the start of the flare, then should iddle at+10ft(3m), 3m, thats a lot.Stand on your feet and imagine 3m(10ft), and compare that to the size of an airliner, and then imagine 15m(50ft), thats 5 times the 3m you visualised, and now visualise an airliner especially a 747 iddling at 15m above the ground, then take the same 747 iddling at 3m, you tell me.

We dont land airliners like a cessna 172: A cessna 172, we can "stall land" it, an airliner we dont, we land airliners at VREF!(sometimes it is not possible to VREF when high winds)
And to land an airliner at VREF, we must have the right approach speed to begin with, lets say VREF=120kt and approach speed is 127, between the thres crossing and touchdown we must loose the extra 7kt, thats where the flare and the pilot skills come into the picture.
An easy example:
VREF =122
App SPD =132
FPM =640
After passing the thres you gently pull the yoke to bring the FPM down to let say around 450, during this you loose let say about 4kt, your SPD is now 128, you continue the flare to loose another 100 fpm bringing it down to 350fpm, you then loose about another 2kt, your SPD is now 126, so if you hold it like this until 10ft, you re good for a VREF touchdown, at 10ft you iddle and do the final flare: the combination iddle+gentle flare would make the remaining extra 6kt to disappear and reduce even further the FPM of another 50-100fpm bringing the TDR to about 300-250 with VREF=120.

So the rule is to always be at +10ft with SPD=VREF+5 about.

I hope it helps

[David Vega]

It's nice to see all this forum activity. I agree with SAX767, this should not feel like work, it's a hobby. But I have to ask, why does it feel like work? Could it be that, like in the game of golf where one basically plays against oneself, but one continues playing to get better? From our Operations Manual:

What attracted most simulator pilots to SunAir Express were the popularity of ATP, the desire to learn more about IFR flight and airline operations. Realism in design and function thus has a priority with SunAir Express pilots. The community interaction between fellow flight enthusiasts also plays a major roll in SunAir Express. And of course, high on our list of priorities is having fun while flying our flight simulators.

Realism in design and function. What we simulate with SunAir Express is conducting airline operations. For the sim pilots it means the simulation of flying for an commercial airline. A real world airline would deal with any of its pilots that shows a problem with how the pilot operates for the airline, and this is what we are doing with our sim pilots. A real world airline hires its pilots after they're convinced they have a certain level of competency, demonstrated at least by the number of hours logged. We don't do that because there's no school or certification for simpilots available. As you know we have candidates complete a flight, which is evaluated, and recently a written test for them to demonstrate basic airmanship knowledge.

So it takes more than just starting the sim on the takeoff runway, gunning the engines, and dive for the landing to complete a flight. No one here can claim to know all there's to know about flying in an airline environment, but we all agreed when we join by adhering to the airline philosophy to continually improve our skills, and that's the challenge. There are many virtual airlines (http://www.avsim.com/dcd/Virtual_Airlines/) which I'm sure have different ways of operating. Some emphasize realism more than SAX, to the point that one doesn't fly until one of their certified dispatchers releases you, others insists that all flights must be part of an assigned rotation, and there are some that want you to simulate whatever you desire, to include fly anywhere you want, in whatever airplane you want.

I will keep striving to get better, that's my hobby, that's what keeps me entertained. Let's use this forum and email to continue learning from each other. For those of you flying FSX, I volunteer to be your copilot on a shared cockpit flight. We both get credit for the flight, and we both learn from each other, plus it's lots of fun.

Dave Vega
SAX702

[airifr]

...... For those of you flying FSX, I volunteer to be your copilot on a shared cockpit flight. We both get credit for the flight, and we both learn from each other, plus it's lots of fun.

Dave Vega
SAX702

Yeah David, I fly FSX , and that would be a real good idea!!..pushing the realism even more
Lets try it!

[Jim Tilley]

I'm all for under -700 ...jt

[orac]

Before I read any of the followup posts I was in favor of the initial proposal disallowing flights to be logged if TDR was greater than 700 fpm. I read some good comments that have led me to change my mind.

Maybe some of us treat it more like a hobby, but we're here because generally we're good at it. Sometimes mistakes happen or weather interferes with a good landing. (And who knows how many bad flights go unseen because the pilot himself chose not to submit a bad flight report?) If the mistakes are random and few, I say no harm no foul. If there's a trend of a particular pilot frequently landing badly, the airline should endeavor to correct that behavior with enhanced training, but not enact punishment for what could be an honest circumstance.

How would the real airlines do it? The pilot gets called into the chief pilot's office to explain the situation. The chief pilot would decide what to do about it. SAX could handle it the same way. Each time a pilot logs a flight over 700 fpm TDR, his hub chief should contact him and ask him to explain. If a pilot does it too many times, restrict him from the left seat until he passes another check ride. If he still has continuing problems, keep that pilot off that type of aircraft. If he can't pass muster on any of the SAX aircraft, well, then it's time for him to move on.

So, I say no, don't disallow the flight hours, but yes, followup with the pilot and if necessary, suggest a corrective action plan that will get his TDRs more in line with the airline's goal.
___
Neil