Airborne_Again wrote:
Why Vref+5 rather than Vref? (Unless you have to cater for gusty wind etc.) My understanding is that Vref is a safe approach speed and that all performance figures are based on it.
The autothrottle is probably only certified for up to +/- 5 knots. And if hand flying deviations of -5/+10 knots are allowed. Therefore the +5 margin so you never fall below Vref during the approach.
The extra speed will be bled off during the flare anyway, so touchdown will occur at Vref (or less).
SkyWagon wrote:
Speed is set to Vref + 5
Why Vref+5 rather than Vref? (Unless you have to cater for gusty wind etc.) My understanding is that Vref is a safe approach speed and that all performance figures are based on it.
I wonder if speed is a factor. Coming in at a high speed just to be “safe” ?
No, unless it is very windy the speed will be vref+a few knots, always the same. Differences may lie in the policies for use of reverse and autobrake depending on many factors. Some airlines require maximum braking when runway condition is X, for instance.
The 737-800 isn’t famous for it’s brakes. While a dash can stop very quickly.
@LeSving
Considering the still air,up to 10 KTs headwind, and tailwind : Speed is set to Vref + 5 , and you have to keep this until flare. Different companies have different criteria for stabilized approach, mostly +10 / -5 KTs to call out , but higher speed is NOT safe. It adds more and more energy to the airplane, thus your landing distance is seriously diminished. The smooth and nice landings(and trials of course ) are increasing my “pucker factor” when I am pilot monitoring.
I have wondered about this as well. I fly somewhat often with airlines, SAS and Norwegian mostly, and about 80-90% 737 and some CRJ, Dash etc. A few years ago this was really something you felt and heard. SAS landed smoothly and and stopped much earlier with minimal/smooth breaking. Norwegian landed with a big bang and used almost the entire runway with lots of noise and braking. Today it seems Norwegian has gotten it right as well. Smooth and nice, mostly at least.
I wonder if speed is a factor. Coming in at a high speed just to be “safe” ?
@Arne I have some hours on B737NG and want to ensure you that as a captain; I do favor positive landings, the book clearly states the importance. The prolonged flare brings some dangerous situations. If the pilot misjudges height above runway surface, a tail strike is a possible threat with not proper speed control . A smooth touchdown is NOT a criteria for safe landing. Every “meter” of the runway is so valuable. All calculations are made with consideration that you fly over threshold at 50 feet.
Regarding to 5P-*P*roper *P*lanning *P*revents *P*oor *P*erformance- rule, and since we are constant decision makers, if you think you would not make it within first 1/3 of the runway , on final, at flare, just push GA button in your airmanship part of your brain, and it is always better to try again.
Thanks for all the explanations. Good to see the positive landings are on purpose, and not just bad airmanship.
I can keep bragging to my passengers about my superior skills and super soft landings (home field is 2.2km, I can afford floating the PA28 for 300m).
I was told it is an SOP at Ryanair for training and flying, always touch down at same spot as the previous guy or as you did yesterday, so they make standard training out of it, if you can do it smoothly it is a bonus if not the pax seats pay the bill for the landing not the next guy waiting for your flare at the threshold !!
One reason for “positive” touchdowns is the lack of experience among a small group of pilots (200h FOs, but can’t blame them – GA in Europe is dead so where are they gonna gain experience?).
But the second reason is quite simple – these days airlines focus on eliminating long flares. At least my company does. Every flight is monitored and long flare is the most common violation by a large margin. A violation is a flare longer than 1000m. A perfect flare results in a touchdown somewhere around 300-450m from the threshold. It’s quite easy to have a greaser using 700-800m of the runway (with a 737). It takes a lot more to do it 300m from the threshold. Obviously everyone tries, except when the runway is flooded (possibility of hydroplaning) or we are limited by landing performance (short runway, high weight due to tankering, etc.).
Arne wrote:
For the last couple of years, on commercial flights I have noticed pilots tend to plant the planes into the runway upon landing, with not much in the way of a flare, just exercising the main oleos. It used to happen every once in a while, but nowadays I find it’s more the rule than the exception, even in perfectly good weather.
I’ve seen in a couple of interviews with CAT pilots (and a training captain) that a very soft landing is not good – touchdown needs to be firm, but not hard. If I remember correctly, around 200fpm
