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NGjockey
3rd Jun 2010, 13:24
I was searching the archive on this topic, but I had to give up since there are more than 13000 threads in the Tech Log section alone!

What is the correct landing technique for medium/heavy jets regarding the speeds flown?

Aside from situations requiring speed increments (reported wind shear, thunderstorms, gusty winds and the likes) the correct speeds and technique should be Vref passing the threshold, then gradually reducing thrust to idle while maintaining pitch until pulling the nose up 1 - 2 degrees for the flare, resulting in a touchdown a few knots BELOW Vref (ideal touchdown speed according to a safety targeted awareness report from the ERA air safety work group should be Vref minus 7 knots).

There seems to be a common misconception spread among many pilots that they will "crash and burn" as soon as speed drops below Vref during flare. In fact, from those many "check speed" calls I have heard in my career when the needle slowly went below Vref after passing the threshold I assume that quite a large number of pilots have been and are still being taught a wrong landing technique.

Or was it ME who was taught the wrong way?

I appreciate your views on this really not so innocuous matter!

LeadSled
3rd Jun 2010, 14:39
NGJockey,

What you are describing is OK, with the requirement flare and reduce the thrust to idle, of course the IAS will start to reduce.

Of far greater importance, regardless of the speed over the fence (within Ops. Manual/Performance limits) is putting the aircraft on the ground with the runway still ahead of you.

It seems more than likely that the most recent 737NG loss in India was another long and/or hot landing, from credible eye witness reports ---- in an aeroplane with relatively high Vref and little brakes, to start with.

Tootle pip!!

misd-agin
3rd Jun 2010, 15:12
At what point in the flare are you below Vref? 10', 15'? High flare with minimal sink rate? I'm mentioning it. 2'? Who cares.

bigduke6
4th Jun 2010, 07:20
As far as I know.....

All Boeings use an approach speed of Vref +5 minimum, to be up to Vref+20 depending on wind and gust. This is held until the 50 feet, then it can be bled off, but under really gusty conditions, you will probably touch down above Vref.

On a non-windy day, plan to touch down at Vref. Landing at Vref-7 like you mention sounds like an invitation for a tailstrike.

But different manufacturers may be calculating approach speeds differently. Years back, flying Dassault/Falcon Jet, used to fly the approach at Vref (plus wind/gust if needed), and touched down at Vref-5.

411A
4th Jun 2010, 07:32
Approach with the L1011, it's Vref+10, except...the -500 model, which is Vref+5 minimum.

ImbracableCrunk
4th Jun 2010, 09:43
I'm studying for recurrent right now, and black and white Boeing 737 FCTM says "With proper airspeed control and thrust management, touchdown occurs at no less than VREF - 5". Normal touchdown speed is VREF30 to VREF30 - 5.

I'm sure someone will say Boeing doesn't know what they're talking about. . . .

WrldWide
4th Jun 2010, 14:14
Not figuring gusts into the equation, on the MD11 we fly Vref+5 which is normal Vapp, until the beginning of the flare when the t/l are reduced to idle, beginning at 50ft or so. At touch down the speed could be anywhere from Vref to Vref less 10. The critical factor would be deck angle upon touchdown, regardless of ones speed, on any particular aircraft if a certain deck angle is exceeded on touchdown there is, as was mentioned in an above post, the threat of tailstrike. Folks flying heavies dont tend to hold it off indefinitely to obtain the greaser, at some point the nose is even lowered so as not to encroach on the tail strike deck angle.

Intruder
5th Jun 2010, 04:49
Airspeed is normally not in my scan at touchdown, or anytime after bringing the throttles back for the flare (744). Just prior to thrust reduction I gauge descent rate, airspeed, and position, and decide how quickly to reduce the thrust. After that, eyes are primarily outside for alignment, height assessment, and runway remaining.

Type1106
5th Jun 2010, 09:05
Intruder says it all - end of discussion?

latetonite
5th Jun 2010, 09:15
Besides a type rating, people nowadays are trying to get experience via the internet.

A37575
5th Jun 2010, 09:54
This is held until the 50 feet, then it can be bled off, but under really gusty conditions, you will probably touch down above Vref

The 737 FCTM states all the gust and half the steady headwind component with the proviso that the latter is bled off approaching touchdown. This means you have to deliberately start to bleed off the steady HW component well before 50 feet - more like 300 feet as you will only lose three knots in the flare. Many over-run accidents are caused by pilots electing not to bleed off the 1/2 HW and thus coming over the fence with excess speed and floating.

rubik101
5th Jun 2010, 16:08
Provided the approach is flown at the correct reference speed, (+5kts-0kts) down to around 30' agl, slowly closing the throttles on the 737, (bearing in mind that the Airbus throttles are simply a switch) at that point will result in a safe and not too firm arrival. The margin between Vref and the stall in the landing config is much greater than the speed loss incurred if this procedure is followed. Anyway, stalling the aircraft from 15' agl will simply mean that the landing is 'firm' but certainly not uncomfortable. Vref-7 looks like a recipe for a clusterphuck waiting to happen. Stick to the Boeing/Airbus procedures and the events you are concerned about will never arise.