While we are all busy going through the alphabet, with FMS, SOP and CRM...
Any other letters of the alphabet...? How about time to think landing performance.
We all know from initial training that our airplanes are supposed to be landed at Vref.
We know that we land at a Vref that is 1.3 x Vs... and the 20 knots additive.
And we studied that our planes landing performance is based on 60% of the runway bla bla bla...
xxx
Reading our friend IGh here above, he reminds us of the spooling of engines.
Good point.
In many types of airplanes I flew, we had two flaps settings.
The 727 could be landed with 30 or 40 flaps, the 707 did 40 or 50 flaps.
And my old 747 can land with 25 or 30 flaps.
xxx
Not much difference in stall speed between the two... some 5 knots.
The big difference is drag, not lift. The difference is power on the engine.
With extra drag, we keep our engines to higher power. Great for spool up.
Sure it burns fuel, sure it makes noise, but maybe is extra safety, no...?
xxx
I recall the UAL Salt Lake City 727-122 accident, mid-1960s...
Captain approached fast, then went to full idle to reduce speed.
Then when he realized he would not reach the runway he added power.
Too late. The engines did not have time to spool up. He was a former DC6 captain.
In a prop airplane, you want power now, you get it. Not in a jet.
xxx
Then there are the gentlemen here who are shy of "extras" over Vref...
Vref+20 is all Boeing says to add for wind components factor. Fine, no objections.
A little hypothetical landing performance exercise here...
Just for classroom and play with your brains.
xxx
Suppose you land a 747-200 on a long 11,000 feet runway (as usual).
Average passenger weight - say 230 tonnes - your Vref is 134 KIAS.
If landing in a stiff wind, your Vref could be 134+20 = 154 KIAS. Still ok.
So, you good CRM and SOP boys would no squeal a word.
Do you really know landing performance, let us see.
xxx
Suppose same conditions, but the wind is a "very stiff" 60 knots.
Why would I possibly carry Vref+30 then... too fast...?
No, gentlemen. I looked at my landing tables.
I see I could land a heavy 747 at 285 tonnes on this runway (I am only at 230 tonnes)
The Vref then would be 155 KIAS... and I would add 20 knots = 175 KIAS.
xxx
Bottom line is this. Nothing wrong about landing at say Vref+30 (or 40).
That would be Vref+30 = 134+30 = 164 KIAS (I could do as much as... 175)
I consider this... Hopefully dry runway, and still being stopped on 60% of the runway.
Maybe even 70%, as I am not that good, I tend to flare for smooth landing.
Go ahead with your objections - I am retiring and know what I say and do.
xxx
Maybe if the L-1011 (Delta 191) in Dallas would have done so, they might still be here.
And approve.
Extra speed is like extra money in the bank, within reason, and knowing performance.
Happy contrails