17
$\begingroup$

Other than extra braking and reverse thrust, is there a specific short-field landing technique for large jet airliners?

In discussions about the famous landings at St Maarten, it is sometimes said that part of the reason for the low passes is due to the relatively short runway, so the 747s try to land right on the numbers, rather than the usual technique of touching down within the first third of the runway.

Such a procedure is fine in a Cessna, but in a large passenger jet? I have my doubts.

$\endgroup$
11
  • $\begingroup$ Other than the weight restrictions - there are no short field requirements for large jetliners. $\endgroup$ Mar 14, 2016 at 7:36
  • $\begingroup$ Do airliners allowed to operate from London city airport count? The steep approaches may be a specific landing technique. $\endgroup$
    – Manu H
    Mar 14, 2016 at 10:53
  • $\begingroup$ @ManuH, steep approach are certainly a specific landing technique, but the reason for those is either noise abatement (in case of London City) or obstacle clearance (in case of some airports in mountainous regions), not short field. $\endgroup$
    – Jan Hudec
    Mar 14, 2016 at 10:58
  • 1
    $\begingroup$ Related $\endgroup$
    – Pondlife
    Mar 14, 2016 at 18:16
  • 4
    $\begingroup$ You can always put a plane down in a small area. Note that containing the fragments and blast effects can prove challenging... $\endgroup$ Jul 17, 2017 at 12:46

4 Answers 4

17
$\begingroup$

Other than extra braking and reverse thrust, is there a specific short-field landing technique for large jet airliners?

Never heard of any. The required landing distance is calculated so that the plane can reliably stop (even if reversers fail) and landing at shorter runway is not allowed.

so the 747s try to land right on the numbers, rather than the usual technique of touching down within the first third of the runway.

The usual technique is to aim for 1,000 ft down the runway and touch down with some flare somewhere around 1,500.

In discussions about the famous landings at St Maarten, it is sometimes said that part of the reason for the low passes is due to the relatively short runway, so the 747s try to land right on the numbers

Actually the TNCM runway 10 has PAPI and TDZ marking a little beyond the usual 1,000 ft mark at around 1,250 ft. Ourairports says the threshold is displaced 162 ft (but it also says runway 9, so it is likely out of date), but according to the satellite images it is a bit over 300 ft plus some runway end safety area, placing the threshold around 500 ft past the fence and the touch-down zone around 1,750 ft past the fence.

Now the normal glide-slope is around 5%. That means the aircraft is supposed to cross the fence at around 90 ft, on average. That seems about right. Of course you can't expect every aircraft to be positioned precisely within a few feet, so now and then some crosses it at maybe 50 ft. That is not intention, but simply a deviation. But of course the photos of planes flying especially low are more likely to be picked for publishing.

Also, a short field landing normally calls for steep approach which make precise aim for landing spot easier. That would actually place the aircraft higher over the beach. But the glide-slope at TNCM is normal 3° (5%) one, so it is not a steep approach.

Such a procedure is fine in a Cessna, but in a large passenger jet? I have my doubts.

In large jet it isn't. Air transport has stricter regulations than general aviation because more is at stake and larger aircraft have stricter limits because the higher energies involved mean errors are harder to fix and have more serious consequences.

$\endgroup$
6
$\begingroup$

I'm not aware of any short field landing techniques for large commercial airliners. But some of the do offer some modifications, that offer improved short field performance. Most of these modifications are aimed at operating the airliners at the Santos Dumont airport, which has a short runway. According to Boeing,

The short-field design package is an option on the 737-600, -700 and -800 and is standard equipment for the new 737-900ER. The enhancements increase payload capability for landing up to 8,000 pounds on the 737-800 and 737-900ER and up to 4,000 pounds on the 737-600 and 737-700.

This is mainly done using a few modifications, which can be factory ordered or retrofitted and include the following changes:

Flight spoilers are capable of 60 degree deflection on touchdown by addition of increased stroke actuators.

Slats are sealed for take-off to flap position 15 (compared to the current 10) to allow the wing to generate more lift at lower rotation angles.

Autoslat function available from flap 1 to 25.

Flap load relief function active from flap 10 or greater.

Two-position tailskid that extends an extra 127mm (5ins) for landing protection. This allows greater angles of attack to be safely flown thereby reducing Vref and hence landing distance.

among others. Around 250 of these modified aircraft are in operations till date. Not to be outdone, Airbus offers similar options in its A320neo.

$\endgroup$
1
  • 1
    $\begingroup$ Note: I'm not sure if this is what you've asked (which @Jan Hudec has answered already), but I've added it just for info. $\endgroup$
    – aeroalias
    Mar 14, 2016 at 16:44
2
$\begingroup$

The short field technique in any jet is to perfectly hit the touchdown zone marker which is 1,000 feet down the runway. They’re 150ft long. Landing on the numbers in a transport category jet would fail any checkride.

$\endgroup$
0
$\begingroup$

I would argue there is nothing in the books specifically called ‘short landing technique’ as any landing in a jet is already designed to be as short as possible. Then it becomes a ‘normal landing technique’.

Sure, if you have many 1000’s meters to spare, you might occasionally go for a greaser and land longer than usual. Generally speaking though, the shorter your flare, the safer it is; more runway left to slow down, maybe reducing the need for reversers or easing up on the brakes so as not to heat them as much.

In that sense, a normal-SOP-landing on a transport jet is already a short-landing-technique.

$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .