Source
r/aviation•
Psi440

When to deploy landing gear?

Question

We live on the southern approach to IAD and so see landing planes overhead all the time. Sometimes their landing gear are down long before they get over our house, sometimes as they pass over, and sometimes not until they are well past. I know it has to do with speed, altitude, etc., and we've noticed that the size of the plane doesn't seem to matter.

My question is whether any of the variation is attributable to pilot preference. Do some pilots just like them down earlier? Or is it all approach parameter determined?

Posted Jul 13, 2022, 2:15 PM UTC

1536
dodgerblue1212•

Usually before landing. After landing is not ideal.

68
snailmale7•

If you keep the gear down , you never have to lower it …Cessna172

19
dos_torties•

Doing so aides in the prevention of the front falling off

2
Internal-Error-7191•

Is that typical?

2
Inside-Finish-2128•

Just like hitting a wave, chance in a million.

2
dcl415•

The sops at my airline says we have to be configured before the FAF, so I normally lower the gear between 1-2 miles before the FAF

15
Antique_Change2805B737•

Before faf? That can be quite early. I am not ging to fly 15nm with the gear down.

2
dcl415•

FAF (Final Approach Fix) normally 4-6 NM to the runway threshold. Are you confused with the IAF?

3
Antique_Change2805B737•

No. But i am from Easa Land and we have quite long final approaches. Standard is 3000ft with 9Nm but we do have some out of 5000ft with 15nm from faf/fap to the runway

3
dcl415•

Ok confusion between Canada and Europe, here the FAF is between 4 and 6 miles from the runway. Thanks for clearing it

2
dcl415•

FAF (Final Approach Fix) normally 4-6 NM to the runway threshold. Are you confused with the IAF?

1
bassthrive•

If we have to descend quickly due to a tight vector, being issued a late descent/clearance by atc or making a short approach, dropping the gear early is a great way to increase drag. Jets don’t like to “get down and slow down” at the same time. The speed brakes alone don’t create nearly as much drag as the landing gear. Not using the gear to “drop anchor” would likely lead to being high/fast on final and result in a go-around because we are not stable.

(Source: 10 year airline pilot)

8
ANITIX87•

I run into this issue all the time in my flight sim. In busy airspace where they want to maintain spacing, I'll get an instruction like "maintain minimum clean speed until established" or something and then I'm clean, with gear up, and have to start descending on the localizer, which leaves me totally unable to slow down. Sometimes I need the boards, the gear, and the flaps (with a nice overspeed alarm) all at the same time.

In the real world, would you ask ATC for a slower speed earlier, or is this a scenario you have to deal with?

1
bassthrive•

Most times you have to deal with it as it has to do with ATC spacing. 250 to the marker is entertaining in ORD.

5
Spin737•

No one here has said anything about ATC speed assignments. If they say 190knots til X and 170knots til Y, I’ll run my flaps and gear to follow those speeds.

737 - if the speed assignment requires >Flaps 10, I need Flaps 15 and THAT requires gear down.

Or I’ll just do gear at 1500’agl so I can get the landing checklist done by 1000’ agl.

3
Internal-Error-7191•

If it takes full power to taxi to the gate, its probably too late.

3
new_tankerKC-135•

All complex aircraft have a "never exceed" speed for when the landing gear is down/extended. I have seen aircraft more than ten miles from an airport with the landing gear extended (strangely enough, that has been An-124s in every instance). I can't explain why, though they are indeed within the speed range they'd be in with gear extended.

2
sea_kaplumbagasiCessna 185•

i deploy it after i land and taxi to gate (Cessna 172 pilot here)

2
WACS_On•

A pretty foolproof technique while you're flying an ILS is to lower the gear once the glideslope indication starts to move. Works every time, even on approaches without DME.

2
Devoplus19ATP CRJ2/7/9, EMB175•

Doesn’t work great when you don’t join the LOC at FAF altitude though, which is pretty much always.

2
WACS_On•

In that case you can just intercept the glideslope early, depending on the altitude/distance of step-down you have to work with. Not a ton of places bring you in above FAF height while also having hard altitudes at the FAF.

Assuming they bring you in high, you can still use the glideslope carrot to configure a little early since by being high you'll be higher on energy anyway.

1
Devoplus19ATP CRJ2/7/9, EMB175•

I suppose. I just figure the company says be configured and on speed by the FAF.

Quite a few places like to bring you on to the slope from above, but then it’s just easier to capture the VNAV path, and switch to the GS when it’s stable.

1
WACS_On•

Haha the plane I fly can't reliably couple to an ILS, and has no terminal RNAV capability, so I've been in hand-fly gang for the last 1500 some-odd hours. Half the time when we try a coupled approach it just cruises through the localizer course, and the other half it tries to nose towards the dirt when it touches the glide slope.

1
LonguesSurMer•

Usually before the Final Approach Fix on an instrument approach

2
Psi440OP•

Thanks for the answers. Got a little lost in the pilot-speak, but I generally get the idea. We live 10 miles due south of IAD 1R and will continue to enjoy watching you all land!

2
150Echo•

Easiest way to put it is "it depends" haha. As you've read, company policy and personal preference come in to play, as well as outside factors like air traffic control requests/restrictions. Every airline has a point where you have to have the gear down, flaps down, and on airspeed. It's up to the pilots to get themselves to that point within tolerances.

1
[deleted]•

[deleted]

1
Well_why_not1953•

I like to drop it as soon as on final so I can readjust airspeed if I need for a smooth unhurried landing. You get busy with flaps, gear, prop, mixture and adjusting approach speed so leave plenty of time to address these things. Gear gets forgotten sometimes if it becomes to automatic and makes a costly mistake if one gets rushed.

1
ross-geller•

They are great for reducing speed. So if the ATC keeps you fast during approach you can put them down and reduce speed instantly when needed i.e., to extend flaps and slow down to approach speed. That might be why you see them lowered down earlier.

If there’s no atc restriction and the wind is favorable, I usually put them down at about 2000ft above aerodrome elevation which is approximately 6-6.5 NM from runway.

Airbus 320 sop says extend flaps 2 at 2000ft agl at the latest and when they are extended, put the gears down.

1
BlaxeTe•

It depends. In my previous company 4nm was the standard point to throw the gear, but now I do it based on speed control. If flaps 15-20 can’t keep the speed, I have to throw the gear, probably around 8nm. Some people do it way earlier. FCOM suggests at „1 Dot below Glide“, which is around 10.5-11nm.

1
OzzypahlotB737•

Where I fly (B737) the norm is 2000' AGL for a flap 30 landing. Earlier if required for drag or the requirements of the approach or ATC. In general, in a jet, pulling the gear out earlier (as used to be SOP in a lot of places, prior to glideslope intercept at the top of the ILS, for example) is a horribly slow and inefficient way to fly.

1
Mystery_Member•

Combination of company SOPs, weather conditions, pilot preference, traffic, and ATC instructions. Later is more fuel efficient. FAA says 1000' AFE in IMC, you must be fully configured (gear down, flaps in landing configuration) and stabilized, 500' AFE in VMC, so always sometime before that.

1
Plane_Guy5•

Any where on downwind leg you do the GUMP(F)S checklist:

Gas Undercarriage(gear) Mixture Propeller (Flaps) Seatbelts/Switches

1
Kellykeli•

Somewhere between 42,000' AGL and 1,000' BGL is deal I believe

1