Gear down on the glideslope

[Mungo Man]

Is it normal for aircraft which are vectored onto the ILS at say LHR a long way out, say 12d+, to leave their gear up while they descend on the glide until they are closer to landing. The approach plates ask us to delay drag and therefore thrust & noise as long as possible but normally I'd put the gear down 1 dot below the glide which obviously isn't an option on a continuous descent. Any comments anyone?

[jollypilot]

Not too sure about LHR, only been in once or twice, but at most major airports vectors may mean you will not intercept the glide until closer in than 12d, CDA or not.

But for a quick easy answer to your question, in the 320 family you often take the gear a lot later than 12d, and fly down the glide with the gear up pretty much every time. I aim to have it down and locked by 2000aal, unless there is a need earlier, ie to help me slow down.

If you look in Rumours and News there is a thread called 'Slowing down on Final Approach'

This is more specifically about 160kts to 4d, however plenty of people have posted detailing how they go about slowing down and configuring at different points - this may be a useful read for you.

JP

[Rainboe]

The approach plates ask us to delay drag and therefore thrust & noise as long as possible but normally I'd put the gear down 1 dot below the glide

Yes do that if you are doing an instrument approach and flying level to the GS as in the sim, but in real life you have Richmond/Windsor down there with Mick Jagger trying to get his beauty sleep at 0615am, so try and not make noise! On a nice day, have you tried dropping the gear and taking more flap at 1500'R? On the 737 it drops you nicely in the slot at 1000'R - my standard procedure. If you are not visual, do it a bit higher, but on the 737, you really don't ever need to do it higher than 2000'R. Noise is the thing now, especially at the London airports. And don't forget those CDAs, they are important. Regard it as a failure if you fly level with power on. So keep it slightly hot and use your energy management- keep an eye on wind component, drop gear early to get speed back if you have to if too hot, all aiming to get you established correct speed and config by about 1000'R when you will start taking power- and DON'T FLY LEVEL (at all!). Drag it over Richmond/Windsor in landing config with power on at 06.15 and you've just demonstrated you're a tool. You've woken the Queen damn you! Go work in a bank instead.

[Dream Land]

Gear down at G/S?

Depends on the airport, ATL or ORD, no, LAX, yes when we have to hold high speed to the marker, non=standard Config 3, gear up works fine on the slope for 160 KTS. in a conga line.

[411A]

'Tis interesting to watch a few First Officers, while I'm flying the aeroplane.
I personally (normally) never extend the landing gear until the final approach fix, and of course, landing flaps follow in short order.
So, on speed and landing flaps extended by say...800 AAL.

Whereas, a few First Officers will extend the landing gear when one dot below the glidepath, with landing flaps soon after, and.....up go the throttles, to keep the speed up, which of course wakes up nearly everyone within five miles.

It must be the way these junior folks are taught in the sim today, as long ago it sure as heck wasn't the same.

[skianyn vannin]

Most big airports want you to fly 160kts to 4DME. On the 146 I fly we normally fly flap 18 (first stage of flap for those unfamiliar with the type) and gear up. At flight idle this give roughly 160kts whilst descending on the glide. Since our SOP's state we must have gear down and flap 24 at 4DME we normally take the gear at about 5 miles then flap 24.

[Intruder]

Most big airports want you to fly 160kts to 4DME.

That may be the case where you fly, but I seldom see that restriction or request in the US or Asia...

Our SOP (747) has us normally putting down the gear before intercepting G/S, and landing flaps at intercept. However, if I can fly required airspeeds after an early G/S intercept with reasonable power (i.e., not at idle) at Flaps 20 or less, I will hold the gear until 2000 or 1500', depending on weather. Any later, and it is difficult to be on a stable approach at 1000' (IMC requirement).

[alexban]

Standard procedure- gear and full flaps before established on G/S. There is also delayed flap procedure which allow for 160 to 4NM. In this case selecting gear down somewhere between 1500-2000 RA and continuing with flap will do the trick.
We use the delayed procedure most of the time,even if not required to maintain 160 to 4.

[411A]

Standard procedure- gear and full flaps before established on G/S.

Very wasteful, in my opinion...and more noise.

We use the delayed procedure most of the time,even if not required to maintain 160 to 4.

Certainly an improvement

Looking a little deeper, it would seem to me that the 'standard' procedure is designed around the new 200 hour First Officer, to have things nice and stable quite a bit further out.

It would also seem to me that it would be far better to teach these same junior F/O's to be just a tad more flexible with ops, thereby creating less noise and save the small amount of fuel.

When I started in heavy jets long ago, this was done (especially in my particular case, as I started as a Commander), and it also would seem to me to be no more of a cost burden for the airline to actually apply a little common sense in the process, and instruct these new jet pilots properly.

Sadly, I suspect it won't happen.

[flt_lt_w_mitty]

especially in my particular case, as I started as a Commander

- hey - that's amazing - I thought EVERYONE had to do time as a cojo? Were you just very good and experienced, or what?

[411A]

....I thought EVERYONE had to do time as a cojo? Were you just very good and experienced, or what?

Experienced, and had plenty of time in large piston and turbo-propellor aircraft, the 4-engine variety, but a fair amount in twins, too.

And, at the right place at the right time....a long time ago, early seventies.
Also, the first jet training was at PanAmerican, the absolute best I have ever received.
First rate, without exception, on the B707.

[Bedlamair]

In my experience, it is the norm on the jets to keep the gear up until about 1500 to 2000 feet. Places like FFM will ask you to keep 170 to the marker (about 1400 feet if memory serves) that's a bit of a trial in a light 747-400 let alone a smaller jet. The limitation is the stabilised approach criteria of any given operator - even 170 at 1400ft allows stability by 500ft though. I don't know about the Airbusses, but Boeings and MD's are quite capable of slowing down sufficiently to allow 160 to 4 miles and the gear to be lowered at around 1500ft (on some turbo-props you can keep 200kts to the marker and be gear down stable at 1000ft, now that was flying!).

[Denti]

Our SOP is to have the gear extendet by latest 2000ft AAL on a precision approach, on non precision approaches the standard is to be fully configured at start of the descend, however if weather and traffic permits we might configure the same as on an ILS, that is deemed non-standard though. All for the classic 737.

If you manage your energy right you can still manage a nice and easy spool up around 600 to 800 AAL, however that depends on vectoring to the final. Gates are 1000ft established in IMC, 500ft in VMC while 1000ft is still encouraged.

Of course our SOPs are designed so that a 200 hour FO can manage them, however at the moment we dont have any FO below 2000h on type.

[Mungo Man]

Well thanks for all the replies. I've had the chance to experiment a little and have had some satisfying approaches where I've used very low thrust to maintain 180 on the glide then slowed down to 160 by taking more flap without the gear, and then maintained 160, gear up to about 5d. Then its gear down, a short stable period then the start the usual slow down to Vap at 4d.

It's actually a nice feeling using min thrust until about 3.2d but still being stable well within limts. I find briefing it before TOD prevents any confusion and it all works out well.

Why don't line trainers teach alternative approach configurations? Must be penny pinching gone mad.

Interesting how a few of you refer more to radalt whereas when I fly I seem to be more aware of distance to go.

[BelArgUSA]

Gear down -

My personal ideas when to go gear down (747-200) -
xxx
At the final approach fix, or
Approaching 1000 feet AGL, or
Approaching 3 or 4 DME from threshold.
xxx
Generally inbound at 160/170 KIAS with only 10 flaps for noise and fuel economy -
Calling 20 flaps at same time when I call gear down - Vref +20 -
Calling 25 flaps when 3 greens for gear down is announced - Vref +10 -
Calling 30 flaps if short/wet runway no later than 500 feet AGL -
xxx
This keeps the neighbors happy (people move there knowing planes are silent) -
And OPEC has me on their "hit list" as I save 500 kg of their black gold -
And I like to impress F/Os with my superior airmanship -
(My revenge until they stop keeping their feet on my O2 mask hose)...
xxx

Happy contrails

[aviatorpepe]

A good rule of thumb is to extend the gear at the final approach fix, which on an ILS is glide slope intercept at glide slope intercept altitude (about 1500 AGL). This is typically about 5 DME from the runway. In some cases however, and depending on the airport demands, you may have to do it sooner or even later. Just remember, you must be stable by 1,000 feet or lower if allowed by your company’s SOP’s.

P

[tom775257]

At Heathrow and other 160 till 4 airports, in the 319/320 at 4 DME I manage speed (ie select Vapp) so as the engines come back to idle we can drop the gear to allow the speed to reduce to Vapp and engines spooled by 1000' (if visual we can be stable at 500'). About as fuel efficient as I can make it, and follows SOP's.

I know it is frowned upon by some to have flap and speed brake but certainly if I need to reduce speed on the glide I need to slow down some how - either speedbrakes or gear to be slow enough for flaps 2 - more draggy. Certainly speed brakes works, and keeps noise down.

Otherwise generally I drop the gear between 5 and 4 miles depending on any tail wind or weight of the a/c. Seems to work for me.

[Clown Act]

411a,

Did they have sliced bread back in your time or was it just really new?

[DooblerChina]

ILS approach, gr down Fl 20 at about 1800AAL usually fully configured by 1000'

There are of course one or two problems with the 160 to 4 rule. A ferry flight in the 757 can give a vref of 112, this means we need to lose 43 knots in the space of 700' assuming we must be stable by 500' or go-around. This needs a little thinking about, of course the easiest is to inform ATC, but thats not always practical.....

Also a question to Mungo Man, were you not trained to fly low drag approaches? I joined as a 200hr guy and was told from day one to fly at fl5 to 2000 then slow down. Its really interesting to see how different companies do it. If I dropped gear above 2000AAL (without good reason i.e. non-precision approach) I would probably get a strange look across from the left hand seat. Having never flown for another company I just assumed that we all operate them the same.

Doobler