I have always tended to slow my aircraft and extend flaps prematurely, mainly through anxiety at approaching with too high a speed.

 

I understand that the flap extension schedule is dependent on approach speeds and aircraft weight. So my knowledge gap is in knowing WHEN to slow, and to what speed.

 

Do you have any simple rules of thumb that I should follow?

Sorry mate I'm being a little lazy, have a read of this

 

http://www.flight.org/blog/2010/11/01/b777-managing-the-mass/

In smaller aircraft I go with 200-210 kts for LOC interception and 180-190 kts for G/S capture with the flaps extended as per the schedule.

 

The high momentum of the B777 makes me a bit anxious, too, so I try to stick to the lower end of those "brackets".

In smaller aircraft I go with 200-210 kts for LOC interception and 180-190 kts for G/S capture with the flaps extended as per the schedule.

 

The high momentum of the B777 makes me a bit anxious, too, so I try to stick to the lower end of those "brackets".

 

Some additional food for thought:

 

VNAV is programmed to give you a descent path that will put you at the FAF (final approach fix) at 170kts. Offpath descent can help with this also.

 

In a more regulated ATC environment, I believe speeds of 220kts downwind, 180kts base, and 160kts on final are typical, at least at Gatwick.

 

I have always tended to slow my aircraft and extend flaps prematurely, mainly through anxiety at approaching with too high a speed.

 

I understand that the flap extension schedule is dependent on approach speeds and aircraft weight. So my knowledge gap is in knowing WHEN to slow, and to what speed.

 

Do you have any simple rules of thumb that I should follow?

 

Hopefully the above will help. Just to make sure, are you happy with how to use the flap speed bugs on the PDF?

Hi Jordan,

Thanks for your reply. Yes, I am happy using the flap speed bugs. My problem is knowing at what point of the approach to use which speeds.

Searching on pprune, I have so far determined that:

1. I should reduce from 180 kts towards 160 kts by 8d
2. Be at 160 kts by 4d

Any additional propositions much appreciated.

Cheers, R

Yeah that's not a bad rule of thumb. Certainly in the UK it's common to be at 180kts at LOC capture, before being instructed by ATC to maintain 160kts to 4DME.

 

Don't be afraid to slow down earlier than this if there's no ATC. Vref for the 77L is quite slow for a heavy (can easily be less than 140kts). The result is that you'll be at 4DME at 160kts, ~1,200ft AGL, giving you 200ft to lose 20kts+ to achieve stable approach criteria. Not always easy.

Hello,

 

you should have a look in the FCTM Manual.

It will depend on which type of approach you are performing.

For an ILS approach, you should plan to be at Flaps 5 and Flaps 5 Speed when on course to intercept the localizer, then arm the localizer. When the LLZ is captured, arm APP. When G/S is alive, gear down, Flaps 15, bug speed to F15 speed, arm speed brakes. When intercepting glideslope, final flaps setting (normally F30) and final approach speed (Vref + 5kt for an automatic landing, or Vref + Wind correction if manual landing)

 

Stephane

Yep, all in the first link I provided

 

 

you should have a look in the FCTM Manual.

 

The Flight Crew Training Manual Manual? 

Hi Richard,

 

Here is what we use in my airline on the 777:

 

 

Configuration is done on distance to threshold, and assumes a normal ILS glideslope angle. Provided the FMC is programmed for the approach, use the PROGRESS page to see the distance to go.

 

14-18 NM: Flap 1

By 10 NM: Flap 5

By 8 NM: Gear Down, Flap 20

By 6 NM: Flap 30

 

Aim to be back at the Flap Up manoeuvre speed (~230 Knots) by the time you want to start configuring. Normally you will have Flap 1 or 5 out by the time you are on an intercept heading to the localiser, this helps managing the momentum to prevent and overshoot of the localiser.

 

By 1,500 FT AGL you want to be stabilised at VREF + 5, and fully configured for landing.

 

The advantage of configuring on distance rather than on altitude off the altimeter is that it simplifies the process without having to worry about aerodrome elevation.

Kyle, does not version have it? It is a manual on how to read the manual

 

 

Ok, jokes aside.

 

As a rule of thumb for the generic ILS approach, I use speeds that work for most jetliners - bug up speed before "base", depending on approach structure. Expect to have 180 and appropriate flaps when loc capture. As loc is captured and FAF approaches, slow down to 160 and flaps at 10-15 or so. Help yourself with spoilers if needed, but you should be 160 by the time GP comes alive - slowing down when going down is hard.

 

I keep 160 and gear up until closing in to 4th mile. Not much reason usually to bother the residents with increased noise from the gear and higher spool all the way down the glide, especially if capture point is particularly high.

 

As I approach the 4 mile point, I get the gear out and next flaps point, usually in the 737 this makes it 15, in 777 I would probably have 20, and at 4 mile point I would set Vapp and extend flaps as I am firther slowing down.

The manuals tell me a great deal about flap settings but little about speeds, hence my original post.

 

Having read the relevant parts of the FCTM again (5.13) plus your comments, my conclusions for a fully automatic landing  are:

1. 250 kts at 10,000' at 30d
2. Flaps 1 on approaching arrival procedure
3. Set flaps 5 and flaps 5 manoever speed when localiser becomes alive
4. 160 kts by d8 and appropriate flaps set
5. Gear down and flaps 15 or 20 when glide slope becomes alive and reduce to flaps 15 or 20 speed
6. Set landing flaps on glide slope capture and reduce to V_ref speed

Your further comments?

Cheers, R

 

PS Peter wrote his item while I was researching mine!

The process you wrote would work well.

 

I am using what some airports mandate for better noiseprotection, which is 160kts to 4 miles DME and gear up if possible. You can try for yourself - or use what you have. Both should work fine.

 

 

The manuals tell me a great deal about flap settings but little about speeds, hence my original post.

I thought there were example profiles in the manuals? It shows you exactly what (recommended) speed and config to be in with where you are relative to the field.

The manuals tell me a great deal about flap settings but little about speeds, hence my original post.

 

Having read the relevant parts of the FCTM again (5.13) plus your comments, my conclusions for a fully automatic landing are:

 

• 250 kts at 10,000' at 30d
• Flaps 1 on approaching arrival procedure
• Set flaps 5 and flaps 5 manoever speed when localiser becomes alive
• 160 kts by d8 and appropriate flaps set
• Gear down and flaps 15 or 20 when glide slope becomes alive and reduce to flaps 15 or 20 speed
• Set landing flaps on glide slope capture and reduce to V_ref speed

Your further comments?

Cheers, R

 

PS Peter wrote his item while I was researching mine!

250kts 10000ft at 30nm to touch down you will be slightly high on profile.

 

The aircraft descends on the 3 deg path very happily with nearly idle thrust with flap 5/15 depends on weight. So the general Rule of thumb is that you need 1 nm of distance to lose 10kts of speed in level flight. It works perfectly on most of the modern heavy jet ie 777/A330 .

 

Hence to lose 250kts to 180kts the difference is 70kts which means you need to slow down 7nm from the G/S intercept point. Or using the old 3x nm = altitude rule of thumb you need about 2100ft.

 

Therefore at 30nm if you are on a straight in approach at 180kts you should be at ~9000ft. So since as I said before if you are at 250kts you need 7nm or 2100ft to slow down. At 30nm 250kts in order to be able to slow down you will need to be flying at 2100ft below 9000ft which is ~7000ft without the need of using the speed brake. Because the rate of descend reduces as you wind the speed down to 180kts the airplane would eventually converge towards the 3 deg profile.

 

Now let say ATC descend you early so that you need to capture the G/S at 3000ft 10nm from the runway ( by typical ILS approach around the world ) . Since we need 7nm to slow down from 250kts to 180kts, you will need to slow down about 17nm (10nm final + 7nm quired to slow down) from the runway so that you will be able to capture the glide path at 180kts.

 

For some reasons 180kts seems to work on both the airbus and the 777., just use flap as required so that the flap maneuvering speed is below 180kts.

 

Once on the glide path. At 8nm, select gear down flap 20, wind the speed to 160kts, after gear down locked, select flap 30. Till around 5nm, then Select speed Vref plus 5.

 

Those 150-160kts till 4 nm are ATC restrictions. The Vref + 5kts approach speed on the 777 can easily reach 150kts at heavy landing weight. So it can easily meet those requirements. If not and you are not confident to be able to slow down in time for a stable short final. Just slow down early and tell ATC unable due operation.

 

Since the distance to run is measured from the airport, so is the Altitude. If the airport is not located at sea level like Mexico City, you will need to add the airport elev to the calculated altitude.

 

If the elev is 6000ft. 10nm from the airport you will be to be at 9000ft (3000ft + 6000ft airport elev) because the airplane altimeter measures altitude from sea level unless QFE is used.

 

PS it doesn't matter whether you are coming in on a straight in approach or not. It still requires the same track miles to run for the airplane to slow down. You can fly Any different type of arrival,doing visual circuits or non precision appr etc. the same method will work.

 

If in doubt try to use the above method to cross check the VNAV descend profile. You should get a similar figure at low altitude. Some times VNAV is more aggressive.

 

Happy flying