|
BAW and NY approach at it
Never flown a widebody. Is 180kt to 5nm incompatible with a stabilised approach? |
Impossible on A330 and B777
|
Flap 30 is usual for 22L at JFK. Flap limiting speed for flap 30 is 180. At best they’ll be doing gear down flap 25 but Boeing don’t recommend using F25 as an intermediate setting. So gear down Flap 20. From 5 slow down to 170 before selecting flap 30 and still be stable at 1000’ is going to be tight. Not helped by the DME at us airfields showing 1.2 ish miles at touchdown. |
Rumor has it he was last spotted somewhere east of Recife on a 130 heading, still not answering the question.
|
KJFK Runway 22L is 2560m long. That’s a pretty short runway for a 747-400. The crew will be planning flap 30, and autobrake 4, with partial/full reverse. Flap 30 has a placard speed of 180 knots, and likely to offer a final approach speed at typical landing weight of less than 140kts? Shall we say 5 miles is approximately 1,500 ft? Maybe less, as the associated DME overreads by more than a mile! BA has very strict Stablised Approach Criteria. (I accept others are less strict.) So that’s 500’ (or less!) to move comfortably away from flap limiting speed, before selecting flap 30, whilst achieving a 35 knot reduction in 500’ or less, in an aircraft with significant momentum. IMVHO, that’s a pretty tight corner to ask this crew to accept, and that’s before we consider the meteorology on the day. Perhaps we might reasonably ask, why that requirement was imposed on that one aircraft on that day. It certainly isn’t normal. Even in New York. If it were, there’d be an awful lot of aircraft going around! Purely subjectively, it looks to me like a pretty stupid request/instruction. |
Never flown a widebody. Is 180kt to 5nm incompatible with a stabilised approach? I can do 160/4 in the 777-200 and 170/5 in the 777-300 in benign conditions without too much drama at average weights but 180/5 would probably need a fair amount of speedbrake and early gear/flap deployment. Don’t know about the 747 but probably more difficult. Anyway, the whole idea of Stabilised Approaches is that you have freed up capacity to monitor for external/internal issues, such as deviations, windshear, other traffic and so on. Being rushed in on a high-workload, last-minute will-we-won’t-we approach is not a great idea. Smacks of “are we up here because you’re down there or are you down there because we’re up here...?” :rolleyes: |
180 to 6 is just doable in a 747, as is 170 to 5 and 160 to 4. Note this is distance to the threshold and not the actual DME reading which is often not co located and requires a headwind on approach and a three degree slope. A decent controller can achieve the same landing rate without the stress by slowing the aircraft earlier and achieving accurate final separation earlier. This controller is trying to mitigate her lack of accuracy and forward planning by asking the flight crew to perform an unwise higher than desirable energy final approach. She then punishes a crew that demonstrate airmanship and refuse an undesirable clearance. They also demonstrate airmanship by refusing the clearance instead of agreeing to it and then decelerating when they want to as many crews would have done. Im sure an ASR was filed and I doubt anything will be done. LD |
22L threshold is at 1.4 DME, so she’s asking for 180+ to 1200’ (3.6 nm from the threshold). How she thinks that’s in any way a sensible requirement is beyond me. |
Ridiculous, this kind of rubbish happens all too frequently. JFK approach need to wind it in.
|
Originally Posted by back to Boeing
(Post 10586196)
Flap 30 is usual for 22L at JFK. Flap limiting speed for flap 30 is 180. At best they’ll be doing gear down flap 25 but Boeing don’t recommend using F25 as an intermediate setting. So gear down Flap 20. From 5 slow down to 170 before selecting flap 30 and still be stable at 1000’ is going to be tight. Not helped by the DME at us airfields showing 1.2 ish miles at touchdown. But, someone who wants zero at the threshold could request the RNAV Y Runway 22L. |
JFK
Originally Posted by itsnotthatbloodyhard
(Post 10586363)
22L threshold is at 1.4 DME, so she’s asking for 180+ to 1200’ (3.6 nm from the threshold). How she thinks that’s in any way a sensible requirement is beyond me. ATC there are great, they really are, but like all of us, they learn on the job. If an operator regularly flys at 180 until 3 miles, an expectation has been set and they'll ask for that. Previous crews likely backed themselves into a corner or were unstablised and continued to 'make ATC happy'. In the US, use the word 'Unable'. there's no need to invoke 'FAA standards' like this crew did. Leave it at that one word and make it ATC's problem. Then either ask for their phone number; or use your company' channels to explain what your procedures and requirements are. ATC do want to work with everybody. |
My take - both the controller and the pilot on the radio were being needlessly snippy toward each other.
The low altitude airspace around JFK can be very congested at times (limited options for vectoring) and arrival flows tightly spaced to maintain expected arrival rates. It is a very challenging piece of airspace to work. The JFK final controller was trying to manage a flow of traffic based on the expectation that everyone could hold 180 KIAS to 5 DME. Maybe not the best plan in the world, but I'm guessing that they use that plan often enough, and crews (mostly) comply, so that was the plan for the moment. British Air said they were unable to maintain the requested airspeed. Fair enough. At that point, the controller needs to either slow everyone behind BA down, possibly causing a domino effect back to the previous controller, or pull BA out of the sequence and reinsert them with additional spacing. That decision had to be made in fairly short order, however, the radio calls to work this out could have been handled a bit more diplomatically by both sides. The proper place to have resolved this dilemma was on the previous frequency. The need to maintain a certain speed to a certain DME could have been inserted into the ATIS broadcast or passed on by the first approach controller at which time the proper spacing could have been worked out. By the time it wound up in the final controller's lap, the options to fix it were limited. |
correct me if I’m wrong but I always thought in the states if the controller gives you a speed to maintain on approach your allowed +/- 10 kts? He could had then done 170kts with no issue! |
Originally Posted by Tomaski
(Post 10586399)
British Air said they were unable to maintain the requested airspeed. Fair enough. At that point, the controller needs to either slow everyone behind BA down, possibly causing a domino effect back to the previous controller, or pull BA out of the sequence and reinsert them with additional spacing. That decision had to be made in fairly short order, however, the radio calls to work this out could have been handled a bit more diplomatically by both sides. |
Check Airman
Suggest you move this to ATC Issues then you may get a response from the World's best controllers - London!:) B48N ( long retired LHR controller ) |
I have always found controllers respond well to reasonable communication. The BA pilot was absolutely right to point out that he was unable to maintain the assigned speed. There is of course a margin but if you accept an impossible speed and then fly ten knots slower the controller will continue to assign impractical speeds. Where it went wrong was BA blocking the frequency with a long winded explanation and approach getting frustrated and responding by taking him out of the sequence. |
Originally Posted by lederhosen
(Post 10586491)
Where it went wrong was BA blocking the frequency with a long winded explanation and approach getting frustrated and responding by taking him out of the sequence. Director or Final frequencies are possibly the worst places (not that any other frequency is the right one) to start a conversation about Your aircraft energy capabilities, especially around very busy intercontinental airport. Anybody flying in radar controlled busy airport terminal areas knows that You will be very likely assigned speeds on final approach, so better be proactive and include during the briefing what speeds You are able to make at the estimated arrival GW with current weather forecast, and adjust the figure (i.e. 180 kt to 6 nm) once You are getting to finals and are aware of your tail/head wind component. In that scenario, probably "Unable, we can make 170 kt to 5 nm" (that is basically 180 kt to 6 nm) would have worked wonders. For sure JFK controllers are in some cases not easy to deal with, but You need to come up with a plan anyway. |
Originally Posted by A320baby
(Post 10586419)
correct me if I’m wrong but I always thought in the states if the controller gives you a speed to maintain on approach your allowed +/- 10 kts? He could had then done 170kts with no issue! |
Thanks for all the replies guys. Seems it’s hard in a 747. I can’t move the thread, Brian. |
By ACMS:
Ridiculous, this kind of rubbish happens all too frequently. JFK approach need to wind it in. My company is paying their company. So, i think, we as pilots, have more rights to complain about ATC. (I know this will upset some people....) Now, IF, JFK atc is paying my company for their service, they have a point (but they do not..) I flew many times to jfk, you just cannot even plan what they want, they do last minute changes even in low vis, changing runways etc. Tell me/us way in advance what you want and we will adapt (help you girls and guys) but don't leave for the last 3-4 minutes. I understand you girls and guys have to cope with a lot of traffic and nationalities, so why don't you all start with speaking a bit slower? I am used to your accent, many or not (esp. grnd freq.......is even more freq congestion!) We can all work together but it has to come from 2 sides, and IMHO we as pilots are more in our rights than ATC, especially after a 8-10 (or more!) LH flight. Off for the weekend, back next Thursday in......JFK T.P. |
| All times are GMT. The time now is 06:14. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.