Landing below RVR limits
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Landing below RVR limits
Just heard the pilot of an executive jet announce that he required an RVR of 1100m. The controller was somewhat surprised so got the pilot to confirm it was 1100m.
Despite the RVR never going above 550m the aircraft landed. Is there different rules for a private flight?
Despite the RVR never going above 550m the aircraft landed. Is there different rules for a private flight?
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This is a quote from CAP 413 which deals with the UK. In simple terms there is nothing stopping the pilot carrying out the approach, but expect to find yourself down at the CAA office explaining yourself.
Another reason could be that this was the RVR they needed for a CAT 1 approach (although very high if the case), so maybe they carried out a CAT 2 approach instead which had a lower RVR requirment.
7.3.8 In the UK, there is an approach ban which states that a pilot may not continue an instrument approach beyond the outer marker or equivalent position, if the reported RVR, or at aerodromes where RVR measurements are not taken or available, the visibility, is below the minimum specified for that approach. Essentially, this means that a pilot may not descend below 1,000 feet above the aerodrome when these conditions exist. This RVR/visibility is known as an 'absolute minimum'.
7.3.9 Should a pilot indicate that he or she intends to commence an instrument approach when the reported RVR/visibility is less than the notified 'absolute minimum' value, the controller should inform the pilot using the following RTF phraseology:
BIGJET 347, you are advised that the
current RVR/visibility is (number)
metres which is below the absolute
minimum for a (name) approach to
runway (number). What are your
intentions?
7.3.10 If the pilot states that he still intends to continue the approach below 1000 ft above aerodrome level, the controller shall inform the pilot.
BIGJET 347, if you continue the
approach and descend below 1000
feet above aerodrome level, it is
believed that you will be
contravening UK legislation and I
shall be required to report the facts.
Acknowledge
7.3.11 This shall be followed at the appropriate times by the following transmissions
BIGJET 347, there is no known
traffic to affect you making a (name)
approach to runway 30
BIGJET 347, there is no known
traffic to affect you landing, surface
wind 280 degrees 16 knots
Another reason could be that this was the RVR they needed for a CAT 1 approach (although very high if the case), so maybe they carried out a CAT 2 approach instead which had a lower RVR requirment.
7.3.8 In the UK, there is an approach ban which states that a pilot may not continue an instrument approach beyond the outer marker or equivalent position, if the reported RVR, or at aerodromes where RVR measurements are not taken or available, the visibility, is below the minimum specified for that approach. Essentially, this means that a pilot may not descend below 1,000 feet above the aerodrome when these conditions exist. This RVR/visibility is known as an 'absolute minimum'.
7.3.9 Should a pilot indicate that he or she intends to commence an instrument approach when the reported RVR/visibility is less than the notified 'absolute minimum' value, the controller should inform the pilot using the following RTF phraseology:
BIGJET 347, you are advised that the
current RVR/visibility is (number)
metres which is below the absolute
minimum for a (name) approach to
runway (number). What are your
intentions?
7.3.10 If the pilot states that he still intends to continue the approach below 1000 ft above aerodrome level, the controller shall inform the pilot.
BIGJET 347, if you continue the
approach and descend below 1000
feet above aerodrome level, it is
believed that you will be
contravening UK legislation and I
shall be required to report the facts.
Acknowledge
7.3.11 This shall be followed at the appropriate times by the following transmissions
BIGJET 347, there is no known
traffic to affect you making a (name)
approach to runway 30
BIGJET 347, there is no known
traffic to affect you landing, surface
wind 280 degrees 16 knots
Avoid imitations
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I wonder if this was a diverting aircraft asking about the METAR, possibly with some mis-communication involved.
Some operators require for planning purposes a diversion airfield to be available with an actual RVR of twice the RVR limit for the nominated approach.
1100 metres is twice 550 metres, the latter being a common minimum RVR for a Cat 1 ILS.
Once the aircraft is airborne (and diverting), the normal 550 metres RVR for the diversion airfield's approach would apply.
Some operators require for planning purposes a diversion airfield to be available with an actual RVR of twice the RVR limit for the nominated approach.
1100 metres is twice 550 metres, the latter being a common minimum RVR for a Cat 1 ILS.
Once the aircraft is airborne (and diverting), the normal 550 metres RVR for the diversion airfield's approach would apply.
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This happened at Luton yesterday. The airport was on low visibility procedures with CAT 3 holding points in use. The RVR’s were up and down with the top end at 550m and the bottom end at 300m. The controller asked him what his intentions were. He stated he wanted to make an approach and commented that he hoped that the easyjet in front of him would blow the fog away. Well it didn’t and he just landed anyway.
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CAP413 is just a radiotelephony manual with example phraseology, not a rulebook. The definitive documents are the ANO and AIP. This is an excerpt from the AIP dealing with aerodrome operating minima. This is a very complex subject which is often misunderstood.
Simplistically, there are no limits on when an approach may be commenced, but if the RVR is below the specified minima then descent may not be made below 1000 feet aal. If, after passing 1000 feet aal the RVR drops below the minima the approach may be continued to the decision height (or minimum descent height for non-precision approaches). The landing may be completed if the required visual reference is obtained at the DH and is maintained.
Simplistically, there are no limits on when an approach may be commenced, but if the RVR is below the specified minima then descent may not be made below 1000 feet aal. If, after passing 1000 feet aal the RVR drops below the minima the approach may be continued to the decision height (or minimum descent height for non-precision approaches). The landing may be completed if the required visual reference is obtained at the DH and is maintained.
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Blowing The Fog Away
This quote brought back memories of some years ago when an Air UK F-27 was diverting to Luton from Stansted but the RVR dropped on 08. An Aer Turas DC-8 was about to depart so he asked he could be on final approach after the DC-8 departed just in case it might move some fog. Sure enough the RVR went up and he landed safely!
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RVR drops below CAT I slightly above DH
Can anyone tell me what should be done when...?
Slightly above DH during CAT I, assume for example at 250ft, controller informs us that RVR drop to 400m. of course at DH is can easily see approach lights.
Should I perform GO AROUND or can I land.....?
Slightly above DH during CAT I, assume for example at 250ft, controller informs us that RVR drop to 400m. of course at DH is can easily see approach lights.
Should I perform GO AROUND or can I land.....?
de minimus non curat lex
And it is easier to see the "visual references" at night. So you have a greater chance than during daylight hours in very marginal conditions.
It is an interesting simulator exercise reducing the touchdown RVR by say 25m at a time starting at 550m. CAT 1.
Commence the approach from 3nm with full approach lighting down to DA.
A competent crew can safely land above 400m.
Below 400m is not really viable using CAT1 DA limits.
As to why 1100m was specified as RVR minima when inbound?
Perhaps the ac had failed equipment, and this is what was required for a non precision approach? Speculation on my part.
It is an interesting simulator exercise reducing the touchdown RVR by say 25m at a time starting at 550m. CAT 1.
Commence the approach from 3nm with full approach lighting down to DA.
A competent crew can safely land above 400m.
Below 400m is not really viable using CAT1 DA limits.
As to why 1100m was specified as RVR minima when inbound?
Perhaps the ac had failed equipment, and this is what was required for a non precision approach? Speculation on my part.
Although the minima for Cat 1 is usually taken to be 550m, some aircraft with specific equipment are cleared to operate to 'lower than Cat 1' minima, usually 300m, without the need for the airport to have the extra lighting required for Cat 2/3 approaches
I must stress this is individual aircraft, not for all aircraft flying for the same operator.
I must stress this is individual aircraft, not for all aircraft flying for the same operator.
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*Had a quick refresh on subject: Mainly about AGL/ILS capability as far as I can see
Last edited by good egg; 4th Jul 2017 at 16:44. Reason: More info
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Depends when you are told. If you are told the RVR has dropped below the minimum RVR required before the outer marker / 1000AGL you are required to discontinue the approach as per the approach ban. However once past this point you are allowed to continue to DA and take a looky and land or G/A depending if you get the required visual references or not.
Dunno if EASA or CAA has different rules AFTER visual reference is acquired...
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Good Egg - It's not the aerodrome that needs to be approved for LTS Ops. The aerodrome states the facilities available and it is the aircraft operators who get the approval.
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ALSO, the hardest part of a low-visibility landing may well be the rollout. If you can't see the runway centerline all the way, AND see the turnoff lines to find your taxiway, you may get yourself in more trouble...
