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17th Oct 2012, 22:20   #1 (permalink)

Join Date: Jul 2007
Location: DIXER 5000 ft or above
Posts: 367
RVR for Landing

Hi everyone,

I recently had a little bit of a discussion with a fellow aviator about the application of JAR OPS 1.405 in a CAT I operation.

In particular I refer to the following part:

Quote:
 The touch-down zone RVR is always controlling. If reported and relevant, the mid point and stop end RVR are also controlling. The minimum RVR value for the mid-point is 125 m or the RVR required for the touch-down zone if less, and 75 m for the stop-end. For aeroplanes equipped with a roll-out guidance or control system, the minimum RVR value for the mid-point is 75 m. Note. “Relevant”, in this context, means that part of the runway used during the high speed phase of the landing down to a speed of approximately 60 knots.
Scenario 1. The RWY is 9000 ft. Assuming that I fly a plane with a relevant landing distance of 3500 ft, and multiple RVR values of 550/125/75, am I legal to continue beyond OM?

Opinion 1. No, in this case, since also the mid point is relevant and controlling, must match at least 550 m. The third part is not relevant in this case but must be at least 75 m, which we have.

Opinion 2. Yes, only the touchdown RVR is controlling, as long as the mp and rollout points are at least 125 and 75 you are good to land.

The matter is about "If reported and relevant, the mid point and stop end RVR are also controlling".

Scenario 2. The RWY is 9000 ft. Assuming that I fly a plane with a relevant landing distance of 2500 ft, and multiple RVR values of 550/100/75, am I legal to continue beyond OM?

Opinion 1. No, you need 550 in the first part, and you have it, but you also need 125 m in the second part, even though that is not relevant.

Opinion 2. Yes, the relevant part for you is only the touchdown RVR, you can ignore the 125/75 minima in this case.

Last edited by dirk85; 17th Oct 2012 at 22:22.

 17th Oct 2012, 23:36 #2 (permalink) Join Date: Aug 1998 Location: Ex-pat Aussie in the UK Posts: 2,704 My thought: you should read your post again - you have failed to include the weather for any of your scenarios, so there isn't sufficient information to comment. As a general observation, though - your 550m is to be able to see the runway touchdown zone, in order to land on it. Your 125m is to be able to steer the aircraft down the runway at high speed without going off the side. Your 75m is to be able to taxi off on the correct exit. Knowing that, you should be able to answer your own question - once you have asked it correctly.
 17th Oct 2012, 23:48 #3 (permalink) Join Date: Jul 2007 Location: DIXER 5000 ft or above Posts: 367 Sorry I was not clear enough. In both the scenarios all the approach and rwy lights are working and aerodrome minima is a standard CAT I (550 m). During the approach the RVR is reported 550/125/75 in scenario 1, and 550/100/75 in scenario 2.
 19th Oct 2012, 13:50 #4 (permalink) Join Date: Jul 2007 Location: DIXER 5000 ft or above Posts: 367 No help?
 19th Oct 2012, 14:45 #5 (permalink) Join Date: Oct 2007 Location: Greece Posts: 98 Scenario 1: Yes Scenario 2: Yes Midpoint RVR is also controlling in scenario 1, but 125 is good to go. Last edited by aristoclis; 19th Oct 2012 at 14:47.
19th Oct 2012, 15:15   #6 (permalink)

Join Date: Dec 2007
Posts: 554
Quote:
 am I legal to continue beyond OM?
in case you're referring to OM as an approach ban point then RVR values given after you passed it are irrelevant.

 19th Oct 2012, 15:16 #7 (permalink) Join Date: Jul 2007 Location: DIXER 5000 ft or above Posts: 367 I know, but let's assume I get those RVR reports before OM...
19th Oct 2012, 17:37   #8 (permalink)

Join Date: Apr 2009
Posts: 214
Dirk, you are good to go in both situations.

Explanation, Situation 1:

You are ok for Touchdown Zone.

Midpoint is 125 so you are ok, read the reg more carefully:
The minimum RVR value for the mid-point is 125 m ok stop, you've got that.
or the RVR required for the touch-down zone if less, No, the RVR required for the touchdown zone is not less than 125m, so 125 it is.

Quote:
 No, in this case, since also the mid point is relevant and controlling, must match at least 550 m.
Why must it match 550? It doesn't say that in the extract of the regulation.

Situation 2: Mid point isn't relevant, you answered that yourself.

 21st Oct 2012, 08:26 #9 (permalink) Join Date: Apr 2003 Location: Sutton Posts: 309 Scenario one - As above you are OK (see Airman post). Scenario two - Depends on the LDR / LDA.Exagerate to appreciate if you were landing on a 4,000 Metre runway (Casablanca say) in a business jet you would be at taxy speed by the mid point...so it is not relevant. In a heavy 737 going into a 1,700M runway then mid point IS relevant and would have to be (minimum) of 125 M.
 21st Oct 2012, 10:09 #10 (permalink) Join Date: Dec 2003 Location: England Posts: 61 For a heavy Category D aircraft landing on say, a 7500 long RW, would the midpoint RVR requirement (I am assuming it IS relevant and controlling in this example) be 150m since the min RVRs for T/O for a Cat D ac are 150/150/150 as opposed to 125/125/125 for Cat C?
 21st Oct 2012, 11:50 #11 (permalink) Join Date: Jul 2007 Location: DIXER 5000 ft or above Posts: 367 Thanks everyone! Your opinions confirm my idea. Stanley Eevil: the regulation doesn't make any differentiation between different categories, so 125m should be enough also in cat D planes. Happy landings!

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