mcdhu,
Only 3 runway changes in 20 minutes? You must know someone there! I was under the impression that they changed the runway direction every 5 minutes to spread the wear, the Swiss are very economical people.
To address your question - Most operators do NOT establish OEI missed approach procedures, they should
As
J_T says, the Australian operators did take this seriously, and I'm a product of that system.
A few points about PANS-OPS missed Approach procedures -
(1) They provide for a 2.5% Obstacle-Clear Gradient with 100 feet clearance of obstacles during the missed approach. This gradient may be higher if required, e.g. Hong Kong,
(2) A 2 engined aircraft at it's Approach Climb Limit is only required to achieve 2.1% climb gradient....... Oh dear!
There's no legislative requirement, as there is for Takeoff, for the Missed Approach with One Engine Inoperative.
There's several ways to address the problem.
First, limit your landing weight to one which will meet a 2.5% (or greater) climb gradient during missed approach (I believe that the JAA is addressing this, but am unsure if they have done so yet). In the Ops Manuals that I prepare, I throw the AFM Approach Climb data into the WPB, and re-issue "new" data for 2.5% with adjustments for those occasions when the required gradient may be higher. This should not be too difficult for the pilot to do, Approach Climb Flap is usually one of the approved Takeoff Flap settings, and data is available.
The biggest problem is the Acceleration Altitude, these are often-times very high (for ATC purposes), and you have no way of knowing if these are created for ATC or Obstacle Clearance purposes. If you want to go all the way to Missed Approach Altitude, you'll probably "bust" the 5 or 10 minute Takeoff Thrust limit. If TRULY caught out, I couldn't give a damn, these limits are created for engine life expectancy, thousands of hours down the track, and I'm far more interested in
MY life expectancy.
The best of all proposals carries a SEVERE caveat. The
SUGGESTION about to be made
ONLY applies only to aircraft with very accurate LNAV systems, preferrably GPS/IRS. Most DEFINATELY the suggestion applies to aircraft with a DIRECT means of flying Track, NOT Heading. Here it is -
Fly the OEISID for the runway, simple, but ensure accurate Tracking of the highest order. The Takeoff splays for the OEISID on Takeoff commence at the Departure end of the Runway, the missed approach begins before the Approach end of the runway. The tolerance for straying off the RWY centre-line until passing the Departure end of the Runway (DER) is
ZERO!!!! Any straying outside Runway direction puts you immediately into the mine-field of No Man's Land! One big plus, is that you are commencing the procedure already several hundred feet above the runway, as opposed to from the runway.
A good example of reverting to the OEISID for a missed approach is Hong Kong RWYs 25L and 25R. Both missed approaches make a Right turn, and take the aircraft over the most horrendouus course of obstacles, whilst the OEISID (intended for Takeoff) makes a Left turn after a suitable distance to a Southerly heading over water. You could maintain this Southerly Track all the way to the Philippines in complete comfort. In this same case, any straying off RWY centre-line (to the Left) would almost guarantee terrain impact.
Pugilistic Animus,
Expect that looooong overdue E-mail. You've certainly given me a lot more to talk about than before!
"The way you guys do this stuff; I don't believe is written down in any publication".
The mode de emploi is not written anywhere, the requirements
ARE and at least CASA Australia do provide good guidance material. There's 100 ways to "skin a cat", so long as we all end up with suitably skinned cats is the bottom line (where did that stupid expression come from?)
John_T,
Thanks for the link to the light reading. Being an insomnia sufferer, that contribution is a welcome addition to my E-Library. Thanks John!
I do agree with Mr. C's observations WRT average line pilot's ability to achieve "better than Net" climb performance, and agree with his concerns about lateral tracking capability. (It must have been Ansett pilots that IC was watching, TAA pilots would never do that
)Hmmm, the latter did apply in an earlier era, but in the modern day with good
Track flying data capability, extended RWY centre-lines on the Map display etc., it can one day be shelved with other tomes relating to weird raw data 'happenings'. This is particularly so in our training where the trainees are hammered, "Don't just correct the swing and initial tracking error, get back on the bleedin' track!".
I'll be sorry when this thread fizzles out, I'm having fun!
I deleted Ian's surname just in case he might not want to be identified .. it probably would be crass of me to ring him to enquire .. JT