05 July 2013

Is anyone at home at Air New Zealand Link and the CAA?

What is going on at Air New Zealand Link and the CAA??? On the 29th of June the Northern Advocate headlined that "Heavy Planes Can't Land in the Wet" at Whangarei (http://www.northernadvocate.co.nz/news/heavy-planes-cant-land-in-wet/1926336/) resulting in maximum passenger loads being decreased from 19 to 12! Obviously Whangarei people would be concerned.
On the 1st of July someone posted on my blog that from the 12th of August Q300s will be introduced to Whangarei. Checking out the Air NZ reservation system it shows that from that date Whangarei will get two Q300 and 2 Beech 1900 flights to Auckland each day as well as the direct Beech 1900 to Wellington.
But it seems no one has told the Northern Advocate...
Yesterday Whangarei Tourism Development Group chairman and Whangarei District Council member Jeroen Jongejans was reported as saying he wanted issues stopping fully laden planes landing at Whangarei Airport in wet weather resolved urgently to prevent irreparable damage being done to the district's reputation (see http://www.northernadvocate.co.nz/news/urgent-call-to-sort-out-plane-debacle/1932540/). And today MP Phil Heatley is reported as asking Transport Minister Gerry Brownlee what's changed at Whangarei Airport that has led to new flight restrictions resulting in passengers kicked off planes if it's raining. (see http://www.northernadvocate.co.nz/news/mp-attacks-flight-safety-rules/1934050/)
I must admit I don't really understand what is going on... The newspaper reports states "CAA's instruction says Eagle Air's Beech 1900 aircraft have to approach the airport runway at a height of 50 feet, up from the 35-feet restriction that had been used at the airport for years." Maybe some in the know can explain what that means.
It don't understand the logic of this either - "Beech aircraft now have to land further down the runway so when it's wet, or there's no headwind, the planes need a lighter landing weight to make sure they can stop in time."

"CAA says the action has been taken as an interim measure while an updated risk assessment is undertaken at Whangarei Airport, and says it's not a safety issue." The Beeches have been operating in their for over 10 years - why is there suddenly the problem? And if it is a problem, why did Air NZ Link not change their schedules from 1 June?
However, I am just an arm chair observer! I'm sure there are great minds being engaged on this. But surely, a simple bit of PR wouldn't have hurt! 
Surely, however, this couldn't have just jumped overnight???



  1. Gidday,

    I'm not involved with this, so I don't know first hand, but here's my reading on a couple of points...

    The 35"/ 50" thing is probably the "threshold crossing height"... if so, then the aircraft has to cross the runway threshold 15" higher on approach, meaning it lands much further down the runway. It seems that the B1900D might need a bit of runway...

    Why this should change after many years of safe operations? I don't know, but given what little we know, it seems that they could have done a reassessment and THEN decided if there had to be a change. On the other hand, maybe there was an incident that we are not aware of?

  2. I have only flown into and out of WRE at nighttime. Am I correct in saying the airport is sorrounded on 3sides by water?? If so, does this make a runway extension impossible?

  3. Supposedly there was a gentleman's agreement between CAA and Eagle saying that they could cross the threshold at 35ft rather than the standard 50ft like everyone else, and the other aerodromes

    Compounding the issue is that the 1900's landing data doesn't allow for the application of reverse thrust on the rollout causing the landing distance calculated to be longer and more restrictive than the actual performance is actually is.

    From 3rd hand information.

  4. An internal source at the airline has long vented his frustrations to me regarding Whangarei Airport and the B1900 operations. Particularly when it's wet. Even with the old threshold height it was still a challenge. The airport has always been operationally marginal and lackluster in terms of any forward expansion.

  5. A set height over a set point, and the aircraft doing a set speed (Vref/Vapp) at this same point is used for performance calculations from the manufacturer.
    i.e producing a graph of landing distance required vs weight of the aircraft at this time.
    50ft is the standard height, and from what I can research, 35ft can be used for a steep approach where there are obstacles on the approach path requiring this. -This must be approved and the aircraft capable.
    As has been pointed out, a 50ft screen height will increase the landing/stopping distance compared to 35ft, and also so will a wet runway.
    The background to 50ft it would appear comes from this gem below I found:

    (a) according to a tale which I heard about 15 years ago during a training course .. the source was one of the instructors .. and a quite elderly chap at that time ... This chap was a long ago FAA engineer, who was around as a young chap in those ancient times. According to his tale, an early military demonstration of, as I recall, a Curtis machine, involved flying in and out of an Army parade ground. The particular parade ground was surrounded by a line of trees whose height was in the order of 50ft. The early CAB folk adopted that as being as good as any figure, on the basis that the need was to have some provision for notional obstacles to be addressed during the takeoff and landing. This then became the standard for light aircraft.