Bombardier Q400 narrow runway supplement

[Parhy01]

Hi all, appreciate if someone could advise me on what exactly is a narrow runway supplement for Q400 aircraft type and how much would it cost (indicative pricing) to have one.


I understand B737 may already have it on delivery but bombardier have it as an chargeable option for operator?

[john_tullamarine]

Now, that's up my alley ..


Going back quite some years ago, ICAO decided that the old geometric basis for matching aeroplanes to minimum required runway width might be a tad suspect ... and wouldn't it be a really good idea to do some flight test work if one wanted to operate off narrower runways ?


Initially, only Australia had any interest in the subject and some 747 simulator investigative work was done by Chris F (the then CASA CTP) .. who is a PPRuNe poster, as well ... and, as I recall, Miles G-B (the then CASA performance engineer). What they found was that, under limiting conditions, a V1 failure was a good recipe for a waltz in the grass off to the side of the runway. Limiting conditions included V1 around Vmcg, aft CG, and wet runway condition.


Up until then, Australia had issued various concessions permitting operations from narrow (ie narrower than required by the ICAO standards) runways. The thought was that this might not be a good idea so a requirement was introduced whereby an operator could elect to demonstrate compatibility of the aeroplane with whatever runway width might be of interest prior to getting a concession.


I happened to be involved with the first batch of testing in Australia and interesting it was to see just how far an aircraft might deviate under limiting conditions (wet runway being simulated by disconnecting the NWS or similar).


Some aircraft don't have a problem, eg Citation, due to the split between min V1 and Vmcg. If I recall correctly, I think Cessna ended up adopting my intial FMS for the Citation and similar words probably now appear in Citation manuals.


Where an aircraft has a problem, it usually is "fixed" by limiting the min V1 for narrow runway operations to a higher speed so that a suitable margin above Vmcg is maintained .. the problem area is that last few knots coming back to Vmcg wherein an aeroplane transforms from pussycat to tiger.


The 733, as I recall, was done for the Australian operators shortly after and, no doubt, there will have been others since .. unfortunately, I've not kept up with the state of play in that requirement.


As to the Q400, it may well be an option .. I suggest it is a chargeable thing for ALL aircraft .. the OEMs are not in the business of giving things away gratis ...


Suggest you make the request to Bombardier, presuming you represent an operator. In any case, we have a few Bombardier folk in appropriate positions in the OEM organisation who are PPRuNe posters so you might end up with some more posts of relevance to the state of play with the Q400.

[George Tower]

I speak under correction but SA Express are operating the Q400 into Richards Bay from Johannesburg. The RWY is 1300m x 21m. So I think a narrow runway supplement already exists in respect of the Q400.

[Cough]

JT -- Quite agree with what you write. TOGA takeoff on the 320 added to 30m runway, added to short runway and an eng fail at V1(matched to Vmcg) was an interesting affair. Glad it was just the sim and I'm also glad I saw what needed to happen...

[john_tullamarine]

an eng fail at V1(matched to Vmcg) was an interesting affair. Glad it was just the sim and I'm also glad I saw what needed to happen..

Good to see your training folk are concerned.

However, was the sim run worked back to max aft CG on a wet runway ? Makes quite a difference to the skating ...

As with crosswind and min V1 situations .. if you have a bit of spare runway, consider running with an increased speed schedule to move away from the Vmcg region a tad .. that last few knots helps out lots.

[Nightstop]

I often operate the A320 into Mykonos during the summer season, it's 1900 metres long & 30 metres width. Never had a wet runway and would be very cautious about going in or out during heavy rainfall. Take off performance is almost always a limiting TOGA take off, optimum config according to the EFB is usually Config 3 but we select Config 2 if able. CG position is approx mid, we load the aircraft to try and achieve that. Limitations for us include a max 20 kt crosswind (including gusts), no failures of anything associated with the rudder or brake units, Captain only landing and take off. Also advance Sim training and currency (at least one trip within 2 years..). A non standard EOSID is required for departure from 34. My last recurrent Sim practice for JMK included both low and high speed RTO's, very demanding. A useful reminder how quickly you have to react with rudder pedal input during such an event.

[john_tullamarine]

Again, one salutes your T&C folk for their risk management.

[oceancrosser]

JT - Now I understand. Flew a Round-the-World charter 10 years ago, which included a stop at Ayers Rock (YAYE 2599x30m). CASA for their approval wanted details of my experienc and training of operating on narrow runways. As it were, I did have experience of narrow runways, though little in the way of training had been administered leading up to that. But a wet runway is not a frequent concern at Ayers Rock anyway...