Narrow Runway Ops

[MES Drvr]

I am looking for info on B-717-200 to operate from narrow/short runways.
B-737 and B-757 do operate from runways narrower than 45 mts which seems to be the recommended width by Boeing. But I am trying to find info on operating from narrower than 30 mts for the B-717-200. I have tried Boeing folks but they keep saying they will get back to us soon. Any help would be greatly appreciated.

[LeadSled]

MES
Runway width.
The first question you need answered is: What is the aircraft certified (recommended minimum) for as standard, by FAA, or if the aircraft has narrow runway certification available from Boeing-- usually for a price. It appears likely the aircraft is "certified" for 30m runway width.
The next thing is: Does the state of registry permit it ---- I am aware of several countries that will impose crosswind/wet-contaminated limitations lower than maximum demonstrated crosswind and/or do not recognise less than 45m for a turbojet over 50,000kg., regardless of original "certification".
I have no particular knowledge of the B717, but the above had been the starting point for several other small passenger aircraft.

[BluSdUp]

I was just in FMM Memmingen airport with the 738.
We have special sim training,captains only to and landing.
No MEL or inflt problems with NWS, Breakes/antiskid reversers and spoilers.
Lower xwind limits dry and wet and no contaminated ops.
Vmc ground is an issue.
FMM is 30 meters and I wonder if Boeing is to keen on let you on a tighter runway.
The good thing with FMM is that it is long so no issues there.

Good luck with Your project.

[galaxy flyer]

The gear track on MD-88 is 16'8", so half spread is 8'4". Add in the 30' allowable deviation at Vmcg for 38'8" from runway centerline to outside centerline (not outside wheel tread!) as where the mains would be in the OEI event near Vmcg. Double that and you have absolute minimum runway width of 77'4". That doesn't account for the outboard tire or any allowance for crosswind or pilot "deviations". 30m or 98' is a sensible min width.


EDIT:
Check certification standard, it might have 25' or 30' as the allowed deviation changed. I'd guess the MD-95 B717 was at a later 25 amendment

[MES Drvr]

The B-717 is certified as a 3C aircraft, which means you need 30mts minimum. But then again the B-757 requirement is 45 mts, but they do operate from certain Greek airports that are only 30 mts wide. Going by the ICAO wingspan rules, the Q-400 need 30 mts, but they have an amendment to operate from as low as 18 mts. The Q-400 and the 717 have pretty much the same wing span. Also the Fokker 100 falls into the same category but they have operated from 23 mts wide runway. VMCG should not be much of an issue as the engines are rear mounted. Any way thanks for all the tips.

[Mad (Flt) Scientist]

If you have redone the "VMCG" work for a deviation consistent with the reduced width, you can easily end up with a lower number than the "normal" 30ft deviation. It means having a faster VMCG to achieve the smaller deflections, but it's one of the possible tradeoffs to allow narrow runway ops. (There's still other considerations than VMCG; TCCA have an AC - 525-014 I believe - that details what THEY expect you to assess to qualify for narrow runway ops)

[galaxy flyer]

Rear mounted engines really aren't a mitigation as the demonstrated deviation accounts for it. While wingspan is often used for runway width specifications, it's gear track that matters. As MfS states, adjustments to V1, using an increased Vmcg, is the common means to reduce width. Other mitigations are crosswind limits, restrictions on wet/contaminated ops.

[john_tullamarine]

This exercise dates back probably 35 years or so to an ICAO recommendation. Australia was one of the few (?) countries to implement it as a requirement.

In the early days, we looked at the Citation, GII, DC9 and, a little later on, other folk did the B737. I have no doubt that other Types have gone through the mill since then.

As others have noted, one of the main concerns relates to Vmcg deviations. The Australian approach came from the viewpoint of a critical operation's being the driver so wet runway and critical crosswind were included. Another matter related to a side step manoeuvre during the landing approach.

I spent my time at the runway head on the video (I had to write the reports so, I guess, that made some sense) and, I must say, it was interesting ... first time around with the DC9 (which, as we all know, is like a train on rails when it comes to a failure ... :hmm:) .. it quite disappeared out of the view finder (we were running a 1000mm 35mm camera lens as I recall and the field of view width was only something in the order of not very much - with the differences in format, this equated to something like hanging a 3500mm lens off a 35mm camera - .. I'd have to look up the files but something in the 0.5-1.0 degree range as I recall. Certainly, it was fine for measuring discrete deviations by scaling a known aircraft dimension).

Zzuf was involved from the Regulatory side in the early days so I am sure that he will pass on his not inconsiderable knowledge on the approach taken by the then Regulatory folk (ie zzuf and his off-sider engineer)

The current Oz requirements are here (https://www.casa.gov.au/files/235a1pdf) for those who wish to run through the document. A bit more prescriptive than the early days where we made it up on the fly via gentlemen's agreements and conservative understanding of what the goal was.

The early days were an interesting lesson in just how vicious Vmcg deviations can be .. for those of you who play with multi-engine conversion training ... please do be careful of Vmcg and Vmca .... tiger country stuff for those who are not sufficiently conservative. Another area where Vmcg can bite hard is with empty ferry flights using min speed schedules where V1 may be Vmcg-limited at low weights.

[safetypee]

..please do be careful of Vmcg and Vmca.. totally agree John.

Video etc, you are obviously not old enough to remember the ‘stoneman’ technique.
Test engineer positioned on the centreline at the far end of the runway with a supply of distinctive small stones.
As the aircraft deviates with engine cut, the engineer runs to the side and drops a stone at the point of maximum deviation.
A very good approximation; don't start on one side or the other because the crew could cheat, and don't do this in long grass, or sand / stone desert overruns !
My view of the hilarious procedure was from the safety of the flight deck, excepting a rare view from the grass at the edge of the runway, or of the engineer running for life during a continued take off with limited performance.

From mach 84 in another thread:- http://www.skybrary.aero/bookshelf/books/3566.pdf

[john_tullamarine]

you are obviously not old enough

.. only a year or three behind your good self ...

the ‘stoneman’ technique.

When this exercise started (at that stage I thought it was nonsense .. that idea was corrected instantly the first time I watched - wide-eyed - as the Diesel 9 disappeared stage left/right as the case may have been off the video monitor) we had no guidance on how to go about it (that sounds regularly familiar over the years) so we sat down over a beer or three and tossed around ideas.

The prime requirement I had was that we wanted to achieve a defensible error less than 6 inches (no metrication nonsense for us).

Rapidly, we discarded a bunch of ideas including such as

(a) estimating deviations from the runway head or side (too much hit and miss and too hard to run a sensible error analysis) - near enough to the stone man technique, I guess.

(b) side looking video using stock standard domestic video kit mounted in the aircraft and looking out a window (what about accounting for aircraft rolling motion ? - bin that one, too)

(c) sand dispenser attached to the aircraft (the chap who came up with that idea bought the next round after he couldn't quantify just how he proposed to allow for lateral accelerations and so forth)

Fairly rapidly, it came down to two options

(a) a long lens video at the runway head, or

(b) a couple of strap down INS units (which wouldn't have given us anything in the way of a significant improvement in accuracy and .. did I mention that the extra-aircraft operating test budget was measured in cents rather than dollars ? .. scrap that idea)

The biggest problem then was to figure out how we were going to go about the exercise.

(a) WRE, as I recall, had some mega-million dollar super long lens kit for tracking low altitude rockets etc. Probably not a likely contender for us

(b) Now, I had a couple of high end domestic video units with C-mount demountable lenses. It took about a beer's worth of scribbling on the back of a fag packet to figure that we needed around a 1000mm lens hanging off the C-mount.

So a few calls to the TV stations to find out how they did it. "You want to do 'what'" ? .. back to square one

Eventually, I realised that the race callers must be using something similar to what we needed when they were calling the weekly neddy races in action. A few more phone calls and I tracked down the race video guru. He was doing exactly what I had in mind .. same camera but, admittedly, with much more expensive high end lenses of much lower focal length than I needed. But at least, now, I knew that the idea would work ... (?)

A few sideline tech issues to sort out and we had ourselves a very workable (and dirt cheap) bit of kit. The video output quality at this sort of focal length due to camera/lens mismatch was dreadful .. but it was fine and fit for purpose

The aforementioned zzuf had all the fun in the sharp end for each bird processed.

Thanks for the link to the Boeing presentation ...

[MES Drvr]

This is from Rob Root, Boeing

Was Runway Width a Factor? Was Runway Width a Factor?
• Of the 117 events, one occurred on a 30m
wide runway, and one occurred on a 42m
wide runway
• Vast majority occurred on 45m wide runways
• 15 occurred on 60m wide runways
• Of the 117 events, one occurred on a 30m
wide runway, and one occurred on a 42m
wide runway
• Vast majority occurred on 45m wide runways
• 15 occurred on 60m wide runways

[MES Drvr]

Again from Mr. Root, Boeing Aircraft:

• 45m is standard runway width (for most large
commercial jet operations)
• As of March, 2002, there were at least 63
airports worldwide with runway width 30m or
less, being served by 737,757 or 767 aircraft
• Boeing has received various requests from
operators for guidance in operating aircraft on
runways as narrow as 23m (75 ft)

[john_tullamarine]

The main problem goes away by the simple expedient of pushing up the minimum TOW used to calculate the departure.

The nature of the Vmcg centreline deviation versus failure speed characteristic curve is such that one only needs to go a little way up in speed to see the problems rapidly reduce.

Whether that is enough for the desired goal remains to be seen but one should see a measurable improvement in runway width required for most Types.

[zzuf]

Ahh JT fond memories. In the DC9 I recall the view through the windscreen was all green - pondered which would be first - Vr or the grass!
Another interesting one was the B733 at Great Falls Montana, with a Boeing crew. We had just lined up for a rejected take-off, my trusty FTE (one MGB) requested a look at the TO chart before we launched. After a few minutes from the back came "we don't actually have the chart for these engines on board"
Taxi in, call Boeing flight test, wait for the chart to be faxed to G Falls. Review the chart, defuel 10 tons, off we go.
The overrun on that runway had to be seen to be believed - the airfield on top of a mesa with an interesting drop to the terrain below.

[underfire]

Since the 737 100/200 with gravel kits were authorized on gravel, dirt, or grass...I guess pavement width could be 0!

[galaxy flyer]

Or very nearly infinite, underfire.

The Boeing presentation is very useful, I've used many times to explain the basic problem, if not the details on one of my types. Be very aware when the V1 number is constant with increasing gross weight and Vr.

[john_tullamarine]

In the DC9 I recall the view through the windscreen was all green

ah, hah ! So that explains the flashes of light in the video post cut .. one TP's clenched teeth transiting the sunshine. But did I learn something the first time the aircraft disappeared from the monitor ....

It was jolly good fun though .. even if Dick (I think he was in the chair in the big office at that time) wouldn't always let us play with his aeroplanes when we wanted to just because the Industry wanted to move freight.

Since the 737 100/200 with gravel kits

Having played with the sim, post rudder mods, at min speed schedules ... one does need to be careful. It was extremely satisfying to see some of the endorsement folk progressively get right on top of the (somewhat more than usual) gyrations pursuant to a cut.

Be very aware when the V1 number

.. indeed, good sir.

[Capot]

Southend has always had a narrow runway; my memory says 30m but Google says it's now 37m and perhaps it always was.

In the past this led to some hairy landings as a result of the unusual impression of distance from the threshold. But the airport's precarious existence over the last 3 decades hasn't been much affected by that particular factor, in among all the other reasons for avoiding it, some of which have now been alleviated (but not all).

[1gintonic]

Southampton also has 37m wide runway. A319/320, B737, B757 and B717 are regular visitors. There are more restrictive xwind limits than normal maximums. Operationally the short runway length combined with the width gives an impression of a runway that is longer than it really is!

[TWOTBAGS]

We have a Narrow Runway Supplement for the EMB-135/145 series.

It required sim testing & cost $60K and then required the approval of the local regulator, the summary is as follows. The supplement is operator specific, I know only three operators have it as it was on the front page of the AFM SUP.

Allows ops to 23m runways, EMB would allow 20m
Has a Mini V1 between 101-104 kts
Has significant XWind limit reduction for both wet and dry runways
Has significant ops limitations for various systems for both MEL & QRH.

The major issue is, to have an engine failure at V1 (wet or dry max Xwind limit) and then not deviate more than 8 meters from the rwy centerline.

Thats how EMB do it, its been a long time since I last flew a Boeing Im not sure any of the few B717 operators will have ever required a NRS so Boeing may not have one on the shelf so to speak. I know it took us about 18 months of operating under a dispensation before the manufacturer and the regulator finally agreed to issuing approval.