B738 Pilots, especially GOL Airlines. Little help.

[sudden Winds]

Hi there!

The airline I work for is starting (non SFP) 738 ops in few weeks and I've noticed some particular aspects regarding the 738's takeoff and landing performance, especially in short runways.

I am aware that, in order to guarantee an acceptable tail clearance, both takeoff (V1,Vr,V2) and approach (Vref30&15) speeds have been "artificially" increased above their aerodinamic values. This has the adverse effect of increasing takeoff and landing distances, thus making short rwy ops a bit more challenging, to say the least.

I'd like to know if your SOPs or airline policies call for any particular restrictions or specific procedures when operating out of or into shorter runways.

Examples of those would be mandatory flaps 40 landings (unless winshear or strong headwinds), max landing weight limitations, more limiting crosswind components, certain flap-setting-vs-weight type policy, or even pilot limitations like minimum time on type, etc...

Any details on the subject from anyone from any airline willing to contribute, will be greatly appreciated.

If anyone wishes to send any kind of material, my email is
[email protected]
Thank you all!!
SW.

[Denti]

We operate a mix of SFP and non-SFP aircraft. There is no fixed pilot or performance restriction. However operations has to make sure that SFP aircraft are scheduled in certain airports to enable the necessary performance, otherwise we might be forced to offload some passengers and/or cargo/bagagge.

Performance is calculated with an EFB tool which knows via the tail number if the aircraft is SFP or not and uses boeing performance data to calculate the required flap settings, derates and assumed temperature based on current conditions and configuration. Landing performance is calculated with an EFB tool as well, both for dispatch and inflight as well as non normal configurations.

The only SOP we have is that we should use flaps 40 with any tailwind component, which is not a bad idea on the -800 but sometimes bloody stupid on the -700 due to the slow speeds.

Of course there are airport restrictions for some airports, all of them class C ones. For example funchal is restricted to take off and landings of experienced and specially trained commanders (experienced is a joke though, 200 hours on type as PIC), innsbruck falls into the same category, but might be still restricted to -700s, at least on an operational level.

[sudden Winds]

Hi Denti,
Good talking to you again...
Thank you for your reply. We are a few years short of EFBs but it´s always good to know how larger companies operate.
Would your company program a non SFP into (say) a 2100 m rwy? assumming normal conditions of wt and wx.
Good luck with the union negotiations.
Best Regards,
sw.

[BOAC]

SW - does your airline not have any performance charts you can look at? At a ?typical? 50T landing weight 2100m is fine.

[exeng]

From my experience regardless of what official landing performance has been provided:

Be very careful when on a wet runway (especially those that become like ice rinks due poor drainage)

If in any doubt when wet use flap 40 and full reverse as early as possible. Do not strive for a smooth touchdown.

The much higher reference speeds combined with poor braking performance could lead to tears.

It is a very different beast to the 700/300 and obviously 200.

The 'briefing' I was given prior to operating was mainly centered around the danger of tailstrike on take off. Whilst this is of concern and must be addresed, the main issue is in my opinion landing performance (or lack of)


Regards
Exeng

[Denti]

Indeed, with no major obstacles 2100m is quite enough for most weights. We operate full 800s (full pax load, usually around 63t+) into a 1850m Runway which can be problematic when wet depending on wind. However the longest outbond sector is around 2 hours, so we won't hit MTOW as we can be limited there depending on temperature and runway condition. Most of us still prefer the 700 there, probably because there is no overrun, only a 50m drop on both ends of the runway (its on top of a hill).

For the 800 50t is actually a pretty lightweight landingweight in my opinion, as the plane has DOWs around 43t.

[sudden Winds]

Hi BOAC,

The airline does have the charts. I haven't had access to them just yet as they're still working on some of the airports. All I want to know is if the operators that have used the airplane for quite a while have come up with any particular policy, procedure, recommendation, etc regarding flap settings for takeoff and landing based on wt, winds, rwy length etc.
Thank you for contributing. I still remember you sent me the cb list a few months ago! thank you for that as well...
sw.

[bubbers44]

We operated 737 200 aircraft out of SNA with 5700 ft with no problem. With your newer AC 2000 meters should be a piece of cake.

[Denti]

Nice info, but irrelevant for today 737s I'm afraid. the 200 was a completely different beast to the NG. So much so that it is nowadays a different typerating.

[BOAC]

I'll try to send a scan of the QRP if you PM me an email address - I no longer have yours. You'll see that 63T into 1850 is OK but requires the dashing skills of Denti (to be sure:)).

[sudden Winds]

Hi BOAC, my email address is [email protected] thank you for all of your help.
SW.
PS: at 63T a non SFP 738 approaches at a little over 140 k. I could definitely use Denti's skills to stop it in 1850m...lol... :}

[BOAC]

Thanks for PM and I have an appointment at Specsavers this afternoon having seen your address in post #1 - doh!

140kts - a mere crawl! We used to stop the Lightning in 7500ft from 165kts even - without a brake chute.

[sudden Winds]

Nice little winged rocket. Low aspect ratios must be fun to fly. Closest I came to flying something like that was a mirage sim. I did enjoy it. Approaches at >190 k. About 10 deg pitch. Chute is really needed unless landing at KSC. High lift devices would have helped.
Good talking to you.

[Centaurus]

This sort of stuff is Pprune at its best which is why I am not afraid to admit I am more or less addicted to it. I love the little vignettes such as that by BOAC and his Lightning. Never had problems with short wet runways in the Mustangs I flew in the early fifties because if you hit the brakes too hard you could stick the thing on its nose and pull up real quick if the prop dug in. Sliding down the long nose to reach the runway would have been tough especially if you hands or bum touched the exhaust pipes on the way down. Of course all this was in theory as fortunately all our runways were long and I never put one on its nose. I did in a Wirraway once when the brakes jammed solid and up we went. Awfully embarrassing it was. Sorry :ok: :E thread drift..

[misd-agin]

737-800 approach speeds are not adjusted because of the fuselage length. Take the stall speeds and multiple F30 by 1.3 and F40 by 1.23(1.25?) and you get the Vref speeds. There is no 'correction'.

Dozens of daily flights into DCA(2090m).
Dozens of daily flights into SNA(1740m).

Lately, due to runway construction at DCA, carriers have been landing on rwy 15/33. 1590 meters. Landing performance restricts landing weight to 140K(63.5T metric).

[sudden Winds]

Hi,

If the speeds have not been corrected to guarantee acceptable tail clearance, how can you explain that for the exact same weight, the B738 F30speed is at least 5 kts faster than the B737? same wing, same landing gear...

The FCTM confirms takeoff speeds are established based on tail clnc among others, and that's the limiting factor for longer bodied airplanes. Why wouldn´t they do the same thing for approach speeds.

Additionally, the SFP does use slower approach speeds, higher pitch attitudes as stated in the FCTM as well.

[Johnny Tightlips]

737-800 approach speeds are not adjusted because of the fuselage length They most definitely are. I have taken the below points from a Boeing landing performance presentation that I have on my laptop.

– Higher approach speed more distance
– Example 737-800 has increased flaps 30 and
40 approach speed for tail clearance.

[sudden Winds]

Hi John,

I strongly agree with you.

Would it be possible to send that presentation to my email account shown in post #1? Thank you!
sw.

[Johnny Tightlips]

You can get it using this link. There is loads of other intresting 737 related topics on it as well.

http://www.captainpilot.com/files/B737/Landing.pdf

Page 19 is the page with the tail clearence notes.

[sudden Winds]

Thanks Johny, interesting stuff.

[BOAC]

For misd-agin's benefit, here is the relevant page from Boeing, 2009. Of course they could be wrong.................

19
Factors Effecting Stopping Distance
• Speed
– Higher approach speed more distance
– Example 737-800 has increased flaps 30 and
40 approach speed for tail clearance.
• Wind - headwind good, tailwind bad
• Slope - uphill good, downhill bad
• Temperature, Altitude
• Inoperative equipment

I expect the 900 too.

[Denti]

Additionally, the SFP does use slower approach speeds, higher pitch attitudes as stated in the FCTM as well

That might depend if you have the two position tailskid which is not necessarily part of the SFP package (it is an customer option).

[Johnny Tightlips]

I was given a great piece of advice by a captain about landing the -800. Runways between 2200 and 2400 meters are the most dangerous for landing. In your mind and on paper the runway sounds long enough but when you add a wet runway, a tailwind and some floating it starts to run out very quick! If the runway is less than 2200 you are prepared and try your best to get it on the markers.

A quote from another captain while landing on a short wet runway one day: I don't care how hard you hit the runway as long as it's on the 1000 foot markers:ok:

[BOAC]

I don't care how hard you hit the runway - has he/she looked at the oleo compression graphs?

[sudden Winds]

Quote: I don't care how hard you hit the runway

It might have been a she then....:}:}:} just kidding!!!!

[Denti]

I don't care how hard you hit the runway as long as it's on the 1000 foot markers

And then he bounces happily along the runway until the midway marker?

A good positive touchdown is something thats good, a crash or bounce is not really good.

[Johnny Tightlips]

People get a grip it was only a figure of speech:ugh:

[sudden Winds]

Folks what app category does the B738 fall under?
Thanks...

[misd-agin]

lbs Vso F15 F30 F40

120,000 108 104 102
130,000 112 108 106
140,000 117 112 110


lbs Vref F15 F30 F40

120,000 142 135 128
130,000 148 141 133
140,000 154 146 139


Vso x 1.3 F15 F30 F40

120,000 140 135 133
130,000 146 140 139
140,000 152 146 143

Vso x 1.25 F40

120,000 128
130,000 133
140,000 138


Vref Flaps 15 is 2 kts 'faster' than 1.3 Vso. So far Flaps 15 Vref has been adjusted by 2 kts.

Vref Flaps 30 is Vso x 1.3. No adjustment.

Vref Flaps 40 (Vso x 1.25) is 4-6 kts SLOWER than Vso x 1.3. The exact opposite of INCREASING the approach speed due to fuselage length.

Vref Flaps 40 uses Vso x 1.25 which is the same as Vso x 1.3 minus 4-6 kts, which would result in a slightly higher pitch attitude.

[JPJP]

We've been operating 737-700's into KEYW (Key West) for some time now; 1463m :eek:

[Denti]

Yep, the 700 is a real nice plane for short runway, and i absolutely love the climb performance (we use full climb thrust even if derating to 2).

[bubbers44]

Our airline was based at SNA in southern California and we had 737 100's and 200 and 300's flying out of there for over a decade with usually every seat full with no problem with 5700 ft of runway. With the higher powered Boeing 737's now Key West is easy. I am glad they are getting good service in there now. It is a fun place to visit but a bit of a drive from MIA. About 3 and a half hours with no traffic.

[exeng]

The 700 is a great performer in LDA - the 800 is not. Much like the 200 was a great performer but the 400 was not.


Regards
Exeng

[sudden Winds]

misd agin,

737-700 at 55 tons Vref 30=129 kts
737-800 at 55 tons Vref 30=136 kts
Both have the same wing...

737-700 at 65 tons V1 Vr V2= 136 137 144 kts
737-800 at 65 tons V1 Vr V2= 141 143 153 kts
Again, same wing.

Out of B737Ng FCTM updated July 29, 2011 Page 3.7

Takeoff speeds are established based on minimum control speed, stall speed, and tail clearance margins. Shorter-bodied airplanes are normally governed by stall speed margin while longer-bodied airplanes are normally limited by tail clearance margin. When a smooth continuous rotation is initiated at VR, tail clearance margin is assured because computed takeoff speeds depicted in the PI chapter of the FCOM, airport analysis, or FMC, are developed to provide adequate tail clearance.

I will be taking a look at those numbers you posted.

Thank you for contributing!

Regards,
sw.

[misd-agin]

Sudden Winds - it's tough to be wrong, and it appears that I could be depending upon how you want to frame the arguement.

S80 uses Vso x 1.25 (approx)
757 uses 1.3
763 uses 1.25
772 uses 1.25
738 uses 1.30 for F30 and 1.25 for F40
737-700 appears to be using 1.25 for F30


763 has a tail strike at a lower pitch attitude than the 738 and 757 but uses 1.25.

Maybe there's more to chosing 1.25 or 1.3 Vso to determine Vref than I(we?) know?

[porch monkey]

Is it possible that it is fiddling the figures to fit with the philosophy that Boeing use regarding flap manouver speeds? On the 737 it goes basically vref 40 + 70 to vref 40 + 50 for flap 1, + 30 for flap 5 etc? In order to keep the manouver margin, might some need to be increased? Hence the differing speeds for what one would otherwise think? Is the same philosophy used on the larger boeings? I only have experience with the 737.....

[BOAC]

Is it possible that - see Post #21?
"– Example 737-800 has increased flaps 30 and
40 approach speed for tail clearance."

There was me thinking the manufacturer would know, too:ugh:

[misd-agin]

BOAC - if Flaps 40 is an increased Vref for tail clearence what speed was it increased from? It's already at 1.25 Vso, which is basically the lowest multiplier used(either 1.25 or 1.3 x Vso).

And the 767-300 has the lowest pitch attitude for a tail strike but it uses 1.25 Vso also. But the 757, which has a higher pitch attitude for a tail strike, uses 1.3 Vso.

It might be :ugh: to you but perhaps you can clarify the 767-300 vs. the 757 as well as the 737-800 F30 vs. F40 "increased speed" issue?

[BOAC]

It might be :ugh: to you but perhaps you can clarify the 767-300 vs. the 757 as well as the 737-800 F30 vs. F40 "increased speed" issue? - in a word, no, and I have no wish to. I take the simple 'approach' here and if that is the speed the manufacturer dictates that will be the speed I try to fly. I prefer to leave working out those speeds to those who understand them.