L-1011-500 RNWY performance querry
 

I know she's an old design now, but I am curious to find out the runway performance of an L-1011-500 from a 6,450ft runway. Rather, the gross take off weight possible from sea level, on a standard day. Are there any PDF graphs available online anywhere ?

Failing that, are there any greybeards out there who could help me please ?

well before the 767-400 became the largest gal outta LGA TORA = ASDA=7000'
Ive seen L-1011's [not sure which model] DC-10's and maybe IIRC an MD11 depart and have a little to spare:)

Well, lets see...

6,450 feet, std day, sea level, no wind, full thrust, flaps 22...
461,000 pounds (approximately).
This presumes no obstacles present, so using flaps 22 is possible, to shorten the take off distance required, to fit the shorter runway.

The -500 model is a VERY good performer, both going and if need be, stopping.
Greatly improved brakes.

...but only with the FAA or JAA certification. A UK CAA certified L1011-500 wouldn't get airborne from 6450ft at any useable mass, it would be Vmcg limited.

Really?
Seems strange to me.
At light weights, Vmcg is down around 131 knots or so, IIRC.
The speed comes up mightly quickly in the -500.

Now, having said this, I haven't operated the aeroplane to CAA performance limitations, so you could be right.
Cambridge (Marshals) is about this length, as I recall, and I've operated from there direct to North America, flap 22, with a 10 knot headwind for departure, no pax of course.
Now, if we look at the takeoff weight limitation, and the runway required...
Runway 11,000 feet, sea level, 25C.
No obstacles
Flap 14
Max weight, 510,000 pounds, which is also the max structural allowed.
Takeoff distance required, 10,700 feet.
Using flap 22 (which was not commonly used), the distance required is less, of course

411A is right about the L-1011-500 performances :ok:

Ah, I never learn. I was shooting from the hip, remembering the RAF TriStars couldn't really get out of anything much less than 8500ft with a useful load, even when using a Vmcg derived from the 22B thrust figures. I'll try and find some graphs to check it properly.

Alex I think you're absolutely right! The -500 was awfully Vmcg limited especially when operating to CAA limits (ie 7 knots x-wind used for calculating Vmcg). By reducing thrust to -22B values on short runways we were able to lift something like 20T more cos we weren't eating up runway trying to get to a V1 that was higher than Vmcg!!

I suspect that even using FAA figures there would not be much payload available at all on 6500' with meaningful fuel.

Happy to be proved wrong tho!

A UK CAA certified L1011-500 wouldn't get airborne from 6450ft at any useable mass, it would be Vmcg limited.

...So how did all the UK CAA certified former BA L10s [and today's BA 74s] get into and out of Cambridge [CBG/EGSC, 1965m, 6447']...? :confused:

Getting in is not a problem but the L1011 at least didn't get out at any useable mass. We didn't need much mass because we only went into Cambridge to ferry the aircraft to and from Brize. I suspect the 747 doesn't have the same VMCG issue as the -500.

Unfortunately the only UK L1011 performance data I have left is for the -1 so I can't back up my memory with an RTOT, maybe someone still on 216 could check it out?

Well, the BA 744's used to use TO-2 (+ derate?) to get out - I guess that significantly reduces Vmcg. Used to stop in about 800 metres, comfortably making the turn off to Marshall's on rwy 23 using Flap 30 and Autobrake 3/4 = very impressive.

Many moons ago when I was at CBG we were not authorized to taxi, but had to get towed off the runway, ...I presume that the taxiways had since been widened.

I have a several old L-1011 sales brochures with takeoff charts, while these charts may or may not be correct I would think they are close.

For the -500 the chart shows a MTOW for a 6450 foot runway to be 428,500 lbs.

For a -1 the chart shows a MTOW of 380,000 lbs.

As I said these charts may be way off or spot on I don't know.

I do know we took an Air Transat -150 out of Lemwerder, Germany and the runway there is only 6234 feet (20 ft elevation). I don't know how much fuel we had on board, probably not much, but we made it to Stansted.

Caution: Thread Creep

BTW, in the USAF (C-5) we calculated Vmcg and accounted for crosswind, about 1kt increase per knot of crosswind. Why does it seem to me that the FAA does not do so? And the CAA uses a nominal 7 knot crosswind! Crosswind has a significant effect on Vmcg

On the Global Express, Vmcg is 88 knots and no correction for crosswind. At light weights, V1 is based on Vmcg and with a strong crosswind might, in fact, have a V1 less than Vmcg--NOT GOOD!

GF

Galaxy Flyer,

.. which is why you see Mutt and me regularly revisiting Vmcg considerations in this forum for the benefit of the newer folk coming along.

Concur with your observations...

For civil certification, Vmcg is a "line in the sand" issue rather than just another tactical calculation to be done as in your operation ... your observation about lightweight departures in strong crosswinds is our particular concern .. quite common in the airline short distance positioning game.

As a sideline observation, the variation itself varies with Type but 0.5kt/kt for twins increasing to something in excess of 1kt/kt for four motored beasties is reasonably typical ..

Numerous old threads have things to say on the topic ..

What is Vmcg?

DAL2728, minimum control speed on the ground = VMCG, but I am kind of at a loss how that relates ?

Still thank you very much all of you... Didn't mean to stirr a hornet's nest. Seems like one does have to go to a museum, or likewise to find these charts nowadays.

Kiwi,
Just tried to post a long reply only to find that the system dumped it!

Here goes in quick time.

Because the -500 has a shortened rear fuselage the rudder is less effective. On a short runway we have to accelerate the a/c to V1 before we get it airborne. However because of high Vmcg, V1 also has to be high and therefore we have to severely limit the weight to enable a very quick acceleration to V1/Vmcg.

By reducing the thrust we dramatically reduce the Vmcg and thus lower V1 as well.

Lower V1 means an increased ability to stop from higher weights and so with less thrust we can lift higher weight off a short runway.

Easy huh?

Lockheed themselves realised the problem and developed a fix for airlines who regularly operated out of short strips. BWIA used this mod in the Carribbean which was a fibreglass rudder extension that restored the effectiveness of the rudder.

The short rear fuselage brought with it many other problems that Lockheed had to address. Some were dynamic high speed gust alleviation (the first of it's kind I believe), over pitching with go-around thrust application and others.

Great machine though!

Not really, we could give you an extremely accurate takeoff analysis for the L1011-500, we still operate 2 of them...... However, this sort of labor costs MONEY!!

Mutt

Mutt, you don't work for ATA do you? I flew on an ATA L-1011-500 not two years ago. Ride of my life.

Nope, our -500's are a little bit more exclusive than that. :):)

Mutt

Mutt,

There are currently 25 L-1011-500's flying. Only three operators have just two and only one operator has aircraft that I would call more EXCLUSIVE than the others. So now I know who you work for.:ok:

Leaving it to the experts to discuss the technical performance, but back in the 1980s this would be a standard-length L1011-1 that was operating out of LGA. Eastern used them down to Miami, Delta to Atlanta and Ft Lauderdale, and TWA to St Louis, full pax loads, probably not a lot of freight, just under 1,000 nm. You guys can probably calculate the rest. I don't recall any US domestic L1011-500 operation. The standard L1011-1 had less capable engines and the longer fuselage of course. The -500 was a hot rod in comparison.

Eastern also used A300s out of LGA but the others stayed with the L1011 until medium-distance widebody flights sort of petered out in the US.

Likewise it was the domestic DC-10-10 that operated out of there, AA and UA to Chicago etc. There's a commercial restriction that prevents operation out of LGA for transcontinentals or other longer routes.

WHBM,

In the fall of 1999 was booked on a Delta L-1011-1 ATL to MIA, one of those flights that was full of cruse passengers. When I got to the airport and checked in I was in formed that there was equipment chage and my seat had been changed. The new equipment was a -500. That was the only -500 I ever flew on a domestic route.

As for the -500 being a "hot rod" we ferried a BA -500 from YYZ to PMD with, no cargo, only the crew and four passengers (7 people total) and very little in the way of catering. I have never experienced a takeoff like that one. I was in the second observer seat and it seemed like they released the brakes and pushed the throttles forward and we were climbing.

I've finally found an RTOT for a UK certified L1011-500 for Runway 23 at Cambridge, flaps 10º and 22B thrust. It shows a MTOM around 149000kg with 10kt headwind at 15ºC. The ZFM is around 113,000kg, that leaves only 36,000kg disposable load. If you use still air to match 411A's figures (OK, the runway is a bit shorter and this is flaps 10º not 22º) you get a MTOM of 136,000kg and 23,000kg disposable load. It shows what an effect the higher VMCG has.

http://jals.co.uk/bgs/download_files/RTOT.jpg

Using CAA regulations/data, of course.:ugh:

Now the FAA was just a bit more...ah, shall we say, less restrictive.
Certainly not 'wrong', just different.

Flaps 22 make a very big difference, but you truly had to go to the AFM performance section, something many pilots would not rather do.
Never understood why....:E

Alex,

I presume that the CAA certificed the L1011 with a 7 kt crosswind, this means that the aircraft has a higher VMCG than a FAA certified aircarft.

I'm still willing to supply the exact figures if anyone crosses my palm with silver :)

Mutt

Yep 411, that's the point. The CAA use of 7kt of adverse crosswind for VMCG certification had a severe effect on the jet's performance out of shorter fields. The JAA has chosen to follow the FAA's lead rather than the CAA's - consequently the VMCG issue is less apparent than it was.

Alex,
The Cambridge chart is for -22B thrust. Any idea what the Vmcg was using -524 power?

About 10kt higher from memory, but it was 20 years ago. I'll try and find out.

Why would any -500 charts use -22B power settings, when the -500 was never offered with -22B engines?

**Why would any -500 charts use -22B power settings, when the -500 was never offered with -22B engines?**

Ah well, there you are, it's a Brit thing, performance wise...:ugh:
Shades of DP Davies, run amok.:E

Why would any -500 charts use -22B power settings
 

It's the old fasioned way of De-Rating the engine so lower VMC speeds can be used. These days you do the same by selecting TO2 or TO3. Clever work around in the early eighties if you ask me.

Other than BWee did anyone else do the mod, it seems to make a significant difference.

Only BWIA, as far as I know.
They had to operate non-stop to LHR, so the TOW was quite a bit.
However, their weights with their -500's were restricted to either 506,000 pounds, and with one airplane, 496,000, I think.

To answer a couple of questions from earlier posts:

The BWIA L-1011's had an extended rudder not a rudder extension. The rudder cord was increased aft of the rear spar with addition of a new, wider, cap assembly. They used the same trailing edge wedge as all other L-1011's. The fairing above the No. 2 engine was also modified so the extended rudder would match with fairing. Unless you know what you are looking for it entire modification is almost un-noticeable. The front spar was modified to by the addition of a counter weight below the existing counterweight. While there was a Service Bulletin to accomplish the modification it was accomplished on only the first two BWIA aircraft, the other three BWIA aircraft were equipped with factory built extended cord rudders. Yes, there were five BWIA L-1011's, four were delivered to BWIA but the fifth (which had been a BWIA option) which was s/n 1250 (the last L-1011 built) was modified to VIP configeration for the Algerian goverment but delivered to Saudia Royal Flight.

All four BWIA operated aircraft were certified with a GTOW of 504,000 lbs. The Saudia Royal Flight aircarft was certified to 510,000 lbs. The change from 504,000 to 510,000 lbs is a paperwork change only (flight manual revision that Lockheed accomplished for a fee) no aircraft modification was required.

Anyone help me with the owner/operator of the 1011's decorating the ramp at Don Muang?

Good grief glhcarl, you sure know your TriTannics!
You sure the 5th BW-500 went to Saudi, rather than Royal Jordanian, which is the story I heard.

ZQA297/30,

Royal Jordanian purchased nine L-1011-500's from Lockheed, six were built to RJ specification s/n's 1217, 1219, 1220, 1229, 1238 and 1249. The other three, s/n's 1246, 1247 and 1248 were built to Air Canada configuration. s/n 1250 was in fact delivered to the Saudia's and it is still there today.

morning mangrel,

I think you will find those a Thai Sky and Thai Eye aircraft.

Hi Mutt,

I guess your two aircraft are not quite as exclusive now!!!

Are you going with them ?

:)