Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

Tristar L-1011 FMS & Autopilot

Tech Log The very best in practical technical discussion on the web

Tristar L-1011 FMS & Autopilot

Old 13th May 2009, 16:54
  #21 (permalink)  
 
Join Date: Nov 2006
Location: SoCalif
Posts: 898
Yes, the L-1011 had the first IIIc autoland. Lockheed and BA engineers reviewing the autoland performance noted that the plane hit in almost the same exact spot every time. When they asked LHR management about possible effects, there was an uproar, and LCC had to put a dither into the landing logic.

The L-1011-1 autoland system was a joint Lear-Siegler and Collins Avionics venture.

Meanwhile, the PB-30 Bendix dual-dual autoland on the DC-10 never was successful, and was a major reason for the bankruptcy of Douglas Aircraft and subsequent purchase by McDonnell. The Sperry autoland in the 747 was no great thing, either.

The L-1011-500 dual-dual autoland was the first digital Cat IIIc. It was a sole Collins development, many of the Lear-Siegler engineers having been adopted. At the same time, Collins did the triplex autoland for the 767/757, a somewhat simpler solution.

GB
Graybeard is offline  
Old 13th May 2009, 18:31
  #22 (permalink)  
 
Join Date: Mar 2007
Location: USofA
Posts: 1,048
Thanks ASFKAP. I thought this was the case and my own personnal experiece was limited mostly to the -100/-250 with only a very occasional -500.
Spooky 2 is offline  
Old 13th May 2009, 21:37
  #23 (permalink)  
 
Join Date: Jan 2006
Location: Georgia, USA
Posts: 455
What about this? No elevator position indicators?
The elevator is slaved off the horiziontal stalilizer and therefore its position is shown on the Surface Position Indicator. Stabilizer nose down elevator trailing edge up, stabilizer nose up elevator trailing edge down.

The incident Jack MacHahan was involved in was caused by the failure of the bearing in the elevator drive quadrant prior to takeoff, during the controls check. When the bearing failed the stabilizer nose was full down and the elevator trailing edge full up. The drive quadrant tilted and was blocked by the elevator drive hockey stick pushrod. So the elevator could no longer follow the stabilizer and remained in the full up position.

There were several AD's and S/B's written to prevent re-ocurrance. With the final fix being a elevator cable jam detector being install in the aft body and a warning light on the flight engineers panel.
glhcarl is offline  
Old 14th May 2009, 03:12
  #24 (permalink)  
 
Join Date: Mar 2000
Location: Arizona USA
Posts: 8,575
and a warning light on the flight engineers panel
And, added to the takeoff configuration warning.

Not wishing to be a pedant but not all 500s were digital.
Yup, quite correct.
Not all had ACS either.
And some had different MTOW's.

Many differences...customer options.
411A is offline  
Old 14th May 2009, 03:33
  #25 (permalink)  
 
Join Date: Jan 2006
Location: Georgia, USA
Posts: 455
And, added to the takeoff configuration warning.
Correct and like the takeoff warning system the elevator jam system is inhibited in flight.

Yup, quite correct.
No all had ACS either.
And some had different MTOW's.
Early -500 were delivered without active controls or the extended wings, these were all later retro fitted. Without active controls the MTOW was limited to 496K.

While there are several different MTOW's available for the -500's with active controls (504K, 510K, & 516K) structurally they are all the same, as it requires manual changes only.
glhcarl is offline  
Old 14th May 2009, 07:51
  #26 (permalink)  
 
Join Date: Jan 2001
Location: Dunstable, Beds UK
Posts: 542
Original Tristars had DG/VG's no INS.
Triple INS became an option and in later years the early Littons became expensive so there was a mod ( That Air Atlanta did ) to go back to VG/DG but added GPS.

I think the first area nav was s/n 1024 which had the Ambac/Decca system.
Also this aircraft ( and 1032) was originally certified at an MTOW 199,900 kgs ( instead of 430,000 lbs to keep it below the 200K limit for airport and nav charges

Some -500's were digital and normal operators cannot interchange them ( But perhaps 411 has found away). Of course if you go down into the E & E bay they have the same shape size and colour black boxes but us professionals have to go by part numbers which are not interchangable. ( some of them only have one digit difference)

The FMS units ( by Ham Standard ) were program for individual operators and to re-prrogram cost an Arm and both legs !

There was an Oil consumption limitations on 1 aircraft. This was the King of Jordans aircraft. It was due to very short legs at low altitiudes. The problem was that the oil seals never got fully presurised

Another problem was the fact that it was a very computerised aircraft ( even toilt flush ) and it was very common to find that re-racking the computer solved the problem. However in the early 70's re-racking a computer was looked upon as a fudge so computers were replaced just to make it look right for the Authorities. Most of these came back from the shop with " no fault found "!
GotTheTshirt is offline  
Old 14th May 2009, 13:06
  #27 (permalink)  
 
Join Date: Mar 2000
Location: Arizona USA
Posts: 8,575
Quote:
MESC or FESC.......?

FESC... original, typing error.

As to possible oil problems with -22B powered aircraft....
To some it appeared that after long storage, the -22B engine consumed quite a lot of oil on the first few flights.
This was seldom the case, however, it was normally found that the actual oil quantity after landing was quite normal, considering the stage length...as the quantity indication was many times faulty.
Often times it would indicate properly just after landing.


Quote:
The FMS units ( by Ham Standard ) were program for individual operators and to re-prrogram cost an Arm and both legs !

Some operators programed in-house at considerable savings.


Quote:
there was a mod ( That Air Atlanta did ) to go back to VG/DG but added GPS.

Yes, and that in the beginning didn't work properly, until two senior FD crew actually RTFB, and showed 'em how to fix it properly...
411A is offline  
Old 14th May 2009, 17:08
  #28 (permalink)  
 
Join Date: Jan 2006
Location: Georgia, USA
Posts: 455
There were 34 L-1011-500's equipped with "digital" autopilots: They include 12 aircraft built in the Pan Am configuration (193Y), 9 Air Canada (193H), 6 Royal Jordanian (293A), 5 TAP (293B) and 2 Air Lanka (293F).

The remaining 16 were used "analog" autopilots: 6 built in BA configuration (193V), 5 BWIA (193G), 3 Delta (193W) and 2 LTU (193J).
glhcarl is offline  
Old 14th May 2009, 17:47
  #29 (permalink)  
 
Join Date: Mar 2006
Location: Choroni, sometimes
Posts: 1,975
What is a "TRISTAR"
hetfield is offline  
Old 14th May 2009, 18:05
  #30 (permalink)  
 
Join Date: Mar 2000
Location: Arizona USA
Posts: 8,575
What is a "TRISTAR"
The finest wide body early generation automated aircraft manufactured in the USA...bar none.
It is second to none in its automation at the time... IE, no other airplane could measure up, NONE.

A proven fact.

A fine design, although somewhat dated...now.
Just like yours truly...dated.
Nevertheless, still going...
411A is offline  
Old 14th May 2009, 18:26
  #31 (permalink)  
 
Join Date: Nov 2007
Location: United Kingdom
Age: 66
Posts: 710
I'm with 411A; the TriStar was indeed a formidable aeroplane. I haven't yet met anyone who flew her to disagree with those sentiments.

Yes, the old girl is now somewhat dated, but I haven't yet flown anything that was so popular with the crews who flew her.

Sadly missed!

TCF
TheChitterneFlyer is offline  
Old 14th May 2009, 18:40
  #32 (permalink)  
 
Join Date: Nov 2000
Location: Puken
Posts: 356
What is a TriStar?

A superb piece of engineering, design and innovation and a true delight to fly.

I don't think we'll see such a ground-breaker (in more than one sense!) for a long time.
Farfrompuken is offline  
Old 14th May 2009, 19:03
  #33 (permalink)  
 
Join Date: Apr 2004
Location: Erehwon
Posts: 1,148
I enjoyed my time on them I must admit.

-500 s with the RAF and then a wake up call flying -100 with Caledonian out of Manchester.

With nearly 400 people on board we were still climbing to FL290 crossing the south coast of UK having taken off from Manchester!

The 22Bs weren't quite as nice as the 524s which made the -500 a relative rocket ship (in it's day).

Thanks Mr Lockheed, had nice times on L1011. I have more hours on the DC10 but prefer the Trimotor any time.

Cat 3C was awesome.
Dengue_Dude is offline  
Old 14th May 2009, 19:36
  #34 (permalink)  
 
Join Date: Mar 2000
Location: Arizona USA
Posts: 8,575
Landing with 200 meters vis/rvr?
Yup, done all the time with the big Lockheed three-holer.
The First Officer does all these, I just sit back and admire Lockheed's amazing performance.
Done to perfection, even today.
And, why not?
The quality was designed in, before the name went on.

Designed and manufactured in California USA...with quite proper RollsRoyce engines.
The engines especially...very good performers.
Stage three, out of the factory, long ago.

Even our 26 year old First Officer today exclaims...'this old Lockheed airplane is head and shoulders above the A320 that I have flown before.'

His words, not mine.
411A is offline  
Old 14th May 2009, 20:00
  #35 (permalink)  
 
Join Date: Apr 2004
Location: Up to FL410
Posts: 90
411A, Its great to see another person who's so keen on the best 3-holer.

A jumpseat ride on the L-1011 made me decide to be a pilot some years ago, and have been following them ever since, and from reading the books it really was ahead of its time.

I'm still on the look out and willing to give my left genetalia to have a go at flying one before they all disappear!
ballyboley is offline  
Old 14th May 2009, 20:16
  #36 (permalink)  
 
Join Date: Mar 2006
Location: california, usa
Posts: 79
What is a "TRISTAR"?
The final and finest iteration of Lockheed passenger aircraft engineering, following the other "stars": Lodestar, Constellation, Orion[Electra], & Jetstar, and sometime-pax/combi birds, the Starlifter and Galaxy: The L-1011 TriStar
727gm is offline  
Old 14th May 2009, 20:44
  #37 (permalink)  
 
Join Date: Jan 2006
Location: Georgia, USA
Posts: 455
Thumbs up

What is a "TRISTAR"
It should be written TriStar.
glhcarl is offline  
Old 14th May 2009, 21:30
  #38 (permalink)  
 
Join Date: Dec 2006
Location: 30W
Age: 51
Posts: 55
Guys, your right and I stand corrected.
Of course I meant the 'abnormal' and not the 'emergency' checklist a little over enthusiasm perhaps.
Nevertheless by the time we (Caledonian) had the Tritanic in its final days it was in a sorry state and indeed the 'abnormal' checklist was a regular feature.
Not quite sure why my age appears as 41 when it is 51....
I just cant wear the same specs as the pro Tristar posters.....as a ground engineer for 20 years before becoming a ginger beer it was the most labour intensive and by far the most troublesome aircraft I ever worked on. I recall the O ring incident but not the carrier...somebody will of course.
memories and Nostalgia...oh yes, queen of the skies? personal opinion....the Trident was the Original 3C aeroplane (long before the Tristar) now that WAS a technology breakthrough!
I still have a picture somewhere of a Trident 1 landing in the fog at Bedford for the first true A/LAND. Apologies for thread creep in advance.
KUMOOZ is offline  
Old 14th May 2009, 22:19
  #39 (permalink)  
 
Join Date: Mar 2000
Location: Arizona USA
Posts: 8,575
Trident 1 landing in the fog at Bedford for the first true A/LAND...
Revenue passenger service, yes.
However, if we dial the clock back just a bit further, we find the Caravelle, with its Lear-designed autoland system as being the 'first'...for a jet aeroplane.
411A is offline  
Old 15th May 2009, 05:53
  #40 (permalink)  
 
Join Date: Nov 2006
Location: SoCalif
Posts: 898
I heard this long ago: The JT-9D, CF-6 and RB-211 were the first big fan engines, and the N1 blades went supersonic on takeoff, of course. That created a loud buzz saw sound in the cabin. The very smart Lockheed and RR engineers drilled and dressed the vanes and did everything possible to kill the sound at the source, and did a pretty good job.

The dumb and lazy Douglas and Boeing engineers just added a ton of sheet lead sound deadening to the cabin sidewalls, which was also effective. Lockheed would not did not accept that weight penalty.

At cruise, the Boeing and Douglas cabins were quiet, thanks to that ton of sheet lead, while the L-1011 was noisy...
Graybeard is offline  

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.