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L-1011 TriStar First Flight History

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rfresh

B-777
Joined
Nov 17, 2005
Posts
161
The L-1011 TriStar's first flight took place on the November 16, 1970 - this milestone was actually planned 5 years earlier. The pilot on the maiden flight was Captain Hank Dees, the co-pilot was Captain Ralph Cokely, the Flight Engineer was Glenn Fisher and there was also a 4th crew member on board: Rod Bray, who was the Flight Test Engineer and he sat behind the Captain.

I knew all of them with the exception of Rod Bray whom I'd never met - my boss was Glenn Fisher and I was hired by Lockheed as an L-1011 Flight Engineer Instructor. I was 25 years old when I took my Flight Engineer rating ride in the No.1 test ship with the FAA - at the time I was the youngest L-1011 Flight Engineer flying on that aircraft.

On the day of the maiden flight, the L-1011 test ship, Serial Number 1001, was boarded by it's crew of four early, the before start checklist was accomplished, the engines were started and it finally taxied to the active runway in Palmdale California - then it sat there for a while - however there was nothing wrong - the flight crew was simply waiting for the exact time to release the brakes - as that moment approached, Hank Dees ran the throttles forward to spool up the engines, then released the brakes and pushed the throttles all the way foward to take off power - and at that moment in time - the L-1011 began it's first take off - and met it's planned first flight date exactly 5 years after it was to do so, to the minute!

Soon after being airborne, the flight crew radioed Lockheed dispatch and declared that the aircraft was airworthy (that is, as much as this could mean at this point in the flight test program!). The flight lasted two hours or so and upon returning to land, the leading edge slats failed to extend - the first problem encountered on the flight.

Not all of the emergency procedures nor all of the abnormal procedures had been defined however at this point. This was considered an abnormal procedure, not an emergency. Hank Dees told co-pilot Ralph Cokely to select flaps at 22 degrees for landing which was about 50% of their travel capacity - he next told the Flight Engineer Glenn Fisher to activate the slat locking switch - this is an electronic switch on the back bulkhead of the cockpit to the right of the Flight Engineer station (which is directly behind the co-pilot) - once activated, it would prevent the slats from moving in any direction, up or down. Later as the abnormal procedures were developed for a slats up landing, the flap setting of 22 degrees continued to be the factory recommended setting.

As the TriStar approached for landing, the chase plane continued to film it using 16mm color film, with the flaps set at 22 degrees (the two "landing" flap settings are 28 and 42 degrees), this would not enable automatic spoiler deployment upon touchdown, so Hank Dees reminded Ralph Cokely to make sure he (Hank) manually pulled on the speed brake handle at touch down to ensure spoiler deployment at touch down.

The chase plane film footage showed the 1011 touched down ever so gently on the mains first, then the nose wheel - the landing was probably Hank Dees smoothest landing of his career - afterwards, it prompted Ralph Cokely to comment to Hank "...if you never make a smoother landing it will be alright..."

Upon touch down, the cockpit camera showed that Hank Dees did not initially deploy the speed brakes (spoilers) and that Ralph Cokely had to reach around the throttles to grab the speed brake handle and pull it full aft for spoiler deployment - there was no sound with the film so most likely Hank commanded Ralph to manually deploy the spoilers.
There were 5 test ships assigned to the flight test program. One was dedicated to autopilot certification. Over 500 autolands were done to certify the L-1011's autopilot - at the time this was the most advanced autopilot/autoland system in commercial aviation. It was FAA certified to Category IIIa Autolands - a certification that the B-747 and DC-10 never achieved as a standard feature in factory production.

Cat IIIa limits are 700 feet RVR (Runway Visual Range) and 0 feet DH (Decison Height). All 1011's left the Lockheed factory certified to CAT IIIa standards.

Due to the numerous fog operations conducted in Europe, British Airways went to the added certification expense to certify their TriStar fleet to CAT IIIb standards: 150 feet RVR and 0 feet DH. No commercial aircraft has ever achieved CAT IIIc standards, which are: 0 RVR and 0 DH! This is a completely blind landing - CAT IIIc would require imbedding some kind of electronic guidence in the taxiways as IIIc implys that the pilot cannot see outside the windshield at all - thus he/she would not be able to even taxi the aircraft to the gate after landing!

Another interesting British Airways certification requirement that came up during TriStar production was FAA Stall Certification - in the US, the FAA requirement for the manufacturer was to only take the aircraft to stall warning (that is, when the stall warning horn sounded in the cockpit) and then recover. For European certification however, the requirement was to take the aircraft to full stall and then recover. So, Lockheed took the 1011 out and full stalled it - then they invited the FAA along and demonstrated to them that the TriStar could enter a deep stall and recover safely. The FAA pilot tried it and in the deep stall the wing dropped and he could not recover it - film taken in the chase plane showed that the 1011 rolled inverted during the recovery attempt and finally was pulled out at around 10,000 feet - and the test started at about 25,000 feet! During recovery the aircraft pulled an excessive amount of G loads - the No. 1 test ship had to be hangered until it's structure was completely inspected before returning it to flight status.

On later British Airways training flights, I was an Instructor Flight Engineer and sat through some of these deep stalls in the actual aircraft - in the deep stall the aircraft shook so much you could not see clearly - the pilots just had to hold on to the control wheels and push forward to recover - it was quite a wild ride to say the least.

For flutter testing, the most dangerous part of flight testing, the No. 1 test ship had a 4 foot square "hole" in the passenger floor just aft of the cockpit - there was a fireman's pole coming down from the ceiling directly over the center of this hole and ending at about passenger floor level - in the event something went wrong during flutter testing, the flight crew was susposed to jump onto this pole and slide down thru the hole in the floor - this would place them directly on top of what would normally be the forward lower cargo door, but in this case the "cargo door" was made out of fiberglass so your boots could punch through it and you'd finally be on the outside of the aircraft - then you simply pull on the D-ring of your parachute! This was the emergency bail out system that was designed into the No. 1 test ship, which was assigned to do the flutter testing - but it never had to be used!
 
Interesting post.

Thanks for posting that. Good read.

Can you write a little about the Direct Lift Control system?

I don't entirely understand this but I read a little that mentioned the L1011 and the Space Shuttle (!!!) both use a "Direct Lift Control" system for the autopilot to track the glideslope.

Is it correct to say the autopilot adjusts flap setting during ILS to maintain GS?

Pilots that I've spoken to, who have flown both the 747 and the L1011, think the autopilot on the TriStar is far superior to the Classic.

Thanks.
 
mar said:
Thanks for posting that. Good read.

Can you write a little about the Direct Lift Control system?

Is it correct to say the autopilot adjusts flap setting during ILS to maintain GS?

Thanks.

Yes, I will post something on the DLC system; if not tonite, then tomorrow.

Oh no...even on the TriStar, the landing flaps setting is fixed for the approach and landing; they do not move once set. The wing spoilers engage into their "DLC" mode to help control GS tracking. Let me post about the DLC and you'll understand better.
 
DLC System

DLC - stands for Direct Lift Control - the L-1011 incorporated a pitch-smoothing flight control system within it's spoilers or speed brakes.

The flight spoilers are those retangle metal "boards" you see on top of the wings near the rear of the wings, on the top surface, infront of the flap system. They provide a way for the pilot to create in-flight drag to slow airspeed by deploying these boards or panels into the air. The pilot can pull on a handle and extend the boards any amount the pilot wishes/needs. The maximum deployment angle is 60 degrees.

DLC alone will extend the spoilers to a maximum of 14 degrees. Upon landing, the spoilers are also deployed (normally) automatically (always fully) to kill lift and thus plant more weight on the main gear wheels sooner - so that the anti-skid system can become armed to operate as soon as possible. This is especially critical when landing in the rain with water on the runway.

On approach, when the flaps are set to either one of the 2 landing positions - 33 degrees or 42 degrees - a computer activates and causes all of the flight spoilers to raise on each wing 7 degrees.

Passengers in the cabin can easily see DLC in action! Now, as the aircraft descends on the glide path, normally if the aircraft gets low, the pilot pulls back on the control wheel and this causes the aircraft to pitch up to fly back into the proper glideslope or glidepath. If the aircraft gets too high, the pilot pushes on the control wheel and this causes the aircraft to pitch down and fly back down into the glideslope.

This is how it is on all other commercial jets - now - here is what DLC does for the TriStar: If the aircraft gets too low, the pilot still responds the same way - pulls back on the wheel - however, what happens with DLC is that the spoilers 'retract' a little, thus removing some drag which causes the wings to create additional lift and the aircraft "lifts" itself back up and into the glidepath with minimum pitch changes.

If too high, when the pilot pushes forward on the wheel, the spoilers raise higher on the wings, creating more drag and causes the aircraft to "drift down" or otherwise "settle" back down into the glide path.

So the DLC's action of extending and retracting the spoilers with control column input isn't designed to increase or decrease drag per se, but to increase or decrease lift by changing the airflow over the wing. The end result of all of this is that up and down pitch changes on final approach are *minimized* for passenger comfort, and also makes for a very stable approach platform.

You'll get a smoother ride on final approach in the L-1011 than on any other commercial jetliner because only the L-1011 has Direct Lift Control - and the passengers can watch it in action on every approach!!
 
You're fast.

Thanks. That answered my question.

Any limitation with an engine out?
 
mar said:
Any limitation with an engine out?

No, engine outs were a piece of cake. I remember getting my ME in a C-310 and doing engine cuts at V1. Like most piston twins, if you weren't on the rudder peddles RIGHT NOW you'd be on your back.

In the L-1011, engine cuts in the real airplane at V1 (in those days we used a simulator and the actual airplane for flight training) were very mild - I still recall the first engine cut at V1 - the nose was yawing ever so slowly - all the pilot had to do was just touch the rudder peddle to stop it. Surprised me because we just cut 42,000 pounds of thrust on a wing engine.
 
Great stuff! Is anyone still flying TriStars these days?
 
I still think that the L-1011 is one of the best looking commercial aircraft flying.

Excellent posts. We need some more like them.
 

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