B727-200 Autopilot

[Vc10Tail]

Any old timers in here can shed the differences between the Sperry SP-50/and SP-100 or SP-150 of this old bird and its individual quirks ) like failure tp capture altitude and causes of AP trip offs, etc)?

How did it behave in severe weather, Icing,Lightning strikes?

How reliable was it with degraded hydraulic power and how it handled one eng out auto coupled approaches?

Thanks

[stilton]

Don't know the specific model numbers of autopilot you speak of but I flew various different models of the B727 from the -100 through the -200 series.


We had a very basic autopilot on our original aircraft, certainly had no altitude capture, that was done manually then Alt Hold was selected. That AP basically could just hold pitch and heading.


We acquired some more advanced -200's in a merger and these aircraft had IAS hold and Altitude capture as well as VS hold.


As far as how it performed in the scenarios you mention, I don't remember too many failures, the AP was pretty basic but it worked well.


You certainly wouldn't be using it on the later stages of an engine out approach though, it was no triple 7 !

[aveng]

Once had a 727-200 auto pilot that disengaged when altitude aquire reached due to a dud (shorted) bulb in the annunciator. From memory SP150 had the aux Nav option that used a IRU. Had up to 10 way points in memory.

[Vc10Tail]

Thank you avenge

SP-50 and SP-150 are the only two I have seen documented but have seen also SP-100

According to its AFM limitations it is certified fown to 80 ft in IMC and 50ft VMC and certified for use with one eng. out. It has to be OFF for two engine out. This beasy can do a single eng go Around no hassles provided speed is good around 200kts and in trim.

Yes a rather ancient AP. I saw some on tge mide selector knob you press for Mach Hold. I guess that was the same function for speed hold.That was ln the SP-150 block. This more modern version had a vertical speed wheel similar to those on 747 Classics. It also had Alt Sel and HDG slect buttons rather than toggle switches.

Those rquipped with Autothrottles: was speed controlled by Speed bugs. EPR was controlled by the EPR "set" knob gauge bug drivers I suppose.By setting the bugs and selecting the AT switch to ON it automatically rolled the throttles to the target EPR on takeoff or only after manual setting if the throttles by tge PF and FE?

[grounded27]

Just a few years ago I was maintaining many of them down to CAT IIIa in A/B mode. How quickly information is forgotten I believe all SP-150. I remember it's Achilles heel being the elevator position transmitters causing everything from porpoising to A/P disconnect after LOC CAP (performs a self test and verifies asymmetry).

[Vc10Tail]

Thank you grounded27.Useful to know.Were the AP tripoffa with Loc capture very common or one off?

[Vc10Tail]

Thanks OK465

Great stuff..why dont they teach us good stuff like that in the AFM!!

Correct Elev Low Pressure light.I think located on the centre fwd panel lefy of tge rydder and elev position indicator and below the Capt Marker beacons.Stab trim cut off on red.

Was the SP-150 AP on 727-200 certified to Cat2A or just Cat1?

Was there also an SP-100 fitted on Miss Piggy?
Miss Piggy had two square lights on the leftish (?) forward instrument panel, one red and one yellow, both of which were functional only with the A/P engaged (either SP-50 or SP-150).

The red one I believe was labeled SYS AB and was to warn if the hydraulic system in use by the A/P dropped below some threshold pressure (1/2 sys pressure or around 1500 psi I believe).

The light was deemed necessary because neither the block 50 nor 150 autopilots would disconnect automatically with hydraulic failure. The A/P would remain engaged electrically with all selected flight mode annunciations but would not be able to 'fly' the aircraft as such.

And the yellow one was the Stab Out of Trim light which is another story.

edit: As I recall now the red light was actually labelled 'Elevator Low Pressure' or something to that effect.

[autoflight]

One of the last 727 off the production line had auto land and auto brakes, as well as a performance data computer and driven EPR bugs

[Vc10Tail]

Wow.That's NEWS! I knew I saw the autobrake control knob in one of the 727 OVHD panel but eas totally unaware if the Autoland capability( whicj I was hoping it would incorporate considering its design was inspired byvthe HS Trident).Am sure it had Autothrottles too this Autoland certified variant.

Was that the same PDC that found its way into the 732-Advc ?

One of the last 727 off the production line had auto land and auto brakes, as well as a performance data computer and driven EPR bugs

[grounded27]

Probably the most common failure was the autopilot tripping off in A/B mode (just about all our aircraft were CAT3A autoland capable) A/B dual land a short while after LOC CAP. I do not believe it would happen in A or B for the above mentioned problem. The operator I speak of had over a hundred of them.

[Vc10Tail]

grounded 27 do you know if yhose Cat3A approved planes were post 1984?

Cheers


Probably the most common failure was the autopilot tripping off in A/B mode (just about all our aircraft were CAT3A autoland capable) A/B dual land a short while after LOC CAP. I do not believe it would happen in A or B for the above mentioned problem. The operator I speak of had over a hundred of them.

[grounded27]

Unfortunately I do not have access to any of their records any more.

[con-pilot]

I'm impressed, all the autopilots knew how to do on our 727s was to break.

But we only had two -100s and an early -200, so nothing advanced. I cannot remember ever letting an autopilot do an approach in the 727s, except in the sim during recurrency.

[galaxy flyer]

It's been awhile and I was a "wrench", but Eastern's later -200s all had autobrakes and autoland, but I don't think any of them had autothrottles. We used the autoland all the time in ATL and SEA.

GF

[con-pilot]

It's been awhile and I was a "wrench", but Eastern's later -200s all had autobrakes and autoland, but I don't think any of them had autothrottles. We used the autoland all the time in ATL and SEA.

GF

Our -200 had auto-brakes and spoilers, but that was it as far as automation went. To be honest I cannot remember if we had altitude capture on the autopilot or not. I really don't think so. No auto-throttles of course.

I had a love/hate relationship with the auto-spoilers on the -200. Sometimes it would save a good landing and other times destroy a great landing. I never got the number of grease on landings I had in the -100s in the -200s, but in my defense I didn't have near as much time in the -200 that I did in the -100.

[misd-agin]

No auto throttles. No auto spoilers. No auto brakes. No altitude capture. Capture altitude with the pitch/roll knob and engage ALT HOLD switch.

PDCS? Computer drove EPR bugs. Gave altitude/thrust data. Kinda dumb. If you flew a heavy flight after a light flight the EPR bugs would read too low for a while in cruise until it eventually figured out "hey, I need more power." If you flew a light flight after a heavy flight the EPR bugs would read to high ( thinking the plane was still to heavy). So you could either scream around the sky at high Mach or set a lower EPR and wait for the PDCS(?) to finally catch up in cruise. It would the awhile. Ten to 20 minutes???

K-factor (drag index) could be checked on the status page. 1.00 normal, light a/c could read as low as .95 on arrival, heavy a/c could have K-factors(drag index) as high as 1.05(+/-). Double check on preflight would give you a clue if you could trust PDCS(???) EPR settings for cruise. Low K factor and heavy flight = set higher EPR's for initial cruise power. High K factor and light flight = set lower than commanded EPR settings.

Memory says K-factor was on page 4/4(?) of status (data?) page. Bleed valves were zeroes and ones on another data/status page. They'd change as you cycled the engine bleeds.

[misd-agin]

Alaska 727's had auto throttles and auto brakes(?). Not sure if they had auto land. We weren't certified so when we flew their a/c we weren't supposed to use any of their fancy automation. ;-)

-19(?) engines. Rocket ship. Huge improvement over the -15's(?).

[con-pilot]

scream around the sky at high Mach

Yep, that was me, the faster the better, especially heading for a RON or on Friday night heading home.

We really didn't care about fuel burn/cost. Taxpayers paid for the fuel. :E

Well actually they paid for everything.

[tdracer]

grounded 27 do you know if yhose Cat3A approved planes were post 1984?
The 727 went out of production in 1984 - the last delivery to FedEx in September 1984.
Obviously, operators were free to incorporate aftermarket 'update' via STC - UPS even did a re-engine with Rolls Tay engines - but no changes to the production configuration post 1984 since there was no production :E

[stilton]

Autoland on a 727 ?


Find that rather hard to believe, can anyone support that ?

[wanabee777]

I'm almost certain that Eastern Airlines had Block V autoland on a few of their 72's.

[MarkerInbound]

Find that rather hard to believe, can anyone support that ?

It is a scary thought.

I've got an Eastern Airlines Flight Manual that lists the requires for CAT IIIa approaches. The first hint is having "A" "B" or "AB" options on the autopilot pitch channel selector.

-19(?) engines. Rocket ship. Huge improvement over the -15's(?).

Dash 15s had 15,500 pounds of thrust. There were -17 and -17R engines with 900 pounds more thrust than the -15. The -17Rs kicked it up another 1000 pounds during an engine failure with the APR armed.

Then there are the Valsan conversions with -217 or -219 engines. The -219s are running 21,700 pounds of thrust down the runway. Ridden in one of those a couple times, true rocket ship performance.

[captjns]

Used to fly a converted -231 into a freighter. Had -219s on the sides and a -17 in the center. Ferrying with 2,000lbs ballast for CG purposes with 20,000lbs of gas the only direction on is going is skyward with IVSI pegged. Controllers used to ask "You guys really a 727?":ok:

Now for the old autopilot with dual channel. I used to engage the aileron portion and hand fly the pitch rather than using the speed/Mach mode on the pitch as too much porpoising resulted. Probably because of CG shifts do to Pax and galley cart movements. On the old -7 powered lead sleds at heavier weights and warm OATs, one may have to descend to regain climb speed.

[grounded27]

Autoland on a 727 ?


Find that rather hard to believe, can anyone support that ?

I already did, yes I know it is hard to believe. It was for me the first time I saw one as I had never maintained a DC10 beyond CAT II before I joined this operator. They were probably modified but to repeat myself the fleet was 100 plus strong and just about all CAT IIIa. I maintained them as so up until a few years ago when they were retired.

[misd-agin]

It must have been the -17's.

The bigger engine conversions were later.

[Spooky 2]

I suspect that the Alaska 727-200ADV were part of the group of airplanes that Alaska got from Singapore 727-212ADV with the -17 engines. They were exceptionally well equipped with AT, ABS and believe auto speed brakes as well. High gross weight somewhere around 198K. Do not recall ever seeing an auto land option in the 727 but it might have been an option. Looking at My Boeing Fleet and it does not show up when doing a word search

[SlowAndSilly]

Courtesy of smartcockpit.com, B727 Automatic Flight (http://www.smartcockpit.com/aircraft-ressources/B727-Automatic_Flight.html) .

Looks like the 727 was capable with block V equipment.

[con-pilot]

OK456

Now that I think back, I seem to remember that on N2777 (or N27 ?), the -100 we got from the FAA, had an auto-land system installed for testing purposes. It was removed before we got the aircraft.

At least that was what we were told by someone from the FAA after we got the 727. Any truth to that rumor that you are aware of?

[misd-agin]

Spooky - I think our -200's w/-15 engines grossed out at around 196,000(??). I thought the AK's were much higher, like 208,000??


Research shows some topped out at 209,500. So 208,000 might have been close.


We didn't fly them anywhere near that weight, just DFW-SEA, so it was a reasonable weight and the improved performance of the -17's was noticeable.

[con-pilot]

At one point it did have a functional A/T system, but when I got in it the A/T was permanently placarded inop.....Gov Mx doing less with less.


That is most likely what I was thinking about. I know when we took it to Dalforth for the new cockpit that they pulled out hundreds of pounds of old wiring that had been install for test equipment back when the FAA had it.

What was interesting was the wiring was telephone wire.

Thanks for helping my memory, again. :p

On the autopilots, one Monday I took off and the autopilot paddles (switches) would not remain on. So I used a rubber band to keep the paddles connected for the week. For some reason maintenance could not fix it until the weekend. I don't have the foggiest why not. And to be honest I can't remember more than four or five times in ten years that we had autopilot problems with the 727s. So that's pretty good.

[Spooky 2]

I don't recall seeing anything over 198K unless it was a Boeing built freighter like the Fed Ex model -200F. As recall there was a different structure that increased the empty weight significantly on those aircraft. Do not recall the MTOGW but 208, sounds a little heavy?


The Singapore -212ADV was a 198,000 airplane and that I'm pretty sure of as we bought one from AK and did a corporate conversion on it.

[stilton]

Max gross weight on the -17R powered 200 series went up to 209,500 pounds.

[Spooky 2]

By chance do you recall who the operator(s) were that used those weights? I cannot find anything in My Boeing Fleet that talks to those weights but that does not mean that they don't exist.

[con-pilot]

By chance do you recall who the operator(s) were that used those weights? I cannot find anything in My Boeing Fleet that talks to those weights but that does not mean that they don't exist.

For some reason American Airlines keeps popping up in my mind for the answer. I think they were the last passenger airlines to get the brand new 727-200 advanced versions.

Very possibly wrong on that.

[galaxy flyer]

At 209,000, it must have been every bit the slug w grossed out D-9 powered early -200 was. I can't remember the gross on those were, but it wasn't pretty on a warm day at gross.

GF

[Spooky 2]

I know it wasn't AA. Suspect it had to be freighter as I pretty darn sure that weight was not available for a pax airplane unless in was a one-off corporate/government delivery. AS I mentioned earlier I can't find any reference to that weight in My Boeing Fleet and goes all the way back to the DC7C if you look hard enough:)

[galaxy flyer]

Not the Boeing DC-7C, successor to the Boeing DC-6 and DC-4? :p

GF

[misd-agin]

AA wasn't 209.500. I think the heaviest were 196,000(?).


I think the Alaska 727's we flew during the 'Alaska Airlines Interchange(?)' max'd out around 208,000. We didn't fly them that heavy so we just had the increased thrust to weight ratio of the -17(?) engines vs. the -15/15A engines. It was noticeable.


Trying to remember from 28-30 years ago...

[con-pilot]

At 209,000, it must have been every bit the slug w grossed out D-9 powered early -200 was. I can't remember the gross on those were, but it wasn't pretty on a warm day at gross.

GF


Still better than the ex-Air France 727-200s with the -7 engines. Thank God I never had to fly one, but we almost leased one of them, until we found out that they had the -7 engines.

I can't imagine what a takeoff out of Denver on a summer day would have been like.

[Spooky 2]

Back in the 80's AK was buying both used and factory new 727's. My only experience was the purchase of one of the former 727-212Avd airplanes they had bought from Singapore. Very low time and exceptionally well equipped. These were -17 powered and had a MGTOW or TAXI, can't recall which of 198,000. I believe SIA only had six of these in service.

[stilton]

Our -15 powered 727-200's had a MGTOW of 198000 pounds.

[Spooky 2]

Okay, what operator was doing that? They must have been somewhat underpowered at those weights with just the -15 engines?

[stilton]

That was Continental and no, they did fine, no rocket ship at that weight
but better than a -9 powered aircraft at 175,500.

[727Man]

Currently flying a Super 727-100 with -217 1&3 -15 in 2, now that's a rocket,
take off straight to FL370 and shortly after FL420!

[Spooky 2]

Interesting as I flew a number of CAL 727's during an interchange and don't recall ever seeing one those higher gross weight 727's. We they by chance at Air Mic as well?

[stilton]

At Continental we had B727-100's with -7 and -9 engines, gross weight was 160,000 pounds, we had 727-200's with the -9 engine with gross weights at 172,500 0r 175,500, the latter were ex Braniff aircraft.


We also had 727-200's with the -15 engine and a MGTOW of 198000 pounds.


Air Mike had some ex Alaska airframes with the -17 engine, not sure of their gross weight limits but I know it was higher still and they had auxiliary tanks.

[Vc10Tail]

Thanks for your contributions conpilot!

Please can you explain more details as to how the Autospoilers messed what would otherwise have been a good landing? Does it introduce a skip followed by a bang!? How do tbey save a bad landing? Do you get pronounced pitch up with their deployment which kinda kills the sink during flare with excess speed?

How do you handle her flare with a 5-10kt tail wind? (Say medium length runway)

Does the 727 ever reward an inadvertent greaser?? :))

Cheers
Our -200 had auto-brakes and spoilers, but that was it as far as automation went. To be honest I cannot remember if we had altitude capture on the autopilot or not. I really don't think so. No auto-throttles of course.

I had a love/hate relationship with the auto-spoilers on the -200. Sometimes it would save a good landing and other times destroy a great landing. I never got the number of grease on landings I had in the -100s in the -200s, but in my defense I didn't have near as much time in the -200 that I did in the -100.

[Vc10Tail]

Kudos for the smart cockpit abberation!

Why would you say auto land Sim.work on 727 felt like kissing your sister? On the cheeks or...?

Did it feel like flirting with danger??

Notice the mis-print error in the 'Smart' Cockpit download.

The statement under Stab Out of Trim about the left half of the light for A system & the right half for B system should be moved up under Elevator Low Pressure Light.

Our -200 sim, which I would guess was based faithfully on one of grounded27's tail numbers, was full up CAT 3A A/P capable.....but except for the value of practicing some insidious A/P, A/T malfunctions in very low viz.....doing an autoland in a sim was like kissing your sister.

[Vc10Tail]

Hi

Is your Sim operational and FAA approved? Do you use it for training? Please inbox me for details. About to fp a 727-TR

Thanks

OK456

Now that I think back, I seem to remember that on N2777 (or N27 ?), the -100 we got from the FAA, had an auto-land system installed for testing purposes. It was removed before we got the aircraft.

At least that was what we were told by someone from the FAA after we got the 727. Any truth to that rumor that you are aware of?

[Vc10Tail]

I have seen a 96 tonne MTOW 727-200 in sone advert so that figure of 109k lbs tallies.

I don't recall seeing anything over 198K unless it was a Boeing built freighter like the Fed Ex model -200F. As recall there was a different structure that increased the empty weight significantly on those aircraft. Do not recall the MTOGW but 208, sounds a little heavy?


The Singapore -212ADV was a 198,000 airplane and that I'm pretty sure of as we bought one from AK and did a corporate conversion on it.

[Vc10Tail]

Hi Spooky

Any idea where those ex SIA 727-200 Adv stable resode at the moment? I know someone looking for a 727F.

Also where do they do engine modifications gor the -15 and -17 tp produce that rocket thrust mentioned earlier in this thread,? Any leads will be appreciated.

I am also lookinh for an old N727-200 Adv AFM.Any ex Eastern,American,Continental,PanAm,TWA or similar league 727 experienced crew with the B727-200 AFM vol1 and Vol 2 who can to donate will be gratefully received. I will pay the shipping charges. :) kindly inbox me.

Cheers

Back in the 80's AK was buying both used and factory new 727's. My only experience was the purchase of one of the former 727-212Avd airplanes they had bought from Singapore. Very low time and exceptionally well equipped. These were -17 powered and had a MGTOW or TAXI, can't recall which of 198,000. I believe SIA only had six of these in service.

[Vc10Tail]

OK465
I agree only to some extent.
I have done Autoland Cat 3 during A320 type rating training.
Yes you do not touch or fondle much till after touch down when engaging thrust reversers. The procedure is not a handling one but a SOP none the less and calls for intense monitoring and Go Around mindedness. The Pilot monitoring is especially busy with the checklist and standard call outs as well as monitoring the trajectory and yhe other pilot "flying".The approach and landing doesnt end till ypu park at the gate. The last real Cat3 approach I experienced in Zurich early morning July 2014.O wad a passrnger that day on A330.Taxing itself seemed a slow laborious challenge due tp limited visibility. Even as we were
Turning to our gate it was difficult tp see the plane parked adjacently. Getting a systems degradation or engine failure below 1000 ft requires being on top of things to make the right decision as low as 50 ft)in the flare!). It is a different ball game to conventional flying, more stressful but highly satisfactory as everything works on the money and you have no tricky crosswind close to autopilot limits for Cat3 which is not much...not to mention a slippery runway.Even Cat3 Autolands can make you sweat..albeit a different kind of sweat. I wonder what limitations were in place for the Cat3a autoland for the three holer? I expect it had have had autobrakes. For Cat2 how well did she hold the ILS? Does she tend to wonder a bit before nailing the ILS?


Vc10Tail,

Doing an autoland in a simulator is pretty much an unrewarding procedural exercise.....

,,,,,you don't get the opportunity to fondle anything or to demonstrate any technique.

[OK465]

.....and calls for intense monitoring and Go Around mindedness.

No different than any approach in the WX....CAT 1, 2 or 3 or GPS or VOR or BC LOC, or (gasp) NDB, etc.

The procedure is not a handling one....

I would assume neither is 'kissing your sister'. :)

The point being that unless you're inputting system malfunctions, the simulator will not screw up an autoland....not that CAT 3 procedural training is not important and of value (including SMGCS and ground ops).

The sim is basically a 'closed loop' not associated with the fear and randomness existing in the real world flying business.

[Spooky 2]

VC10tail, There were several of these 727-212's on the market over that last 12 months. Roush (sp?) racing had a beautiful one that had been converted by Valsan and believe made into a freighter as well so they could move their race cars. If you google them you can probably find out if it's still around.

[Vc10Tail]

With due respect OK465, why do you think Special Cat2 and Cat 3 Crew qualification is required?

I agree on one thing.."hands off" your sister but be prepared to grab her when you see "Cat2/3 invalid"!

No different than any approach in the WX....CAT 1, 2 or 3 or GPS or VOR or BC LOC, or (gasp) NDB, etc.



I would assume neither is 'kissing your sister'. :)

The point being that unless you're inputting system malfunctions, the simulator will not screw up an autoland....not that CAT 3 procedural training is not important and of value (including SMGCS and ground ops).

The sim is basically a 'closed loop' not associated with the fear and randomness existing in the real world flying business.