NDB approach in the 70s with a jetliner

[Bizjetdriver142]

Hi Everyone,

recently spent some time thinking about how things were done in the old times
like the 1970s and I got somehow stuck with this question.How would you fly or have flown a NBD only approach like this one at Reno with a classic airliner like a dc-9 or 727/737?:
http://www.flightsimbooks.com/foi/charts/page207.jpg
Probably not a big problem , but I'm stuck with several things somehow.

1.First of all, what altitude are you supposed to have overhead the IAF (SPK NDB)?
2.The next question would be ,what flap/gear configuration did they set at what point of the approach ?
3.Did you arrive fully configured above the IAF to make things easier with the timing ,so you can calculate the whole approach with a rather constant Groundspeed?
4.And how far would you fly outbound from IAF ?
No further than 10 miles thats clear,but would how do you time it?
In a way so that once you've completed the course reversal you can descent constantly with a 3degree path from 9000ft to 8200ft?
In other words so you end up at a distance of roughly 2.7 NM from the NDB?

Seems hard to do all this while at the time configuring at the plane therefore changing the groundspeed again and the time calculation all the time.

These may be stupid questions to some, but I'd be thankful if someone could provide some insight if and how this was typically done back then without the help of GPS ,FMS or DME which seem to be omnipresent nowadays.

[aterpster]

1.First of all, what altitude are you supposed to have overhead the IAF (SPK NDB)?

At the altitude published from the four feeder fixes, 11,000 (TRUCK), 9,000 (FMG), 10,500 (NICER), or PYRAM (10,500)

2.The next question would be ,what flap/gear configuration did they set at what point of the approach ?

Speaking for my company on the 727, we would arrive at SPARKS outbound at Flaps 2, and 180 to 200 knots.

3.Did you arrive fully configured above the IAF to make things easier with the timing ,so you can calculate the whole approach with a rather constant Groundspeed?

No, there wasn't andy timining until SPARKS inbound.

4.And how far would you fly outbound from IAF ?

About 45 seconds. Entering the procedure turn outbound Flaps 5, 180, reducing to 160.

No further than 10 miles thats clear,but would how do you time it?
In a way so that once you've completed the course reversal you can descent constantly with a 3degree path from 9000ft to 8200ft?
In other words so you end up at a distance of roughly 2.7 NM from the NDB?

Rolling out inbound to SPARKS, Flaps 15, 150. Over SPARKS, start descent reducing to Vref+ 10 knots. Landing flaps when visual and landing assured.

Seems hard to do all this while at the time configuring at the plane therefore changing the groundspeed again and the time calculation all the time.

These may be stupid questions to some, but I'd be thankful if someone could provide some insight if and how this was typically done back then without the help of GPS ,FMS or DME which seem to be omnipresent nowadays.
Thanks a lot in advance,best regards,
John

We seldom did NDB IAPs at the airports we went to. Most had ILS by the time I started in early 1964. Some folks flew to remote locations where they had to do this. Reno had ILS by the late 1950s. But, landing to the north was lousy, with a back course IAP.

[hetfield]

1.First of all, what altitude are you supposed to have overhead the IAF (SPK NDB)?
2.The next question would be ,what flap/gear configuration did they set at what point of the approach ?
3.Did you arrive fully configured above the IAF to make things easier with the timing ,so you can calculate the whole approach with a rather constant Groundspeed?
4.And how far would you fly outbound from IAF ?
No further than 10 miles thats clear,but would how do you time it?
In a way so that once you've completed the course reversal you can descent constantly with a 3degree path from 9000ft to 8200ft?
In other words so you end up at a distance of roughly 2.7 NM from the NDB?

Seems hard to do all this while at the time configuring at the plane therefore changing the groundspeed again and the time calculation all the time.Okay I'll give it a try

1. At least 9.000 (MA / Hldg Alt)
2. On 727 our SOP was to config to F15 before or reaching SPK (depending where you were comming from)
3. No, over SPK we dropped the gear, starting final descent and selected landing flaps
4. Time it to cross SPK at 8.200, yes leaving 9.000 on inbd course approx 2.7 NM before SPK


Later on our SOP had changed to leave SPK in landing config, if in IMC.

regards

[MarkerInbound]

Dive and drive. I'd have hit SPARKS outbound flaps 5 and 180, gone out bound a minute, flaps 15 in the turn slowing to 150, gear down established inbound followed by flaps 25 and 30. Crossing SPARKS inbound if you halve the fuel flow (727 with JT8D engines) it took you to hold 8200 feet in the landing configuration it will set up a 900 foot per minute descent to 6700, power back up to hold MDA till DICEY and then when you have the runway in sight whatever looks right.

[westhawk]

Back when wasn't as long ago as you seem to think!

Not an airliner, but as recently as ten tears ago, I was flying an IAI-1124 Westwind with no FMS or IFR certified GPS. We flew airways by reference to VORs and had to do NDB approaches occasionally. At least we had working RMIs and dual VOR and ADF receivers. In that way at least, we felt like we were flying in the earlier days of aviation!

We learned a trick from the airlines about using our VFR GPS to fly direct routings though: Somewhere over Southern Utah; Ahh Salt Lake Center Westwind 123 at three-three-zero on a vector of zero-six-three direct Hoxie. Salt Lake: Roger 123, continue on self-vector to Hoxie! In the year 2000, that's exactly what Fedex and several others were doing and we followed their lead. Maybe one controller in 10 would vector you back to airway. It was so much nicer when flying the other Westwind with it's UNS-1 and easier yet when I got hold of my first glass panel plane.

Someday in the not too distant future, someone will post a question on PPRuNe about what it was like to fly an ILS!

[Bizjetdriver142]

Thanks everyone for your answers on this, especially Aterpster for his lengthy reply.
Things are much clearer now!Really appreciate your help.

Best regards,

John

[aterpster]

Thanks everyone for your answers on this, especially Aterpster for his lengthy reply.

Things are much clearer now!Really appreciate your help.


As someone correctly pointed out timing is from DICEY (the FAF).

[BOAC]

It merely adds to my concerns for the 'modern pilot' that this plate is seen as a problem.

[hetfield]

It merely adds to my concerns for the 'modern pilot' that this plate is seen as a problem.


Modern times...:D

[Brit312]

Could you please explain to an old F/E who is not supposed to know anything about this nav thing but from the chart how do you know when to start the proceedure turn. Without a basic time setting how can adjust for a varying tailwind so as to arrive at an accurate turn.

All ADFs I remember
1] You time from overhead the fix outbound adjusting for wind to
determine the point to start the proceedure turn [basic time given
on chart]
2] Time the leg of the proceedure turn either 45degs or 30 degs again
adjusting for wind start to start turn
3] If you have guessed it all OK then you will be at the correct
height, the correct geographical position and aligned with the fix
when turn complete
4] You again time inbound from fix for missed approach point

Now that is how I remember it with no INS or DME, but the memory might be failing me

[cosmo kramer]

The missed approach point is defined by LMM. Hence, a timing DICEY inbound is relevant only to a calculated decision point prior LMM, since you would have a hard time losing 1500 feet AGL in 0.5 nm from overhead LMM to the threshold. Or if LMM is unserviceable.

SPK outbound, however must be timed, as Brit312 correctly states.

Doc 8168:
3.2.2.3
a) 45°/180° procedure turn, starts at a facility or fix and consists of:
1) a straight leg with track guidance. This straight leg may be timed or may be limited by a radial or DME distance; (Radial or DME not available in this case. Timing normally 1-3 mins)
2) a 45° turn;
3) a straight leg without track guidance. This straight leg is timed. It is:
i) 1 minute from the start of the turn for Category A and B aircraft; and
ii) 1 minute 15 seconds from the start of the turn for CategoryC D and E aircraft; and
4) a 180° turn in the opposite direction to intercept the inbound track.


Like BOAC, I too fail to see what's difficult here. Only thing that complicates things compared to the present day NDB approaches that we regularly fly here in Europe and particularly the neighboring regions, is the lack of DME. However, stating a stopwatch shouldn't be that difficult. :)

[aterpster]

The missed approach point is defined by LMM. Hence, a timing DICEY inbound is relevant only to a calculated decision point prior LMM, since you would have a hard time losing 1500 feet AGL in 0.5 nm from overhead LMM to the threshold. Or if LMM is unserviceable.

The timing table is from DICEY to the MAP. Many of us had only one ADF receiver and were prohibited from tuning away from the primary NDB.

[galaxy flyer]

Now, do it on a fixed card ADF for your FAA examiner! Elmer Sharpe at KHPN in '72 for me.

GF

[fireflybob]

NDB approach in the 70s

We were still doing them in the 80s in the B737-200 going into places like Mahon where the minima was lower because the NDB was straight in but the VOR was offset. We seemed to manage quite well. Oh and btw we usually hand flew them without too much effort.

Want a groundspeed check? All we had was a "barrel" dme presentation so you used the stopwatch! We even navigated to the Canaries with just VOR, ADF and DME!

Fuel checks? We actually used things called graphs to do this (no FMC)! Maintain speed in the cruise - we used MANUAL thrust adjustment (no autothrottle).

How did we manage?

[Bizjetdriver142]

Well thanks everyone ,I'm not about to justify any of my questions here.But the main point of this thread was not to ask how a NDB approach is flown in general.That was not the point nor the big difficulty, especially not with the omnipresent DME
nowadays as Cosmo Kramer was so quick to point out.

The main issue behind all this for me was, how this one done without DME, and to be
more precise how the vertical profile of the approach was flown back then and in which configuration.

I just wanted to know wether the timing was done to the effect to achieve a constant
angle descent beginning from the point where the course reversal was completed so that
you pass the SPARKS NDB and DICEY on your way down a constant 3degree descent path or if it was flown basically chop'n drop even in a DC9/727 type of AC.
Thats all.

Best regards,

John

[MarkerInbound]

OK465,

8168 is the ICAO document of how to build an instrument approach (don't worry, I had to look it up.) I was going to explain teardrops and holds on the protected side, thanks. The only guidance I can find is less than 200 knots after the IAF. Let's just say we're more "cowboy" over here.

GF, it was Chuck Dawson at KFTW in 82 for me for the Three type.

[aterpster]

The main issue behind all this for me was, how this one done without DME, and to be more precise how the vertical profile of the approach was flown back then and in which configuration.

Dive and Drive or, as another poster put it, Chop and Drop.

My company did teach to start rounding out the descent 100 feet above MDA.

The potential for disaster in an airplane like the 727 was not insignificant, thus the referenced Reno procedure was seldom used. The FAA had a very agressive program to install ILS IAPs at all major or semi-major (aka Reno) in the late 1960s into the early 1970s.

[Broomstick Flier]

Hi BOAC,

It merely adds to my concerns for the 'modern pilot' that this plate is seen as a problem.

Rest assured that at least on my corner NDBs are still widely available for approaches and many new pilots (CPL/IR) are faced with ADF approaches during initial training and even check-fligths. Speaking from personal experience, I was asked to shoot the following during my initial CPL/IR ride:

http://www.aisweb.aer.mil.br/arquivos/cartas/png/ED44FAEA-EA1F-43C8-B75F0D560617DF6D_page_1.png

and

http://www.aisweb.aer.mil.br/arquivos/cartas/png/F6847464-13EF-479D-9E6C31105A7D23E0_page_1.png

Recently I made an IFR assesment on a local airline and they asked me, on a very basic Frasca simulator, to show my profeciency in NDB basics, like QDM/QDR changes ... neat stuff :8

Cheers,
BF

On time, very nice thread :ok:

[Desert185]

I'll blend generic with flying it in a steam-gauge DC-8.

Check the RMI "dogears" to the ADF position. Since there are no off flags the NDB ident should be monitored during the approach. I always use the BFO function to get a good tune on the ADFs. The digital ADFs don't have this feature, and often don't work too well in countries leaning towards the third world definition where the transmitter is slightly off frequency. Thankfully, RNO doesn't have this issue.

Set the altitude alerter to the initial approach altitude (10,500) then, 8,200, then MDA (6,060). RA should be set to 1700'.

This would be flown with no FD or autopilot after turning inbound, as using them would overly complicate and distract from tracking the RMI inbound and leveling at the proper altitudes.

Overhead SPARKS @ 10,500 from NICER outbound with flaps 35 and gear down (approach configuration prior to the NDB outbound). Speed will be ~150 KIAS, depending on weight. If you fly it clean, speed will be too high and you'll easily exceed the 10 NM in the procedure turn. I would begin the PT as soon as I got close to intercepting the outbound course or that 10 NM limit is going to happen pretty quickly.

The configuration will allow a fast enough descent from 10,500 to 9,000 during the PT. The NDB inbound altitude is only 800' less at 8,200'.

Flying the PT level with flaps 35 and gear down will result in ~3,500 PPH fuel flow, which will be a good reference for flying level @ minimums. Just set the thrust and fly level. Airspeed will be very close, and just a tiny bit of power change will have you onspeed so you don't have to hunt for the correct power setting.

You don't fly a constant groundspeed. You fly flap 35 approach speed and figure your inbound groundspeed for timing to the MAP. At 150 kts, the time to MAP is 2+07, which will be more than enough time to descend from 8,200 at the FAF at 1,500 FPM to the Category D minimums of 6060'.

Normally, at 1,000' AGL the descent rate is reduced to 1,000 FPM (FF: 2500 PPH).

When getting the runway in sight, flaps to 50 degrees (full) and slow another 10 knots.

Having said all that, the NDB minimums are so high that the approach is rarely used. Even at night, shooting a visual to RNO from normal vectoring altitudes. Even the normal ILS has high mins. Some companies and aircraft are certified for the Silver ILS, which has much lower mins for aircraft with steep-profile, MAP, climb gradients. See that obstruction just south of the runways @ 5,023'? That's Rattlesnake Hill. That, combined with the high terrain surrounding the airport is why the mins are so high. Imagine losing an engine on the MAP...

Welcome to the challenging, rewarding, fascinating and entertaining world of the steam-gauge. :cool:

[BizJetJock]

Commonly referred to as PANS-OPS, is totally irrelevant here since the procedure is in the US where TERPS criteria are used, with quite significant differences.

[stilton]

Brings back great B727 memories, you really had to keep thinking and that was a good thing.




But 'Dive and drive' belongs in the history books now.




A stabilised rate of descent from the FAF to the runway with is the only way to go and much safer.



With todays LNAV / VNAV technology we are a lot safer, as long as you monitor carefully and really know what's going on.

[rudderrudderrat]

Even in the 70s on B707s we did CDFA approaches using a computed Height v Time table (discussed in the brief before TOD,) Height checks every 20 secs on the approach. (QFE days).

My company abandoned dive & drive after leaving props for jets.

[fireflybob]

"Dogs Ears" for the RMI selection brings back memories - very important part of the approach check.

One pilot I flew with used to call them "Suicide switches" - more than one a/c over the course of aviation history has done the whole letdown on the wrong beacon because the Dogs Ears were incorrectly set. I recall there was a CFIT at Palermo decades ago for this reason.

[Bizjetdriver142]

Thanks again Aterpster, Desert185,and all the rest.Quite interesting all this.
Aterpster, since you mentioned in your company is was taught to start rounding out of the descent about 100 ft above the MDA, I've got a follow up question.

Did you actually continue then in level flight at MDA towards the MAP like you would do in a prop?

Because if your approach speed in final config from DICEY inbound would be around 150kts for example, it takes you about 2:07 minutes according to the chart to reach LMM, the missed approach point.With a normal sinkrate of around 750 ft/min you would've reached the MDA of 6060ft for class C/D aircraft already after a little less than 1minute after passing DICEY at 6700ft.
So you would have still 1 minute to go towards LMM.In a prop this is no problem,
but with a jetliner it seems hard to do, since passsing LMM at MDA would leave
you about 1700ft above the airfield at a distance of 0.5NM from the threshold.

Or did you go around immediately if you had no visual contact upon reaching MDA?With go-around I mean starting your climb&gear and flap retraction, the missed approach procedure itself can only be flown laterally once your at the MAP,I know.

Thank you,

John

P.S.:Forgot to ask,what are RMI dog-ears?

[Tinstaafl]

They select the RMI display to VOR1 or ADF1, and VOR2 or ADF2.

[aterpster]

bizjetdriver142:

Reno is not a very good example because the HAT (TERPs for Height Above Touchdown) is so high. More typically, a U.S. air carrier airport would have an NDB HAT of 500 to 700 feet.

Final approach speed at Vref +10 and flaps 15 would probably be more on the order of 135 to 140 KIAS. When becoming visual we would select Flaps 30. The reason we used Vref + 10 and flaps 15 was to provide for the "Drive" portion of "Dive and Drive." If you had to run the time out chances are you were going to miss the approach even if you got a glimpse of the runway at the last moment. Lots of discipline required. And, with an NDB IAP the runway might be seriously offset. (At Reno that wouldn't be the case if you had two ADF receivers and thus could lock-step them, but only our international 707s had two ADF receivers.)

Also, most U.S. NDB IAPs that were not associated with an ILS runway would have only one NDB. The Reno runway shown on the chart also had an ILS, thus the LMM.

Here is a photo of an RMI. The VOR/ADF selectors are at the lower left and right respectively.

RMI (Radio Magnetic Indicator) (http://www.allstar.fiu.edu/aero/rmi.htm)

And, as others have said, Dive and Drive went out in later years.

[cosmo kramer]

For those interested:

ICAO Doc 8168 or "Procedures for Air navigation services" consists of two volumes.

Volume 1, called "Flight Procedures" is the foundation for all IFR operation. And it is mandatory read for all pilots.

From the forewords of Doc 8168:
Volume I — Flight Procedures describes operational procedures recommended for the guidance of flight operations personnel and flight crew. It also outlines the various parameters on which the criteria in Volume II are based so as to illustrate the need to adhere strictly to the published procedures in order to achieve and maintain an acceptable level of safety in operations.

MarkerInbound, volume II is "Construction of Visual and Instrument Flight Procedures"...
Volume II — Construction of Visual and Instrument Flight Procedures is intended for the guidance of procedures specialists and describes the essential areas and obstacle clearance requirements for the achievement of safe, regular instrument flight operations. It provides the basic guidelines to States, and those operators and organizations producing instrument flight charts that will result in uniform practices at all aerodromes where instrument flight procedures are carried out.
...and as can be seen in italic it is not essential read for pilots.

[Desert185]

Bizjet driver: So you would have still 1 minute to go towards LMM.In a prop this is no problem,
but with a jetliner it seems hard to do, since passsing LMM at MDA would leave you about 1700ft above the airfield at a distance of 0.5NM from the threshold.


Well, that's the problem at RNO even today unless one is doing the Silver ILS with lower mins, which is not normally published for the general public. A circle is your only option. Back then, circling was an option. Today, many carriers don't allow circling unless the weather is 1000-3 (the NDB mins were 1700-3). I say "were", because an NDB app no longer exists at RNO. Also, most type ratings these days exclude being able to circle. I once flew with a sim instructor who had never seen a circle in a large aircraft (his DC-8 type had the circling exclusion), so he wanted to see one demonstrated in the sim. Some would say not circling is safe, and I would agree, but I would also agree that we are dumbing-down the capabilities of the pilot's. Some poor "pilots", who I generally call "drivers" are very reluctant to do a visual approach, even when that is the only option (like the 25's at PANC). I saw a foreign carrier try it three times and then land at Elmendorf next door. Personally, I miss the IGS13 at Hong Kong's old Kai Tak. Don't get me wrong, automation is a good thing, but so is a capable pilot who can do his job should the automation fail or be deferred.

RNO is a different animal with usually higher ceilings and visibility, with vis going down in snow showers during the winter. The current ILS 16R has Category A-D mins at 2100-7 with no circling. The GS is 3.1 degrees, so the DA on the GS is seven miles from the runway.

The VOR-D has Category D circling mins at 1600-3...VFR.

Don't allow yourself to be a dog watching television. Fly the damn airplane once in awhile. The human still has to interface. What a concept.

[MarkerInbound]

As BizJetJock said, this is a TERPS based approached and we have our Instrument Flying Handbook and Instrument Procedures Handbook for guidance.

[cosmo kramer]

That doesn't absolve you from having knowledge of international regulations. There are 195 countries in the world besides USA. I suppose your license allows to fly to these countries?

ICAO is the foundation of civil aviation. Each country may have local deviations. You have to know the International regulation and the local regulations applicable to any counties you fly. In other words ICAO Doc 8168 is the master document, and TERPS is a local exemption.

Frankly, I find it quite disturbing that such an essential documents is apparently more or less unknown to American pilots. Maybe this should give cause for consideration when American pilots complain that they have to do JAA exams to fly in Europe.

Anyway, TERPS or PANS-OPS - I am sure that we can agree that we would time our procedure turns.

[galaxy flyer]

It is in the same sense as the AIM is.

GF

[cosmo kramer]

USA is an ICAO member state, so yes it's regulatory.

[westhawk]

Being an ICAO signatory does not mean that ICAO docs are mandatory under that state's laws. Only those provisions which are adopted under the laws of the signatory state in question become mandatory in any legal sense.

[grounded27]

Hey, back seat driver here. Probably 10-12 years back into luanda with an MD-11. The drivers had no problem with the NDB and the approach / landing.... More concerned with getting shot at than anything.

[aterpster]

cosmos kramer:

ICAO is the foundation of civil aviation. Each country may have local deviations. You have to know the International regulation and the local regulations applicable to any counties you fly. In other words ICAO Doc 8168 is the master document, and TERPS is a local exemption.

Would it be so nice that all ICAO countries that use PANS-OPS were faithfully consistent in its application.

TERPS is used in all three North American countries so the 90%, or so, GA pilots who fly only within or between those three countries are nicely covered without even having knowledge of Doc 8168, of which TERPS is most decidedly not a subset.

Alas, the United Nations does not do much better in aviation matters than in the other matters it mucks around with.

For those 10%, or so, of North American pilots who fly airplanes capable of venturing across the ponds, we have some good international procedures schools for business aviators. And, most of the airlines who fly international do a good job of teaching the pertinent variations from the United Nation "standards" by placing emphasis on whether it is to be Western Europe, or Africa, or the Middle East, or South America, or Asia, or India, et al.

But, the bottom line: any pilot who thinks he can read basic PANS-OPS and be covered is ignoring the reality of actually being qualified to fly into not only a specific country, but being qualified to a specific airport or airports within those countries. That's the "end game" for survival.

Neither PANS-OPS nor TERPS are regulatory, rather they are instrument procedures design and construction criteria. Procedural operations regulations are regulatory by definition, but they have no application outside the state in which they apply. Some operating regulations and procedures are universal; many are not.

[Bizjetdriver142]

aterpster:
Thanks for the further explanation regarding the approach and RMI dogears
Have a nice day,

John