727 Early high sink rate crashes
 

"Almost immediately after the original 727's were delivered, there were several landing accidents resulting from an excessively high sink rate, caused by slow engine spool up times and not flying the approach by the numbers."

I've heard this information several times over the years, but searching the internet, I can't find any authoritative verification. Is it true? Can anyone point me to a writeup by a safety agency confirming it?

There were four within six months. All had high sink rate, unarrested descent.

UA Lake Michigan 8/65

AA CVG 11/65

UA SLC 11/65

All Nippon - Tokyo Bay 2/66

Additionally a PA ship crashed 11/66 in E. Germany, suspected similar circumstances

As a result of this problem, TWA blocked the Flaps 40 setting. Flaps 40 provided so much drag that a high sink rate could develop and it may be difficult to stop once it begins.

To remedy this, the Flaps 40 setting was physically blocked on all TWA 727s. Flaps 30 was the most we were authorized to use, and the most we could select due to the physical block on the flap lever. Flaps 30 does not offer nearly as much drag, making the high-sink situation less of an issue.

727 Landing short
 

Pilot error!!!!!!!!!

Just the same, I really admired the way they took the wings apart to land a 727. There was almost nothing left when you touched down!

To remedy this, the Flaps 40 setting was physically blocked on all TWA 727s

Each to his own ... unless the memory is failing, my recollection is that the 100 was always an absolute pussycat (ie land it like a C150) and the 200 not all that different for 30/40 other than for one's having to preprogram the mindset to the flap setting .. as I recall, other than for really gusty conditions, 40 was no great problem .. but, of course, for the 200 ... flare too high and not recognise it .. and EVERYONE on board knew all about it a few seconds later ..

"This lesson (spooled-up) is still in contention with one very large operator that refuses to acknowledge nor comply with the FAA's and FSF "energy management element" of the STABILIZED APPROACH concept [they assert their own alternative standard ("at stabilized thrust") which is rejected by our industry]."
********************************************************

What do they use? Didn't some regulatory oversight agree with their procedures?

There was a learning curve going from straight wing propellor driven a/c to swept wing jet a/c. High altitude aerodynamics, high speed aerodynamics, high sink rate, slow spool issues, balanced field issues, etc, etc.

barit1

Join Date: Feb 2005
Location: flyover country USA
Age: 66
Posts: 2,142


There were four within six months. All had high sink rate, unarrested descent.

UA Lake Michigan 8/65

AA CVG 11/65

UA SLC 11/65

All Nippon - Tokyo Bay 2/66

Additionally a PA ship crashed 11/66 in E. Germany, suspected similar circumstances
Last edited by barit1 : 7th July 2008 at 21:50.
http://www.pprune.org/forums/images/...er_offline.gif http://www.pprune.org/forums/images/buttons/report.gif


The UAL crash into Lake Michigan was miles (20+?) from the airport. Indication of misread altimeter, by 10,000, caused the accident. During descent accepted a descent to 6,000. Unfortunately a/c was already at 2,000, well below it's cleared altitude.

AA CVG was visual approach and they lost sight of the airport. Crashed 4 miles from the runway and is more consistent with CFIT as opposed to unstabilized final approach segment.

All Nippon Tokyo impacted 12 kms from the airport. CFIT as opposed to unstabilized final approach segment.

Pan Am East Germany crash - crashed over military training area on initial approach segment. Some suspected accidental shoot down by East Germany/Russian military. Western crash investigators weren't allowed on site. Eventually some of the parts were unexpectedly driven to the West Berlin border and handed over. (Pan Am brat in West Berlin at the time). Final cause was unknown, but it wasn't unstabilized final approach segment crash.

grumpyoldgeek - in my opinion (IMO), except for the UA SLC crash, these accidents don't qualify.

You can search www.airdisaster.com, or other crash investigative websites, and enter B-727 in the databases. There might be others that IMO would qualify. I'd also check out B-707, DC-8, DC-9 and B-737 crashes in the 1960-1970's. They might have had some unstabilized final approach segment crashes that are, over time, getting lumped together.

Barit1,

Just reread my post. We could get into a circular argument about high sink rate, unarrested descent vs. CFIT crashes. Almost every accident is by definition "unarrested descent".

IMO the AA CVG crash is an example. Crew took a visual approach, ceiling reported at 1500 BKN. While trying to tune ILS frequency and get established on ILS they flew into the ground. Unstable approach? Blame it on high sink rate/unarrested descent? Or perhaps basic loss of situation awareness and basic instrument crosschecking?

Me? I'd blame it on loss of SA and basic flying. The NTSB makes no mention of high sink rate/spool issues.

NTSB? PROBABLE CAUSE(S)
PILOT-PLTS DID NOT MONITOR ALTIMETERS DURNG APPRCH
WEATHER - RAIN

grumpyoldgeek,

After rereading you post I realized I focused on the high sink rate and unspooled portion of your post. Had I focused on the "not flying the approach by the numbers" I would agree that all of these crashes can be attributed to that probable cause.

That's almost a Catch-22 - did poor flying cause the crash? Yes. IMO only one is directly attributed to high sink rate problems(SLC), AA CVG might have been except they crashed 4 miles from the airport as opposed to less than 1-2 miles from the field.

IMHO
 

It's been almost 25 years since I flew both the 727-100 and 727-200, but as I recall, the SOP for that aircraft at my company required being stabilized on the approach no later than 1500 feet AGL (as opposed to 1000 feet AGL for the other aircraft in our fleet). This was due to the aircraft's ability to develop high sink rates with a dirty configuration, relatively low airpseed, and unspolled thrust conditions.

While I haven't that much time in the 727 (maybe only 2800 hours total time), I recall that, in order to get a good landing, the flare technique was somewhat different from other aircraft I flew. As I recall, as you came across the fence, you eased back on the yoke slightly...as doing so, increasing thrust slightly. Then, as nearing the runway, we relaxed the back pressure...perhaps even pushing a bit on the yoke...and perhaps increasing just a bit more thrust. Such techinque resulted on rolling it on at Vref +5 to Vref +10 or so.

Again, as I recall, the airplane stopped well...so much so that the nose wheel brakes were removed by most carriers....not necessary. Between the big main wheels and brake assemblies, and the reverse of those three engines, stopping usually wasn't a problem.

Overall, the airplane flew like a dream. I loved it. But, you had to be careful not to scrape the tail skid...especially an issue on the -200 model. Thus, on takeoff, we normally did the 'two-step' rotation technique. I can't recall, specifically, the numbers...but I'm thinking the -200 hit the tail skid (struts compressed) at 10.5 degrees nose up...11.25 degrees nose up on the -100...so, we did the first step rotation to about 9.5 degrees, until she lifted off, then, further rotated to an initial target pitch of 15 degrees (+/- for the various factors).

Sorry if my memory is failing...which is proved daily...so, someone please correct me.

PantLoad

No, that's pretty accurate. I ended up with about 7,000 hours in the 727, mostly in the 100. I my experience as well I found the 100 much easier to land smoothly than the 200. If fact it is astonishing how fast you can stop a 727 on landing.

Now, in regards to the flaps 40 landings. We were cautioned about the high sink rate that you get into with 40 flaps, however, we were told that reason that most airlines had blocked out the 40 position was two fold. First was for fuel savings, it takes a lot more power at flaps 40 verus 30 on final and secondly for noise abatement. We had flaps 40 available on our 100s and 200, we seldom used that position for the above reasons. When the aircraft were modified for stage III the 40 position were blocked. However, we could remove the block if we deemed it necessary for operational reasons.

One thing I can tell about landing with flaps 40, when you pull the power off, you land, right then. I never dumped the 02 masks, but I've been on board when other pilots did. In fact one memorable landing a guy not only dumped the masks, but the life rafts as well. And that was a flaps 30 landing.

I got the privilege of flying the 727-100, the -200 with the -7, -9 and -15 engines along with two re-engined 727s with the JT8D-200 series engines. It was not a difficult machine to fly but it did require planning.

The initial flaps dribbled out very slowly but it was possible to go to flaps 25 without the gear horn that could NOT be silenced. Flaps 30 or 40 and you had the horn. Drag increased considerably beyond flaps 15 but it was possible to leave thrust at around 2700-3000lbs/eng and configure to the next flap setting as the drag increased. And you could actually go down AND slow down in the 727, something not available in the 737 or the 757/767.

At flaps 30 the machine was very stable BUT if you had a speed decrease, it was necessary to keep adding power until the speed decay was arrested and then start bringing power back off. You could NOT add a bit of power.. add a bit of power and arrest the speed decay. You had to be aggressive.

Flaps 40 increased drag considerably but not unduly. I had flown the KC-135 and we used flaps 50 so maybe I was conditioned. Some fellow aviators never used 40 but if you added about 4-500lbs/hr/eng, things worked out nicely, especially on wet or contaminated runways. We used to call flaps 40 "give me 50 percent wing disassembly'. Our flaps 40 position was never locked out although I believe after the merger that did occur. (I got bumped during the merger).

You could definitely develop a high sink rate in the 'seven two' but you could also do that in the early Lear 20 series.

As for landing, there were multiple techniques. For me, it was reduce power and hold the nose exactly where it was. Others used a BIG flare and many of the BI guys had perfected the 'shove' where they released a bit of back pressure after the slight flare and that cushioned the landing.

I never got the 'rubber jungle' in a landing but had a few friends that did. You could definitely rattle some teeth with a firm landing.

The Mighty Tri-Motor is one of the grandest flying machines ever built IMHO. I enjoyed my time on it although I could never figure out the slightly off center yoke in the -100. I enjoyed the 727 much more than my time on the 737.

Unrelated Question...Forgive Me
 

Wileydog3....

Did you fly the early KC-135 with the old engines that had water on takeoff? How much thrust did those engines have...both with and without
water?

It's my understanding that the max takeoff weight for the 135 (under war time conditions) was 300,000 lbs. Is that correct?

Just want to calculate the thrust to weight is with one engine inopt. I heard the plane, at 300,000 lbs, didn't fly too well with one engine inopt.

PantLoad

There was also this accident, involving B727-112C YA-FAR of Ariana Afghan Airlines on approach to runway 27 (as it was then) at London (Gatwick) on 5 January 1969.

Although never having flown the 727, I have to say that I have always understood it to be "potentially unstable in the landing configuration".


JD
:)

Thanks for all the great info. This is stuff that isn't available anywhere else in the world. Shades of Earnest Gann's writing here.

I remember those two step rotations as PAX, flying out of SEA and PDX. The second rotation felt more like 45 degrees in the back.

ILG,

You stated that TWA's blocking the Flaps 40 was for an unrelated reason, but I can tell you that while in 727 class at TWA we were told specifically that the Flaps 40 setting was blocked as a direct result of the SLC accident, related to excess drag at flaps 40. Had they been at Flaps 30, the sink rate could have been arrested and there would not have been a problem.

Sorry, I should have included in my post that in my training, Dalfort ie. Braniff, that we were told that some airlines did block out the 40 position for the sink rate issue as well for fuel and noise.

If I recall correctly with flaps 40 you needed around 5,000 fuel flow but only 3,000 with 30 on final. For minor power adjustments I just used #2 and left 1 and 3 at a constant setting.

One of the things I loved to do in the 727, when able, was to close the throttles at 10,000 feet and not touch them again until flaps 30 and gear down. Usually could not do that because of ATC and/or traffic.

T-tail
 

The problem with the 727 that was not understood initially was the deep stall.

The T design of the horizontal stabilizer elevator allowed the wing to blank the tail when the airplane was allowed to get too slow in a nose high attitude.

The drag of 40 degrees of flap could slow a 727 pretty rapidly unless a lot of power was added at the same time as the flaps were lowered.

The airflow to the aft mounted engines was also disrupted. With the elevator or even a stabilator in this condition (nose high and slow) and no air getting to the engines, the aircraft was uncontrollable. It was stuck in a stalled or near stalled condition.

This was new territory in this second generation jet, and several were lost before the problem was figured out. Flap limits and higher minimum airspeeds took care of the problems, and as long as the new limitations were adhered to, the aircraft was safe.

As for the difference in landing performance between the -100 and the -200, it had to do with main gear position in relation to the CG. when flaring the longer -200, the main gear could be slammed into the runway as the nose came up. Hence the slight pitchdown or relaxation of back pressure on the control wheel just before touchdown that savvy pilots learned.

We don't see designers opting for T tails these days.

I never flew the 727 but have fair amount on the various 737. Interesting about your point above of increasing the thrust slightly during the flare.

I have seen this technique used in the 737 and also in the simulator. When asked the pilots concerned their technical reason for giving a "burst" of throttle at the flare, people couldn't explain why - although I realised after watching many of these power bursts it was often a reflex action - despite their aircraft was perfectly positioned in the flare for a good landing. In other words it seemed a good idea at the time!

In the simulator I found it difficult to convince some 737 pilots that there was simply no point in this burst of thrust as all it did was cause the aircraft to sometimes balloon slightly and land deeper into the runway. In some pilots this habit was so ingrained one could not break it rather like the jerk that occurs involuntarily when you hit your knee lightly.

Although everyone knows the standard Boeing 737 technique, I am always amazed by the variation in how colleagues actually flare, and in the end result! Flying a mixture of classic and NG also encourages different techniques.

For various reasons the NG is definitely less forgiving in the flare. Recent trips with Ryanair have demonstrated this when paxing. My answer to the Centaurus question, why blip the power, is that increasing power on the 737 also raises the nose. We tried a few blocked elevator approaches a few years ago, with time left over in the sim, which was extremely enlightening.

We actually call the somewhat firm arrival a 'Boeing landing' in my company. The Boeing push as it has been referred to elsewhere and described a couple of posts above by Wiley Dog seems to work for some. At the end of the day passenger perceptions of the landing come way behind considerations of safety and convenience such as taxi distance etc.

In the sim I stick to the standard technique as frankly I am unconvinced about the fidelity of the sim in the flare and anyway there are no pax and cabin crew to worry about.

T tail effects- the whole relevant point..
 

Finally, thanks to Robert Campbell's post, we get to the point...

T Tail, rear biased wing, airflow over tail, high sink rate. airlfow compression and strut effects, localised drag envelope, and g break effects.

Its simple and applies to other T tailers too!

Isn't the rule on the RJ 146 (T tail but wing mounted engines) to add power and that once you start hauling on the stick she's coming down like a lift unless you whap on the the thrust?0

727 -Never get low and slow- an old rule methinks.

Get a T tailer low and slow, and all the adverse factors will combine in one almighty moment- and lead you to disaster- a massive sink rate and then, if you sit their fat and happy and have not rammed on LOTS of power in one go, they will fall over backwards in deep stall.

The high T tail gives more moment arm of authority and better airflow over the elevators authority except during take off and nose high approach- because the tail surfaces ( the horizontal ones) - 'dip' into the wing wash and become less effective. Whereas a conventional low tail dips below the wash in nose high attitude and is thus more effective.

On a certain light buisness jet, there are some lovely angled vanes under the rear end which dip below the wing wake when too nose high and pitch the tail up - as required.

The 727 - like the VC10 - has a very tall tail fin - the vertical empenage - thus delaying the 'dip' performance loss by keeping the elevators higher than they are on say - a Trident a BAC 1-11 or on one of those stubby tailed modern twinjet T tailer feeder airliners that also lack thrust reverse.

In the development years , Boeing, Douglas and Vickers all shared knowledge on the performance issues of the T tail- and the DC-9 had its tail made taller and its horizontal stabilisers made wider as a result.

The Russians knew too- show me a Russian design T tail rear engine jet with a Trident or BAC 1-11 style, short, low stubby T tail- there are none- they all follow the 727 and VC10 type high fin, broad elevator design - with or without end plates on the fin top.

It is not true that desingers are eschewing the T tail these days- as claimed in these posts. Embraer, Bombardier, Lear, Gulfstream - etc all still deploy the efficiency of the T tail- which by the way was invented by a certain Hans Multhopp in 1930s Germany - he worked with Kurt tank and in June 1945 under 'Operation paperclip' was grabbed and sent to the RAE at Farnborough (along with the Horten brothers) until the Americnas grabbed him and gve him a new life in the USA where he made major contributions to US aviation design and lifting body design.

So, the 727 early handling issues were down to power, flaps, attitude and an understandable failure by pilots and the community in general to really appreciate that when the book says add power on approach and make sure you have deployed the lift protective slats, it meant do it and do it big time- not in a drip drip application.

The 727 wing was amazing - what a plane - handled like a dream. Just avoid being wing clean at 180 knots with low power and no anticipation dialled in to the brain. Just like on then VC10 then - or so say those far better experienced than me.

Anyone remember the classic flight test picture of the 727 demonstrating a go-around, I think at Renton circa 1963? The nose is pitched up at what appears to be an impossible, well extremely impressive, angle towards the sky. The gear is up and the ground extremely close. It gives pause for thought, given some of the comments on here about flying the aircraft.

Makes me wonder.

I'm sure many of you have seen that film of ( I beleive it was NASA ) 727 test landing, where the tail + last few meters of empennage is ripped off, due to excessively high sink.

The test being conducted was a high sink landing thing, except that the pilot exceeded parameters.

I am wondering whether the test was done because of the specific problem with the 727 discussed here ?

( i.e. research into the causes...)

I think that with the numbers of Bombardier and Embraer RJs built in recent years (over 1,000 of each), plus the previous generations still in service, there are probably more T-tails in service now than at any time in previous decades.

Those early 727s would have been handled by high time DC6 etc crews, maybe even dating back to WW2 experience. The RJs nowadays are often crewed by those on their first airline position. Yet those early 727 difficulties are not encountered. Reason ?

An analysis I saw many years ago about the early 727 accidents and the subsequent investigation stated that even the test pilots found they were getting caught out in certain circumstances, apart from one guy who was ex-Navy with carrier landing experience. I wonder what that experience was that aided him ?

When I first met Russians they talked about how Russian crews made such good landings compared to BA on the A320, which I regarded as so much nonsense. After quite a lot of exposure to Tu154s since then I can tell you that every single landing has been a greaser, it really is quite amazing the difference in landing capability. I wonder if anyone can attempt a justification.

I believe the film you are referring to was actually the MD-80 prototype in October 1979 at Edwards AFB, which had an FAA crew handling it at the time and which did indeed exceed the design sink rate (not that it looked like that in the film, I have to say). McDD repaired it and attempted to deliver it to customer Swissair, who refused to have it. Nor would anyone else, after about 10 years it was broken up.

Twas a DC-9 Tyres. Couldn't find the video on the web I'm afraid.

Aha that was it

Yes thank you both

T tail flying skills
 

WHBM makes a very good point- those early crews were by historical fact, all ex prop men. They were used to nose down approaches, prop wash over the wings providing lift at low power settting, and had never encountered a 727 wing -the one that unpacks itself so that its slats and flaps hang off it like clothes on a washing line. And they and the rest of the pilot community had very little knowledge of the T tail and rear cg, rear engined handling characteristics.

the ex navy carrier pilot would of course have ben traiend in long jet powered, full flap nose high approaches onto carrier decks - that's why he was ahead of his prop history companions. Phantoms perhaps? Or soemthign earlier maybe.

Glider pilots have an analagy with the T tail low and slow- not -rule - never let the speed drop off on finals, never turn late and slow with a low airspeed - uses attitude and speed brakes as a throttle. add speed on finals -especially in a strong ehad wind- kep the wing loaded with lift and energy.

Used to fly with a captain at the National, all approaches were flown at vref+15...than he would put on wind additives, when I asked him about it, he said there were a lot of early 72 crashes from high sink rates (I think it was the unspooled engines). Made for exciting approaches at the old SRQ and FMY airports.

I've just looked at the dates/times of the five accidents referred to at the start, and all five appear to have happened during darkness, something we have not touched on previously.

Also, look at that high time but very low jet experience of the skippers.

UA Chicago : 17,142 hours, 82 hours on type.
AA Cincinnati : 16,387 hours, 225 hours on type.
UA Salt Lake : 17,743 hours, 334 hours on type.
PA Berlin : 14,212 hours, 59 hours on type.

That is a very insightful analysis. I remember an amazing article in Flying magazine by Len Morgan describing his 720 transition, which was basically self taught. As he put it he had never reached cruising altitude in the airplane, before he first flew with passengers. Nothing unusual there I hear you say. But remember there was no sim and the training was done in the airplane. He was then assigned the least popular base being the old Denver airport (short runway) in the middle of winter! No namby pamby line training. Having survived that he felt pretty qualified.

Slc 727
 

If I remember correctly, the UAL SLC 727 accident involved the pilots getting into the nose high, high sink attitude at a rather high altitude.

The deep stall and blanked T tail and engine inlets were just starting to be discussed at the time. I do know that ADs were flying out of OAK city, and there was talk of grounding the 727 fleet. I don't remember if they were grounded, but at least 10kts were added to all minimum airspeeds.

I was flying night freight from SFO and LAX to SLC and PHX in DC-3s at the time. We used to eat at a coffee shop that was very close to the approach end of 25R at LAX. We'd watch the freighters landing while having breakfast at 2AM.

On two occasions I remember seeing UAL 727-100s just about fall out of the sky during the last 100 ft. or so of the descent, the engines finally spooling up enough to save the landings.

I have a friend who flew with me at the Otis Spunkmeyer DC-3 operation. He retired from PSA with seniority #1 just before US Air took them over. His favorite airplane was the 727-100 which he got into from the Electra. He's over 80 now. I'll call him and find out what he remembers.

3500 hrs (+/-) 727. Land the plane like any other airplane, no push over, no power in flare, etc, etc. Flare, power at idle at touchdown.

So if the a/c is speed stable, what happens in ground effect if you increase your power? :sad: Used to love watching the 130 kts approaches become the 140kt + landings, past the touchdown zone. := Ah, but it was a greaser, and the passengers loved it. :yuk:

727 had an interesting takeoff rotation. The pitch feel would undergo a slight change, almost like a slight dead spot, during the rotation. You'd rotation, the plane would assume a takeoff attitude, and then sit there for a heartbeat or two before continuing it's takeoff/rotation. I think that's where guys got the saying 'you fly this airplane off the ground'.

Len Morgan's advice
 

Just checked out Morgan's "Landing the three holer" article in Flying Magazine

Morgan says that with the -200 if it started balloning on touchdown the trick was to ADD power to restore elevator authority and re-land the aircraft. If you cut the power as per so-called 'normal', you lost elevator authority and the thing would start bitching on you - so to speak..

Let's not get into the rut that the 727 was in any way dangerous- it was not - not with over 2,00 sold - and indeed as per by earlier post- like the VC10, due to its very high tail, it could climb at very steep angles -ones that would have condemned a Trident or BAC 1-11 to deep stall regime.

I once went on a LH 727 jumpseat ride out of Frankfurt in the 1980s. 3 crew of course- engineer to help monitor attitude and speed. LH rammed on the power and got the nose well up- all with no drama. On approach they poured on the power -got the Pratt's really pumping. SAS and KLm did the same thing with the DC-9 and then MD 80s (SAS).

Must have cost everyone a fortune in fuel.

I love that line, 'land the plane like any other airplane'. It all seems so easy doesn't it. I seem to remember a well known (and highly respected) parcel carrier wrote a 727 off not so long ago in Florida, during a night landing. The same carrier also operates a large fleet of MD11s a number of which have been written off during landing incidents commanded by highly experienced 727 pilots. You can fill in the caption below the picture of the smoking wreck as you wish, my preference is for 'Shoot bubba, if landing this baby is so easy, what are we doing upside down?!'

Hhhm, vergiss es. (Forget about it).

Having flown that ship for 8 years, but yes A340, A320 and A300 are about (!) to land very likely. The 727-200/230 isn't.

IMHO, most airlines didn't order them at all. E.G. LH had only four out of 35 or so equipped with NLG Brakes. To my knowledge, they never ever had been used......

Good one Hetfeld, I failed to notice it was April first. Mind you, you are up way past bedtime unless you are out of time zone. Crate of VB mate?

Utc +2

;)

So pretty close to God's country. Good on ya mate!

Slats One

Join Date: Mar 2006
Location: wiltshire uk
Age: 46
Posts: 37


Len Morgan's advice
Just checked out Morgan's "Landing the three holer" article in Flying Magazine

Morgan says that with the -200 if it started balloning on touchdown the trick was to ADD power to restore elevator authority and re-land the aircraft. If you cut the power as per so-called 'normal', you lost elevator authority and the thing would start bitching on you - so to speak..


Guys come up with this stuff and it becomes gospel?

Eg, the plane ballons at roughly 120-130 kts(typical landing speeds). But it needs power to restore elevator authority? How did Boeing ever get the plane certified if it lost elevator authority, especially during landing phase?
How did they ever do stalls? Approach to stalls? Slow flight? Stickshaker certification? How did guys ever fly the nosewheel onto the ground, down to speeds as low as 60, 80, or 100kts, if pitch authority was lost during low power operations.

Would guys add power in balloons? It wasn't uncommon to do so, but it's all a factor of how fast you were, how high the balloon was, etc, etc. Adding power had the benefit of an upward thrust vector, which could reduce the potential 'crunch' that might occur if the situation was poorly handled.

The plane had a fair amount of drag. Much more than current generation a/c and would deaccelerate fairly quickly with power off. IMO that's why guys felt more comfortable landing it 'hot' or with power.

It was very unforgiving of any crab on touchdown. Any crab at touchdown, and sideways drift, could make a nice touchdown seem much worse than it actually was.

Today's a/c DC-9, S80, 737/747/757/767/777, A300 are less demanding, but many folks think the 727 was the nicest flying airliner ever built.