Honduras plane crash
 

Also on CNN, less info there

Caution: some of the pictures in following link are disturbing

See: Honduras: 14 muertos en accidente aéreo - País - LaPrensa.hn

Pictures, crew and passenger manifest and report (Spanish).

BBC have it now:

BBC News - Honduras vice-minister Robelo among 14 plane crash dead

"Honduras vice-minister Robelo among 14 plane crash dead"

Let 410
 

The TGU R02 approach had to be done accurately or you would hit that hill with an early descent. The DME for the approach when I was flying there in a 757 was deemed unreliable to the south so we used an NDB bearing to start the final step down. I always verified the accuracy of my on board crossing the VOR outbound navigation to back up the NDB bearing knowing what an early descent would cause. We couldn't land straight in but had to circle to land. The minimums were a lower MDA that direction so if we missed the approach from the north we could go lower approaching from the south. TGU is an airport that doesn't give you a whole lot of room for error. I loved it. Landed there hundreds of times.

bubbers44:

http://tinyurl.com/4sst64l

The article in Avherald shows the approximate location of the wreck, an approach plate, plus discusses the risks inherent in an early descent.

Crash: Central American Airways L410 near Tegucigalpa on Feb 14th 2011, impacted trees on approach

... a landing vid from the cockpit

YouTube - Cockpit view of a jet landing into Tegucigalpa Honduras TGU

... plus an AA'57 dropping in for a visit

YouTube - Wicked Landing Toncontin Int`l - AA B752

aterpster, in this photo, you can see VOR/DME TNT, which is 1.7NM from the threshold. The reports, however, place the crash much farther out at Cerro de Hula — it's the 5660' peak about 7NM out and before abeam the start of the final step-down.

dvv:

If the posting showing the crash site is correct, then it would seem to be a failure (for reasons unkown) to level off at MDA coming out of the procedure turn. The photo, nonetheless, shows how challenging this airport is.

I should have said step-down altitude, not MDA.

Used to be more fun before they took off the top of the hill south of the runway.

My friend who managed our ops in TGU said the airport winds were 360@12 knots but the winds at the crash site were over 40 knots. That would produce a significant down draft on the south side of the hills. This may have contributed to going below their step down altitude. The captain was a friend of his.

I have experienced the very strong updraft on the north side turning final but expect the downdraft on the south side would be about the same. Maybe now they have the 02 VOR DME approach approved again but when I retired we needed the NDB bearing for final step down.

bubbers44:

They also now have RNP AR approaches to both runways for those who can do those. The RNP AR to Runway 20 is pretty good, but the one to Runway 2 is what I would call an RNP to visual conditions; not exactly what RNP AR is supposed to do.

I agree. Continental and us usually arrived at TGU within minutes of each other so this day it was VMC and continental was directly below us 1,000 ft so we were following them in as #2 to land. They decided, probably for training, to do the RNP arrival so we had to hover over them for several minutes for their 3+ mile excursion to the west for a long left base. We could have landed and parked by the time they landed on 02. I told our manager who was testing that approach for us what a waste of money and training it was for us to do the same thing. I told him I have landed here over 500 times and only one time had to divert. No airliner landed that day because of low ceilings. We didn't change our approaches and probably saved 100s of thousands of dollars. 90% of the landings are on 02 because of the prevailing wind and as you said the RNP approach doesn't help on 02.

I guess I took us off topic, sorry, but I don't think an RNP procedure would have helped them make a safer approach because even though they were doing the 20 approach, because of the north wind, they would have had to circle to 02.

The hill in question was several miles south of the picture. Properly flown this, in my opinion, is a safe airport. Just fly the approach. Any approach, improperly flown, can end up in disaster. Any landing, disregarding tailwind, wet runway can be a disaster. How many landing accidents at TGU were not caused by pilot error. Probably none. You have to know what you are doing to land there. You don't have to be an ace, just do it right. TGU was my favorite because it was challenging, but safe. The people were great and the passengers always clapped when you came to a stop without killing anybody. Never happened in Miami.

bubbers44:

Can't quite reconcile your two posts:

Isn't it far more likely they were flying the VOR DME Rwy 02 procedure?

Yes, they were doing the VOR DME 02 approach. I was referring to the post saying the RNP 02 approach doesn't do more than set you up for a visual into the valley but the RNP 20 approach lines you up with 20 and with any significant north wind they would have to circle.

I can't find any RNAV approaches to MHTG on my computer but would like to see what their minimums are. We never approved these approaches so we have no access to them. If you Continental guys that have it would post it, I would appreciate it. As I said, I had no problem with the basic approach getting in so want to see the advantage of the RNAV approach. Thanks.

We landed there one day when we were an hour late and Continental had diverted to SAP. We filled up our extra seats with their stranded passengers so walked over to their ops and said why are'nt you landing,look at the sky? Their captain said they must have landed below minimums. He finally took off and came back to pick up the passengers who couldn't get on our flight. We had blue skies when we took off. Yes, we liked getting their passengers, but felt sorry for the ones we left for no reason since the captain must have been using old wx data. More than likely it was the best wx he could get in Honduras.
I tried to get over to say hi to their pilots when I could. They were good guys and liked a bit of adventure. PMing would be fine if you prefer.

keezy44, it's all in the AIP: AIS | MHTG - TONCONTÍN
http://busybee.dvv.org:8000/flying/M..._1%20small.png

Thanks dvv, I have never seen the RNAV 02 approach so had no idea they could go to 850 ft AFL at MAP. We had to have 2700 ft AFL for the VOR 20 approach. Looking at it I am glad we never got certified for it. We didn't get GPS until my last couple of years before retirement but losing systems on that base leg with mountains on both sides would be very interesting. I now stand corrected and the RNAV 02 from the north would have prevented this accident. I still can't believe they approved this approach to those low minimums with mountains all around them and that close. Can you skin that close to mountains on an ILS? I didn't think so but never having done a GPS RNAV approach have no knowledge of the rules so I will shut up.

bubbers44:

This is not an ordinary GPS approach. It is an RNP Authorization Required approach. (RNP AR). Whenever an RNP AR approach requires less than RNP 0.30 or the missed approach requires RNP of less than 1.0, then the position has to be backed up by at least one IRU for additional FMS position. Thus, if the GPS fails, the IRU or IRUs (usually three) will provide sufficient position accuracy to complete the missed approach procedure.

bubbers44,
I still find it highly unlikely that the L410 and her crew were authorized to execute the RNP approach. So they had been left with the VOR/DME approach they were executing, anyway.

dvv:
There is no possible way the L410 had an IRU and all the FMS redundancy required for the RNP AR Rwy 2 IAP.

It is likely the crash side is somewhere in the vicinity of the procedure turn fix on the VOR/DME Rwy 02 (a misnomer, because it is a CLT only IAP).

Nonetheless, a discussion of the RNP AR approaches is certainly germaine to a discussion of the topography of this airport.

Newspaper reports place the crash at a distance of about 1km from this 1989 crash:

http://avia.servebeer.com/TEGUCIGALP...-%20N88705.png

US DOT publication DOT-TSC-FA9D1-99-01

This topo shows the crash site based on that chart. It doesn't seem reasonable because that site is some 1,000 feet below MDA:

http://terps.com/charts/Graph%20crash%20site.pdf

dvv, I have full knowledge of all non RNAV approaches into TGU but non of RNAV approaches. The way the '89 727 hit the same hill as this crash indicates they both made the same mistake and descended early.That approach required full attention to the step down altitudes. Maybe they got in a downdraft approaching the hill with high winds on their nose. Maybe they just didn't read the chart right. We rarely did this approach because we approached from the north.

bubbers44, I won't be surprised if we never know the cause of the crash with any degree of certainty - I'm not even sure there were a CVR and FDR on board the L410.

BTW, googling around, I've found that they're building a wind farm on Cerro de Hula, which might make this VOR/DME approach even more interesting...

Many similarities ? TAWS Saves - Opportunities for error.

• A non precision approach.
• A chart for a DME procedure. The plan format shows waypoints as distance to the DME, but the profile has both distance to the threshold and DME. NB #24 the difference between the blue and red flight paths is approx 1.7nm = difference between threshold and DME location!!
• No visual descent point shown. 5620ft procedure altitude might suggest 7nm from the threshold (300ft/nm); if so then why not put the straight-in MAP there? Then this would not be compatible with a 2nm visual minima.
• No table of altitude against distance for the procedure; the VS table appears to be for the MAP and not a VDP, thus not suitable for a continuous descent procedure.

Crash site; if it is according to #25, then just continue down the red flight path (#24) – and if the airfield was in sight, then consider a visual illusion / misjudged terrain clearance – cf Taipei.
Unfortunately its happened before and will again until TAWS/EGPWS is fitted.

PEI 3721:

This is not a straight-in approach procedure. If you did a constant angle or rate of descent procedure you would eat direct prior to the VOR station.

at, thanks I overlooked that point.
However, why not provide constant descent information to the MAP (altitude and range to the DME) which would raise the flight path over the terrain, yet not compromise any circling capability.
A pedantic comment, but describing the procedure as VOR/DME implies similarities with a straight in approach, whereas it is actually a VOR/DME airfield ‘contact’ procedure.

Has it been established that the aircraft was on the procedure vice flying a circling maneuver?

According to a Spanish language paper in Honduras, the airline was reported to have fitted the aircraft with a FDR. It was recovered, and was going to be sent to the US or Europe for analysis.

DGAC reconstruirá escena del fatal accidente con otro avión - LaTribuna.hn

You can not land straight in in an airliner on this 02 approach. You overfly the runway at about 5,000 ft and circle to the left if landing on 02 or dog leg and come back to 20. I have done both procedures and they work fine. Captains hate going to 20 from this approach because they can't see anything the way they are turning.

Disorientation
 

Ref Post 24 by dvv (1989 crash of B727) and that it was Let L -410 in this accident (I do not know about the avionics onboard, but presume it to be primitive), and with interest in Spatial Disorientation, I have the following observations:-
(a) the flight path of the tragic flight in 1989 initially seemed to be high, when at a certain point the pilot started to fly lower than the mandated glide path.
(b) If the Let L-410 pilots also flew a similar approach, then they were attempting to maintain a certain visual angle to their approach to this airfield, with the hill feature obstructing the r/w.
(c) Could they, both B727 and Let L-410 had an aberrant "visual" approach making them go below the mandated glide path?
(d) If they flew low, apparently the r/w layout and how it appears for a pilot flying with a hill feature obstructing the approach, giving rise to their perceived correct approach but in the end, it was probably a visual perceptual error.
Has Spatial Disorientation, error in visual perception to be specific, been considered in this case?
PS: I am not a pilot, hence may be incorrect in certain presumptions.

The a/c had both FDR & CVR. The FDR is on its way to the Czech Republic and the CVR is on its way to the U.S.

Possible causes
 

Was this the same RWY that the TACA A320 slid off a couple of years ago?

On this L410, I thought that the EGPWS would have clicked in to keep that Hill out of harm's way? Thoughts?

Swiss Cheese, for the EGPWS to kick in, it should be there in the first place, and I wouldn't assume it was. And yes, the A320 slid off the other end of the only runway at Toncontín.

Unlikely, since in both cases the runway was obscured by clouds. In the case of the 727, the accident reports concluded that the cause was poor instrument approach procedures, rather than being a victim of some sort of visual distortion.

The 727 in '89 just descended too early. Obviously happened in this crash also. The approach to 02 needs close attention to be safe.

bubbers44:

Close attention is required to all aspects of that airport, its runway length and slopes, and its terrain environment. That is why it is treated as a special qualifications airport for U.S. air carriers and I would think those from other nations, too.

Once on the visual portion of the approach it is very challenging landing north on 02. Landing long or fast can put you off the 70 ft cliff. The 20 approach is coming into the pass to TGU so is very safe. The 02 approach puts you over terrain that will make an early descent a disaster. All the accidents I have read about happened on the 02 approach descending early.90% of the 20 approaches were a circle to 02 because of the prevailing wind.

The displaced threshold gave you 5400 ft of runway with a downslope of about 1 degree at 3300 ft MSL with a 70 ft cliff at the end. You could only make minor mistakes on this one. Wet runways made it even more challenging. We always had our landing distance charts out landing at TGU. It wasn't that hard to land there when you were comfortable with the procedures but the new guys were spooked by it at first. Some never went back.

bubbers44:

Watching that YouTube video of the 737 floating down Runway 02 gives me a major case of heartburn. It seems taking a transport jet to a Runway 02 landing when the runway is wet is setting the stage for another Sao Paulo.

French simulation of Sao Paulo:

YouTube - TAM CRASH IN SAO PAULO - BRAZIL