The Minister stated that the flight plan for the ill-fated second flight was an Instrument Flight Rule flight plan from Halim Airport, to the Pelabuhan Ratu area and back, with a planned altitude of 10,000ft. The flight was planned to take around 30 minutes.
Timeline
0710UTC aircraft requested engine start.
0721UTC aircraft took off from Runway 06 and climbed to 10,000ft.
0724UTC aircraft contacted ATC at Soekarno Hatta airport along radial 200 from Halim VOR (VHF Omnidirectional Range beacon).
0726UTC aircraft requested to descend to 6,000ft.
0728UTC aicraft requested to make a right orbit over Atang Sanjaya (Bogor) Training Area.
0752UTC ATC attempted to call aircraft as it disappeared from radar.
0755UTC ATC reported the missing aircraft to the Air Traffic Service Coordinator.
0835UTC SAR "Uncertainty Phase" declared.
0905UTC ATC contacted Search and Rescue
0955UTC SAR "Alerting Phase" declared.
1122UTC "Distress Phase" declared after aircraft endurance time elapsed.
My flight path analysis/speculation of accident in Part 2 of article series is very similar to the official statements made so far.
My Remarks
This corelates with my analysis at SSJ100 Accident: Innovent but Deadly Part 2. Everything up to Point 3, matches. However, the descent from 10,000ft does NOT make sense if they planned to go to the Pelabuhan Ratu area, which is about another 25 nautical miles from where the aircraft did its orbit.
Based on this, a rough descent profile analysis can now be assembled, which will be put in Part 3 of the the "Innocent but Deadly" article series. (To be updated/linked here)
I didn't expect this to be bigtime news, but I guess since the rapid pace of development surrounding the Sukhoi Superjet 100 crash has slowed down, old rumors begin to surface. This time, the allegation of SABOTAGE.
Today, I read a tweet from Olga Kayukova (@Olga_Kayukova (Russian) / @Olga_Kayukova_e (English), Head of Communications, United Aircraft Corporation.
"We've never supported the insanity of the idea of the western provocation on the crash. No matter how people want to speculate on that."
"We have the investigation board and our experts involved. That's the basis for commenting."
I'm amazed at how Olga can keep her cool over the past few weeks, with the amount of crazy speculation that has been raised.
"In our comments we rely only on the official investigation process. The media invents totally insane stories, another media repeats."
"Nobody in Sukhoi nor in UAC spreads or supports crazy ideas. It's speculations."
How did this sabotage rumor start?
It was reported by many witnesses, that on the day of the crash, a USAF C-17 arrived at Halim Airport, and parked on the South Apron (where the Russian Il-76s were parked during the salvage efforts). After the aircraft disappeared from ATC radar, the C-17 left departed.
It certainly sounds fishy, and several journalists also asked me whilst interviewing about the circumstances around the accident. Since no one speculated further on the sabotage, I decided not to write about it, that is until I saw Olga's link to the Daily Mail article today.
"'We know that they have special technology - that we also have - to jam signals from the ground or cause parameter readings to malfunction,' said the unnamed intelligence official, highlighting a US military presence at Jakarta Airport from where the plane took off on May 9."
The facts as I know it - USAF Diplomatic Mission Support Operations
The US Air Force provides diplomatic mission support flights. 1 (a C-12 / King Air executive turboprop aircraft) is based in Halim in case Jakarta ends up in a riot that key diplomatic staff have to be evacuated. This aircraft runs around Halim airport regularly, but this was not what was reported during the day.
The US Air Force aircraft present in Halim that day was reported as a C-17. How coincidental, SSJ-100 in Jakarta, at the same time the C-17 turned up. But, it's nothing more than a coincident. The USAF C-17 regularly fly to Halim Airport (once or twice a month, but no less than once every 3 months, depending on the agreement between the Indonesian and US Governments), also to support the US diplomatic mission in Jakarta. The aircraft would land, and park at the southern apron, offload stuff, and then onload some stuff, refuels, and depart again. Often, they spend about 1 - 2 hours before departure seemingly doing nothing.
What does these "support flights" do?
Simple: Emergency supplies for the embassy. The US Embassy, has emergency ration supplies in case of war or civil obedience. The amount of foods and supplies they keep, is not for me to know or disclose, but those supplies have to be rotated regularly, and the rotation require a closed-loop secure supply chain. That is why they had to use the USAF to support this supply rotation.
Furthermore, the US does not want a repeat of the "Embassy Scandal" that happened in Iran, where shredded and destroyed documents were painstakingly reconstructed by the Iranians and then published as "Documents from the US Espionage Den" (اسناد لانه جاسوس امریكا), which contained information that are still classified by the US even today. One of the tasks was to evacuate shredded documents for secured destruction. I am told that when the aircraft has completed off loading supplies, re-loaded it, and then refuelled, one of the reasons for waiting around for an extra hour or two, was to wait for the last batches of "shredded documents" to be airlifted. And no, these documents are not carried in trucks, it can be as simple as someone with a small back pack, inconspicuously entering the aircraft, and leaving the aircraft without it.
They're just standard C-17s. No non-standard fancy gizmos put on them. The US is more scared of losing its secret technology in a plane crash caused by poor fuel quality being provided by civil suppliers (eg: Pertamina at Halim Airport). Observers of the military signals, intelligence, and counter-intelligence equipment in aviation know that to bring down an airplane such as the Superjet-100 in "mysterious circumstances", require lots of fancy gizmos, and at sizes that would make it obvious the aircraft carrying the gizmos are not a standard one!
My opinion remains, this USAF C-17 aircraft present at Halim that day, was a non-issue in this accident. Even a staunchly anti-American journalist interviewing me could accept that. I told him it would be far easier for anyone to bring the airplane down through other means (hey, ex-Soviet MANPADS are reported to be widely available in the blackmarket!) and getaway with it.
A farewell to the dead is always grave and sad but the words that we choose to express how we feel being left behind by those who departed often brings meaning to something that was previously under appreciated. This blog article is an epilogue given by my good friend Himanda Amrullah, to Indonesia's leading aviation photo journalists, DN Yusuf, who perished in the Sukhoi Superjet 100 at Mount Salak earlier this month.
DN Yusuf immortalized in a wall poster in Manda's room
In 1995, I was still 11 years old. From a roadside magazine stall in South Jakarta, I got my very first Angkasa (Sky) magazine. After I got the magazine, I, who was still a young kid, was overjoyed seeing the photos of various aircraft type which gave me an everlasting impression, unlike those I saw in the Yellow Pages, which I used to look at before I got to know this Angkasa Magazine.
My parents supported my enthusiasm for the aviation world and would buy me an Angkasa magazine every month. It was from there where I began to know the names behind the photos that impressed me, along with the small letters in a corner of a photo, to credit the photographer, and the name that was stuck in my mind was, DN Yusuf, who took most of the aircraft and airport photos in Indonesia for Angkasa magazine.
When Manda heard about the tragedy, he waited at Halim Airport to hear news, and took these photos.
Long before the internet invasion, long before the birth of Indoflyer aviation enthusiast community, or aviation photography sites such as airliners.net and jetphotos.net, it was the work of DN Yusuf that gave me the knowledge and opened my mind into airplanes and the aviation world. It was from his work that I began to know the detailed anatomy of various civil and military aircraft.
Between the accident site and Halim Airport, the helicopters come and go...
It wasn't all about the images, the photos from DN Yusuf were accompanied by articles of Angkasa reporters. After I entered university, the works of DN Yusuf and Angkasa reporter Dody Aviantara, and the others in the Angkasa team, gave me the motivation I needed to chase my dream to become a pilot.
I visited the Angkasa office for the first time in 1997, but I did not meet DN Yusuf then. I finally met him in 2004, and it was then when I wrote my first article for Angkasa.
... and bodies begin to arrive...
After I got to know DN Yusuf, it was apparent to me that he was not just a photo-journalist doing his routine runs as a journalist for Angkasa. He had an aviator spirit and an overwhelming passion for aviation which he took along with him as he performed his duties as a professional photo-journalist. It was then obvious why his works were so powerful that it inspired many young aspiring youths wanting to jump into the aviation world in Indonesia.
Awaiting for the next one...
In 2008, I was given the opportunity to work as a photo-journalist with the Media Indonesia newspaper. Covering aviation news was something that I always looked forward to because it was then that I could meet DN Yusuf on many occassions. After covering the news, we would normally sit together and engage in a long discussion on aviation, and hear his experience covering various aviation events that came with challenges. Not long after those discussions, an article on DN Yusuf's experience, was printed on the Angkasa magazine.
The last time I met him, was at the Bali International Flight Academy graduation ceremony for the 4th batch in 2011, where the graduates all went to Garuda Indonesia. At that time, I was a pilot undergoing training with Lion Air.
DN Yusuf said to me:
"Bro, very few people have the opportunity to be like you, back then you were just a flight simmer playing at home, then you became a journalist and finally you're becoming a pilot.
Write about your experience, not many journalists end up as pilots, you have many photos and works that cannot be made by other people. I'll wait articles you write on your various experiences..."
Brother DN Yusuf, all this is because of the motivation and inspiration you have given through your work and perseverence as a highly dedicated photo-journalist.
The photo of DN Yusuf leads his own funeral procession
I thank you DN Yusuf, I am blessed and fortunate to have met a person such as you.
DN Yusuf and his colleague, Dody Aviantara, died while on duty covering the Sukhoi Superjet 100 demo flight, they died in honor.
Farewell My Friend...
ABOUT MANDA:
I first knew Manda in his university days when life was always a dilemma between "what can be reached" and "what is dreamt." His story only spanned a few years but is filled with meaning, expressed in his "Children of the Sky" writings that, described his struggle to achieve his dream to become a pilot and the story of his best friend, the late Fandy Aditama, up to the point when Manda became a pilot with Lion Air. Upon reading his epilogue for DN Yusuf, I realized that I was not the only person who asked for Manda to write about his journey. DN Yusuf did so too. From dreamers to doers, the love of flight brings an abstract bond between enthusiasts.
Controversy and coverage of the Sukhoi SSJ100 crash continue, albeit now not continuously in the headlines. One point that people continue to ask me is: "Surely the Sukhoi crew the risks associated with the local geography, didn't any local pilot join the flight crew in the cockpit?"
Answer: YES, the first flight had a local pilot in the observer seat in the cockpit.
Photos of the 1st demo flight showed a Capt. Setyaki from Sky Aviation occupying the observer seat. However, little is known on what capacity did he occupy that seat. Was it to assist the flight crew? Provide area familiarity cues/pointers? Or purely to enjoy the flight.
Whatever the reason, the fact remains, he was there. Even if he was there purely as a "previledged passenger", his presence would surely be able to add a pair of eyes to watch out for "unique local risks."
Approaching AL, with Capt. Setyaki on the jumpseat taking photos himself
Fortunately or unfortunately (depending on how you look at it), he wasn't on the second flight. I am sure that any information given by the jumpseat occupier with regards to the local area would be useful for the flight crew.
However, whether that information or his presence on the second flight could/should have prevented this accident or not, is questionable. After all, even my friends who fly in and out of Jakarta's main airport everyday and fly over Halim as they head to the east said, they don't know exactly how far the distances are from Halim to Mt. Salak and Mt. Pangrango, as it's not on the airway they frequent. They'd also think in zones, much like what's depicted on the charts, such as MSAs (Minimum Sector Altitude) and MORAs (Minimum Off Route Altitude), which also provide some cushion of obstacle clearance. Capt. Setyaki at Sky Aviation, don't normally fly in and out of Jakarta anyways, Jakarta isn't on the route network for Sky Aviation, so his pointers would be "general" albeit complete.
Would a sightseeing pilot in the observer seat know where the airplane was? Sure! I'm not a pilot, and even I can read the navigation display and the horizontal situation indicator below the artificial horizon, and obtain a quick picture on where the aircraft was in this photo:
First Officer's Panel (Photo by Andy D / @infohots)
My opinion remains that, a local pilot present in the flight deck on the second flight may not have prevented the accident, unless you put someone who is familiar with the area (which are air force pilots (and mainly helicopter pilots from Atang Sanjaya), or instructors and student pilots based in Halim who frequently use the Bogor Training Area) in both Visual and Instrument Flight Rules. The latter two types of pilots, aren't the usual guys companies want to put in the flight deck on a sales demo flight of a new commercial airliner.
I was very unsatisfied with the results I got from the first round of trajectory simulation for the SSJ-100 crash in Jakarta a week ago (blog article here: SSJ 100 descent: Innocent but deadly - Part 1). It does not match the crash site. I tried to find the cockpit photos by my friend Andy D (@infohots) who went on the first flight, to no avail. I felt that extrapolating based on the First Officer's panel alone is really a waste of time. No matter how I try to find alternatives, I keep coming back to the same conclusion.
All that changed today when Andy turned up again on the net and posted at the SSJ-100 crash topic in Indoflyer, and that he contacted me as well. His photos in Photobucket ran out of bandwidth and he loaded it elsewhere. I asked him to send the originals to me, so he did, along with what he can remember from his flight. It changed everything!
Captain's Panel (photo by Andy D/ @infohots)
The Captain's Primary Flight Display showed basically the same thing as the first officer's, and the detail of the new photos corrects a few errors I made:
Aircraft Indicated/Calibrated Airspeed: 238 knots
Aircraft was passing 7300ft (the difference with the other photo is only a matter of timing)
Autopilot was on, with Heading Select mode and Vertical Speed mode (029° and -1300 feet per minute), Altitude Select was 6000ft (not 2500).
The major difference in finding is on the Captain's Navigation Display:
Aircraft's Flight Management Computer was programmed and at the the aircraft was tracking towards a pseudo-waypoint called AL01 (position is roughly 150° at 3 nautical miles from AL Non-Directional Beacon)
The cyan coloured dashed-line, is actually a course-line from Halim VOR, with the selected course inbound of 241° which would put it very near the the Instrument Landing System localizer centerline for runway 24.
The display range is set at 40 nautical miles, giving the dashed white arc a distance of 20 nautical miles from the aircraft. This differs from the First Officer Navigation Display, set to 20 nautical mile range.
The green line showing the aircraft's planned track, forward of the aircraft is the same as the First Officer's, BUT, the difference (thanks to the larger selected display range), shows that the aircraft had only been going straight for 15 nautical miles or so. This contradicts the previous assumption of 25 nautical miles or so in the previous article.
First Officer's Panel (Photo by Andy D / @infohots)
A closer look at the First Officer's Navigation display, also reveal some changes. The cyan coloured dotted line, does not represent the previous flight path (this was a VERY stupid mistake for me to make!), as mentioned above, it is a course-line from Halim VOR. The previous article assumes that the line was tracking a course of 195°. Closer inspection, and some revised analysis reveals that the course line was selected to 200°.
These findings, invalidates the planned flight path assumptions made in the previous article. The revised assumption of the flight path of the first demo flight is:
I have decided to not clutter the map with my writing, but marked key items in the map.
For the Cyan coloured items:
1 A line depicting a course of 200° outbound from Halim VOR.
2 A 20 nautical mile radius ring.
3 AL Non-Directional Beacon.
The Magenta coloured items:
1 Aircraft took off from runway 24, and made a left turn to the southwest towards Bogor Training Area while climbing to 10,000ft.
2 Entering Bogor Training Area, aircraft turned left to the east.
3 A right-hand orbit (360° turn) was made at position HLM200/20 (20 nautical miles from Halim VOR on radial 200°).
4 After completing the orbit, aircraft leaves Bogor Training Area towards AL01, and begins to descend to 6,000ft sometime after completing the turn.
5 Approximate position of aircraft when the flight deck photos were taken (Near radial 150° at 10 nautical miles from Halim VOR), as aircraft descended towards 6,000ft. Aircraft then descended further along the magenta line until on the ILS for runway 24, and landed.
Note: Bogor (Atang Sanjaya) Training Area (WIR4) coordinates for those interested, are: 06°31'00"S 106°30'00"E, 06°31'00"S 106°50'00"E, 06°38'00"S 106°50'00"E, 06°38'00"S 106°30'00"E, 06°31'00"S 106°30'00"E, and extends from the Ground to 6,000ft.
This is hugely different from what was written in my previous article, but this is based on Andy D's story, which I view as reasonably accurate. We also know that the second flight, took off from runway 06. Just like in the previous article, I am assuming that at least one waypoint remains the same: HLM200/20 (20 nautical miles from Halim VOR at radial 200°).
My assumption of the second flight:
For the Cyan coloured items:
1 A line depicting a course of 200° outbound from Halim VOR.
2 A 20 nautical mile radius ring.
The Magenta coloured items:
1 Aircraft took off from runway 06, and made a right turn to intercept the Halim VOR radial 200° whilst climbing to 10,000ft.
2 Aircraft continued on a course of 200° and reached 10,000ft, to enter the Bogor Training Area. The request to descend to 6,000ft and the right hand orbit would be made shortly after this.
3 After entering the training area, a right-hand orbit (360° turn) was made at position HLM200/20 (20 nautical miles from Halim VOR on radial 200°), and the aircraft also descended to 6,000ft. Note: This should keep the aircraft within the training area throughout the orbit turn.
What should have happened then:
4 After completing the orbit, aircraft leaves Bogor Training Area on the same heading before performing the orbit, and it is to obtain Air Traffic Control (ATC) Clearance to head back to Halim for the approach to runway 06.
5 Aircraft would continue to descend to 1600 until performing a visual approach to runway 06, or reach the position of HLM250/5 (5 nautical miles from Halim at radial 250°), and land.
We know points 4 & 5 never happened because the aircraft never made it back to the airport. But why?
What may have happened:
After completing the orbit, to go back to Halim Airport, the crew would have had to notify ATC of their intention and obtain clearance for it. However, we know that the ATC handling that area is at Soekarno-Hatta Airport (CGK), handling approach and departures through the area to/from that airport, and also covering aircraft going in and out of Halim Airport that is not at the Tower Frequency. At that time of day, it is the beginning of the afternoon rush hour at CGK, and the ATC handling the Sukhoi Superjet could also be handling about another 15 aircraft, in an area from Halim to the north.
The ATC frequencies can be quite busy during the rush hour period, and there is a possibility that the Sukhoi could not talk to the ATC (the radios only permit one station to talk at any one time). If they could not get to talk to the ATC due to the amount of other traffic, the crew would do what others are trained to do, maintain the last heading after completing the orbit. Unfortunately, this headed straight to Mount Salak. The Yellow Triangle with the Red Outline shows the possible path of the aircraft doing that, and we can see that if they didn't hit the peak, they would be very close to it.
I'm sure this would raise some questions:
1. Why didn't they just continue as planned by turning back towards Halim or remain in the Training Area?
Well, they asked for clearance to orbit, this is because they filed for a flight with a set of waypoints. However, doing an orbit isn't normal for "flying from A to B", so unless ATC asks them to do something else, they had to ask the ATC. They could have asked the ATC to make a right orbit and then proceed as filed back to Halim, but that would be our 20/20 hindsight asking. Yes, it would be better if they did, but it is perfectly acceptable not to.
2. Perfectly acceptable not to? But surely they must have known they were heading towards a mountain?
Again, that is our 20/20 hindsight talking. If they knew they were going to hit a mountain, they would have avoided it. You do not need to ask permission from the ATC to avoid Cumulus Granitus (aka: MOUNTAIN)... you avoid it first, then tell the ATC later.
Again, there are indications that the mountain was obscured by cloud, so they wouldn't see it while they were in transit towards the training area.
The weather imagery by LAPAN showing weather conditions near Mt. Salak at the time of the accident.
3. If the mountain wasn't covered by cloud in the previous flight, surely they would have remembered?
Not quite. Remember what I wrote in part 1:
We have the luxury in this article with the chart that has terrain information. It is reported that the crew did receive a local area briefing for Bogor Training Area, which describes the area, including the surrounding terrain, and should have included information on Mt. Salak. The charts showing the terrain would likely be VFR (Visual Flight Rules) charts, which does not include airway information, but a lot of other information for VFR flying. Yes, the pilot had to sign off that he received the briefing. However, he planned to fly at 10,000ft. Mt. Salak is only 7200ft. Attention would probably be given to the nearby and much bigger Mt. Pangrango.
If we look at the Lido chart above, we can see the MORA (Minimum Off Route Altitude) is 11,900ft. This is to give adequate clearance from Mt. Pangrango at 9,900ft, not Mt. Salak.
Furthermore, the charts the crew used, are Jepessen charts. They would not be using any Standard Instrument Departures (SIDs) or Standard Arrivals (STARs), since they're not going to another city, they would not be looking at the en-route chart except maybe for checking the MORA. The approach chart for Halim, has terrain information MSA of 6,900ft south of HLM VOR, but nothing else, and the mountains are outside the MSA circle and not covered by the approach charts.
4. So why did they descend during the orbit on the second flight but not at the first flight?
The simple explanation would be, the runway change. As I said before in the previous article, it is a general rule of thumb for jet aircraft to need 3 nautical miles to lose 1000ft of altitude. To descend 10,000 feet they would need a distance of 30 nautical miles. Even with this revised speculation, if they would be too high for the approach if they didn't descend from 10,000ft by the time they completed the orbit. Again, mental calculations would be going on in the pilot's head as they plan for the descent. If they would make the orbit at 20 nautical miles from the airport, they can make a 180 turn after the orbit, after complete that turn they would also be at 20 nautical miles from the airport. 6,000ft needs 18 nautical miles, and they still got that final approach segment of 5 nautical miles. So, descending to 6,000ft so you can be at that altitude at 20 nautical miles, is perfectly normal. The runway change from runway 24 to runway 06, had shortened the flight by a significant amount, hence the major difference in top-of-descent points between the two fligths.
5. Surely they would have the right charts to keep them away from terrain?
This was an IFR (instrument flight rules) flight and not a VFR (visual flight rules) flight. I am not going to discuss this much on this article, I had covered it enough in the previous article about what charts they used (Jeppesen charts, the ones used in my articles are Lido charts). However, just to show what charts they had in front of them, these photos shows it all:
Chart on left is an approach chart, chart on right is an airport ground chart
Approach chart shown for the first flight, the second flight would have that chart replaced with the one for runway 06.
Note that no other charts are visible, no enroute charts, no VFR charts, and yes, this is perfectly acceptable for short IFR flying to and from the same airport.
Changes from Part 1?
The Bogor Training Area argument made by the ATC, is logical, and relatively innocent (I'm not into the blaming game... that's for criminal investigators and lawyers... I'm here for safety, which needs a "blameless" investigation, or in my case, objective speculation.
The other change is that this can now explain the orbits. These are made when you need to extend the flight time, such as for sales demonstration flight like this. It also means that the crew were aware of the general local environment, and in a reasonable and foreseeable attempt to mitigate risk, they chose to use the Bogor Training Area, and make the orbits to extend the flying time by an acceptable amount. However, neither the crew nor the ATC, could have reasonably foreseen (without hindsight) the significant increase in risk posed by the runway change, as the planned use of the Training Area was perfectly safe for operations with runway 24 at Halim. Well, they didn't use the Training Area, they used the area above the training area, this provided additional safety margin from the surrounding terrain... as long as you fly to/from runway 24. Unfortunately, the second flight used runway 06.
Conclusion:
Runway changes screws up pilots' descent planning on a daily basis. These guys on the Sukhoi were good, very good! Top notch test pilots, they stayed ahead of their game in the descent planning in an unfamiliar situation, but at the cost of additional risks they did not foresee (and not out of carelessness), to which blame-pointers will feast on the dead. In my opinion, it remains that lack of familiarity with local operating conditions, resulted the tragedy. Possible busy ATC and its radio frequency, and its effects in conjunction with the surrounding terrain, was likely not foreseen by anyone involved in the planning.
Again, I will say that unless the investigators find something else, the information currently available to the public, does not indicate any "pilot bravado" or "ATC cover-ups" (in fact, they're quite open about it but will not disclose anything more than what they need to disclose at this point in time).
This article, is just an objective speculation aimed at answering some of the questions running around everyone. The truth at the end of the day can be close to this, or very far from this. However, it is my hope that this article can provide answers against reckless speculators, and the blame-pointers.
I end this article by saying that the simple question on why they descended and why ATC gave them permission to do so, in my books, is answered; and that one of my flight simulator guinea pigs, tested the above theory. His aircraft didn't end up in the mountain, but it very nearly did, and at 6000ft he missed the crash site by a mere 500 meters...
Following on from SSJ Descent: Innocent but deadly, I theorized on how the plane could innocently made the descent, and how the ATC could also be blameless for authorizing the descent. That article does not explain how it ended up hitting the mountain. In this article I am showing where it crashed, but not how it ended up there. This accident is already very tragic, but criticism on the pace of the salvage efforts, like many other things in this accident, irks me. Let me add to the tragedy a little bit: the aircraft ended up at possible the worst place in the whole mountain!
So, where did it end up? Coordinate information given so far vary. The variation of these coordinates led to some locations that fed more speculation, etc.
Let's start with what we have... this photo:
Now, to find the exact location is impossible. Maps for Java are relatively accurate, but for Indonesia as a whole, it's a nightmare! Hey, I should know, I used to be in the mapping business remember? Ironically, how I started mapping and flying at the same time, all started by flying between Mount Salak and Mount Pangrango 9 years ago! One of the best free resource we have today is Google Earth. The nice 3D feature enables us to do things that until recently are limited to expert GIS people.
Finding the location starts by trying to match the photo, with running around Mount Salak on Google Earth using various angles, heights, and viewpoints, and then narrow down the possible sites one by one. The strange thing is, only 1 place matched the photo... this:
Where is this location? On Google Earth, the red triangle there, is at 6°42'48.14"S 106°44'8.44"E.
This is a plan view of the location.
Why do I say it is the worst place in the mountain?
It is located near the peak of the mountain.
The terrain wall it hit, is amongst the largest in terms of height from top to bottom, in the whole mountain, and it is one of the steepest.
It is in a narrow confined location.
This makes the impact site difficult to spot even from the air, let alone from the ground. Access to the site is also very difficult. What makes it worse (and worst of all), the narrow confinement of the location, not only access is difficult (by land or air), retrieving anything from there and bringing it elsewhere is a huge challenge. I guess the slow progress of the SAR team is testimony of the difficult situation.
From the previous article SSJ Descent: Innocent but deadly, I wrote about how the crew might not realize that Mt. Salak was there. However, the explanation in that article, makes it extremely difficult to reconcile with the crash site. The trajectory from that analysis, would yield an impact from the north east or from the east. On the photo of the crash site on the cliff wall, it should show a predominantly left-to-right trajectory, but the photo shows impact characteristics that relatively right-to-left, which means, the aircraft had to come from the north and at relatively high speed (300 knots ground speed is just within "high speed impact" category in my books). BUT... details of the crash site, description of the bodies found, description of "engines relatively intact", etc, all point to a low to medium speed impact.
Therefore, there HAS to be a different theoretical trajectory for the aircraft that is different from my previous article. It looks like I found it just now... but it'll take time for me to write it as I need to take time to make sure it looks plausible, and doesn't break my own ethical boundary for "objective speculation."
In the meantime, here are some more Google Earth images on how the impact site looks from the north:
The impact site from the east. Coming in from the east does not match the impact site characteristics, and they should have hit the ridge before the crater instead if they were to crash.
An incoming path from between north and north east, is a lot more likely. There is a lot of space for them to end up hitting the cliff, without too many probable incoming paths.
It is a question that has been bugging me, and probably a lot of other people too.
Why did he descend? Why did the ATC authorize the request to descend?
I am not into the blaming game, but I want my questions answered. The official answer, will have to come from the official investigators. In the meantime, I can't stop my mind from exploring plausible theories.
We can see that it is obvious that there are terrain just south of the 25 nautical mile MSA (Minimum Sector Altitude) circle. The MSA for the south is 6,900ft. The MORA (Minimum Off Route Altitude) for the Mt. Salak area is 11,900ft, thanks to the higher and bigger Mt. Pangrango just to the east.
IFR vs VFR... Instrument vs Visual Flight Rules
Question: If it's an IFR flight, MSA 6,900ft? MORA 11,900ft? Why descend?
The next question I asked: "Was this an IFR flight or a VFR flight?" Wait, it could be a VFR flight. If it is a VFR flight, he should have done all he needed to remain in 5 kilometers of visibility, and stay away from the clouds and terrain. But, did he lose Visual Meteorological Conditions (VMC)?
If one loses VMC on a VFR flight, one is in Instrument Meteorological Conditions (IMC). Best thing to do, bug out! If unsure, make a 180 turn and come back to where you were before, it might as well be the fastest way to return to VMC. Ducking under the cloud, is an option, but only if you know what's down there, otherwise, you'd be asking for trouble. The question then becomes, "did he know there was a mountain down there?"
If I stay on this, I'd be running around in circles. Then I asked...
Where did they go on the previous flight?
I discussed this with my friend and fellow AvGeek, Andy D (@infohots) who went on the first demo flight that day. He said he couldn't see much because he sat on the aisle seat, but the flight was short, and no "funny maneuvers" were made (which is alleged by some media). That flight took off and landed on runway 24 at Halim Airport.
He managed to take a photo of the flight deck before landing at Halim Airport.
SSJ100 co-pilot displays on first demo flight as the aircraft nears Halim Airport
We can see that the aircraft was on a heading of 029°, doing 238 knots indicated air speed, passing 7200ft, 10 nautical miles from Halim airport roughly at a bearing of 150°. The next waypoint programmed in the aircraft FMC (Flight Management Computer) is AL01, a pseudo-waypoint (AL 150°/3nm approx) at 10.1 nautical miles away, used to allow for a nice turn onto the ILS 24 at AL NDB. We can also see that the aircraft is on Heading Select, Speed Select, and Vertical Speed Select modes (029°, 230 knots, -1300 feet per minute), with Altitude Select at 6000 feet. Winds indicated on the top left of the Navigation Display shows 150° at 8 knots, a ground speed of 274 knots, and true airspeed of 270 knots. The orange box surrounding the "SPEED" on the Flight Mode Announciator, hints that the aircraft is faster than the selected speed, but the autothrust has already commanded idle thrust.
The green line shows the FMC flight path, and we can see that the aircraft has been flying straight for over 10 nautical miles when the photo was taken. There is also a dotted cyan coloured line extending from Halim Airport to the bottom of the screen. Taking measurements of these lines, it can be estimated that the cyan line roughly follows a line extending out of Halim VOR (HLM) at a course of roughly 200°. Coincidentally, airway R206 extends from Halim VOR at a course of 195° with a MEA (minimum enroute altitude) of 10,000 south of Halim).
Initial Testing of a Theory
Where do the green and cyan lines intersect? Let us go for a convenient location, 30 nautical miles out from Halim along airway R206.
We can program the Flight Management Computer this way: 1. Depart Runway 24 2. Proceed to HLM195/30 (radial 195° at 30 nautical miles from Halim VOR) 3. Proceed to AL150/3 (radial 150° at 3 nautical miles from AL non-directional beacon) 4. Proceed to AL NDB 5. Proceed with ILS approach runway 24. 6. Set the cruise altitude at 10,000ft Total distance would be about 80 to 85 nautical miles.
Initial theory of the 1st flight based on the photograph Cyan: Planned, Green: Descriptive Flight Path
To go back to Halim, for an ILS24 (instrument landing system approach for runway 24), they would simply turn left towards AL01. Ideal! They stayed at the MEA, above any immediate terrain risk. Top of Descent would be after the turn was completed, and after they were well away from terrain. Simple rule-of-thumb of jet flying of "3 Nautical Miles per 1000ft" on descent concurs with this, and they were quite close to Halim Airport when still at 7200ft.
Runway Change for Second Demo Flight
Andy, told me that he heard the discussions that the next flight would be required to be done to/from Runway 06. The reason for this is, as he recalls, is to keep the aircraft away from conflict from traffic to/from the main international airport, Soekarno Hatta (CGK/WIII) to the north east as they expect the runway in use to be 07L/R. The change to runway 06 for Halim would ensure that traffic inbound to Halim Airport would stay away from the departure flows from CGK, and below the incoming flow to CGK.
The above, is important for the ATC (Air Traffic Control) at Jakarta, which literally swamped with traffic on a daily basis at peak hours. The second demo flight would take at the beginning of "Golden Hour", a term several colleagues use to describe the afternoon peak traffic flow periods at CGK.
So, with a simple runway change to 06, the waypoints would now be: 1. Depart Halim runway 06 2. Proceed to HLM195/30 (radial 195° at 30 nautical miles from Halim VOR) 3. Proceed to HLM250/5 (radial 250° at 5 nautical miles from Halim VOR, this is the straight in portion for the Halim VOR approach for runway 06 as there is no ILS for runway 06) 4. Land at Halim runway 06. 5. Set the cruise altitude at 10,000ft Total distance would be about 55 to 60 nautical miles. With the cruise altitude set to 10,000ft like the previous flight to stay clear of any terrain.
Suspected planned flight path for second demo flight. Cyan: Waypoint-to-waypoint. Green: Descriptive estimate.
Effects of Runway Change and FMC default waypoint Fly-By turn method
The plan for the second flight, would be much shorter, at 57 nautical miles. From after completing the turn near the mountains, the distance to go to land would roughly be less than 30 nautical miles. Counting the effects of the "fly-by" method of FMC navigation for turns, there will always be a short cut made due to the arc in the turn.
Unless a particular waypoint is set as "Fly-Over", the default FMC turn method for the waypoint would be "Fly-By" where it would turn inside the straight lines into and out of the waypoint, using standard turn rates, to prevent overshooting the next planned course line to the next waypoint. This is why for both flights, I use the cyan colour for the FMC plan, and the green colour for the estimated actual flight path or flight path anticipated by the FMC. There are however, limitations to how much the FMC would shortcut in sharp turns. Depending on the speed, very sharp turns will remain at standard turn rates, but the flight path stays no further than a set radius from the waypoint, and allow some overshooting of the next segment course. This is to prevent wide deviations from airways when there are sharp turns, reducing navigational accuracy.
The FMC does this because it is designed to optimize the flight in terms of distance, time, and cost. Fly-by reduces the distance, fly-over increases the distance travelled. The problem is that for fly-by turn method, the flight paths of the turn aren't always repeatable, depending on the conditions at the time (wind, speed, etc). So the green line in the charts are only descriptive.
With the paths of these demo flights, the shortcuts generated by the FMC can be quite big as a percentage of the total distance travelled. This brings the Top of Descent much earlier.
Calculating your descent
Given the FMC waypoint fly-by default method, the top of descent from 10,000 feet for the second flight would likely be before the turn back to Halim. The descent request could have ben made within the Bogor Training Area.
The turn back to Halim is almost a 180° turn. If the turn was commenced at 25 nautical miles away from HLM, the turn would be completed with the same distance from Halim. That would also allow the aircraft to come reasonably close to the waypoint at 30 nautical miles during the turn. From there, the aircraft has about 20 nautical miles to go to the final approach, which require extra distance to slow down and allow the aircraft to configure for the final approach. This slowing down can take between 3 to 5 nautical miles in level flight. The mental calculation that would go on in the pilot's head could be something like:
5 nautical miles for slowing down to final approach therefore
15 nautical miles to descend after completing the turn.
15 nautical miles means I can lose 5000ft.
To be at 1500 feet in 15 nautical miles, I need to be at about 6000 feet or lower leaving the turn.
To lose 4000 feet, I'm going to need about 12 nautical miles.
At 300 knots true airspeed, the 180° turn will take about 8 nautical miles, losing 2000ft to 2500ft or so.
That means I need to start my descent before I reach 4 nautical miles before commencing the turn, therefore start the descent about 21 nautical miles from Halim, before the turn back to Halim.
To give a few miles spare distance, I can start descending perhaps at around 17 nautical miles from Halim or so.
Guess what, 17 nautical miles is within Bogor Training Area, and nearer to the northern edge of the area. The explanation by the ATC that they allowed the aircraft to descend to 6000ft because the aircraft was at Bogor Training Area, is very logical, and without abusing our 20/20 hindsight, perfectly innocent.
From the Lido chart, we can see the deadly implication of this. The aircraft impacted terrain at around 6200ft elevation at a position of around 27 to 28 nautical miles from Halim. To lose 3800ft, one needs about 11 to 12 nautical miles. This could mean he descended at around DME15. The 2 nautical miles, may sound a lot, but, that's about 24 seconds only at 300 knots.
But surely he must have known he was heading towards a mountain???
Yes, sure, thanks to our 20/20 hindsight, it's simple to jump to that conclusion. Let's throw out our 20/20 hindsight.
First question, did he see the mountain?
Weather data gathered by LAPAN's Atmospheric and Science Center
A Kompas newspaper article came out on 11th May, citing the Atmosphere and Science Center of LAPAN, Indonesia's national space and aviation agency, stated that the aircraft was likely to have been surrounded by weather. There were cumulonimbus clouds in the area, and the weather satellite image below, shows the situation near the time of the accident. Mt. Salak, was very likely to have been obscured by cloud.
Second question, did he know the mountain was there?
We have the luxury in this article with the chart that has terrain information. It is reported that the crew did receive a local area briefing for Bogor Training Area, which describes the area, including the surrounding terrain, and should have included information on Mt. Salak. The charts showing the terrain would likely be Visual Flying Rules (VFR) charts, which does not include airway information, but a lot of other information for VFR flying. Yes, the pilot had to sign off that he received the briefing. However, he planned to fly at 10,000ft. Mt. Salak is only 7200ft. Attention would probably be given to the nearby and much bigger Mt. Pangrango.
Halim AFC chart by Lido (Lufthansa)
If we look at the Lido chart above, we can see the MORA (Minimum Off Route Altitude) is 11,900ft. This is to give adequate clearance from Mt. Pangrango at 9,900ft, not Mt. Salak.
Furthermore, the charts the crew used, are Jeppesen charts. They would not be using any Standard Instrument Departures (SIDs) or Standard Arrivals (STARs), since they're not going to another city, they would not be looking at the en-route chart except maybe for checking the MORA. The approach chart for Halim, has terrain information MSA of 6,900ft south of HLM VOR, but nothing else, and the mountains are outside the MSA circle and not covered by the approach charts.
The pictures uploaded by Andy D (shown in part 2), only showed that the crew had the approach and ground charts when he took photographs of the cockpit. No enroute charts, no VFR charts (and these are quite sizeable even when folded), but since he was flying IFR, why would he need the VFR charts? So, it is unlikely that they had the charts showing where Mt. Salak was.
Third question, couldn't they see Mt. Salak on the flights? Surely they should have seen the 7200ft mountain on a 10,000cruise altitude?
Well, not really. If we look at this video:
Video by Fotografersha/Lystseva Marina/@lystseva
We can see at 3:39, to 3:50 the general visibility condition for the first flight. Less than 10 kilometers. On the take-off cabin view shown at 5:10 to 5:30, the visibility is about 7 kilometers (this didn't get any better at Halim for the final take off shown at 7:38, and at the beginning of the video).
On the first flight, the flight distance to D30 is closer than the second flight. They would be close to D30 at top of climb. This leaves a very narrow time window for Mt. Salak to appear and be seen in front of them. During the climb, their view of Mt. Salak would have been relatively obstructed by the aircraft's nose attitude, therefore wouldn't raise attention. If it was obstructed by cloud, they would have completely forgotten about it because attention would be given to Mt. Pangrango instead. This is the dominating mountain for the Jakarta area, it rises to 9,900ft, and very visible during the left turn back to Halim for the first flight.
This would latch on to the mental picture for the second flight. If they lose visibility, they would surely want to stay away from Mt. Pangrango. Mt. Salak, was innocently forgotten.
Looking out for Mt. Salak - Flight Simulator fans as guinea pigs
I tested several flight simulator friends, inviting them to "reconstruct the SSJ100 crash." The ones selected had to have the real terrain mesh, conduct the flight and debriefing was made on each flight. The flights were:
SimFlight 1: Depart runway 24 Halim, proceed to 45 nautical miles on a radial of 195° from Halim, and turn back to land runway 24. Cruise altitude would be 15,000 feet.
SimFlight 2: The same as SimFlight1, but use runway 06.
SimFlight 3: Depart runway 24 Halim, proceed to 30 nautical miles on a radial of 195° from Halim, and turn back to land runway 24. Cruise altitude would be 10,000 feet.
SimFlight 4: Same as SimFlight 3, but use runway 06.
On all flights, weather was set to clear skies, to exaggerate the mental picture on what they see and suppress mental clutter.
Each debriefing started with them asking me back, "What's the point of this?" They thought we were going to simulate the crash, not the factors surrounding it. What was found:
Everyone commented that during climb, the mountain they can see would be Mt. Pangrango and not Mt. Salak.
Everyone commented that during cruise, attention would be given to Mt. Pangrango because the peak elevation isn't far from the planned cruise altitude.
Everyone raised attention to Mt. Pangrango when and after making the left turn to turn back to Halim (before the descent and approach runway 24).
None mentioned their awareness of Mt. Salak. When questioned, no one can describe the position of Mt. Salak in comparison to their position.
I asked several pilots who fly in and out of Jakarta's CGK, where the SID to the east would take them over HLM VOR. All knew that the were 2 mountains south of Jakarta, but as expected, none could recall the rough distances from HLM to the terrain. Even those who had trained in the Bogor Training Area, cannot recall the distance from area to Mt. Salak. They just took the assumptive prevention of "let's not go south of the training area." The pilots, generally agree with my findings on pilot perception from the flight sim tests.
Conclusion for Part 1: This blog article does not attempt to explain or speculate on how the crash happened, but only to seek a logical explanation on why the request for descent was made and the clearance to descent was given. It is extremely unlikely that they saw Mt. Salak when they made the request for descent. It is quite unlikely that their main concern about terrain was Mt. Salak, worrying about keeping separation from Mt. Pangrango would be sensible.
It is ironic that a simple runway change would cause such a dramatic change in situation, risk, etc. But it happened, and happened innocently. If this explanation is logical, we should therefore dismiss:
Allegations of pilot bravado, and carelessness
Allegations of ATC carelessness and cover-ups (and hey, the ATC had other aircraft to monitor too, not just this aircraft!)
The final descent for RA-97004 is seemingly innocent, but deadly.
This is only "Objective Speculation," using publicly available data and information. It is aimed at answering/countering the reckless speculation and allegations that are out there. For official stuff, well, go and look for the official press releases, and when it comes out, the final report. In Part 2, I will discuss the updated version of the speculation provided in this article, using updated information that were made available to the public from various sources. Note: Updated info received and is included in Part 2: SSJ 100 descent: Innocent but deadly - Part 2, and article on my view of the crash site is at: SSJ 100 crash site: The worst place in the whole mountain.
