4th Aug 2018 Junkers JU52 crashed in Switzerland
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That video is a useful teaching tool, well done. The pilots made a routing choice I would not have made. Normalization of deviance, perhaps?
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Anyone understands why power was REDUCED before flying low into the basin?
Was it an attempt to synch the engines? Or was it just because they wanted to avoid accelerating during their slight descent to "look through" the "eye" on the ridge? Or was it to reduce turbulence?
I am confused as this power reduction is so much in contrary to usual logic, that if you don't have height (AGL), you better have lots of speed and power.
Was it an attempt to synch the engines? Or was it just because they wanted to avoid accelerating during their slight descent to "look through" the "eye" on the ridge? Or was it to reduce turbulence?
I am confused as this power reduction is so much in contrary to usual logic, that if you don't have height (AGL), you better have lots of speed and power.
HB-HOT flew past the Tschingelhörner mountain peaks and began to reduce in altitude, dropping more than 15 m in approximately 6 seconds. During this phase, the power of the engines was rapidly reduced by 30 to 50 rpm, which meant that the engines were increasingly running at a similar speed (5) . During this process, the pitch angle increased and the flight path angle continuously became more negative.
(5) This course of events is typical when synchronising the speeds of the engines"
(5) This course of events is typical when synchronising the speeds of the engines"
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the power of the engines was rapidly reduced by 30 to 50 rpm,
Two captains
Unfortunately often pilot performance goes out of the window when two mates fly together...The confusion one can also see with PF and PNF incident reports such as the recent irish one.
My first carrier had a ridiculous proceedure of the non flying pilot handling the throttles which again wasn't optimal in several ways.
It would appear that one "captain" had his head in the cockpit trying to synchronize the engines and I wouldn't be surprised if the other wasn't aware of what he was doing and vice versa.
Mountain flying as per the French gliding description of below the crest (vol de pente) is a complicated science which has no givens.
It envolves flying at times under a wing span from the face depending on the steepness of the slope, at an initial speed with energy in hand and ALWAYS WITH AN ESCAPE PATH.
In extremis one can be surprised as I was on a slope bordering the quarry adjacent to the Cape Gliding Club where I found myself and student inverted at 200ft agl.
The thermic activity generally follows the up slope even in the lee, breaking away from trigger points, converging above the crests and with down drafts away from the slope and often in the middle between two crests. (Except when the airflow has gone katabatic).
Low performance motorised flying machines are a danger as downdrafts can easily exceed 2,000 fpm and that is without any wave or rotor influence.
Neil Williams, a former British aerobatic champion who had the wing fold on a Zlin, died flying a Spanish Heinkel 111 in the 1970s doing something similar but with his wife and a couple of engineers on board.
Similarly it is thought that Steve Fossett, the round the world baloonist who tried to set a new world record height gain, did something similar.
Neither of these had fare paying pax on board nor the same level of oversight from the regulators.
My first carrier had a ridiculous proceedure of the non flying pilot handling the throttles which again wasn't optimal in several ways.
It would appear that one "captain" had his head in the cockpit trying to synchronize the engines and I wouldn't be surprised if the other wasn't aware of what he was doing and vice versa.
Mountain flying as per the French gliding description of below the crest (vol de pente) is a complicated science which has no givens.
It envolves flying at times under a wing span from the face depending on the steepness of the slope, at an initial speed with energy in hand and ALWAYS WITH AN ESCAPE PATH.
In extremis one can be surprised as I was on a slope bordering the quarry adjacent to the Cape Gliding Club where I found myself and student inverted at 200ft agl.
The thermic activity generally follows the up slope even in the lee, breaking away from trigger points, converging above the crests and with down drafts away from the slope and often in the middle between two crests. (Except when the airflow has gone katabatic).
Low performance motorised flying machines are a danger as downdrafts can easily exceed 2,000 fpm and that is without any wave or rotor influence.
Neil Williams, a former British aerobatic champion who had the wing fold on a Zlin, died flying a Spanish Heinkel 111 in the 1970s doing something similar but with his wife and a couple of engineers on board.
Similarly it is thought that Steve Fossett, the round the world baloonist who tried to set a new world record height gain, did something similar.
Neither of these had fare paying pax on board nor the same level of oversight from the regulators.
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SUST have published their final report into the accident. English version here - https://www.sust.admin.ch/inhalte/AV...B_HB-HOT_E.pdf
WOW, what a devastating report. The reality is that regulators almost always simply don't have the people who have the kind of experience to be able to accurately assess the ability of organizations operating aircraft under a "Historically significant aircraft" designation to attain and maintain airworthy aircraft and operate them safely. It is almost entirely up to the operators to step up and make the commitment to do the right things. Unfortunately like the Collins B 17 crash and this accident some ( most ?) organizations are not up to the task.
Sadly I think the day when people will no longer have the opportunity to experience a flight in an amazing historically significant airplane is rapidly coming. Insurance companies and regulators are going to cover their butts by making it impractical to operate these kind of aircraft. Organizations who operate historically significant aircraft have to take a hard look in the mirror and up their game. One more high profile crash with passenger fatalities and I think it is over for everyone....
Sadly I think the day when people will no longer have the opportunity to experience a flight in an amazing historically significant airplane is rapidly coming. Insurance companies and regulators are going to cover their butts by making it impractical to operate these kind of aircraft. Organizations who operate historically significant aircraft have to take a hard look in the mirror and up their game. One more high profile crash with passenger fatalities and I think it is over for everyone....
Now the planes are being rebuild structually and outfitted with P&W Wasps. They will be able to continue to fly scenic flights - but they are no longer "Tante-JUs"
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And I guess you alll start to get this video suggested to you by Youtube. While in most cases, you can see multiple escape routes for an engine failure or strong downdrafts, at 5:12 there is a situation similar to the accident site. But I think the site is different. So the regular route over the Alp may have been flown with more than one such high-risk / no turn-back sections.
Figures 22 & 23 attempt to show how moving from a downdraft to an updraft can increase angle of attack. Aerodynamically any sudden change in vertical air movement does change angle of attack. Add a sudden tailwind component and you may well be stalled as I have found out in my glider.
In my case I was downwind of a ridge in a 15 kt wind aloft having just turned final. Second hand I heard that another pilot had a similar encounter quite a long time ago.
The rest of the time, people fly the approach without incident.
The crew may have crossed this ridge with a similar flight path many times in the JU52 and other aircraft, but this time the thermals combined with a wind coming from a certain direction with a certain speed that upset the applecart.
In my case I was downwind of a ridge in a 15 kt wind aloft having just turned final. Second hand I heard that another pilot had a similar encounter quite a long time ago.
The rest of the time, people fly the approach without incident.
The crew may have crossed this ridge with a similar flight path many times in the JU52 and other aircraft, but this time the thermals combined with a wind coming from a certain direction with a certain speed that upset the applecart.
Interesting. I too wonder about normalisation of deviance. Flying up the centre of the valley, losing the turnaround option, is something I was taught not to do. I was also taught not to fly up a dead end valley like that with a wind on the nose. Almost guaranteed to have some downdraughts, tricky if power is limited. These every experienced pilots must have known this but perhaps had been lulled by repetition and plenty of successful flights before.
The progressive slow raising of the nose suggests a loss of attitude awareness. For mountain flying a lot of emphasis was on the horizon illusion s, with the need to keep checking the instruments. In the French Alps I was warned about the possible rapid loss of airspeed from downdraft to sudden updraft while flying through gusty turbulence near the mountainsides. Again I wonder if time and experience had dulled the concern.
A sobering report, with useful stark reminders.
'Blind Pew' - excellent post, entirely agree with you.
Ouch.
The progressive slow raising of the nose suggests a loss of attitude awareness. For mountain flying a lot of emphasis was on the horizon illusion s, with the need to keep checking the instruments. In the French Alps I was warned about the possible rapid loss of airspeed from downdraft to sudden updraft while flying through gusty turbulence near the mountainsides. Again I wonder if time and experience had dulled the concern.
A sobering report, with useful stark reminders.
'Blind Pew' - excellent post, entirely agree with you.
Ouch.
