Menu Sign In Contact FAQ
Banner
Welcome to our forums

TB10 HB-EZW down near Lucerne

dirkdj wrote:

Unless you lean the mixture properly for take-off hot and high, you will be even more underpowered. Many flat-land pilots under-use the mixture control.

Thankfully there are no flat land pilots at that airport…. least of all the one who perished. He was a military pilot (FA18) plus the chief pilot and chief test pilot of Pilatus aircraft, amongst other things on the control of the first flight of the PC24 and responsible for the whole flight test program. He flew the TB10 quite often, it was owned by the flying group of the employees of Pilatus aircraft.

Friend of mine who was one of the last people to fly the very plane before the accident calculated it out. At 4000 ft with ISA plus 15°, the AFM predicts a climb rate of 900 fpm at MTOW. My friend sais, he’d reckon 700 fpm are more realistic. The distance from the rotation point to the pass is 8 km, translating in 3-20 minutes flight time. The altitude of the pass is at 2900 ft according to him (I read 3000 ft before), airport elevation at 1525 ft, DA as we have calculated before around 4000-5000 ft over the pass. Minimum crossing altitude is around 3500 ft.

So the net altitude difference is about 1500 ft and to the minimum crossing height around 2000 ft.

With a flight time of 3-20 to there, to hit the top of the pass would mean a climb rate of 450 fpm, which a 180 hp airplane should be easily able to do even at MTOW at 4000 ft DA. At 700 fpm, you’d be able to climb 2300 ft, so to about 3700 ft AMSL, which is 800 ft above the pass. According to AFM even 4000 ft would be possible.

One bit he describes is that at Vy the forward visibility is rather bad so most people climb with lesser pitch and higher speed. This could be significant. But then again, that pilot has crossed that pass countless times in this airplane and should well be able to judge the flight path even out of the side windows. Yet, by the looks of it, he hit a tree at the very top of the pass and consequently crashed into the forest.

LSZH, Switzerland

My remark was not intended or directed to anyone. Just a reminder to lean for takeoff when needed. The highest airfield in Belgium is EBSH at 1850ft. When the temp is ISA+20, you better lean for takeoff, trees are high and near.

EBKT

Mooney_Driver wrote:

One bit he describes is that at Vy the forward visibility is rather bad so most people climb with lesser pitch and higher speed. This could be significant. But then again, that pilot has crossed that pass countless times in this airplane and should well be able to judge the flight path even out of the side windows. Yet, by the looks of it, he hit a tree at the very top of the pass and consequently crashed into the forest.

Just looking at the flight path, the ground speed was initially around 82 knots and he was climbing at 330 feet per minute. After a minute, his ground speed had slowed to 72 knots and his rate of climb was 400 feet. Just before impact his ground speed reduced to 48 knots whilst rate of climb slowed to 250 feet per minute. My belief is that he was just too low to avoid the wind streaming over the ridge, pushing him down. Hot, heavy and with wind out of the north. Had one of those been missing, he would have likely cleared the ridge.

EDL*, Germany

Timothy wrote:

Many of us will remember seeing a friend of ours and his wife take off in a lowish powered aircraft (Jodel? I forget) from Chateau la Chassagne in scorching heat a few years ago.

We watched as he struggled to get airborne between the trees at the end of the runway and then disappeared from view. We just waited, appalled, for the bang and the smoke. We waited and waited and eventually saw them way below us in the valley skimming the trees and eventually climbing slowly towards Dijon. It was a very strong reminder to all of us that hot and high is a lethal combination. The rest of the party then decided to wait until the heat of the day subsided.

Won’t forget that ever – watching them fly waveringly between and below the tops of a clearing in the trees at the end of the runway – and then disappearing… I decided to wait till the heat subsided AND to send my passengers on by car to collect them at Dijon… despite having two 260hp engines and minimum fuel.

dirkdj wrote:

Unless you lean the mixture properly for take-off hot and high, you will be even more underpowered. Many flat-land pilots under-use the mixture control.

Just a quick heads up / reminder for those who may fly the SR20 – although it is not a turbo, that aircraft has a density compensating fuel metering system. Never lean an SR20 for takeoff. The SR22 (Non turbo variant) does not have a density compensating system, so there is potential for confusion if you fly both.

Well, it gets more confusing.

He did clear the ridge and then turned left instead of straight ahead where his flight path should have taken him. The crash site is not at the pass, but quite a bit northeast of it. I did talk to someone who knows the area well yesterday and he is flabbergasted on how this plane got to where it ended up.

We have to be careful with flight tracking sites, all of them, their data are not exactly FDR readouts.

LSZH, Switzerland
LRTC, LRPV, LFPN

At 4000 ft with ISA plus 15°, the AFM predicts a climb rate of 900 fpm at MTOW.

This sounds very high to me. The comparison from a former thread here on euroga TB 9 10 performance
shows lower numbers that do correlate amlot better with the flarm data.

Last Edited by Sir_Percy at 08 Aug 15:20

LFHNflightstudent wrote:

They appear to have hit a tree according to an eyewitness…

As in, before they hit the ground? … OR does the tree have a causal relationship to the accident.

Of course all hearsay. according to this an eyewitness analysis of it is that they hit 1 or more trees on the mountain ridge before crashing. As i said – all hearsay.

Es war kurz vor 10 Uhr am Samstagmorgen, als Eduard Keiser damit beschäftigt war, die reifen Äpfel von einem Baum abzulesen. Der 58-jährige Augenzeuge stand auf einer Leiter, sein Blick war nach oben gerichtet. Keiser erinnert sich: «Ich sah, wie das Flugzeug über die Krete des Loppers flog und unmittelbar danach in Schieflage geriet. Ich hoffte, der Pilot könne das Flugzeug noch abfangen.» Dem war aber nicht so. Keiser vermutet, dass der Pilot auf der Krete einen oder mehrere Bäume touchierte

LFHN - Bellegarde - Vouvray France
Sign in to add your message

Back to Top