5
$\begingroup$

I saw this youtube video today: Flying over Mt Everest. A lovely view of stunning nature - quite spectacular. However, I looked up the plane - or at least what I think is the plane - and found that it might be a propeller plane: 9N-AHV (I saw this registration number in the video).

The plane appears to be a BAe Jetstream 41 - check that link for details - it is Wikipedia.

Of particular interest (maybe):

  • Service ceiling: 26,000 ft (7,900 m)
  • Service ceiling on one engine: 15,000 ft (4,572 m)

Tibetan Plateau: "...average elevation exceeding 4,500 metres (14,800 ft)".

So it sounds like an engine failure for this plane type means that it can not descend to the acceptable service ceiling? The service ceiling is the maximum usable altitude of an aircraft.

This seems unsafe?

I am not a pilot, but I hear it is rare to fly over Himalaya / Mount Everest / Tibet because planes can't go low enough for passengers to breathe without oxygen if there is an emergency? If they lose an engine they have to descend I read. There is also a lot of turbulence. Why Planes Don't Fly Over Himalayas.

Airports: Lhasa and Kathmandu - short runways - not many places for emergency landings due to medical emergencies and such. And they wrote "the place is desolate with little people around". That sounds a bit funny seeing as the area is situated between China and India :-). Remote it is though. And China has 94% of its population in the eastern part of the country (towards the sea).

Links:

$\endgroup$
7
  • 2
    $\begingroup$ From my experience driving through Tibet I can tell you that 4500m really isn't enough. The highway routinely climbs over 5000m to get to the other side of a mountain. What people call "Tibetan Plateau" most of the time is central Tibet around Lhasa where it's high but almost flat and 4500m might be OK. But on the east side, no, at 4500m you will hit something pretty quickly. $\endgroup$ Apr 20 at 16:45
  • 2
    $\begingroup$ And no, there are not a lot of fights over Tibet because there are not a lot of people traveling there (and not a lot of people living there, either). As a result there's only one major airport near Lhasa. (At least 9 out of 10 people I know considers it "hazardous" or "risky" even flying to Lhasa, where it's "only" 3600m). Tibet is a beautiful place as long as you can handle the elevation. $\endgroup$ Apr 20 at 16:58
  • 5
    $\begingroup$ "Is it safe...?" is highly subjective. Every flight carries risk. In fact, every day you're alive carries risk. Most flights over the Plateau would be perfectly safe. I think the valid way to phrase the question is, "Does the flight meet aviation rules for that area?" Aviation rules will govern things like minimum altitude, glide range, fuel reserves, single-engine performance, etc. Either the flight meets those rules, or it does not. $\endgroup$
    – abelenky
    Apr 20 at 18:23
  • $\begingroup$ It is obviously less safe than flying over flat sea level terrain in good weather, with multiple divert airfields available. The points you raise in your question are valid and indicate that you have a solid grasp of risk assessment. So that makes me wonder what kind of an answer you seek? $\endgroup$ Apr 20 at 20:10
  • 1
    $\begingroup$ @EarlGrey It is given in Pressure Altitude, which is as a first approximation equal to altitude above mean sea level (AMSL). Local weather phenomena can influence local pressure though. $\endgroup$
    – Bianfable
    Apr 22 at 6:59
5
$\begingroup$

The video starts with Mt Everest straight ahead while in a left turn. And based on the video description, the flight took off from Kathmandu. The Nepalese AIP depicts this Mountain Flight Route, shown in red below, and the turn we see is the video would be the turn going back to Kathmandu.

enter image description here
https://e-aip.caanepal.gov.np

Note that the Tibetan Plateau is north of the Himalayan range. If something goes wrong, a safe altitude less than the Jetstream's 15,000 feet limitation is within reach to the south or on the way back to Kathmandu:

enter image description here
skyvector.com

$\endgroup$
6
  • $\begingroup$ That't great information, thanks! Any idea why they use propeller plane? Better for turbulence? Cheaper to fly? The plane size needed not readily available with jet engines? More reliable? Now it borders on a brand new question I guess. $\endgroup$ Apr 21 at 17:25
  • $\begingroup$ @SteinÅsmul: That Jetstream is a turboprop, i.e. as reliable as jets. If there's high demand, sure they could consider bigger planes. $\endgroup$
    – ymb1
    Apr 21 at 17:27
  • $\begingroup$ Jiri airport is a barely recognizable grass strip in a rather narrow valley. Fairly useless in an emergency. But the route as a whole is along the southern slope of the mountains, so escape to lower ground is readily available. South of the 094 radial KTM it's no more than 10,000–12,000 ft, comfortably below the Jetstream's single engine ceiling. $\endgroup$
    – Jan Hudec
    Apr 21 at 17:49
  • $\begingroup$ @JanHudec: I agree. I had already rephrased the bit about Jiri once I noticed the runway length. $\endgroup$
    – ymb1
    Apr 21 at 18:06
  • $\begingroup$ Jiri might be 6,000 ft, but the hill just north of it is around 12,000ft, so the airport altitude alone is not telling much. But according to map (here is one with proper contours), and from what I remember from the simulator, it is no higher than that to the south and south-west. $\endgroup$
    – Jan Hudec
    Apr 21 at 19:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.