Sorta like this HUV?
In my Grob 109B motorglider Vne is 130 kts (IAS) up to 6500 ft, 122 kts up to 10.000 ft, 116 kts up to 13.000 ft, 110 kts up to 16.500 ft, and 104 kts up to 20.000 ft.
Does this mean your ASI has a red arc instead of a red line? The company Grob ceased to exist because of flutter (totally unrelated to the G109 of course).
@ Pilot DAR. Ouch. Exactly. In this case even the whole tail section seems to break off. And it is clearly seen that the wings bend downwards violently just before impact.
@ acimha. Very good question. In fact, the G109 has an ASI redline just like any other aircraft. It marks 130 KTS, which is Vne below 6.500 ft. So, whenever anyone flies high in a G109, they had better read the fine print. I suppose there is a placard in the cockpit somewhere. I wonder if this is usual in (motor)gliders.
How do you mean the company Grob is gone? They have always been slow to answer mail and slow to repair things, but I have seen Service Bulletin’s dated as late as December 2013 for the Grob 115.
Ok, Grob Aerospace went bankrupt, and some time later Grob Aircraft restarted support and G115 production. I do remember that crash.
Somebody must be operating the Grob TC because the UK RAF has over 100 of the trainers (recently all upgraded with active TCAS, following the mid-air between two of them). And, with G-reg, you are grounded if the TC owner goes bust.
Picking up this where the Vne is pushed down partly because the aircraft can climb a lot higher, doesn’t it follow that the Vne marking in something like a TB20 (official ceiling 18-20k) must have a fat margin if flying at say 5k?
The TB20 Vne is 187kt IAS and if you were doing that at 20k (which is easily done in a descent) that is a TAS of 253kt (mach 0.41).
Peter wrote:
The TB20 Vne is 187kt IAS and if you were doing that at 20k (which is easily done in a descent) that is a TAS of 253kt (mach 0.41).
And I think the numbers are even higher for TB21 at FL250!
275kt, mach 0.46.
Peter wrote:
Picking up this where the Vne is pushed down partly because the aircraft can climb a lot higher, doesn’t it follow that the Vne marking in something like a TB20 (official ceiling 18-20k) must have a fat margin if flying at say 5k?
The problem is that you don’t know to what extent the Vne is structure or flutter limited. However the difference between Vno och Vne should give you some clue as Vno is purely a structural limitation.
Many gliders have different Vne depending on altitude.
