Metro falls out of the sky

[ITCZ]

I was under the impression that the first thing to give way on the Metro above Vmo would be the center windscreen; Any truth to this?

With a max pressure diff of 7.5psi trying to push 200-odd square inches of centre window OUT, maybe not!

Think you heard a metro "urban legend"

[Duff Man]

Binos. Correct - radar ground speed during descent was minimal (in a left orbit from memory). The high speed was seen after radar established valid mode C when the aircraft levelled off and recommenced climb. Don't think it's my place to mention the callsign. Anyway I'm sure the pilot called class E "VFR descent" to avoid paperwork

[NAMPS]

Was the requirement for 250kts below 10,000 cancelled?

[turbinejunkie]

ITCZ,

Not meaning to be anal, but I think a small correction to your post is needed for the benefit of other readers (since the limitation is a major structural one for the aircraft):

With a max pressure diff of 7.5psi

Max diff in the Metro is 7.25Psi (at which point the safety dump valve will open). Max normal operating diff is 7.0 Psi.

Regards,

TJ

[Far Canard]

"Vmo in the metro is restricted by the engine/propeller combination not the airframe"


OVER THE TOP
Where did you get this from?

[ITCZ]

turbinejunkie, you are quite correct -- it has been a while!

[Mode SHHH]

Actually a sweeping right orbit, Duff Man but the rest was pretty accurate. Just over 400kts GS, and the radar couldn't keep up with the Mode C and gave an invalid reading for most of the descent (only other time I've seen that was when I asked a Hornet for best rate of climb off the deck to F130 and he levelled out two miles and thirty seconds later and asked if that was okay ). Our Merlin friend got from F160 to just over A050 in under a minute. Then back up to over A100 in the next minute! Scary to watch from the comfort of my chair so must have been positively heart-stopping in the cockpit. There were a whole lot of people in that room hoping that it was all going to end well.

[Speeds high]

With a max pressure diff of 7.5psi trying to push 200-odd square inches of centre window OUT, maybe not!

Ummmm, so at 5 miles, 1500 feet, with about 0.1 PSI diff and 246 knots there is how much pressure on that window?

Mabey the windows not the weakest link, but i dont think your reason is the one why (if that make's sense).

[The Messiah]

Yes Vmo/Mmo is an engine/prop speed limitation which is common amongst fixed shaft Garretts like the Metro, MU-2 etc.

I got my info from Garrett when flying the type.

[AIRCAB]

Were there passengers or was it just crew on board?

Was it a Bk based merlin or metro??

If it was a merlin pretty obvious who's it is.. I wonder if the old boy was the pilot??