VS in comet

[Jakemaster]

Sorry for all the stupid questions....

So I'm trying to learn to fly the comet properly, but my numbers almost seem off. I'm used to flying modern jetliners, so bear with me...

I looked at the flying tips, says normal climb speed is 260 knots. I was climbing at 1500FPM at about 160. So I assume the trick is to accelerate to 260 and then use the IAS hold mode for the climb, but it seems to me that would mean a very low vertical speed. What vertical speed should I expect for a climb to cruise altitude?

[MALTBY D]

No problem. Not saying you'll always get the correct answer, but you ask away.

You get different drag characteristics at different speeds.
Trimmed at 160 kt, you'll be flying with a large Angle of Attack & that will bring a fair amount of drag into the equation.
Accelerate to 260, the AoA is reduced and you'll probably get a better climb rate.

The Comet will have no problem with climb rate at 260 & faster. According to the stuff I read, they'd climb at 330kt in the 4B.
It did have a very high power to weight ratio. Mainly because it was small, rather than having huge amounts of power.

And yes, once at 260 kt, engage IAS mode & keep engines at 7400 RPM.
When it gets to Mach 0.72, take of IAS mode and use the A/P manual pitch Up/Down switch to keep Mach 0.72 instead.

DM

[DispatchDragon]

Jake

I can validate what David says - The Comet actually had a very high rate of climb - especially when you consider
Dan Air operate them on 1.5 - 2.5 hour legs (The bucket and spade route) when they were designed to operate
7-8 hour legs they were never close to MTOW - in fact their rate of climb was so good - that they were one of two
aircraft that were NOT subject to noise abatement in the mid 70s (Pre-Stage2) when departing Luton.
Anyone hazard a guess what the other aircraft was?

Leif

[Garry Russell]

:think: Convair 990??

Garry

[DispatchDragon]

Lord no the Spantax Convairs that came in were Loud and DIRTY -- No a hint - not British and Black and Yellow

;-)

Leif

[Garry Russell]

Monarch Boeing 720?

Garry

[DispatchDragon]

;-) of course - the 720 was in the same position as the Dan Air Comets - basically a transcontiental (US that is) aircraft
operating 2-3 hour legs for the Bucketandspaders out of Luton (I think the longest legs they operated were to Teneriffe,
Malta and Heraklion.

Leif

[Garry Russell]

That's why I thought it was the 990 given the high power, but not such a long range.

The 720 was a bit of a hot rod

Garry

[Trev Clark]

Taking this back on topic :roll: , has anybody else noticed that the VS function seems reversed in the AP i.e. when you increase your rate of climb, the tooltip on your curser has a minus sign and vice versa. If this is an error, then (as someone who had the beta I should have found it earlier ) or am I missing something with vintage AP's. Most of my flying is circuit work, but tonight I thought I would fly my monthly Granada to LGW Dan-Air for a change!

[DispatchDragon]

Mine does the same Trev - but Im trying to think - theres another aircraft that does the same with that particular AP.

And Sorry that Garry and I sort of slipped off the trail there - I guess my original point was the the Comet as His Lordship
pointed out like many early jets Best Rate of Climb and Best Climb speed were like day and night- vastly different. And if you
take a look at the Comets wing chord you can understand how very high AOA/ROC created a lot of drag.

Leif.