Talk:CR-7 R.A.P.I.E.R. Engine

Suborbital capabilities

An Aeris 3A with an FL-400 fuel tank in place of one of the fuel tanks and a ram air intake mounted on the top with a tailpiece is capable of suborbital flight, exceeding those of the Aeris 4A (with my mediocre skill), up to 150km.— Preceding unsigned comment added by Thompcan (talk • contribs) 15:51, 15 May 2014‎ (UTC)

The Aeris 4A is orbit capable so a suborbital flight won't exceed the capabilities of the Aeris 4A. — xZise [talk] 16:23, 15 May 2014 (CDT)

correction of ISP stats

I mounted a Rapier and a Turbojet on the same plane to compare their Isp-height behaviour. As far as I could see on several runs, they behave exactly the same, i.e. 800 at sea level, about 2500 peak at 5000 m and about 1200 at 35000 m.

Furthermore I created a stationary test-stand to check for air consumption. Not surprisingly both engines take exactly the same ammount of air for the same amount of fuel. Having the same Isp-curve in mind, they both take the same ammount of air for the same generated thrust.

The power up / down curve also is identical.

After all, the Rapier is just a bit weaker Turbojet (190 vs. 225 KN) with the same weight, thus having a slightly worse TWR, otherwise the exact same characteristics. Therefore it generates the thrust of about six Rockomax 48-7s in rocket mode while having a slightly better Isp (360 vs 350), meaning that a spaceplane with the same Air / rocket thrust is lighter with the Rapier than with the Turbojet / 78-7s combinaton.

The main disatvantage is the missing power generation.

P.S.: This is my first Wiki edit,so please be lenient towards me...