Originally Posted by sfzpilot (Post 571171)

Hey guys and gals,

I am an instrument pilot who was flying with BOS_CTR in the Cherokee a a few weeks ago. I heard something like this: Callsign, descend to cross 35 Miles NW of the MHT airport at and maintain 11,000. I was just wondering, do the FMC's cross a DME or do guys create a fix which is defined by the 35 DME? Or do you guys use pen and paper like the old days?

Thanks so much!

Originally Posted by sfzpilot (Post 571171)

Hey guys and gals,

I am an instrument pilot who was flying with BOS_CTR in the Cherokee a a few weeks ago. I heard something like this: Callsign, descend to cross 35 Miles NW of the MHT airport at and maintain 11,000. I was just wondering, do the FMC's cross a DME or do guys create a fix which is defined by the 35 DME? Or do you guys use pen and paper like the old days?

Thanks so much!

Originally Posted by andy171773 (Post 571183)

good ol north central ey?

i got my commercial single there..did all my training outta EWB

but yea

You just program it in from KMHT for the airport (just putting MHT would be the VOR) and viola

you can even make a green 35 mile ring around the airport!

oh technology...

Originally Posted by sfzpilot (Post 571171)

Hey guys and gals,

I am an instrument pilot who was flying with BOS_CTR in the Cherokee a a few weeks ago. I heard something like this: Callsign, descend to cross 35 Miles NW of the MHT airport at and maintain 11,000. I was just wondering, do the FMC's cross a DME or do guys create a fix which is defined by the 35 DME? Or do you guys use pen and paper like the old days?

Thanks so much!

Originally Posted by marco (Post 571243)

You can also do the mental math another way if you like to hang at your cruise altitude until the last second and know the performance of your airplane and the time that you should cross the fix:
a. determine altitude to lose
b. determine the descent rate you want to lose that altitude to make the crossing and convert to minutes
c. start your descent when you are that many minutes away from the fix

ex: cruise altitude is FL310, crossing restriction is 35 out of MHT at 11000 = 20000 feet to lose. I want to descend at 5000' per minute: 20/5=4 minutes. -Start my descent 4 minutes out.
-Cruising at 400kts is roughly 7 miles per minute, multiply by descent time: 7x4=28 and add to 35 (crossing fix): 28+35=63. (round up for fudge)
-Start descending at 65 miles out of MHT at 5000'/min maintain your cruise airspeed.

Now if ATC gives you an airspeed restriction while you're in the dive, you're not gonna make the altitude at the fix. Maybe I do need pen and paper for this one!!