• NC Software is proud to announce the release of APDL - Airline Pilot Logbook version 10.0. Click here to view APDL on the Apple App store and install now.
  • Logbook Pro for Apple iOS version 8.1 is now available on the App Store. Major update including signature endorsements and dark/light theme support. Click here to install now.

NBAA reserves

GravityHater

Well-known member
Joined
Aug 12, 2004
Posts
1,168
Total Time
3000
Can someone quote the NBAA ifr recommended reserves? I thought I'd read it is cruise of 45 mins (beyond destination).
If not, scratch this thread.
If so, I am trying to reconcile how they got that, in view of (how I read) the FARs on the topic.
Do they (the FARs) not say enough fuel for:
-T-O, climb, cruise, and descent, approach at destination
-climb, cruise, descent, approach at alternate
-climb, cruise for 45mins
 

BoilerUP

Citation style...
Joined
Nov 11, 2003
Posts
5,311
Total Time
1500+
http://dictionary.babylon.com/NBAA_IFR_Fuel_Reserves

Fuel Reserves = Fuel for go around at destination airport + climb to 500 ft. and hold for 5 minutes + fly to and land at alternate airport 200 NMi. away + fuel to hold at 5000 ft. for 30 minutes.
http://www.touringmachine.com/Articles/regulations/95/

NBAA reserves show up in flying magazines all the time when the specs for business aircraft are presented. They are defined on the NBAA site as, The NBAA IFR Reserves is defined as the route of flight in the profile that begins at the “K–L” leg and goes through to the end of the flight profile. This is where the aircraft begins its missed approach to divert to an alternate.

The “K-L leg” of the profile is a 200 NM distance that is done at an optimum rate of climb to 5,000′ after missed approach, holding for 5 minutes at loiter power for clearance, optimum rate of climb enroute to optimum cruise altitude, economy cruise to alternate, and then a descent enroute to Sea Level at 3,000 feet per minute max and land. Upon landing, fuel reserve should meet IFR minimums as appropriate for loitering at 5,000 feet.

Basically, this is a way to compare the endurance of different aircraft on a consistent basis and doesn’t really have anything to do with legal reserves.
 

BoilerUP

Citation style...
Joined
Nov 11, 2003
Posts
5,311
Total Time
1500+
For a direct comparison...

Cessna's materials for a CJ2+ state that its NBAA IFR Reserves for a 100nm alternate are 777lb and 1000lb for a 200nm alternate.

IFR Fuel Reserves (defined as alternate plus 45 minutes @ 15,000') are 796lb for 100nm alternate and 1021lb for a 200nm alternate.

VFR Fuel Reserves (45 min @ 15,000') are 468lb.
 

GravityHater

Well-known member
Joined
Aug 12, 2004
Posts
1,168
Total Time
3000
Our airplane holds 3300#.

For the last flight (to an area with lifr), we used 2000# getting to destination.

I was looking at the fuel needed to fulfil the far's ifr reserve requirements:

Missed, climb to new cruise altitude, descent and approach to alternate....550lbs (it was nearby)
Then: missed at alternate, climb to and cruise for 45 mins....800lbs.

Total 1350# reserve.

I did the same for the nbaa method and got 1400#

so these two methods seem comparable.
 

GravityHater

Well-known member
Joined
Aug 12, 2004
Posts
1,168
Total Time
3000
The numbers above are for a CJ with Williams FJ441A's
I am wondering how the CJ2 gets such low reserve numbers??

Cessna's materials for a CJ2+ state that its NBAA IFR Reserves for a 100nm alternate are 777lb and 1000lb for a 200nm alternate.

IFR Fuel Reserves (defined as alternate plus 45 minutes @ 15,000') are 796lb for 100nm alternate and 1021lb for a 200nm alternate.

VFR Fuel Reserves (45 min @ 15,000') are 468lb.
 

GravityHater

Well-known member
Joined
Aug 12, 2004
Posts
1,168
Total Time
3000
Anyone have the NBAA reserve specifications? I'm not a member and can't access them from their site.
 

BoilerUP

Citation style...
Joined
Nov 11, 2003
Posts
5,311
Total Time
1500+
Anyone have the NBAA reserve specifications? I'm not a member and can't access them from their site.

200 NM (sometimes noted as 100 NM) distance that is done at an optimum rate of climb to 5,000′ after missed approach, holding for 5 minutes at loiter power for clearance, optimum rate of climb enroute to optimum cruise altitude, economy cruise to alternate, and then a descent enroute to Sea Level at 3,000 feet per minute max and land. Upon landing, fuel reserve should meet IFR minimums as appropriate for loitering at 5,000 feet.
 

GravityHater

Well-known member
Joined
Aug 12, 2004
Posts
1,168
Total Time
3000
What about the "K-L" leg, and it could be 100 or 200nm? Quite some variation there.

200 NM (sometimes noted as 100 NM) distance that is done at an optimum rate of climb to 5,000′ after missed approach, holding for 5 minutes at loiter power for clearance, optimum rate of climb enroute to optimum cruise altitude, economy cruise to alternate, and then a descent enroute to Sea Level at 3,000 feet per minute max and land. Upon landing, fuel reserve should meet IFR minimums as appropriate for loitering at 5,000 feet.
 

GravityHater

Well-known member
Joined
Aug 12, 2004
Posts
1,168
Total Time
3000
I gathered up some notes of fuel flows from past flights (ie real numbers) and came up with this:

climb off the missed to 5K - 50lbs (1500pphX2mins)
hold @5K for 5 mins - 100lbs (1000pphX5mins)
climb to altitude - 300lbs (past experience)
cruise 200nm - 700lbs (270kts, 0.7hrsX1000pph)
descent & ldg - 100lbs (past experience)
another hold @5K for 20 mins - 300lbs (1000pphX0.3hrs)

Total: 1550lbs
or almost exactly half our fuel.

Need help with this one!

Yes, legal ifr reserves are different but I am interested in what the NBAA is saying.
 
Top