A question for Baron drivers

[purethrust]

The use of low pressure auxiliary fuel pumps for t/o and landing.

When I did my baron/travelair endorsement, I was taught to use the low pressure pumps for these phases of flight - quite happy to do so. I have spoken to a number of baron drivers and it seems that many don't use the pumps. The manual advises their use during any operating mode to eliminate pressure fluctuations resulting from high ambient temperatures and/or altitudes.

Surely, the use of a backup to the mechanical pumps at such critical phaes of flight is a good idea.

Any advice or thoughts would be appreciated.

[Sheep Guts]

I think youll find in the POH it states above 35 DEG C or something like that on takeoff not sure on landing been a few years now. I did use mine used to operate in the topend allways in that temp region on takeoff.

regards
Sheep

[dogcharlietree]

I agree with Sheep. The POH states when they shall be turned ON. (For POH now read AFM) therefore, it must be adhered to and anyone who operates (or does not) contravening the AFM leaves themselves w i d e o p e n.

[Bagot_Community_Locator]

From memory, the POH says to use the Low Boost Fuel Pumps in temps above 90 F (32 C).

I queried my chief pilot about it once and he said there is no need to ever use them - even though the temp was usually "about" the 90 F (32 C) mark. I remember he even once pointed to the OAT gauge and said "see, it is NOT above 90F".

Therefore I never switched them ON for take-off/landing and never had any problems. This company had been operating Barons in the tropics for maybe 20 years so I suppose they knew best about how to operate them.

However I once flew in a Baron belonging to a different operator on the airport and I noticed the pilot did switch ON the low boost pumps for take-off / landing. This was on a flight late in the afternoon and I am quite sure the temp. would have been below 90 F at the time.

[Chimbu chuckles]

Interesting that in the Bonanza, same engine, you must check that the boost pump is off before takeoff.

Remember the AFM was written by the airframe manufacturer not the engine manufacturer...and with a Lawyer vetting the wording.

I have two copies of the AFM for my Bonanza, one is original and one is the new one that CASA insisted I buy recently (same part number)...it's a 32+ year old document that CASA is saying must be adhered to without fail!

C***s Against Safe Aviation.

Chuck.

[Freek Flyer]

Been a while, but don't the bonanzas have a high pressure boost? Not the low pressure aux pump in question?

[puff]

The barons have that lovely up for HIGH, and down for LOW function, go the wrong way and the engine stops! I do remember a Bonanza E33 landing on a beach at the Gold Coast a few years ago when pilot turned on the fuel pump when turning a long finals onto 14 at OOL, ended up on the beach, very expensive mistake!

VERY strange when one manufacturer has a fuel pump that you turn on for takeoff and landing, and the other has a HP fuel pump that if you use it when the engine driven pump is operational will flood it until it dies, in the baron you certainly need to be pretty sure what each function is for when both are on the same button!

[Chimbu chuckles]

My A36 Boost Pump switch has a high and low selection...The AFM requires the boost pump to be off. It is entirely possible (even likely) that the two speed pump is a mod and the AFM doesn't reflect that.

Unfortunatly CASA in their infinite wisdom :rolleyes: require absolute adhearance to (often old/out of date) documents to the point where it gets rediculous. It's part of their mindless drive towards absolute protection against being held accountable for anything. Nothing whatsoever to do with increased safety!

A 'Low' setting on takeoff in high ambient temps sounds plausible but that doesn't mean it's correct. There is no reference to possible fuel flow problems caused by high ambient temps in my Bonanza manual.

There needs to be great care taken that well intentioned (uninformed) opinion or (bad) habit doesn't get passed off for absolute Gospel just because people can't be bothered reading the AFM.

Can anyone quote from a Baron AFM and put us out of our misery:D?

Same airframe manufacturer for both aircraft, same engine manufacturer, very similar installation....but different procedure?

One is correct and ones not but you can bet CASA will insist on whichever procedure is wrong being followed blindly just because someone at Beechcraft hasn't thought it through.


Chuck.

[Jamair]

Just for you Chuck:D

From the POH, Beechcraft Baron 58

"Section IV (Normal Procedures)

BEFORE TAKEOFF

3. Aux Fuel Pumps - OFF (if ambient temperature is 90f or above, use LOW pressure boost)

NOTE
In high ambient temperatures, low pressure boost may be used may be required to prevent excessive fuel flow fluctuations.


BEFORE LANDING

3. Aux fuel pumps - OFF, OR LOW AS PER AMBIENT TEMPERATURE

(Books capitals, not mine)


Section VII, (Systems Description)

AUXILIARY FUEL PUMPS

An individual two-speed electric auxiliary fuel pump is provided for each engine. HIGH pressure, OFF or LOW pressure is selected with each auxiliary fuel pump swith on the pilot's subpanel. High pressure is used for providing fuel pressure before starting, and provides near maximum engine performance, should the engine driven fuel pump fail. Low pressure may be used in any operating mode to eliminate pressure fluctuations resulting from high ambient temperatures and/or high altitudes. The high pressure position should not be selected while the engine is operating except in the event of engine-driven pump failure since the high pressure mode supplies a greater pressure than can be accepted by the injection system during normal operation."

Should conclude the subject?:)

[Chimbu chuckles]

Perfect Jamair:D

When are ya bringing the Truck ta the big smoke:D?

Chuck.