# What exactly is a QRH?

In this question about aircraft dumping fuel I was told that there may possible be guidance in the QRH. I know that there are a lot of guidelines given to pilots, but I've never heard of this one. Would anyone care to explain, from a pilots perspective, what exactly a QRH is and how it's used in modern aircraft operation?

• See how it looks like here. This is a B737NG QRH. – mins Aug 21 '14 at 17:03

A QRH is a Quick Reference Handbook and is an approved (by some overseeing entity) document specific to an airplane and operator that contains checklists for just about anything the airplane can experience. At my airline we had copies in the airplane and also in our company flight manual (CFM).

The entry point into a QRH checklist is one of a few things

1. Memory items
2. EICAS message
3. An abnormal event

For option 1, there are various checklists that must be memorized and performed at a moments notice with no reference to the checklist. Some of these are things like trim runaways, engine fire/severe damage, emergency descent. Once the memory part of the checklist is complete you refer to the printed version of the checklist in the QRH to verify and perform additional steps beyond the part you were required to memorize.

For the other options, any time anything abnormal happens or an EICAS message is presented, there are indices by procedure name and also by EICAS message into a specific procedure in the QRH to follow. These procedures may reference other procedures.

For example, If I were to experience a dual engine failure, I would pick up my QRH and find the procedure "DUAL ENGINE FAILURE", this procedure says I should have the master warning light illuminated (and an aural triple chime) and I should see the EICAS message (in red) "ENG 1-2 OUT". After verifying this presentation and verifying I am in the right procedure, I would perform:

Airspeed....................MINIMUM 260 KIAS
Altitude....................MAXIMUM FL250
APU.........................START
ENGINE AIRSTART procedure...PERFORM  (note, this is another QRH procedure)

CAUTION: IF THE APU HAS BEEN USED TO START THE ENGINES,
DO NOT ALTERNATE THE FADECs AFTER START

Note: If the APU is not available, only equipment supplied by the
Essential DC Bus 1 and 2 will be available.  Engine windmilling
should drive engine driven hydraulic pumps and supply hydraulic
pressure.

IF neither engine can be restarted:
DITCHING or FORCED LANDING procedure......PERFORM

• It does not have to be FAA approved. It has to be approved by appropriate overseeing authority (I am not sure whether that is country of operator, country of registration or country of manufacture though). – Jan Hudec Mar 31 '14 at 6:23
• @JanHudec thanks for the clarification. I have edited the answer to reflect your comment. – casey Mar 31 '14 at 14:31

A QRH is a Quick Reference Handbook.

It is basically the checklist used in the aircraft along with other useful information, which varies from QRH to QRH, but can include things like system diagrams, maximum cruising altitudes for the current conditions, takeoff and landing performance, etc.

It is usually a small form, spiral bound document that is convenient and easy-to-use in the cockpit:

• Among the important features of a paper QRH are the tabs, which make it "quick" to find the section you need. (You can sort-of see them above, this example has nice big ones) – voretaq7 Mar 28 '14 at 20:42
• @voretaq7 Ahh yes, that would be the "quick" portion of QRH! – Lnafziger Mar 28 '14 at 21:14
• Airlines that operate aircraft originally built for other airlines also put in the QRH the differences between the various airplanes. The more different aircraft of the same model the airline operates, the thicker the QRH becomes. Unfortunately the thicker it becomes the less quick it becomes. Both 747 carriers I worked for had aircraft from five or more carriers that had originally ordered the airplanes. Former TWA airplanes were the most different, especially the pilots forward overhead panel. – Terry Mar 28 '14 at 22:38