flyvulcan
Well-Known Member
Hi Orion (and other designers),
I will be contacting you shortly outside the forum but I have some questions that others may find interesting so I figured I would ask on public forum so other interested parties can learn from my enquiry.
I have been doing some preliminary work on the design of a small single seat twin engined jet. My starting tools have been Airplane PDQ and X-Plane but as has been noted in these forums, these are extremely basic starting points. I will shortly build a mockup to check for system/pilot fit to carry out further refining of the initial concept. After that, I would be ready to proceed to the stage where I need to obtain professional engineering help. It should be noted that the aim of my project is an aircraft for ME only, at least initially.
In brief, my concept is a small aircraft, approximately the size and layout of a BD5J. The twin engines would probably be mounted externally on pylons at the rear of the aircraft. The engines that I am considering using are the Hewland H80T of 110 lbs thrust each giving a total of 220lbs (see website as follows if interested http://www.heward-microjets.co.uk/engines_nimbush80.shtml). There is also more information about these engines at the following Yahoo Groups forum http://groups.yahoo.com/group/TheJetSet/.
Having worked with aluminium, I initially planned on using that but I believe a glass aircraft would be better and I am proceeding to investigate the glass option.
The role of my aircraft is to have fun in for 1/2 to 1 hour so a +6/-4g flight envelope would be nice. Fixed tricycle gear is fine as top speed is not my priority and simplicity is important. A Vne of around 200kias with a Vmo of 180kias and a "cruise" of around 150kias are target figures for planning. I am used to operating "clean" jets so energy management to limit normal operations to 180kias should not be a problem.
I anticipate an empty weight in the region of 320lbs, pilot of 210lbs and a fuel load of 120lbs giving an AUW of 650lbs.
There would be a basic electrical system powered by batteries to run the engine/fuel/radio systems with no capability for in-flight recharging.
My questions are as follows:
1. X-Plane is now up to version 9 and it is claimed that the aerodynamic modelling is quite accurate. I've done a search on this forum but the last comments about x-plane were from a few years ago. Is it still your view that x-plane probably wont give a particularly accurate representation of the flight characteristics of an experimental prototype?
2. This is a bit of a "how long is a piece of string" question, but if I approached an aeronautical engineering firm to complete the design work for an aircraft as I described above, what would you estimate as the approximate cost for their services, assuming I want a safe aircraft to operate in the experimental category?
3. Would you hazard a guess of the cost for a prototyping company to build the basic structure of such an aircraft (forget engine/instrument costs as I would provide these)?
Your advice would be appreciated.
Dave
I will be contacting you shortly outside the forum but I have some questions that others may find interesting so I figured I would ask on public forum so other interested parties can learn from my enquiry.
I have been doing some preliminary work on the design of a small single seat twin engined jet. My starting tools have been Airplane PDQ and X-Plane but as has been noted in these forums, these are extremely basic starting points. I will shortly build a mockup to check for system/pilot fit to carry out further refining of the initial concept. After that, I would be ready to proceed to the stage where I need to obtain professional engineering help. It should be noted that the aim of my project is an aircraft for ME only, at least initially.
In brief, my concept is a small aircraft, approximately the size and layout of a BD5J. The twin engines would probably be mounted externally on pylons at the rear of the aircraft. The engines that I am considering using are the Hewland H80T of 110 lbs thrust each giving a total of 220lbs (see website as follows if interested http://www.heward-microjets.co.uk/engines_nimbush80.shtml). There is also more information about these engines at the following Yahoo Groups forum http://groups.yahoo.com/group/TheJetSet/.
Having worked with aluminium, I initially planned on using that but I believe a glass aircraft would be better and I am proceeding to investigate the glass option.
The role of my aircraft is to have fun in for 1/2 to 1 hour so a +6/-4g flight envelope would be nice. Fixed tricycle gear is fine as top speed is not my priority and simplicity is important. A Vne of around 200kias with a Vmo of 180kias and a "cruise" of around 150kias are target figures for planning. I am used to operating "clean" jets so energy management to limit normal operations to 180kias should not be a problem.
I anticipate an empty weight in the region of 320lbs, pilot of 210lbs and a fuel load of 120lbs giving an AUW of 650lbs.
There would be a basic electrical system powered by batteries to run the engine/fuel/radio systems with no capability for in-flight recharging.
My questions are as follows:
1. X-Plane is now up to version 9 and it is claimed that the aerodynamic modelling is quite accurate. I've done a search on this forum but the last comments about x-plane were from a few years ago. Is it still your view that x-plane probably wont give a particularly accurate representation of the flight characteristics of an experimental prototype?
2. This is a bit of a "how long is a piece of string" question, but if I approached an aeronautical engineering firm to complete the design work for an aircraft as I described above, what would you estimate as the approximate cost for their services, assuming I want a safe aircraft to operate in the experimental category?
3. Would you hazard a guess of the cost for a prototyping company to build the basic structure of such an aircraft (forget engine/instrument costs as I would provide these)?
Your advice would be appreciated.
Dave
